DATACMNS-867 - First draft.

src/main/java/org/springframework/data/auditing/AnnotationAuditingMetadata.java

@@ -21,6 +21,7 @@ import java.util.Collections;
 import java.util.Date;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
 
 import org.springframework.data.annotation.CreatedBy;
@@ -29,6 +30,7 @@ import org.springframework.data.annotation.LastModifiedBy;
 import org.springframework.data.annotation.LastModifiedDate;
 import org.springframework.data.convert.Jsr310Converters;
 import org.springframework.data.convert.ThreeTenBackPortConverters;
+import org.springframework.data.util.Optionals;
 import org.springframework.data.util.ReflectionUtils;
 import org.springframework.data.util.ReflectionUtils.AnnotationFieldFilter;
 import org.springframework.util.Assert;
@@ -68,10 +70,10 @@ final class AnnotationAuditingMetadata {
 		SUPPORTED_DATE_TYPES = Collections.unmodifiableList(types);
 	}
 
-	private final Field createdByField;
-	private final Field createdDateField;
-	private final Field lastModifiedByField;
-	private final Field lastModifiedDateField;
+	private final Optional<Field> createdByField;
+	private final Optional<Field> createdDateField;
+	private final Optional<Field> lastModifiedByField;
+	private final Optional<Field> lastModifiedDateField;
 
 	/**
 	 * Creates a new {@link AnnotationAuditingMetadata} instance for the given type.
@@ -82,10 +84,10 @@ final class AnnotationAuditingMetadata {
 
 		Assert.notNull(type, "Given type must not be null!");
 
-		this.createdByField = ReflectionUtils.findField(type, CREATED_BY_FILTER);
-		this.createdDateField = ReflectionUtils.findField(type, CREATED_DATE_FILTER);
-		this.lastModifiedByField = ReflectionUtils.findField(type, LAST_MODIFIED_BY_FILTER);
-		this.lastModifiedDateField = ReflectionUtils.findField(type, LAST_MODIFIED_DATE_FILTER);
+		this.createdByField = Optional.ofNullable(ReflectionUtils.findField(type, CREATED_BY_FILTER));
+		this.createdDateField = Optional.ofNullable(ReflectionUtils.findField(type, CREATED_DATE_FILTER));
+		this.lastModifiedByField = Optional.ofNullable(ReflectionUtils.findField(type, LAST_MODIFIED_BY_FILTER));
+		this.lastModifiedDateField = Optional.ofNullable(ReflectionUtils.findField(type, LAST_MODIFIED_DATE_FILTER));
 
 		assertValidDateFieldType(createdDateField);
 		assertValidDateFieldType(lastModifiedDateField);
@@ -94,23 +96,26 @@ final class AnnotationAuditingMetadata {
 	/**
 	 * Checks whether the given field has a type that is a supported date type.
 	 * 
-	 * @param field can be {@literal null}.
+	 * @param field
 	 */
-	private void assertValidDateFieldType(Field field) {
+	private void assertValidDateFieldType(Optional<Field> field) {
 
-		if (field == null || SUPPORTED_DATE_TYPES.contains(field.getType().getName())) {
-			return;
-		}
+		field.ifPresent(it -> {
 
-		Class<?> type = field.getType();
+			if (SUPPORTED_DATE_TYPES.contains(it.getType().getName())) {
+				return;
+			}
 
-		if (Jsr310Converters.supports(type) || ThreeTenBackPortConverters.supports(type)) {
-			return;
-		}
+			Class<?> type = it.getType();
 
-		throw new IllegalStateException(String.format(
-				"Found created/modified date field with type %s but only %s as well as java.time types are supported!", type,
-				SUPPORTED_DATE_TYPES));
+			if (Jsr310Converters.supports(type) || ThreeTenBackPortConverters.supports(type)) {
+				return;
+			}
+
+			throw new IllegalStateException(String.format(
+					"Found created/modified date field with type %s but only %s as well as java.time types are supported!", type,
+					SUPPORTED_DATE_TYPES));
+		});
 	}
 
 	/**
@@ -119,52 +124,41 @@ final class AnnotationAuditingMetadata {
 	 * @param type the type to inspect, must not be {@literal null}.
 	 */
 	public static AnnotationAuditingMetadata getMetadata(Class<?> type) {
-
-		if (METADATA_CACHE.containsKey(type)) {
-			return METADATA_CACHE.get(type);
-		}
-
-		AnnotationAuditingMetadata metadata = new AnnotationAuditingMetadata(type);
-		METADATA_CACHE.put(type, metadata);
-		return metadata;
+		return METADATA_CACHE.computeIfAbsent(type, it -> new AnnotationAuditingMetadata(it));
 	}
 
 	/**
 	 * Returns whether the {@link Class} represented in this instance is auditable or not.
 	 */
 	public boolean isAuditable() {
-		if (createdByField == null && createdDateField == null && lastModifiedByField == null
-				&& lastModifiedDateField == null) {
-			return false;
-		}
-		return true;
+		return Optionals.isAnyPresent(createdByField, createdDateField, lastModifiedByField, lastModifiedDateField);
 	}
 
 	/**
-	 * Return the field annotated by {@link CreatedBy}, or {@literal null}.
+	 * Return the field annotated by {@link CreatedBy}.
 	 */
-	public Field getCreatedByField() {
+	public Optional<Field> getCreatedByField() {
 		return createdByField;
 	}
 
 	/**
-	 * Return the field annotated by {@link CreatedDate}, or {@literal null}.
+	 * Return the field annotated by {@link CreatedDate}.
 	 */
-	public Field getCreatedDateField() {
+	public Optional<Field> getCreatedDateField() {
 		return createdDateField;
 	}
 
 	/**
-	 * Return the field annotated by {@link LastModifiedBy}, or {@literal null}.
+	 * Return the field annotated by {@link LastModifiedBy}.
 	 */
-	public Field getLastModifiedByField() {
+	public Optional<Field> getLastModifiedByField() {
 		return lastModifiedByField;
 	}
 
 	/**
-	 * Return the field annotated by {@link LastModifiedDate}, or {@literal null}.
+	 * Return the field annotated by {@link LastModifiedDate}.
 	 */
-	public Field getLastModifiedDateField() {
+	public Optional<Field> getLastModifiedDateField() {
 		return lastModifiedDateField;
 	}
 }

src/main/java/org/springframework/data/auditing/AuditableBeanWrapper.java

@@ -15,7 +15,8 @@
  */
 package org.springframework.data.auditing;
 
-import java.util.Calendar;
+import java.time.temporal.TemporalAccessor;
+import java.util.Optional;
 
 /**
  * Interface to abstract the ways setting the auditing information can be implemented.
@@ -30,34 +31,34 @@ public interface AuditableBeanWrapper {
 	 * 
 	 * @param value
 	 */
-	void setCreatedBy(Object value);
+	Optional<? extends Object> setCreatedBy(Optional<? extends Object> value);
 
 	/**
 	 * Set the date the object was created.
 	 * 
 	 * @param value
 	 */
-	void setCreatedDate(Calendar value);
+	Optional<TemporalAccessor> setCreatedDate(Optional<TemporalAccessor> value);
 
 	/**
 	 * Set the last modifier of the object.
 	 * 
 	 * @param value
 	 */
-	void setLastModifiedBy(Object value);
+	Optional<? extends Object> setLastModifiedBy(Optional<? extends Object> value);
 
 	/**
 	 * Returns the date of the last modification date of the backing bean.
 	 * 
-	 * @return the date of the last modification, can be {@literal null}.
+	 * @return the date of the last modification.
 	 * @since 1.10
 	 */
-	Calendar getLastModifiedDate();
+	Optional<TemporalAccessor> getLastModifiedDate();
 
 	/**
 	 * Set the last modification date.
 	 * 
 	 * @param value
 	 */
-	void setLastModifiedDate(Calendar value);
+	Optional<TemporalAccessor> setLastModifiedDate(Optional<TemporalAccessor> value);
 }

src/main/java/org/springframework/data/auditing/AuditableBeanWrapperFactory.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.auditing;
 
+import java.util.Optional;
+
 /**
  * A factory to lookup {@link AuditableBeanWrapper}s.
  * 
@@ -24,11 +26,10 @@ package org.springframework.data.auditing;
 public interface AuditableBeanWrapperFactory {
 
 	/**
-	 * Returns the {@link AuditableBeanWrapper} for the given source obejct if it's eligible for auditing.
+	 * Returns the {@link AuditableBeanWrapper} for the given source object if it's eligible for auditing.
 	 * 
-	 * @param source can be {@literal null}.
-	 * @return the {@link AuditableBeanWrapper} for the given source obejct if it's eligible for auditing or
-	 *         {@literal null} otherwise.
+	 * @param source.
+	 * @return the {@link AuditableBeanWrapper} for the given source object if it's eligible for auditing.
 	 */
-	AuditableBeanWrapper getBeanWrapperFor(Object source);
+	Optional<AuditableBeanWrapper> getBeanWrapperFor(Optional<? extends Object> source);
 }

src/main/java/org/springframework/data/auditing/AuditingHandler.java

@@ -15,8 +15,9 @@
  */
 package org.springframework.data.auditing;
 
+import java.time.temporal.TemporalAccessor;
 import java.util.Arrays;
-import java.util.Calendar;
+import java.util.Optional;
 
 import org.joda.time.DateTime;
 import org.slf4j.Logger;
@@ -43,7 +44,7 @@ public class AuditingHandler implements InitializingBean {
 	private final DefaultAuditableBeanWrapperFactory factory;
 
 	private DateTimeProvider dateTimeProvider = CurrentDateTimeProvider.INSTANCE;
-	private AuditorAware<?> auditorAware;
+	private Optional<AuditorAware<?>> auditorAware;
 	private boolean dateTimeForNow = true;
 	private boolean modifyOnCreation = true;
 
@@ -56,7 +57,6 @@ public class AuditingHandler implements InitializingBean {
 	 * @deprecated use {@link AuditingHandler(PersistentEntities)} instead.
 	 */
 	@Deprecated
-	@SuppressWarnings("unchecked")
 	public AuditingHandler(
 			MappingContext<? extends PersistentEntity<?, ?>, ? extends PersistentProperty<?>> mappingContext) {
 		this(new PersistentEntities(Arrays.asList(mappingContext)));
@@ -72,7 +72,9 @@ public class AuditingHandler implements InitializingBean {
 	public AuditingHandler(PersistentEntities entities) {
 
 		Assert.notNull(entities, "PersistentEntities must not be null!");
+
 		this.factory = new MappingAuditableBeanWrapperFactory(entities);
+		this.auditorAware = Optional.empty();
 	}
 
 	/**
@@ -80,10 +82,10 @@ public class AuditingHandler implements InitializingBean {
 	 * 
 	 * @param auditorAware must not be {@literal null}.
 	 */
-	public void setAuditorAware(final AuditorAware<?> auditorAware) {
+	public void setAuditorAware(AuditorAware<?> auditorAware) {
 
 		Assert.notNull(auditorAware, "AuditorAware must not be null!");
-		this.auditorAware = auditorAware;
+		this.auditorAware = Optional.of(auditorAware);
 	}
 
 	/**
@@ -121,7 +123,7 @@ public class AuditingHandler implements InitializingBean {
 	 * 
 	 * @param source
 	 */
-	public void markCreated(Object source) {
+	public void markCreated(Optional<? extends Object> source) {
 		touch(source, true);
 	}
 
@@ -130,35 +132,35 @@ public class AuditingHandler implements InitializingBean {
 	 * 
 	 * @param source
 	 */
-	public void markModified(Object source) {
+	public void markModified(Optional<? extends Object> source) {
 		touch(source, false);
 	}
 
 	/**
 	 * Returns whether the given source is considered to be auditable in the first place
-	 * 
-	 * @param source can be {@literal null}.
+	 *
+	 * @param source must not be {@literal null}.
 	 * @return
 	 */
-	protected final boolean isAuditable(Object source) {
-		return factory.getBeanWrapperFor(source) != null;
+	protected final boolean isAuditable(Optional<Object> source) {
+		return source.flatMap(o -> factory.getBeanWrapperFor(source)).isPresent();
 	}
 
-	private void touch(Object target, boolean isNew) {
+	private void touch(Optional<? extends Object> target, boolean isNew) {
 
-		AuditableBeanWrapper wrapper = factory.getBeanWrapperFor(target);
+		Optional<AuditableBeanWrapper> wrapper = factory.getBeanWrapperFor(target);
 
-		if (wrapper == null) {
-			return;
-		}
+		wrapper.ifPresent(it -> {
 
-		Object auditor = touchAuditor(wrapper, isNew);
-		Calendar now = dateTimeForNow ? touchDate(wrapper, isNew) : null;
+			Optional<Object> auditor = touchAuditor(it, isNew);
+			Optional<TemporalAccessor> now = dateTimeForNow ? touchDate(it, isNew) : Optional.empty();
 
-		Object defaultedNow = now == null ? "not set" : now;
-		Object defaultedAuditor = auditor == null ? "unknown" : auditor;
+			Object defaultedNow = now.map(Object::toString).orElse("not set");
+			Object defaultedAuditor = auditor.map(Object::toString).orElse("unknown");
 
-		LOGGER.debug("Touched {} - Last modification at {} by {}", new Object[] { target, defaultedNow, defaultedAuditor });
+			LOGGER.debug("Touched {} - Last modification at {} by {}",
+					new Object[] { target, defaultedNow, defaultedAuditor });
+		});
 	}
 
 	/**
@@ -167,23 +169,22 @@ public class AuditingHandler implements InitializingBean {
 	 * @param auditable
 	 * @return
 	 */
-	private Object touchAuditor(AuditableBeanWrapper wrapper, boolean isNew) {
+	private Optional<Object> touchAuditor(AuditableBeanWrapper wrapper, boolean isNew) {
 
-		if (null == auditorAware) {
-			return null;
-		}
+		return auditorAware.map(it -> {
 
-		Object auditor = auditorAware.getCurrentAuditor();
+			Optional<?> auditor = it.getCurrentAuditor();
 
-		if (isNew) {
-			wrapper.setCreatedBy(auditor);
-			if (!modifyOnCreation) {
-				return auditor;
+			if (isNew) {
+				wrapper.setCreatedBy(auditor);
+				if (!modifyOnCreation) {
+					return auditor;
+				}
 			}
-		}
 
-		wrapper.setLastModifiedBy(auditor);
-		return auditor;
+			return wrapper.setLastModifiedBy(auditor);
+		});
+
 	}
 
 	/**
@@ -192,9 +193,9 @@ public class AuditingHandler implements InitializingBean {
 	 * @param wrapper
 	 * @return
 	 */
-	private Calendar touchDate(AuditableBeanWrapper wrapper, boolean isNew) {
+	private Optional<TemporalAccessor> touchDate(AuditableBeanWrapper wrapper, boolean isNew) {
 
-		Calendar now = dateTimeProvider.getNow();
+		Optional<TemporalAccessor> now = dateTimeProvider.getNow();
 
 		if (isNew) {
 			wrapper.setCreatedDate(now);
@@ -203,8 +204,7 @@ public class AuditingHandler implements InitializingBean {
 			}
 		}
 
-		wrapper.setLastModifiedDate(now);
-		return now;
+		return wrapper.setLastModifiedDate(now);
 	}
 
 	/*

src/main/java/org/springframework/data/auditing/CurrentDateTimeProvider.java

@@ -15,8 +15,9 @@
  */
 package org.springframework.data.auditing;
 
-import java.util.Calendar;
-import java.util.GregorianCalendar;
+import java.time.ZonedDateTime;
+import java.time.temporal.TemporalAccessor;
+import java.util.Optional;
 
 import org.joda.time.DateTime;
 
@@ -35,7 +36,7 @@ public enum CurrentDateTimeProvider implements DateTimeProvider {
 	 * @see org.springframework.data.auditing.DateTimeProvider#getNow()
 	 */
 	@Override
-	public Calendar getNow() {
-		return new GregorianCalendar();
+	public Optional<TemporalAccessor> getNow() {
+		return Optional.of(ZonedDateTime.now());
 	}
 }

src/main/java/org/springframework/data/auditing/DateTimeProvider.java

@@ -15,7 +15,8 @@
  */
 package org.springframework.data.auditing;
 
-import java.util.Calendar;
+import java.time.temporal.TemporalAccessor;
+import java.util.Optional;
 
 /**
  * SPI to calculate the current time to be used when auditing.
@@ -30,5 +31,5 @@ public interface DateTimeProvider {
 	 * 
 	 * @return
 	 */
-	Calendar getNow();
+	Optional<TemporalAccessor> getNow();
 }

src/main/java/org/springframework/data/auditing/DefaultAuditableBeanWrapperFactory.java

@@ -15,21 +15,24 @@
  */
 package org.springframework.data.auditing;
 
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+
 import java.lang.reflect.Field;
+import java.time.temporal.TemporalAccessor;
 import java.util.Calendar;
 import java.util.Date;
+import java.util.Optional;
 
-import org.joda.time.DateTime;
-import org.joda.time.LocalDateTime;
+import org.springframework.core.ResolvableType;
 import org.springframework.core.convert.ConversionService;
-import org.springframework.core.convert.converter.Converter;
+import org.springframework.data.convert.JodaTimeConverters;
 import org.springframework.data.convert.Jsr310Converters;
 import org.springframework.data.convert.ThreeTenBackPortConverters;
 import org.springframework.data.domain.Auditable;
 import org.springframework.data.util.ReflectionUtils;
 import org.springframework.format.support.DefaultFormattingConversionService;
 import org.springframework.util.Assert;
-import org.springframework.util.ClassUtils;
 
 /**
  * A factory class to {@link AuditableBeanWrapper} instances.
@@ -46,23 +49,22 @@ class DefaultAuditableBeanWrapperFactory implements AuditableBeanWrapperFactory
 	 * @return
 	 */
 	@SuppressWarnings("unchecked")
-	public AuditableBeanWrapper getBeanWrapperFor(Object source) {
+	public Optional<AuditableBeanWrapper> getBeanWrapperFor(Optional<? extends Object> source) {
+
+		return source.map(it -> {
+
+			if (it instanceof Auditable) {
+				return new AuditableInterfaceBeanWrapper((Auditable<Object, ?, TemporalAccessor>) it);
+			}
+
+			AnnotationAuditingMetadata metadata = AnnotationAuditingMetadata.getMetadata(it.getClass());
+
+			if (metadata.isAuditable()) {
+				return new ReflectionAuditingBeanWrapper(it);
+			}
 
-		if (source == null) {
 			return null;
-		}
-
-		if (source instanceof Auditable) {
-			return new AuditableInterfaceBeanWrapper((Auditable<Object, ?>) source);
-		}
-
-		AnnotationAuditingMetadata metadata = AnnotationAuditingMetadata.getMetadata(source.getClass());
-
-		if (metadata.isAuditable()) {
-			return new ReflectionAuditingBeanWrapper(source);
-		}
-
-		return null;
+		});
 	}
 
 	/**
@@ -70,36 +72,53 @@ class DefaultAuditableBeanWrapperFactory implements AuditableBeanWrapperFactory
 	 * 
 	 * @author Oliver Gierke
 	 */
+	@RequiredArgsConstructor
 	static class AuditableInterfaceBeanWrapper extends DateConvertingAuditableBeanWrapper {
 
-		private final Auditable<Object, ?> auditable;
+		private final @NonNull Auditable<Object, ?, TemporalAccessor> auditable;
+		private final Class<? extends TemporalAccessor> type;
+
+		@SuppressWarnings("unchecked")
+		public AuditableInterfaceBeanWrapper(Auditable<Object, ?, TemporalAccessor> auditable) {
 
-		public AuditableInterfaceBeanWrapper(Auditable<Object, ?> auditable) {
 			this.auditable = auditable;
+			this.type = (Class<? extends TemporalAccessor>) ResolvableType.forClass(Auditable.class, auditable.getClass())
+					.getGeneric(2).getRawClass();
 		}
 
 		/* 
 		 * (non-Javadoc)
-		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setCreatedBy(java.lang.Object)
+		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setCreatedBy(java.util.Optional)
 		 */
-		public void setCreatedBy(Object value) {
+		@Override
+		public Optional<? extends Object> setCreatedBy(Optional<? extends Object> value) {
+
 			auditable.setCreatedBy(value);
-		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setCreatedDate(org.joda.time.DateTime)
-		 */
-		public void setCreatedDate(Calendar value) {
-			auditable.setCreatedDate(new DateTime(value));
+			return value;
 		}
 
 		/* 
 		 * (non-Javadoc)
-		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setLastModifiedBy(java.lang.Object)
+		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setCreatedDate(java.util.Optional)
 		 */
-		public void setLastModifiedBy(Object value) {
+		@Override
+		public Optional<TemporalAccessor> setCreatedDate(Optional<TemporalAccessor> value) {
+
+			auditable.setCreatedDate(getAsTemporalAccessor(value, type));
+
+			return value;
+		}
+
+		/* 
+		 * (non-Javadoc)
+		 * @see org.springframework.data.auditing.DefaultAuditableBeanWrapperFactory.AuditableInterfaceBeanWrapper#setLastModifiedBy(java.util.Optional)
+		 */
+		@Override
+		public Optional<? extends Object> setLastModifiedBy(Optional<? extends Object> value) {
 			auditable.setLastModifiedBy(value);
+
+			return value;
 		}
 
 		/* 
@@ -107,16 +126,20 @@ class DefaultAuditableBeanWrapperFactory implements AuditableBeanWrapperFactory
 		 * @see org.springframework.data.auditing.AuditableBeanWrapper#getLastModifiedDate()
 		 */
 		@Override
-		public Calendar getLastModifiedDate() {
-			return getAsCalendar(auditable.getLastModifiedDate());
+		public Optional<TemporalAccessor> getLastModifiedDate() {
+			return getAsTemporalAccessor(auditable.getLastModifiedDate(), TemporalAccessor.class);
 		}
 
-		/*
+		/* 
 		 * (non-Javadoc)
-		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setLastModifiedDate(org.joda.time.DateTime)
+		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setLastModifiedDate(java.util.Optional)
 		 */
-		public void setLastModifiedDate(Calendar value) {
-			auditable.setLastModifiedDate(new DateTime(value));
+		@Override
+		public Optional<TemporalAccessor> setLastModifiedDate(Optional<TemporalAccessor> value) {
+
+			auditable.setLastModifiedDate(getAsTemporalAccessor(value, type));
+
+			return value;
 		}
 	}
 
@@ -129,9 +152,6 @@ class DefaultAuditableBeanWrapperFactory implements AuditableBeanWrapperFactory
 	 */
 	abstract static class DateConvertingAuditableBeanWrapper implements AuditableBeanWrapper {
 
-		private static final boolean IS_JODA_TIME_PRESENT = ClassUtils.isPresent("org.joda.time.DateTime",
-				ReflectionAuditingBeanWrapper.class.getClassLoader());
-
 		private final ConversionService conversionService;
 
 		/**
@@ -141,18 +161,9 @@ class DefaultAuditableBeanWrapperFactory implements AuditableBeanWrapperFactory
 
 			DefaultFormattingConversionService conversionService = new DefaultFormattingConversionService();
 
-			if (IS_JODA_TIME_PRESENT) {
-				conversionService.addConverter(CalendarToDateTimeConverter.INSTANCE);
-				conversionService.addConverter(CalendarToLocalDateTimeConverter.INSTANCE);
-			}
-
-			for (Converter<?, ?> converter : Jsr310Converters.getConvertersToRegister()) {
-				conversionService.addConverter(converter);
-			}
-
-			for (Converter<?, ?> converter : ThreeTenBackPortConverters.getConvertersToRegister()) {
-				conversionService.addConverter(converter);
-			}
+			JodaTimeConverters.getConvertersToRegister().forEach(it -> conversionService.addConverter(it));
+			Jsr310Converters.getConvertersToRegister().forEach(it -> conversionService.addConverter(it));
+			ThreeTenBackPortConverters.getConvertersToRegister().forEach(it -> conversionService.addConverter(it));
 
 			this.conversionService = conversionService;
 		}
@@ -165,28 +176,27 @@ class DefaultAuditableBeanWrapperFactory implements AuditableBeanWrapperFactory
 		 * @param source must not be {@literal null}.
 		 * @return
 		 */
-		protected Object getDateValueToSet(Calendar value, Class<?> targetType, Object source) {
+		protected Optional<Object> getDateValueToSet(Optional<TemporalAccessor> value, Class<?> targetType, Object source) {
 
-			if (value == null) {
-				return null;
-			}
+			return value.map(it -> {
 
-			if (Calendar.class.equals(targetType)) {
-				return value;
-			}
+				if (TemporalAccessor.class.equals(targetType)) {
+					return it;
+				}
 
-			if (conversionService.canConvert(Calendar.class, targetType)) {
-				return conversionService.convert(value, targetType);
-			}
+				if (conversionService.canConvert(it.getClass(), targetType)) {
+					return conversionService.convert(it, targetType);
+				}
 
-			if (conversionService.canConvert(Date.class, targetType)) {
+				if (conversionService.canConvert(Date.class, targetType)) {
 
-				Date date = conversionService.convert(value, Date.class);
-				return conversionService.convert(date, targetType);
-			}
+					Date date = conversionService.convert(it, Date.class);
+					return conversionService.convert(date, targetType);
+				}
 
-			throw new IllegalArgumentException(String.format("Invalid date type for member %s! Supported types are %s.",
-					source, AnnotationAuditingMetadata.SUPPORTED_DATE_TYPES));
+				throw new IllegalArgumentException(String.format("Invalid date type for member %s! Supported types are %s.",
+						source, AnnotationAuditingMetadata.SUPPORTED_DATE_TYPES));
+			});
 		}
 
 		/**
@@ -195,22 +205,17 @@ class DefaultAuditableBeanWrapperFactory implements AuditableBeanWrapperFactory
 		 * @param source can be {@literal null}.
 		 * @return
 		 */
-		protected Calendar getAsCalendar(Object source) {
+		@SuppressWarnings("unchecked")
+		protected <T> Optional<T> getAsTemporalAccessor(Optional<?> source, Class<T> target) {
 
-			if (source == null || source instanceof Calendar) {
-				return (Calendar) source;
-			}
-
-			// Apply conversion to date if necessary and possible
-			source = !(source instanceof Date) && conversionService.canConvert(source.getClass(), Date.class) ? conversionService
-					.convert(source, Date.class) : source;
-
-			return conversionService.convert(source, Calendar.class);
+			return source.map(it -> {
+				return target.isInstance(it) ? (T) it : conversionService.convert(it, target);
+			});
 		}
 	}
 
 	/**
-	 * An {@link AuditableBeanWrapper} implementation that sets values on the target object using refelction.
+	 * An {@link AuditableBeanWrapper} implementation that sets values on the target object using reflection.
 	 * 
 	 * @author Oliver Gierke
 	 */
@@ -234,26 +239,29 @@ class DefaultAuditableBeanWrapperFactory implements AuditableBeanWrapperFactory
 
 		/* 
 		 * (non-Javadoc)
-		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setCreatedBy(java.lang.Object)
+		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setCreatedBy(java.util.Optional)
 		 */
-		public void setCreatedBy(Object value) {
-			setField(metadata.getCreatedByField(), value);
-		}
-
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setCreatedDate(java.util.Calendar)
-		 */
-		public void setCreatedDate(Calendar value) {
-			setDateField(metadata.getCreatedDateField(), value);
+		@Override
+		public Optional<? extends Object> setCreatedBy(Optional<? extends Object> value) {
+			return setField(metadata.getCreatedByField(), value);
 		}
 
 		/* 
 		 * (non-Javadoc)
-		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setLastModifiedBy(java.lang.Object)
+		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setCreatedDate(java.util.Optional)
 		 */
-		public void setLastModifiedBy(Object value) {
-			setField(metadata.getLastModifiedByField(), value);
+		@Override
+		public Optional<TemporalAccessor> setCreatedDate(Optional<TemporalAccessor> value) {
+			return setDateField(metadata.getCreatedDateField(), value);
+		}
+
+		/* 
+		 * (non-Javadoc)
+		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setLastModifiedBy(java.util.Optional)
+		 */
+		@Override
+		public Optional<? extends Object> setLastModifiedBy(Optional<? extends Object> value) {
+			return setField(metadata.getLastModifiedByField(), value);
 		}
 
 		/* 
@@ -261,18 +269,39 @@ class DefaultAuditableBeanWrapperFactory implements AuditableBeanWrapperFactory
 		 * @see org.springframework.data.auditing.AuditableBeanWrapper#getLastModifiedDate()
 		 */
 		@Override
-		public Calendar getLastModifiedDate() {
+		public Optional<TemporalAccessor> getLastModifiedDate() {
 
-			return getAsCalendar(org.springframework.util.ReflectionUtils.getField(metadata.getLastModifiedDateField(),
-					target));
+			return getAsTemporalAccessor(metadata.getLastModifiedDateField().map(field -> {
+
+				Object value = org.springframework.util.ReflectionUtils.getField(field, target);
+				return Optional.class.isInstance(value) ? ((Optional<?>) value).orElse(null) : value;
+
+			}), TemporalAccessor.class);
 		}
 
-		/*
+		/* 
 		 * (non-Javadoc)
-		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setLastModifiedDate(java.util.Calendar)
+		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setLastModifiedDate(java.util.Optional)
 		 */
-		public void setLastModifiedDate(Calendar value) {
-			setDateField(metadata.getLastModifiedDateField(), value);
+		@Override
+		public Optional<TemporalAccessor> setLastModifiedDate(Optional<TemporalAccessor> value) {
+			return setDateField(metadata.getLastModifiedDateField(), value);
+		}
+
+		/**
+		 * Sets the given field to the given value if present.
+		 * 
+		 * @param field
+		 * @param value
+		 */
+		private Optional<? extends Object> setField(Optional<Field> field, Optional<? extends Object> value) {
+
+			field.ifPresent(it -> {
+				ReflectionUtils.setField(it, target,
+						Optional.class.isAssignableFrom(it.getType()) ? value : value.orElse(null));
+			});
+
+			return value;
 		}
 
 		/**
@@ -281,46 +310,15 @@ class DefaultAuditableBeanWrapperFactory implements AuditableBeanWrapperFactory
 		 * @param field
 		 * @param value
 		 */
-		private void setField(Field field, Object value) {
+		private Optional<TemporalAccessor> setDateField(Optional<Field> field, Optional<TemporalAccessor> value) {
 
-			if (field != null) {
-				ReflectionUtils.setField(field, target, value);
-			}
-		}
+			field.ifPresent(it -> {
+				Optional<Object> toSet = getDateValueToSet(value, it.getType(), it);
+				ReflectionUtils.setField(it, target,
+						Optional.class.isAssignableFrom(it.getType()) ? toSet : toSet.orElse(null));
+			});
 
-		/**
-		 * Sets the given field to the given value if the field is not {@literal null}.
-		 * 
-		 * @param field
-		 * @param value
-		 */
-		private void setDateField(Field field, Calendar value) {
-
-			if (field == null) {
-				return;
-			}
-
-			ReflectionUtils.setField(field, target, getDateValueToSet(value, field.getType(), field));
-		}
-	}
-
-	private static enum CalendarToDateTimeConverter implements Converter<Calendar, DateTime> {
-
-		INSTANCE;
-
-		@Override
-		public DateTime convert(Calendar source) {
-			return new DateTime(source);
-		}
-	}
-
-	private static enum CalendarToLocalDateTimeConverter implements Converter<Calendar, LocalDateTime> {
-
-		INSTANCE;
-
-		@Override
-		public LocalDateTime convert(Calendar source) {
-			return new LocalDateTime(source);
+			return value;
 		}
 	}
 }

src/main/java/org/springframework/data/auditing/IsNewAwareAuditingHandler.java

@@ -16,6 +16,7 @@
 package org.springframework.data.auditing;
 
 import java.util.Arrays;
+import java.util.Optional;
 
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentProperty;
@@ -24,11 +25,12 @@ import org.springframework.data.mapping.context.MappingContextIsNewStrategyFacto
 import org.springframework.data.mapping.context.PersistentEntities;
 import org.springframework.data.support.IsNewStrategy;
 import org.springframework.data.support.IsNewStrategyFactory;
+import org.springframework.util.Assert;
 
 /**
  * {@link AuditingHandler} extension that uses an {@link IsNewStrategyFactory} to expose a generic
- * {@link #markAudited(Object)} method that will route calls to {@link #markCreated(Object)} or
- * {@link #markModified(Object)} based on the {@link IsNewStrategy} determined from the factory.
+ * {@link #markAudited(Optional)} method that will route calls to {@link #markCreated(Optional)} or
+ * {@link #markModified(Optional)} based on the {@link IsNewStrategy} determined from the factory.
  * 
  * @author Oliver Gierke
  * @since 1.5
@@ -45,7 +47,6 @@ public class IsNewAwareAuditingHandler extends AuditingHandler {
 	 * @deprecated use {@link IsNewAwareAuditingHandler(PersistentEntities)} instead.
 	 */
 	@Deprecated
-	@SuppressWarnings("unchecked")
 	public IsNewAwareAuditingHandler(
 			MappingContext<? extends PersistentEntity<?, ?>, ? extends PersistentProperty<?>> mappingContext) {
 		this(new PersistentEntities(Arrays.asList(mappingContext)));
@@ -54,7 +55,7 @@ public class IsNewAwareAuditingHandler extends AuditingHandler {
 	/**
 	 * Creates a new {@link IsNewAwareAuditingHandler} for the given {@link MappingContext}.
 	 * 
-	 * @param mappingContext must not be {@literal null}.
+	 * @param entities must not be {@literal null}.
 	 * @since 1.10
 	 */
 	public IsNewAwareAuditingHandler(PersistentEntities entities) {
@@ -66,23 +67,28 @@ public class IsNewAwareAuditingHandler extends AuditingHandler {
 
 	/**
 	 * Marks the given object created or modified based on the {@link IsNewStrategy} returned by the
-	 * {@link IsNewStrategyFactory} configured. Will rout the calls to {@link #markCreated(Object)} and
-	 * {@link #markModified(Object)} accordingly.
+	 * {@link IsNewStrategyFactory} configured. Will rout the calls to {@link #markCreated(Optional)} and
+	 * {@link #markModified(Optional)} accordingly.
 	 * 
 	 * @param object
 	 */
-	public void markAudited(Object object) {
+	public void markAudited(Optional<Object> object) {
+
+		Assert.notNull(object, "Source object must not be null!");
 
 		if (!isAuditable(object)) {
 			return;
 		}
 
-		IsNewStrategy strategy = isNewStrategyFactory.getIsNewStrategy(object.getClass());
+		object.ifPresent(it -> {
 
-		if (strategy.isNew(object)) {
-			markCreated(object);
-		} else {
-			markModified(object);
-		}
+			IsNewStrategy strategy = isNewStrategyFactory.getIsNewStrategy(it.getClass());
+
+			if (strategy.isNew(object)) {
+				markCreated(object);
+			} else {
+				markModified(object);
+			}
+		});
 	}
 }

src/main/java/org/springframework/data/auditing/MappingAuditableBeanWrapperFactory.java

@@ -15,9 +15,10 @@
  */
 package org.springframework.data.auditing;
 
-import java.util.Calendar;
+import java.time.temporal.TemporalAccessor;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Optional;
 
 import org.springframework.data.annotation.CreatedBy;
 import org.springframework.data.annotation.CreatedDate;
@@ -29,6 +30,7 @@ import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.PersistentPropertyAccessor;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mapping.context.PersistentEntities;
+import org.springframework.data.util.Optionals;
 import org.springframework.util.Assert;
 
 /**
@@ -62,32 +64,27 @@ public class MappingAuditableBeanWrapperFactory extends DefaultAuditableBeanWrap
 	 * @see org.springframework.data.auditing.AuditableBeanWrapperFactory#getBeanWrapperFor(java.lang.Object)
 	 */
 	@Override
-	public AuditableBeanWrapper getBeanWrapperFor(Object source) {
+	public Optional<AuditableBeanWrapper> getBeanWrapperFor(Optional<? extends Object> source) {
 
-		if (source == null) {
-			return null;
-		}
+		return source.flatMap(it -> {
 
-		if (source instanceof Auditable) {
-			return super.getBeanWrapperFor(source);
-		}
+			if (it instanceof Auditable) {
+				return super.getBeanWrapperFor(source);
+			}
 
-		Class<?> type = source.getClass();
-		PersistentEntity<?, ?> entity = entities.getPersistentEntity(type);
+			Class<?> type = it.getClass();
+			PersistentEntity<?, ?> entity = entities.getPersistentEntity(type);
 
-		if (entity == null) {
-			return super.getBeanWrapperFor(source);
-		}
+			if (entity == null) {
+				return super.getBeanWrapperFor(source);
+			}
 
-		MappingAuditingMetadata metadata = metadataCache.get(type);
+			MappingAuditingMetadata metadata = metadataCache.computeIfAbsent(type,
+					foo -> new MappingAuditingMetadata(entity));
 
-		if (metadata == null) {
-			metadata = new MappingAuditingMetadata(entity);
-			metadataCache.put(type, metadata);
-		}
-
-		PersistentPropertyAccessor accessor = entity.getPropertyAccessor(source);
-		return metadata.isAuditable() ? new MappingMetadataAuditableBeanWrapper(accessor, metadata) : null;
+			return Optional.ofNullable(metadata.isAuditable()
+					? new MappingMetadataAuditableBeanWrapper(entity.getPropertyAccessor(it), metadata) : null);
+		});
 	}
 
 	/**
@@ -98,8 +95,8 @@ public class MappingAuditableBeanWrapperFactory extends DefaultAuditableBeanWrap
 	 */
 	static class MappingAuditingMetadata {
 
-		private final PersistentProperty<?> createdByProperty, createdDateProperty, lastModifiedByProperty,
-				lastModifiedDateProperty;
+		private final Optional<? extends PersistentProperty<?>> createdByProperty, createdDateProperty,
+				lastModifiedByProperty, lastModifiedDateProperty;
 
 		/**
 		 * Creates a new {@link MappingAuditingMetadata} instance from the given {@link PersistentEntity}.
@@ -123,8 +120,8 @@ public class MappingAuditableBeanWrapperFactory extends DefaultAuditableBeanWrap
 		 * @return
 		 */
 		public boolean isAuditable() {
-			return createdByProperty != null || createdDateProperty != null || lastModifiedByProperty != null
-					|| lastModifiedDateProperty != null;
+			return Optionals.isAnyPresent(createdByProperty, createdDateProperty, lastModifiedByProperty,
+					lastModifiedDateProperty);
 		}
 	}
 
@@ -158,40 +155,44 @@ public class MappingAuditableBeanWrapperFactory extends DefaultAuditableBeanWrap
 
 		/* 
 		 * (non-Javadoc)
-		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setCreatedBy(java.lang.Object)
+		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setCreatedBy(java.util.Optional)
 		 */
 		@Override
-		public void setCreatedBy(Object value) {
+		public Optional<? extends Object> setCreatedBy(Optional<? extends Object> value) {
 
-			if (metadata.createdByProperty != null) {
-				this.accessor.setProperty(metadata.createdByProperty, value);
-			}
+			metadata.createdByProperty.ifPresent(it -> {
+				this.accessor.setProperty(it, value);
+			});
+
+			return value;
 		}
 
 		/* 
 		 * (non-Javadoc)
-		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setCreatedDate(java.util.Calendar)
+		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setCreatedDate(java.util.Optional)
 		 */
 		@Override
-		public void setCreatedDate(Calendar value) {
+		public Optional<TemporalAccessor> setCreatedDate(Optional<TemporalAccessor> value) {
 
-			PersistentProperty<?> property = metadata.createdDateProperty;
+			metadata.createdDateProperty.ifPresent(it -> {
+				this.accessor.setProperty(it, getDateValueToSet(value, it.getType(), it));
+			});
 
-			if (property != null) {
-				this.accessor.setProperty(property, getDateValueToSet(value, property.getType(), property));
-			}
+			return value;
 		}
 
 		/* 
 		 * (non-Javadoc)
-		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setLastModifiedBy(java.lang.Object)
+		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setLastModifiedBy(java.util.Optional)
 		 */
 		@Override
-		public void setLastModifiedBy(Object value) {
+		public Optional<? extends Object> setLastModifiedBy(Optional<? extends Object> value) {
 
-			if (metadata.lastModifiedByProperty != null) {
-				this.accessor.setProperty(metadata.lastModifiedByProperty, value);
-			}
+			metadata.lastModifiedByProperty.ifPresent(it -> {
+				this.accessor.setProperty(it, value);
+			});
+
+			return value;
 		}
 
 		/* 
@@ -199,29 +200,23 @@ public class MappingAuditableBeanWrapperFactory extends DefaultAuditableBeanWrap
 		 * @see org.springframework.data.auditing.AuditableBeanWrapper#getLastModifiedDate()
 		 */
 		@Override
-		public Calendar getLastModifiedDate() {
-
-			PersistentProperty<?> property = metadata.lastModifiedDateProperty;
-
-			if (property == null) {
-				return null;
-			}
-
-			return getAsCalendar(accessor.getProperty(property));
+		public Optional<TemporalAccessor> getLastModifiedDate() {
+			return getAsTemporalAccessor(metadata.lastModifiedDateProperty.map(it -> accessor.getProperty(it)),
+					TemporalAccessor.class);
 		}
 
 		/* 
 		 * (non-Javadoc)
-		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setLastModifiedDate(java.util.Calendar)
+		 * @see org.springframework.data.auditing.AuditableBeanWrapper#setLastModifiedDate(java.util.Optional)
 		 */
 		@Override
-		public void setLastModifiedDate(Calendar value) {
+		public Optional<TemporalAccessor> setLastModifiedDate(Optional<TemporalAccessor> value) {
 
-			PersistentProperty<?> property = metadata.lastModifiedDateProperty;
+			metadata.lastModifiedDateProperty.ifPresent(it -> {
+				this.accessor.setProperty(it, getDateValueToSet(value, it.getType(), it));
+			});
 
-			if (property != null) {
-				this.accessor.setProperty(property, getDateValueToSet(value, property.getType(), property));
-			}
+			return value;
 		}
 	}
 }

src/main/java/org/springframework/data/convert/BytecodeGeneratingEntityInstantiator.java

@@ -1,60 +0,0 @@
-/*
- * Copyright 2015 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.data.convert;
-
-import org.springframework.data.mapping.PersistentEntity;
-import org.springframework.data.mapping.PersistentProperty;
-import org.springframework.data.mapping.PreferredConstructor;
-import org.springframework.data.mapping.model.ParameterValueProvider;
-
-/**
- * An {@link EntityInstantiator} that can generate byte code to speed-up dynamic object instantiation. Uses the
- * {@link PersistentEntity}'s {@link PreferredConstructor} to instantiate an instance of the entity by dynamically
- * generating factory methods with appropriate constructor invocations via ASM. If we cannot generate byte code for a
- * type, we gracefully fall-back to the {@link ReflectionEntityInstantiator}.
- * 
- * @author Thomas Darimont
- * @author Oliver Gierke
- * @since 1.10
- * @deprecated since 1.11 in favor of {@link ClassGeneratingEntityInstantiator}.
- */
-@Deprecated
-public enum BytecodeGeneratingEntityInstantiator implements EntityInstantiator {
-
-	INSTANCE;
-
-	private final ClassGeneratingEntityInstantiator delegate = new ClassGeneratingEntityInstantiator();
-
-	/* 
-	 * (non-Javadoc)
-	 * @see org.springframework.data.convert.EntityInstantiator#createInstance(org.springframework.data.mapping.PersistentEntity, org.springframework.data.mapping.model.ParameterValueProvider)
-	 */
-	@Override
-	public <T, E extends PersistentEntity<? extends T, P>, P extends PersistentProperty<P>> T createInstance(E entity,
-			ParameterValueProvider<P> provider) {
-
-		return this.delegate.createInstance(entity, provider);
-	}
-
-	/**
-	 * @author Thomas Darimont
-	 * @deprecated
-	 */
-	public interface ObjectInstantiator {
-
-		Object newInstance(Object... args);
-	}
-}

src/main/java/org/springframework/data/convert/ClassGeneratingEntityInstantiator.java

@@ -21,11 +21,10 @@ import java.lang.reflect.Constructor;
 import java.lang.reflect.Modifier;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 
 import org.springframework.asm.ClassWriter;
 import org.springframework.asm.MethodVisitor;
@@ -34,7 +33,6 @@ import org.springframework.asm.Type;
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.PreferredConstructor;
-import org.springframework.data.mapping.PreferredConstructor.Parameter;
 import org.springframework.data.mapping.model.MappingInstantiationException;
 import org.springframework.data.mapping.model.ParameterValueProvider;
 import org.springframework.data.util.TypeInformation;
@@ -140,12 +138,10 @@ public class ClassGeneratingEntityInstantiator implements EntityInstantiator {
 			return true;
 		}
 
-		PreferredConstructor<?, ?> persistenceConstructor = entity.getPersistenceConstructor();
-		if (persistenceConstructor == null || !Modifier.isPublic(persistenceConstructor.getConstructor().getModifiers())) {
-			return true;
-		}
-
-		return false;
+		return entity.getPersistenceConstructor()//
+				.map(PreferredConstructor::getConstructor)//
+				.map(Constructor::getModifiers)//
+				.map(modifier -> !Modifier.isPublic(modifier)).orElse(false);
 	}
 
 	/**
@@ -200,7 +196,7 @@ public class ClassGeneratingEntityInstantiator implements EntityInstantiator {
 			try {
 				return (T) instantiator.newInstance(params);
 			} catch (Exception e) {
-				throw new MappingInstantiationException(entity, Arrays.asList(params), e);
+				throw new MappingInstantiationException(Optional.of(entity), Arrays.asList(params), e);
 			}
 		}
 
@@ -212,19 +208,19 @@ public class ClassGeneratingEntityInstantiator implements EntityInstantiator {
 		 * @return
 		 */
 		private <P extends PersistentProperty<P>, T> Object[] extractInvocationArguments(
-				PreferredConstructor<? extends T, P> constructor, ParameterValueProvider<P> provider) {
+				Optional<? extends PreferredConstructor<? extends T, P>> constructor, ParameterValueProvider<P> provider) {
 
-			if (provider == null || constructor == null || !constructor.hasParameters()) {
-				return EMPTY_ARRAY;
-			}
+			return constructor.map(it -> {
 
-			List<Object> params = new ArrayList<Object>();
+				if (provider == null || !it.hasParameters()) {
+					return EMPTY_ARRAY;
+				}
 
-			for (Parameter<?, P> parameter : constructor.getParameters()) {
-				params.add(provider.getParameterValue(parameter));
-			}
+				return it.getParameters().stream()//
+						.map(parameter -> provider.getParameterValue(parameter))//
+						.toArray();
 
-			return params.toArray();
+			}).orElse(EMPTY_ARRAY);
 		}
 	}
 
@@ -366,26 +362,31 @@ public class ClassGeneratingEntityInstantiator implements EntityInstantiator {
 			mv.visitTypeInsn(NEW, entityTypeResourcePath);
 			mv.visitInsn(DUP);
 
-			Constructor<?> ctor = entity.getPersistenceConstructor().getConstructor();
-			Class<?>[] parameterTypes = ctor.getParameterTypes();
-			for (int i = 0; i < parameterTypes.length; i++) {
-				mv.visitVarInsn(ALOAD, 1);
+			entity.getPersistenceConstructor().ifPresent(constructor -> {
 
-				visitArrayIndex(mv, i);
+				Constructor<?> ctor = constructor.getConstructor();
+				Class<?>[] parameterTypes = ctor.getParameterTypes();
 
-				mv.visitInsn(AALOAD);
+				for (int i = 0; i < parameterTypes.length; i++) {
 
-				if (parameterTypes[i].isPrimitive()) {
-					insertUnboxInsns(mv, Type.getType(parameterTypes[i]).toString().charAt(0), "");
-				} else {
-					mv.visitTypeInsn(CHECKCAST, Type.getInternalName(parameterTypes[i]));
+					mv.visitVarInsn(ALOAD, 1);
+
+					visitArrayIndex(mv, i);
+
+					mv.visitInsn(AALOAD);
+
+					if (parameterTypes[i].isPrimitive()) {
+						insertUnboxInsns(mv, Type.getType(parameterTypes[i]).toString().charAt(0), "");
+					} else {
+						mv.visitTypeInsn(CHECKCAST, Type.getInternalName(parameterTypes[i]));
+					}
 				}
-			}
-			mv.visitMethodInsn(INVOKESPECIAL, entityTypeResourcePath, INIT, Type.getConstructorDescriptor(ctor), false);
 
-			mv.visitInsn(ARETURN);
-			mv.visitMaxs(0, 0); // (0, 0) = computed via ClassWriter.COMPUTE_MAXS
-			mv.visitEnd();
+				mv.visitMethodInsn(INVOKESPECIAL, entityTypeResourcePath, INIT, Type.getConstructorDescriptor(ctor), false);
+				mv.visitInsn(ARETURN);
+				mv.visitMaxs(0, 0); // (0, 0) = computed via ClassWriter.COMPUTE_MAXS
+				mv.visitEnd();
+			});
 		}
 
 		/**

src/main/java/org/springframework/data/convert/JodaTimeConverters.java

@@ -61,6 +61,9 @@ public abstract class JodaTimeConverters {
 		converters.add(DateToDateTimeConverter.INSTANCE);
 		converters.add(DateToDateMidnightConverter.INSTANCE);
 
+		converters.add(LocalDateTimeToJodaLocalDateTime.INSTANCE);
+		converters.add(LocalDateTimeToJodaDateTime.INSTANCE);
+
 		return converters;
 	}
 
@@ -135,4 +138,36 @@ public abstract class JodaTimeConverters {
 			return source == null ? null : new DateMidnight(source.getTime());
 		}
 	}
+
+	public static enum LocalDateTimeToJodaLocalDateTime implements Converter<java.time.LocalDateTime, LocalDateTime> {
+
+		INSTANCE;
+
+		/* 
+		 * (non-Javadoc)
+		 * @see org.springframework.core.convert.converter.Converter#convert(java.lang.Object)
+		 */
+		@Override
+		public LocalDateTime convert(java.time.LocalDateTime source) {
+			return source == null ? null
+					: LocalDateTime.fromDateFields(
+							org.springframework.data.convert.Jsr310Converters.LocalDateTimeToDateConverter.INSTANCE.convert(source));
+		}
+	}
+
+	public static enum LocalDateTimeToJodaDateTime implements Converter<java.time.LocalDateTime, DateTime> {
+
+		INSTANCE;
+
+		/* 
+		 * (non-Javadoc)
+		 * @see org.springframework.core.convert.converter.Converter#convert(java.lang.Object)
+		 */
+		@Override
+		public DateTime convert(java.time.LocalDateTime source) {
+			return source == null ? null
+					: new DateTime(
+							org.springframework.data.convert.Jsr310Converters.LocalDateTimeToDateConverter.INSTANCE.convert(source));
+		}
+	}
 }

src/main/java/org/springframework/data/convert/ReflectionEntityInstantiator.java

@@ -16,16 +16,16 @@
 package org.springframework.data.convert;
 
 import java.lang.reflect.Array;
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
 
 import org.springframework.beans.BeanInstantiationException;
 import org.springframework.beans.BeanUtils;
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.PreferredConstructor;
-import org.springframework.data.mapping.PreferredConstructor.Parameter;
 import org.springframework.data.mapping.model.MappingInstantiationException;
 import org.springframework.data.mapping.model.ParameterValueProvider;
 
@@ -43,39 +43,45 @@ public enum ReflectionEntityInstantiator implements EntityInstantiator {
 	public <T, E extends PersistentEntity<? extends T, P>, P extends PersistentProperty<P>> T createInstance(E entity,
 			ParameterValueProvider<P> provider) {
 
-		PreferredConstructor<? extends T, P> constructor = entity.getPersistenceConstructor();
+		return entity.getPersistenceConstructor().map(constructor -> {
 
-		if (constructor == null) {
+			List<Object> params = Optional.ofNullable(provider)//
+					.map(it -> constructor.getParameters().stream()//
+							.map(parameter -> it.getParameterValue(parameter).orElse(null))//
+							.collect(Collectors.toList()))//
+					.orElse(Collections.emptyList());
 
 			try {
-				Class<?> clazz = entity.getType();
+				return (T) BeanUtils.instantiateClass(constructor.getConstructor(), params.toArray());
+			} catch (BeanInstantiationException e) {
+				throw new MappingInstantiationException(Optional.of(entity), params, e);
+			}
+
+		}).orElseGet(() -> {
+
+			try {
+
+				Class<? extends T> clazz = entity.getType();
+
 				if (clazz.isArray()) {
+
 					Class<?> ctype = clazz;
 					int dims = 0;
+
 					while (ctype.isArray()) {
 						ctype = ctype.getComponentType();
 						dims++;
 					}
+
 					return (T) Array.newInstance(clazz, dims);
+
 				} else {
-					return BeanUtils.instantiateClass(entity.getType());
+					return BeanUtils.instantiateClass(clazz);
 				}
+
 			} catch (BeanInstantiationException e) {
-				throw new MappingInstantiationException(entity, Collections.emptyList(), e);
+				throw new MappingInstantiationException(Optional.of(entity), Collections.emptyList(), e);
 			}
-		}
-
-		List<Object> params = new ArrayList<Object>();
-		if (null != provider && constructor.hasParameters()) {
-			for (Parameter<?, P> parameter : constructor.getParameters()) {
-				params.add(provider.getParameterValue(parameter));
-			}
-		}
-
-		try {
-			return BeanUtils.instantiateClass(constructor.getConstructor(), params.toArray());
-		} catch (BeanInstantiationException e) {
-			throw new MappingInstantiationException(entity, params, e);
-		}
+		});
 	}
 }

src/main/java/org/springframework/data/convert/ThreeTenBackPortConverters.java

@@ -186,4 +186,5 @@ public abstract class ThreeTenBackPortConverters {
 			return ZoneId.of(source);
 		}
 	}
+
 }

src/main/java/org/springframework/data/domain/Auditable.java

@@ -16,8 +16,8 @@
 package org.springframework.data.domain;
 
 import java.io.Serializable;
-
-import org.joda.time.DateTime;
+import java.time.temporal.TemporalAccessor;
+import java.util.Optional;
 
 /**
  * Interface for auditable entities. Allows storing and retrieving creation and modification information. The changing
@@ -27,61 +27,61 @@ import org.joda.time.DateTime;
  * @param <ID> the type of the audited type's identifier
  * @author Oliver Gierke
  */
-public interface Auditable<U, ID extends Serializable> extends Persistable<ID> {
+public interface Auditable<U, ID extends Serializable, T extends TemporalAccessor> extends Persistable<ID> {
 
 	/**
 	 * Returns the user who created this entity.
 	 * 
 	 * @return the createdBy
 	 */
-	U getCreatedBy();
+	Optional<U> getCreatedBy();
 
 	/**
 	 * Sets the user who created this entity.
 	 * 
 	 * @param createdBy the creating entity to set
 	 */
-	void setCreatedBy(final U createdBy);
+	void setCreatedBy(Optional<? extends U> createdBy);
 
 	/**
 	 * Returns the creation date of the entity.
 	 * 
 	 * @return the createdDate
 	 */
-	DateTime getCreatedDate();
+	Optional<T> getCreatedDate();
 
 	/**
 	 * Sets the creation date of the entity.
 	 * 
 	 * @param creationDate the creation date to set
 	 */
-	void setCreatedDate(final DateTime creationDate);
+	void setCreatedDate(Optional<? extends T> creationDate);
 
 	/**
 	 * Returns the user who modified the entity lastly.
 	 * 
 	 * @return the lastModifiedBy
 	 */
-	U getLastModifiedBy();
+	Optional<U> getLastModifiedBy();
 
 	/**
 	 * Sets the user who modified the entity lastly.
 	 * 
 	 * @param lastModifiedBy the last modifying entity to set
 	 */
-	void setLastModifiedBy(final U lastModifiedBy);
+	void setLastModifiedBy(Optional<? extends U> lastModifiedBy);
 
 	/**
 	 * Returns the date of the last modification.
 	 * 
 	 * @return the lastModifiedDate
 	 */
-	DateTime getLastModifiedDate();
+	Optional<T> getLastModifiedDate();
 
 	/**
 	 * Sets the date of the last modification.
 	 * 
 	 * @param lastModifiedDate the date of the last modification to set
 	 */
-	void setLastModifiedDate(final DateTime lastModifiedDate);
+	void setLastModifiedDate(Optional<? extends T> lastModifiedDate);
 }

src/main/java/org/springframework/data/domain/AuditorAware.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.domain;
 
+import java.util.Optional;
+
 /**
  * Interface for components that are aware of the application's current auditor. This will be some kind of user mostly.
  * 
@@ -28,5 +30,5 @@ public interface AuditorAware<T> {
 	 * 
 	 * @return the current auditor
 	 */
-	T getCurrentAuditor();
+	Optional<T> getCurrentAuditor();
 }

src/main/java/org/springframework/data/history/AnnotationRevisionMetadata.java

@@ -1,93 +1,94 @@
-/*
- * Copyright 2012 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.data.history;
-
-import java.lang.annotation.Annotation;
-
-import org.joda.time.DateTime;
-import org.springframework.data.util.AnnotationDetectionFieldCallback;
-import org.springframework.util.Assert;
-import org.springframework.util.ReflectionUtils;
-
-/**
- * A {@link RevisionMetadata} implementation that inspects the given object for fields with the configured annotations
- * and returns the field's values on calls to {@link #getRevisionDate()} and {@link #getRevisionNumber()}.
- * 
- * @author Oliver Gierke
- */
-public class AnnotationRevisionMetadata<N extends Number & Comparable<N>> implements RevisionMetadata<N> {
-
-	private final Object entity;
-	private final N revisionNumber;
-	private final DateTime revisionDate;
-
-	/**
-	 * Creates a new {@link AnnotationRevisionMetadata} inspecing the given entity for the given annotations. If no
-	 * annotations will be provided these values will not be looked up from the entity and return {@literal null}.
-	 * 
-	 * @param entity must not be {@literal null}.
-	 * @param revisionNumberAnnotation
-	 * @param revisionTimeStampAnnotation
-	 */
-	public AnnotationRevisionMetadata(final Object entity, Class<? extends Annotation> revisionNumberAnnotation,
-			Class<? extends Annotation> revisionTimeStampAnnotation) {
-
-		Assert.notNull(entity, "Entity must not be null!");
-		this.entity = entity;
-
-		if (revisionNumberAnnotation != null) {
-			AnnotationDetectionFieldCallback numberCallback = new AnnotationDetectionFieldCallback(revisionNumberAnnotation);
-			ReflectionUtils.doWithFields(entity.getClass(), numberCallback);
-			this.revisionNumber = numberCallback.getValue(entity);
-		} else {
-			this.revisionNumber = null;
-		}
-
-		if (revisionTimeStampAnnotation != null) {
-			AnnotationDetectionFieldCallback revisionCallback = new AnnotationDetectionFieldCallback(
-					revisionTimeStampAnnotation);
-			ReflectionUtils.doWithFields(entity.getClass(), revisionCallback);
-			this.revisionDate = new DateTime(revisionCallback.<Object> getValue(entity));
-		} else {
-			this.revisionDate = null;
-		}
-	}
-
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.repository.history.RevisionMetadata#getRevisionNumber()
-	 */
-	public N getRevisionNumber() {
-		return revisionNumber;
-	}
-
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.repository.history.RevisionMetadata#getRevisionDate()
-	 */
-	public DateTime getRevisionDate() {
-		return revisionDate;
-	}
-
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.repository.history.RevisionMetadata#getDelegate()
-	 */
-	@SuppressWarnings("unchecked")
-	public <T> T getDelegate() {
-		return (T) entity;
-	}
-}
+/*
+ * Copyright 2012 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.history;
+
+import java.lang.annotation.Annotation;
+import java.time.LocalDateTime;
+import java.util.Optional;
+
+import org.springframework.data.util.AnnotationDetectionFieldCallback;
+import org.springframework.util.Assert;
+import org.springframework.util.ReflectionUtils;
+
+/**
+ * A {@link RevisionMetadata} implementation that inspects the given object for fields with the configured annotations
+ * and returns the field's values on calls to {@link #getRevisionDate()} and {@link #getRevisionNumber()}.
+ *
+ * @author Oliver Gierke
+ */
+public class AnnotationRevisionMetadata<N extends Number & Comparable<N>> implements RevisionMetadata<N> {
+
+	private final Object entity;
+	private final N revisionNumber;
+	private final LocalDateTime revisionDate;
+
+	/**
+	 * Creates a new {@link AnnotationRevisionMetadata} inspecting the given entity for the given annotations. If no
+	 * annotations will be provided these values will not be looked up from the entity and return {@literal null}.
+	 *
+	 * @param entity must not be {@literal null}.
+	 * @param revisionNumberAnnotation
+	 * @param revisionTimeStampAnnotation
+	 */
+	public AnnotationRevisionMetadata(final Object entity, Class<? extends Annotation> revisionNumberAnnotation,
+			Class<? extends Annotation> revisionTimeStampAnnotation) {
+
+		Assert.notNull(entity, "Entity must not be null!");
+		this.entity = entity;
+
+		if (revisionNumberAnnotation != null) {
+			AnnotationDetectionFieldCallback numberCallback = new AnnotationDetectionFieldCallback(revisionNumberAnnotation);
+			ReflectionUtils.doWithFields(entity.getClass(), numberCallback);
+			this.revisionNumber = numberCallback.getValue(entity);
+		} else {
+			this.revisionNumber = null;
+		}
+
+		if (revisionTimeStampAnnotation != null) {
+			AnnotationDetectionFieldCallback revisionCallback = new AnnotationDetectionFieldCallback(
+					revisionTimeStampAnnotation);
+			ReflectionUtils.doWithFields(entity.getClass(), revisionCallback);
+			this.revisionDate = revisionCallback.getValue(entity);
+		} else {
+			this.revisionDate = null;
+		}
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.history.RevisionMetadata#getRevisionNumber()
+	 */
+	public Optional<N> getRevisionNumber() {
+		return Optional.ofNullable(revisionNumber);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.history.RevisionMetadata#getRevisionDate()
+	 */
+	public Optional<LocalDateTime> getRevisionDate() {
+		return Optional.ofNullable(revisionDate);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.history.RevisionMetadata#getDelegate()
+	 */
+	@SuppressWarnings("unchecked")
+	public <T> T getDelegate() {
+		return (T) entity;
+	}
+}

src/main/java/org/springframework/data/history/Revision.java

@@ -15,8 +15,13 @@
  */
 package org.springframework.data.history;
 
-import org.joda.time.DateTime;
-import org.springframework.util.Assert;
+import lombok.AccessLevel;
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+import lombok.Value;
+
+import java.time.LocalDateTime;
+import java.util.Optional;
 
 /**
  * Wrapper to contain {@link RevisionMetadata} as well as the revisioned entity.
@@ -24,24 +29,29 @@ import org.springframework.util.Assert;
  * @author Oliver Gierke
  * @author Philipp Huegelmeyer
  */
+@Value
+@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
 public final class Revision<N extends Number & Comparable<N>, T> implements Comparable<Revision<N, ?>> {
 
-	private final RevisionMetadata<N> metadata;
-	private final T entity;
+	/**
+	 * The {@link RevisionMetadata} for the current {@link Revision}.
+	 */
+	@NonNull RevisionMetadata<N> metadata;
 
 	/**
-	 * Creates a new {@link Revision} consisting of the given {@link RevisionMetadata} and entity.
+	 * The underlying entity.
+	 */
+	@NonNull T entity;
+
+	/**
+	 * Creates a new {@link Revision} for the given {@link RevisionMetadata} and entity.
 	 * 
 	 * @param metadata must not be {@literal null}.
 	 * @param entity must not be {@literal null}.
+	 * @return
 	 */
-	public Revision(RevisionMetadata<N> metadata, T entity) {
-
-		Assert.notNull(metadata, "Metadata must not be null!");
-		Assert.notNull(entity, "Entity must not be null!");
-
-		this.metadata = metadata;
-		this.entity = entity;
+	public static <N extends Number & Comparable<N>, T> Revision<N, T> of(RevisionMetadata<N> metadata, T entity) {
+		return new Revision<N, T>(metadata, entity);
 	}
 
 	/**
@@ -49,7 +59,7 @@ public final class Revision<N extends Number & Comparable<N>, T> implements Comp
 	 * 
 	 * @return the revision number.
 	 */
-	public N getRevisionNumber() {
+	public Optional<N> getRevisionNumber() {
 		return metadata.getRevisionNumber();
 	}
 
@@ -58,67 +68,22 @@ public final class Revision<N extends Number & Comparable<N>, T> implements Comp
 	 * 
 	 * @return
 	 */
-	public DateTime getRevisionDate() {
+	public Optional<LocalDateTime> getRevisionDate() {
 		return metadata.getRevisionDate();
 	}
 
-	/**
-	 * Returns the underlying entity.
-	 * 
-	 * @return the entity
-	 */
-	public T getEntity() {
-		return entity;
-	}
-
-	/**
-	 * Returns the {@link RevisionMetadata} for the current {@link Revision}.
-	 * 
-	 * @return the metadata
-	 */
-	public RevisionMetadata<N> getMetadata() {
-		return metadata;
-	}
-
 	/*
 	 * (non-Javadoc)
 	 * @see java.lang.Comparable#compareTo(java.lang.Object)
 	 */
 	public int compareTo(Revision<N, ?> that) {
-		return getRevisionNumber().compareTo(that.getRevisionNumber());
-	}
 
-	/* (non-Javadoc)
-	 * @see java.lang.Object#equals(java.lang.Object)
-	 */
-	@Override
-	@SuppressWarnings("unchecked")
-	public boolean equals(Object obj) {
+		Optional<N> thisRevisionNumber = getRevisionNumber();
+		Optional<N> thatRevisionNumber = that.getRevisionNumber();
 
-		if (this == obj) {
-			return true;
-		}
-
-		if (!(obj instanceof Revision)) {
-			return false;
-		}
-
-		Revision<N, T> that = (Revision<N, T>) obj;
-		boolean sameRevisionNumber = this.metadata.getRevisionNumber().equals(that.metadata.getRevisionNumber());
-		return !sameRevisionNumber ? false : this.entity.equals(that.entity);
-	}
-
-	/* 
-	 * (non-Javadoc)
-	 * @see java.lang.Object#hashCode()
-	 */
-	@Override
-	public int hashCode() {
-
-		int result = 17;
-		result += 31 * metadata.hashCode();
-		result += 31 * entity.hashCode();
-		return result;
+		return thisRevisionNumber.map(left -> {
+			return thatRevisionNumber.map(right -> left.compareTo(right)).orElse(1);
+		}).orElse(-1);
 	}
 
 	/* 

src/main/java/org/springframework/data/history/RevisionMetadata.java

@@ -1,48 +1,49 @@
-/*
- * Copyright 2012 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.data.history;
-
-import org.joda.time.DateTime;
-
-/**
- * Metadata about a revision.
- * 
- * @author Philipp Huegelmeyer
- * @author Oliver Gierke
- */
-public interface RevisionMetadata<N extends Number & Comparable<N>> {
-
-	/**
-	 * Returns the revision number of the revision.
-	 * 
-	 * @return
-	 */
-	N getRevisionNumber();
-
-	/**
-	 * Returns the date of the revision.
-	 * 
-	 * @return
-	 */
-	DateTime getRevisionDate();
-
-	/**
-	 * Returns the underlying revision metadata which might provider more detailed implementation specific information.
-	 * 
-	 * @return
-	 */
-	<T> T getDelegate();
-}
+/*
+ * Copyright 2012 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.history;
+
+import java.time.LocalDateTime;
+import java.util.Optional;
+
+/**
+ * Metadata about a revision.
+ *
+ * @author Philipp Huegelmeyer
+ * @author Oliver Gierke
+ */
+public interface RevisionMetadata<N extends Number & Comparable<N>> {
+
+	/**
+	 * Returns the revision number of the revision.
+	 *
+	 * @return
+	 */
+	Optional<N> getRevisionNumber();
+
+	/**
+	 * Returns the date of the revision.
+	 *
+	 * @return
+	 */
+	Optional<LocalDateTime> getRevisionDate();
+
+	/**
+	 * Returns the underlying revision metadata which might provider more detailed implementation specific information.
+	 *
+	 * @return
+	 */
+	<T> T getDelegate();
+}

src/main/java/org/springframework/data/history/Revisions.java

@@ -15,10 +15,11 @@
  */
 package org.springframework.data.history;
 
-import java.util.ArrayList;
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.Iterator;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.springframework.util.Assert;
 
@@ -30,6 +31,8 @@ import org.springframework.util.Assert;
  */
 public class Revisions<N extends Number & Comparable<N>, T> implements Iterable<Revision<N, T>> {
 
+	private final Comparator<Revision<N, T>> NATURAL_ORDER = Comparator.naturalOrder();
+
 	private final List<Revision<N, T>> revisions;
 	private final boolean latestLast;
 
@@ -39,7 +42,7 @@ public class Revisions<N extends Number & Comparable<N>, T> implements Iterable<
 	 * 
 	 * @param revisions must not be {@literal null}.
 	 */
-	public Revisions(List<? extends Revision<N, T>> revisions) {
+	private Revisions(List<? extends Revision<N, T>> revisions) {
 		this(revisions, true);
 	}
 
@@ -52,14 +55,16 @@ public class Revisions<N extends Number & Comparable<N>, T> implements Iterable<
 	private Revisions(List<? extends Revision<N, T>> revisions, boolean latestLast) {
 
 		Assert.notNull(revisions, "Revisions must not be null!");
-		this.revisions = new ArrayList<Revision<N, T>>(revisions);
+
+		this.revisions = revisions.stream()//
+				.sorted(latestLast ? NATURAL_ORDER : NATURAL_ORDER.reversed())//
+				.collect(Collectors.toList());
+
 		this.latestLast = latestLast;
+	}
 
-		Collections.sort(this.revisions);
-
-		if (!latestLast) {
-			Collections.reverse(this.revisions);
-		}
+	public static <N extends Number & Comparable<N>, T> Revisions<N, T> of(List<? extends Revision<N, T>> revisions) {
+		return new Revisions<N, T>(revisions);
 	}
 
 	/**
@@ -78,9 +83,7 @@ public class Revisions<N extends Number & Comparable<N>, T> implements Iterable<
 	 * @return
 	 */
 	public Revisions<N, T> reverse() {
-		List<Revision<N, T>> result = new ArrayList<Revision<N, T>>(revisions);
-		Collections.reverse(result);
-		return new Revisions<N, T>(result, !latestLast);
+		return new Revisions<N, T>(revisions, !latestLast);
 	}
 
 	/* 

src/main/java/org/springframework/data/mapping/IdentifierAccessor.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.mapping;
 
+import java.util.Optional;
+
 /**
  * Interface for a component allowing the access of identifier values.
  * 
@@ -27,5 +29,5 @@ public interface IdentifierAccessor {
 	 * 
 	 * @return
 	 */
-	Object getIdentifier();
+	Optional<? extends Object> getIdentifier();
 }

src/main/java/org/springframework/data/mapping/PersistentEntity.java

@@ -16,6 +16,7 @@
 package org.springframework.data.mapping;
 
 import java.lang.annotation.Annotation;
+import java.util.Optional;
 
 import org.springframework.data.convert.EntityInstantiator;
 import org.springframework.data.util.TypeInformation;
@@ -40,11 +41,11 @@ public interface PersistentEntity<T, P extends PersistentProperty<P>> {
 	/**
 	 * Returns the {@link PreferredConstructor} to be used to instantiate objects of this {@link PersistentEntity}.
 	 * 
-	 * @return {@literal null} in case no suitable constructor for automatic construction can be found. This usually
-	 *         indicates that the instantiation of the object of that persistent entity is done through either a customer
-	 *         {@link EntityInstantiator} or handled by custom conversion mechanisms entirely.
+	 * @return An empty {@link Optional} in case no suitable constructor for automatic construction can be found. This
+	 *         usually indicates that the instantiation of the object of that persistent entity is done through either a
+	 *         customer {@link EntityInstantiator} or handled by custom conversion mechanisms entirely.
 	 */
-	PreferredConstructor<T, P> getPersistenceConstructor();
+	Optional<PreferredConstructor<T, P>> getPersistenceConstructor();
 
 	/**
 	 * Returns whether the given {@link PersistentProperty} is referred to by a constructor argument of the
@@ -78,7 +79,7 @@ public interface PersistentEntity<T, P extends PersistentProperty<P>> {
 	 * 
 	 * @return the id property of the {@link PersistentEntity}.
 	 */
-	P getIdProperty();
+	Optional<P> getIdProperty();
 
 	/**
 	 * Returns the version property of the {@link PersistentEntity}. Can be {@literal null} in case no version property is
@@ -86,7 +87,7 @@ public interface PersistentEntity<T, P extends PersistentProperty<P>> {
 	 * 
 	 * @return the version property of the {@link PersistentEntity}.
 	 */
-	P getVersionProperty();
+	Optional<P> getVersionProperty();
 
 	/**
 	 * Obtains a {@link PersistentProperty} instance by name.
@@ -94,7 +95,7 @@ public interface PersistentEntity<T, P extends PersistentProperty<P>> {
 	 * @param name The name of the property
 	 * @return the {@link PersistentProperty} or {@literal null} if it doesn't exist.
 	 */
-	P getPersistentProperty(String name);
+	Optional<P> getPersistentProperty(String name);
 
 	/**
 	 * Returns the property equipped with an annotation of the given type.
@@ -103,7 +104,7 @@ public interface PersistentEntity<T, P extends PersistentProperty<P>> {
 	 * @return
 	 * @since 1.8
 	 */
-	P getPersistentProperty(Class<? extends Annotation> annotationType);
+	Optional<P> getPersistentProperty(Class<? extends Annotation> annotationType);
 
 	/**
 	 * Returns whether the {@link PersistentEntity} has an id property. If this call returns {@literal true},
@@ -134,7 +135,7 @@ public interface PersistentEntity<T, P extends PersistentProperty<P>> {
 	 * 
 	 * @return
 	 */
-	Object getTypeAlias();
+	Optional<? extends Object> getTypeAlias();
 
 	/**
 	 * Returns the {@link TypeInformation} backing this {@link PersistentEntity}.
@@ -169,7 +170,7 @@ public interface PersistentEntity<T, P extends PersistentProperty<P>> {
 	 * @return
 	 * @since 1.8
 	 */
-	<A extends Annotation> A findAnnotation(Class<A> annotationType);
+	<A extends Annotation> Optional<A> findAnnotation(Class<A> annotationType);
 
 	/**
 	 * Returns a {@link PersistentPropertyAccessor} to access property values of the given bean.

src/main/java/org/springframework/data/mapping/PersistentProperty.java

@@ -20,6 +20,7 @@ import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.Collection;
 import java.util.Map;
+import java.util.Optional;
 
 import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.data.util.TypeInformation;
@@ -74,19 +75,19 @@ public interface PersistentProperty<P extends PersistentProperty<P>> {
 	 * 
 	 * @return the getter method to access the property value if available, otherwise {@literal null}.
 	 */
-	Method getGetter();
+	Optional<Method> getGetter();
 
 	/**
 	 * Returns the setter method to set a property value. Might return {@literal null} in case there is no setter
 	 * available.
 	 * 
-	 * @returnthe setter method to set a property value if available, otherwise {@literal null}.
+	 * @return the setter method to set a property value if available, otherwise {@literal null}.
 	 */
-	Method getSetter();
+	Optional<Method> getSetter();
 
-	Field getField();
+	Optional<Field> getField();
 
-	String getSpelExpression();
+	Optional<String> getSpelExpression();
 
 	Association<P> getAssociation();
 
@@ -201,7 +202,7 @@ public interface PersistentProperty<P extends PersistentProperty<P>> {
 	 * @return the annotation of the given type if present or {@literal null} otherwise.
 	 * @see AnnotationUtils#findAnnotation(Method, Class)
 	 */
-	<A extends Annotation> A findAnnotation(Class<A> annotationType);
+	<A extends Annotation> Optional<A> findAnnotation(Class<A> annotationType);
 
 	/**
 	 * Looks up the annotation of the given type on the property and the owning type if no annotation can be found on it.
@@ -210,7 +211,7 @@ public interface PersistentProperty<P extends PersistentProperty<P>> {
 	 * @param annotationType must not be {@literal null}.
 	 * @return
 	 */
-	<A extends Annotation> A findPropertyOrOwnerAnnotation(Class<A> annotationType);
+	<A extends Annotation> Optional<A> findPropertyOrOwnerAnnotation(Class<A> annotationType);
 
 	/**
 	 * Returns whether the {@link PersistentProperty} has an annotation of the given type.

src/main/java/org/springframework/data/mapping/PersistentPropertyAccessor.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.mapping;
 
+import java.util.Optional;
+
 import org.springframework.data.mapping.model.ConvertingPropertyAccessor;
 
 /**
@@ -38,7 +40,7 @@ public interface PersistentPropertyAccessor {
 	 * @throws org.springframework.data.mapping.model.MappingException in case an exception occurred when setting the
 	 *           property value.
 	 */
-	void setProperty(PersistentProperty<?> property, Object value);
+	void setProperty(PersistentProperty<?> property, Optional<? extends Object> value);
 
 	/**
 	 * Returns the value of the given {@link PersistentProperty} of the underlying bean instance.
@@ -47,7 +49,7 @@ public interface PersistentPropertyAccessor {
 	 * @param property must not be {@literal null}.
 	 * @return can be {@literal null}.
 	 */
-	Object getProperty(PersistentProperty<?> property);
+	Optional<? extends Object> getProperty(PersistentProperty<?> property);
 
 	/**
 	 * Returns the underlying bean.

src/main/java/org/springframework/data/mapping/PreferredConstructor.java

@@ -15,7 +15,7 @@
  */
 package org.springframework.data.mapping;
 
-import static org.springframework.util.ObjectUtils.*;
+import lombok.EqualsAndHashCode;
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Constructor;
@@ -23,11 +23,14 @@ import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.data.annotation.PersistenceConstructor;
+import org.springframework.data.util.Lazy;
+import org.springframework.data.util.Streamable;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.Assert;
 import org.springframework.util.ReflectionUtils;
@@ -56,6 +59,7 @@ public class PreferredConstructor<T, P extends PersistentProperty<P>> {
 	 * @param constructor must not be {@literal null}.
 	 * @param parameters must not be {@literal null}.
 	 */
+	@SafeVarargs
 	public PreferredConstructor(Constructor<T> constructor, Parameter<Object, P>... parameters) {
 
 		Assert.notNull(constructor, "Constructor must not be null!");
@@ -80,8 +84,8 @@ public class PreferredConstructor<T, P extends PersistentProperty<P>> {
 	 * 
 	 * @return
 	 */
-	public Iterable<Parameter<Object, P>> getParameters() {
-		return parameters;
+	public Streamable<Parameter<Object, P>> getParameters() {
+		return Streamable.of(parameters);
 	}
 
 	/**
@@ -181,15 +185,16 @@ public class PreferredConstructor<T, P extends PersistentProperty<P>> {
 	 * @param <T> the type of the parameter
 	 * @author Oliver Gierke
 	 */
+	@EqualsAndHashCode(exclude = { "enclosingClassCache", "hasSpelExpression" })
 	public static class Parameter<T, P extends PersistentProperty<P>> {
 
-		private final String name;
+		private final Optional<String> name;
 		private final TypeInformation<T> type;
-		private final String key;
-		private final PersistentEntity<T, P> entity;
+		private final Optional<String> key;
+		private final Optional<PersistentEntity<T, P>> entity;
 
-		private Boolean enclosingClassCache;
-		private Boolean hasSpelExpression;
+		private final Lazy<Boolean> enclosingClassCache;
+		private final Lazy<Boolean> hasSpelExpression;
 
 		/**
 		 * Creates a new {@link Parameter} with the given name, {@link TypeInformation} as well as an array of
@@ -199,9 +204,10 @@ public class PreferredConstructor<T, P extends PersistentProperty<P>> {
 		 * @param name the name of the parameter, can be {@literal null}
 		 * @param type must not be {@literal null}
 		 * @param annotations must not be {@literal null} but can be empty
-		 * @param entity can be {@literal null}.
+		 * @param entity must not be {@literal null}.
 		 */
-		public Parameter(String name, TypeInformation<T> type, Annotation[] annotations, PersistentEntity<T, P> entity) {
+		public Parameter(Optional<String> name, TypeInformation<T> type, Annotation[] annotations,
+				Optional<PersistentEntity<T, P>> entity) {
 
 			Assert.notNull(type, "Type must not be null!");
 			Assert.notNull(annotations, "Annotations must not be null!");
@@ -210,23 +216,27 @@ public class PreferredConstructor<T, P extends PersistentProperty<P>> {
 			this.type = type;
 			this.key = getValue(annotations);
 			this.entity = entity;
+
+			this.enclosingClassCache = Lazy.of(() -> {
+				Class<T> owningType = entity.orElseThrow(() -> new IllegalStateException()).getType();
+				return owningType.isMemberClass() && type.getType().equals(owningType.getEnclosingClass());
+			});
+
+			this.hasSpelExpression = Lazy.of(() -> getSpelExpression().map(StringUtils::hasText).orElse(false));
 		}
 
-		private String getValue(Annotation[] annotations) {
-			for (Annotation anno : annotations) {
-				if (anno.annotationType() == Value.class) {
-					return ((Value) anno).value();
-				}
-			}
-			return null;
+		private static Optional<String> getValue(Annotation[] annotations) {
+			return Arrays.stream(annotations).//
+					filter(it -> it.annotationType() == Value.class).//
+					findFirst().map(it -> ((Value) it).value());
 		}
 
 		/**
-		 * Returns the name of the parameter or {@literal null} if none was given.
+		 * Returns the name of the parameter.
 		 * 
 		 * @return
 		 */
-		public String getName() {
+		public Optional<String> getName() {
 			return name;
 		}
 
@@ -253,7 +263,7 @@ public class PreferredConstructor<T, P extends PersistentProperty<P>> {
 		 * 
 		 * @return
 		 */
-		public String getSpelExpression() {
+		public Optional<String> getSpelExpression() {
 			return key;
 		}
 
@@ -263,12 +273,7 @@ public class PreferredConstructor<T, P extends PersistentProperty<P>> {
 		 * @return
 		 */
 		public boolean hasSpelExpression() {
-
-			if (this.hasSpelExpression == null) {
-				this.hasSpelExpression = StringUtils.hasText(getSpelExpression());
-			}
-
-			return this.hasSpelExpression;
+			return hasSpelExpression.get();
 		}
 
 		/**
@@ -279,60 +284,17 @@ public class PreferredConstructor<T, P extends PersistentProperty<P>> {
 		 */
 		boolean maps(PersistentProperty<?> property) {
 
-			P referencedProperty = entity == null ? null : entity.getPersistentProperty(name);
-			return property == null ? false : property.equals(referencedProperty);
-		}
-
-		private boolean isEnclosingClassParameter() {
-
-			if (enclosingClassCache == null) {
-				Class<T> owningType = entity.getType();
-				this.enclosingClassCache = owningType.isMemberClass() && type.getType().equals(owningType.getEnclosingClass());
-			}
-
-			return enclosingClassCache;
-		}
-
-		/* 
-		 * (non-Javadoc)
-		 * @see java.lang.Object#equals(java.lang.Object)
-		 */
-		@Override
-		public boolean equals(Object obj) {
-
-			if (this == obj) {
-				return true;
-			}
-
-			if (!(obj instanceof Parameter)) {
+			if (!name.isPresent()) {
 				return false;
 			}
 
-			Parameter<?, ?> that = (Parameter<?, ?>) obj;
-
-			boolean nameEquals = this.name == null ? that.name == null : this.name.equals(that.name);
-			boolean keyEquals = this.key == null ? that.key == null : this.key.equals(that.key);
-			boolean entityEquals = this.entity == null ? that.entity == null : this.entity.equals(that.entity);
-
-			// Explicitly delay equals check on type as it might be expensive
-			return nameEquals && keyEquals && entityEquals && this.type.equals(that.type);
+			return entity//
+					.flatMap(it -> it.getPersistentProperty(name.get()))//
+					.map(it -> property.equals(it)).orElse(false);
 		}
 
-		/* 
-		 * (non-Javadoc)
-		 * @see java.lang.Object#hashCode()
-		 */
-		@Override
-		public int hashCode() {
-
-			int result = 17;
-
-			result += 31 * nullSafeHashCode(this.name);
-			result += 31 * nullSafeHashCode(this.key);
-			result += 31 * nullSafeHashCode(this.entity);
-			result += 31 * this.type.hashCode();
-
-			return result;
+		private boolean isEnclosingClassParameter() {
+			return enclosingClassCache.get();
 		}
 	}
 }

src/main/java/org/springframework/data/mapping/PropertyPath.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.mapping;
 
+import lombok.EqualsAndHashCode;
+
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Iterator;
@@ -24,9 +26,9 @@ import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import org.springframework.data.util.ClassTypeInformation;
+import org.springframework.data.util.Streamable;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.Assert;
-import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 
 /**
@@ -34,7 +36,8 @@ import org.springframework.util.StringUtils;
  * 
  * @author Oliver Gierke
  */
-public class PropertyPath implements Iterable<PropertyPath> {
+@EqualsAndHashCode
+public class PropertyPath implements Streamable<PropertyPath> {
 
 	private static final String DELIMITERS = "_\\.";
 	private static final String ALL_UPPERCASE = "[A-Z0-9._$]+";
@@ -170,43 +173,6 @@ public class PropertyPath implements Iterable<PropertyPath> {
 		return isCollection;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see java.lang.Object#equals(java.lang.Object)
-	 */
-	@Override
-	public boolean equals(Object obj) {
-
-		if (this == obj) {
-			return true;
-		}
-
-		if (obj == null || !getClass().equals(obj.getClass())) {
-			return false;
-		}
-
-		PropertyPath that = (PropertyPath) obj;
-
-		return this.name.equals(that.name) && this.type.equals(that.type)
-				&& ObjectUtils.nullSafeEquals(this.next, that.next);
-	}
-
-	/*
-	 * (non-Javadoc)
-	 * @see java.lang.Object#hashCode()
-	 */
-	@Override
-	public int hashCode() {
-
-		int result = 17;
-
-		result += 31 * name.hashCode();
-		result += 31 * type.hashCode();
-		result += 31 * (next == null ? 0 : next.hashCode());
-
-		return result;
-	}
-
 	/* 
 	 * (non-Javadoc)
 	 * @see java.lang.Iterable#iterator()

src/main/java/org/springframework/data/mapping/context/AbstractMappingContext.java

@@ -25,6 +25,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
@@ -43,6 +44,7 @@ import org.springframework.data.mapping.model.MutablePersistentEntity;
 import org.springframework.data.mapping.model.PersistentPropertyAccessorFactory;
 import org.springframework.data.mapping.model.SimpleTypeHolder;
 import org.springframework.data.util.ClassTypeInformation;
+import org.springframework.data.util.Pair;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.Assert;
 import org.springframework.util.ReflectionUtils;
@@ -251,27 +253,34 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 		while (iterator.hasNext()) {
 
 			String segment = iterator.next();
-			P persistentProperty = current.getPersistentProperty(segment);
+			final DefaultPersistentPropertyPath<P> foo = path;
+			final E bar = current;
 
-			if (persistentProperty == null) {
+			Pair<DefaultPersistentPropertyPath<P>, E> pair = getPair(path, iterator, segment, current).orElseThrow(() -> {
 
 				String source = StringUtils.collectionToDelimitedString(parts, ".");
-				String resolvedPath = path.toDotPath();
+				String resolvedPath = foo.toDotPath();
 
-				throw new InvalidPersistentPropertyPath(source, type, segment, resolvedPath,
-						String.format("No property %s found on %s!", segment, current.getName()));
-			}
+				return new InvalidPersistentPropertyPath(source, type, segment, resolvedPath,
+						String.format("No property %s found on %s!", segment, bar.getName()));
+			});
 
-			path = path.append(persistentProperty);
-
-			if (iterator.hasNext()) {
-				current = getPersistentEntity(persistentProperty.getTypeInformation().getActualType());
-			}
+			path = pair.getFirst();
+			current = pair.getSecond();
 		}
 
 		return path;
 	}
 
+	private Optional<Pair<DefaultPersistentPropertyPath<P>, E>> getPair(DefaultPersistentPropertyPath<P> path,
+			Iterator<String> iterator, String segment, E entity) {
+
+		Optional<P> persistentProperty = entity.getPersistentProperty(segment);
+
+		return persistentProperty.map(it -> Pair.of(path.append(it),
+				iterator.hasNext() ? getPersistentEntity(it.getTypeInformation().getActualType()) : entity));
+	}
+
 	/**
 	 * Adds the given type to the {@link MappingContext}.
 	 *
@@ -389,7 +398,7 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 	 * @param simpleTypeHolder
 	 * @return
 	 */
-	protected abstract P createPersistentProperty(Field field, PropertyDescriptor descriptor, E owner,
+	protected abstract P createPersistentProperty(Optional<Field> field, PropertyDescriptor descriptor, E owner,
 			SimpleTypeHolder simpleTypeHolder);
 
 	/*
@@ -462,7 +471,7 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 			String fieldName = field.getName();
 
 			ReflectionUtils.makeAccessible(field);
-			createAndRegisterProperty(field, descriptors.get(fieldName));
+			createAndRegisterProperty(Optional.of(field), descriptors.get(fieldName));
 
 			this.remainingDescriptors.remove(fieldName);
 		}
@@ -477,12 +486,12 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 
 			for (PropertyDescriptor descriptor : remainingDescriptors.values()) {
 				if (PersistentPropertyFilter.INSTANCE.matches(descriptor)) {
-					createAndRegisterProperty(null, descriptor);
+					createAndRegisterProperty(Optional.empty(), descriptor);
 				}
 			}
 		}
 
-		private void createAndRegisterProperty(Field field, PropertyDescriptor descriptor) {
+		private void createAndRegisterProperty(Optional<Field> field, PropertyDescriptor descriptor) {
 
 			P property = createPersistentProperty(field, descriptor, entity, simpleTypeHolder);
 
@@ -511,7 +520,7 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 	}
 
 	/**
-	 * Filter rejecting static fields as well as artifically introduced ones. See
+	 * Filter rejecting static fields as well as artificially introduced ones. See
 	 * {@link PersistentPropertyFilter#UNMAPPED_PROPERTIES} for details.
 	 *
 	 * @author Oliver Gierke

src/main/java/org/springframework/data/mapping/context/DefaultPersistentPropertyPath.java

@@ -72,7 +72,6 @@ class DefaultPersistentPropertyPath<T extends PersistentProperty<T>> implements
 	 * @return a new {@link DefaultPersistentPropertyPath} with the given property appended to the current one.
 	 * @throws IllegalArgumentException in case the property is not a property of the type of the current leaf property.
 	 */
-	@SuppressWarnings("unchecked")
 	public DefaultPersistentPropertyPath<T> append(T property) {
 
 		Assert.notNull(property, "Property must not be null!");

src/main/java/org/springframework/data/mapping/context/MappingContextIsNewStrategyFactory.java

@@ -16,6 +16,7 @@
 package org.springframework.data.mapping.context;
 
 import java.util.Arrays;
+import java.util.Optional;
 
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentProperty;
@@ -45,7 +46,6 @@ public class MappingContextIsNewStrategyFactory extends IsNewStrategyFactorySupp
 	 * @deprecated use {@link MappingContextIsNewStrategyFactory(PersistentEntities)} instead.
 	 */
 	@Deprecated
-	@SuppressWarnings("unchecked")
 	public MappingContextIsNewStrategyFactory(MappingContext<? extends PersistentEntity<?, ?>, ?> context) {
 		this(new PersistentEntities(Arrays.asList(context)));
 	}
@@ -76,9 +76,9 @@ public class MappingContextIsNewStrategyFactory extends IsNewStrategyFactorySupp
 		}
 
 		if (entity.hasVersionProperty()) {
-			return new PropertyIsNullOrZeroNumberIsNewStrategy(entity.getVersionProperty());
+			return new PropertyIsNullOrZeroNumberIsNewStrategy(entity.getVersionProperty().get());
 		} else if (entity.hasIdProperty()) {
-			return new PropertyIsNullIsNewStrategy(entity.getIdProperty());
+			return new PropertyIsNullIsNewStrategy(entity.getIdProperty().get());
 		} else {
 			throw new MappingException(String.format("Cannot determine IsNewStrategy for type %s!", type));
 		}
@@ -104,16 +104,21 @@ public class MappingContextIsNewStrategyFactory extends IsNewStrategyFactorySupp
 			this.property = property;
 		}
 
-		/* 
+		/*
 		 * (non-Javadoc)
-		 * @see org.springframework.data.mapping.model.IsNewStrategy#isNew(java.lang.Object)
+		 * @see org.springframework.data.support.IsNewStrategy#isNew(java.util.Optional)
 		 */
-		public boolean isNew(Object entity) {
+		@Override
+		public boolean isNew(Optional<? extends Object> entity) {
 
-			PersistentPropertyAccessor accessor = property.getOwner().getPropertyAccessor(entity);
-			Object propertyValue = accessor.getProperty(property);
+			return entity.map(it -> {
 
-			return decideIsNew(propertyValue);
+				PersistentPropertyAccessor accessor = property.getOwner().getPropertyAccessor(it);
+				Object propertyValue = accessor.getProperty(property);
+
+				return decideIsNew(propertyValue);
+
+			}).orElse(false);
 		}
 
 		protected abstract boolean decideIsNew(Object property);

src/main/java/org/springframework/data/mapping/model/AbstractPersistentProperty.java

@@ -20,8 +20,8 @@ import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.Collections;
 import java.util.Map;
+import java.util.Optional;
 
-import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.data.annotation.Reference;
 import org.springframework.data.mapping.Association;
 import org.springframework.data.mapping.PersistentEntity;
@@ -46,25 +46,25 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	}
 
 	protected final String name;
-	protected final PropertyDescriptor propertyDescriptor;
+	protected final Optional<PropertyDescriptor> propertyDescriptor;
 	protected final TypeInformation<?> information;
 	protected final Class<?> rawType;
-	protected final Field field;
+	protected final Optional<Field> field;
 	protected final Association<P> association;
 	protected final PersistentEntity<?, P> owner;
 	private final SimpleTypeHolder simpleTypeHolder;
 	private final int hashCode;
 
-	public AbstractPersistentProperty(Field field, PropertyDescriptor propertyDescriptor, PersistentEntity<?, P> owner,
-			SimpleTypeHolder simpleTypeHolder) {
+	public AbstractPersistentProperty(Optional<Field> field, PropertyDescriptor propertyDescriptor,
+			PersistentEntity<?, P> owner, SimpleTypeHolder simpleTypeHolder) {
 
 		Assert.notNull(simpleTypeHolder, "SimpleTypeHolder must not be null!");
 		Assert.notNull(owner, "Owner entity must not be null!");
 
-		this.name = field == null ? propertyDescriptor.getName() : field.getName();
-		this.rawType = field == null ? propertyDescriptor.getPropertyType() : field.getType();
+		this.name = field.map(Field::getName).orElseGet(() -> propertyDescriptor.getName());
+		this.rawType = field.<Class<?>> map(Field::getType).orElseGet(() -> propertyDescriptor.getPropertyType());
 		this.information = owner.getTypeInformation().getProperty(this.name);
-		this.propertyDescriptor = propertyDescriptor;
+		this.propertyDescriptor = Optional.ofNullable(propertyDescriptor);
 		this.field = field;
 		this.association = isAssociation() ? createAssociation() : null;
 		this.owner = owner;
@@ -150,19 +150,9 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 * @see org.springframework.data.mapping.PersistentProperty#getGetter()
 	 */
 	@Override
-	public Method getGetter() {
-
-		if (propertyDescriptor == null) {
-			return null;
-		}
-
-		Method getter = propertyDescriptor.getReadMethod();
-
-		if (getter == null) {
-			return null;
-		}
-
-		return rawType.isAssignableFrom(getter.getReturnType()) ? getter : null;
+	public Optional<Method> getGetter() {
+		return propertyDescriptor.map(it -> it.getReadMethod())//
+				.filter(it -> rawType.isAssignableFrom(it.getReturnType()));
 	}
 
 	/* 
@@ -170,19 +160,9 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 * @see org.springframework.data.mapping.PersistentProperty#getSetter()
 	 */
 	@Override
-	public Method getSetter() {
-
-		if (propertyDescriptor == null) {
-			return null;
-		}
-
-		Method setter = propertyDescriptor.getWriteMethod();
-
-		if (setter == null) {
-			return null;
-		}
-
-		return setter.getParameterTypes()[0].isAssignableFrom(rawType) ? setter : null;
+	public Optional<Method> getSetter() {
+		return propertyDescriptor.map(it -> it.getWriteMethod())//
+				.filter(it -> it.getParameterTypes()[0].isAssignableFrom(rawType));
 	}
 
 	/*
@@ -190,7 +170,7 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 * @see org.springframework.data.mapping.PersistentProperty#getField()
 	 */
 	@Override
-	public Field getField() {
+	public Optional<Field> getField() {
 		return field;
 	}
 
@@ -199,8 +179,8 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 * @see org.springframework.data.mapping.PersistentProperty#getSpelExpression()
 	 */
 	@Override
-	public String getSpelExpression() {
-		return null;
+	public Optional<String> getSpelExpression() {
+		return Optional.empty();
 	}
 
 	/*
@@ -227,7 +207,7 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 */
 	@Override
 	public boolean isAssociation() {
-		return field == null ? false : AnnotationUtils.getAnnotation(field, Reference.class) != null;
+		return isAnnotationPresent(Reference.class);
 	}
 
 	/*
@@ -351,6 +331,8 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 */
 	@Override
 	public String toString() {
-		return this.field == null ? this.propertyDescriptor.toString() : this.field.toString();
+		return field.map(Object::toString)//
+				.orElseGet(() -> propertyDescriptor.map(Object::toString)//
+						.orElseThrow(() -> new IllegalStateException("Either Field or PropertyDescriptor has to be present!")));
 	}
 }

src/main/java/org/springframework/data/mapping/model/AnnotationBasedPersistentProperty.java

@@ -17,11 +17,14 @@ package org.springframework.data.mapping.model;
 
 import java.beans.PropertyDescriptor;
 import java.lang.annotation.Annotation;
+import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.Field;
-import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Optional;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
@@ -36,6 +39,7 @@ import org.springframework.data.annotation.Version;
 import org.springframework.data.mapping.Association;
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentProperty;
+import org.springframework.data.util.Optionals;
 import org.springframework.util.Assert;
 
 /**
@@ -44,13 +48,13 @@ import org.springframework.util.Assert;
  * @author Oliver Gierke
  * @author Christoph Strobl
  */
-public abstract class AnnotationBasedPersistentProperty<P extends PersistentProperty<P>> extends
-		AbstractPersistentProperty<P> {
+public abstract class AnnotationBasedPersistentProperty<P extends PersistentProperty<P>>
+		extends AbstractPersistentProperty<P> {
 
 	private static final String SPRING_DATA_PACKAGE = "org.springframework.data";
 
-	private final Value value;
-	private final Map<Class<? extends Annotation>, Annotation> annotationCache = new HashMap<Class<? extends Annotation>, Annotation>();
+	private final Optional<Value> value;
+	private final Map<Class<? extends Annotation>, Optional<? extends Annotation>> annotationCache = new HashMap<>();
 
 	private Boolean isTransient;
 	private boolean usePropertyAccess;
@@ -62,15 +66,15 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 	 * @param propertyDescriptor can be {@literal null}.
 	 * @param owner must not be {@literal null}.
 	 */
-	public AnnotationBasedPersistentProperty(Field field, PropertyDescriptor propertyDescriptor,
+	public AnnotationBasedPersistentProperty(Optional<Field> field, PropertyDescriptor propertyDescriptor,
 			PersistentEntity<?, P> owner, SimpleTypeHolder simpleTypeHolder) {
 
 		super(field, propertyDescriptor, owner, simpleTypeHolder);
 
 		populateAnnotationCache(field);
 
-		AccessType accessType = findPropertyOrOwnerAnnotation(AccessType.class);
-		this.usePropertyAccess = accessType == null ? false : Type.PROPERTY.equals(accessType.value());
+		this.usePropertyAccess = findPropertyOrOwnerAnnotation(AccessType.class).map(it -> Type.PROPERTY.equals(it.value()))
+				.orElse(false);
 		this.value = findAnnotation(Value.class);
 	}
 
@@ -81,40 +85,36 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 	 * @param field
 	 * @throws MappingException in case we find an ambiguous mapping on the accessor methods
 	 */
-	private final void populateAnnotationCache(Field field) {
+	private final void populateAnnotationCache(Optional<Field> field) {
 
-		for (Method method : Arrays.asList(getGetter(), getSetter())) {
+		Optionals.toStream(getGetter(), getSetter()).forEach(it -> {
 
-			if (method == null) {
-				continue;
-			}
-
-			for (Annotation annotation : method.getAnnotations()) {
+			for (Annotation annotation : it.getAnnotations()) {
 
 				Class<? extends Annotation> annotationType = annotation.annotationType();
 
-				validateAnnotation(annotation, "Ambiguous mapping! Annotation %s configured "
-						+ "multiple times on accessor methods of property %s in class %s!", annotationType.getSimpleName(),
-						getName(), getOwner().getType().getSimpleName());
+				validateAnnotation(annotation,
+						"Ambiguous mapping! Annotation %s configured "
+								+ "multiple times on accessor methods of property %s in class %s!",
+						annotationType.getSimpleName(), getName(), getOwner().getType().getSimpleName());
 
-				annotationCache.put(annotationType, annotation);
+				annotationCache.put(annotationType, Optional.of(annotation));
 			}
-		}
+		});
 
-		if (field == null) {
-			return;
-		}
+		field.ifPresent(it -> {
 
-		for (Annotation annotation : field.getAnnotations()) {
+			for (Annotation annotation : it.getAnnotations()) {
 
-			Class<? extends Annotation> annotationType = annotation.annotationType();
+				Class<? extends Annotation> annotationType = annotation.annotationType();
 
-			validateAnnotation(annotation, "Ambiguous mapping! Annotation %s configured "
-					+ "on field %s and one of its accessor methods in class %s!", annotationType.getSimpleName(),
-					field.getName(), getOwner().getType().getSimpleName());
+				validateAnnotation(annotation,
+						"Ambiguous mapping! Annotation %s configured " + "on field %s and one of its accessor methods in class %s!",
+						annotationType.getSimpleName(), it.getName(), getOwner().getType().getSimpleName());
 
-			annotationCache.put(annotationType, annotation);
-		}
+				annotationCache.put(annotationType, Optional.of(annotation));
+			}
+		});
 	}
 
 	/**
@@ -133,7 +133,8 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 			return;
 		}
 
-		if (annotationCache.containsKey(annotationType) && !annotationCache.get(annotationType).equals(candidate)) {
+		if (annotationCache.containsKey(annotationType)
+				&& !annotationCache.get(annotationType).equals(Optional.of(candidate))) {
 			throw new MappingException(String.format(message, arguments));
 		}
 	}
@@ -145,8 +146,8 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 	 * @see org.springframework.data.mapping.model.AbstractPersistentProperty#getSpelExpression()
 	 */
 	@Override
-	public String getSpelExpression() {
-		return value == null ? null : value.value();
+	public Optional<String> getSpelExpression() {
+		return value.map(Value::value);
 	}
 
 	/**
@@ -209,29 +210,18 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 	 * @return
 	 */
 	@SuppressWarnings("unchecked")
-	public <A extends Annotation> A findAnnotation(Class<A> annotationType) {
+	public <A extends Annotation> Optional<A> findAnnotation(Class<A> annotationType) {
 
 		Assert.notNull(annotationType, "Annotation type must not be null!");
 
 		if (annotationCache != null && annotationCache.containsKey(annotationType)) {
-			return (A) annotationCache.get(annotationType);
+			return (Optional<A>) annotationCache.get(annotationType);
 		}
 
-		for (Method method : Arrays.asList(getGetter(), getSetter())) {
-
-			if (method == null) {
-				continue;
-			}
-
-			A annotation = AnnotatedElementUtils.findMergedAnnotation(method, annotationType);
-
-			if (annotation != null) {
-				return cacheAndReturn(annotationType, annotation);
-			}
-		}
-
-		return cacheAndReturn(annotationType,
-				field == null ? null : AnnotatedElementUtils.findMergedAnnotation(field, annotationType));
+		return cacheAndReturn(annotationType, getAccessors()//
+				.map(it -> it.map(inner -> AnnotatedElementUtils.findMergedAnnotation(inner, annotationType)))//
+				.flatMap(it -> Optionals.toStream(it))//
+				.findFirst());
 	}
 
 	/* 
@@ -239,10 +229,10 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 	 * @see org.springframework.data.mapping.PersistentProperty#findPropertyOrOwnerAnnotation(java.lang.Class)
 	 */
 	@Override
-	public <A extends Annotation> A findPropertyOrOwnerAnnotation(Class<A> annotationType) {
+	public <A extends Annotation> Optional<A> findPropertyOrOwnerAnnotation(Class<A> annotationType) {
 
-		A annotation = findAnnotation(annotationType);
-		return annotation == null ? owner.findAnnotation(annotationType) : annotation;
+		Optional<A> annotation = findAnnotation(annotationType);
+		return annotation.isPresent() ? annotation : owner.findAnnotation(annotationType);
 	}
 
 	/**
@@ -251,7 +241,7 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 	 * @param annotation
 	 * @return
 	 */
-	private <A extends Annotation> A cacheAndReturn(Class<? extends A> type, A annotation) {
+	private <A extends Annotation> Optional<A> cacheAndReturn(Class<? extends A> type, Optional<A> annotation) {
 
 		if (annotationCache != null) {
 			annotationCache.put(type, annotation);
@@ -267,7 +257,7 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 	 * @return
 	 */
 	public boolean isAnnotationPresent(Class<? extends Annotation> annotationType) {
-		return findAnnotation(annotationType) != null;
+		return findAnnotation(annotationType).isPresent();
 	}
 
 	/* 
@@ -290,14 +280,15 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 			populateAnnotationCache(field);
 		}
 
-		StringBuilder builder = new StringBuilder();
-
-		for (Annotation annotation : annotationCache.values()) {
-			if (annotation != null) {
-				builder.append(annotation.toString()).append(" ");
-			}
-		}
+		StringBuilder builder = new StringBuilder().append(annotationCache.values().stream()//
+				.flatMap(it -> Optionals.toStream(it))//
+				.map(Object::toString)//
+				.collect(Collectors.joining(" ")));
 
 		return builder.toString() + super.toString();
 	}
+
+	private Stream<Optional<? extends AnnotatedElement>> getAccessors() {
+		return Arrays.<Optional<? extends AnnotatedElement>> asList(getGetter(), getSetter(), getField()).stream();
+	}
 }

src/main/java/org/springframework/data/mapping/model/BasicPersistentEntity.java

@@ -27,6 +27,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.TreeSet;
 
@@ -44,6 +45,7 @@ import org.springframework.data.mapping.PreferredConstructor;
 import org.springframework.data.mapping.PropertyHandler;
 import org.springframework.data.mapping.SimpleAssociationHandler;
 import org.springframework.data.mapping.SimplePropertyHandler;
+import org.springframework.data.util.Lazy;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
@@ -64,26 +66,28 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	private static final String TYPE_MISMATCH = "Target bean of type %s is not of type of the persistent entity (%s)!";
 	private static final String NULL_ASSOCIATION = "%s.addAssociation(…) was called with a null association! Usually indicates a problem in a Spring Data MappingContext implementation. Be sure to file a bug at https://jira.spring.io!";
 
-	private final PreferredConstructor<T, P> constructor;
+	private final Optional<PreferredConstructor<T, P>> constructor;
 	private final TypeInformation<T> information;
 	private final List<P> properties;
-	private final Comparator<P> comparator;
+	private final Optional<Comparator<P>> comparator;
 	private final Set<Association<P>> associations;
 
 	private final Map<String, P> propertyCache;
-	private final Map<Class<? extends Annotation>, Annotation> annotationCache;
+	private final Map<Class<? extends Annotation>, Optional<Annotation>> annotationCache;
 
-	private P idProperty;
-	private P versionProperty;
+	private Optional<P> idProperty = Optional.empty();
+	private Optional<P> versionProperty = Optional.empty();
 	private PersistentPropertyAccessorFactory propertyAccessorFactory;
 
+	private final Lazy<Optional<? extends Object>> typeAlias;
+
 	/**
 	 * Creates a new {@link BasicPersistentEntity} from the given {@link TypeInformation}.
 	 *
 	 * @param information must not be {@literal null}.
 	 */
 	public BasicPersistentEntity(TypeInformation<T> information) {
-		this(information, null);
+		this(information, Optional.empty());
 	}
 
 	/**
@@ -94,27 +98,31 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 * @param information must not be {@literal null}.
 	 * @param comparator can be {@literal null}.
 	 */
-	public BasicPersistentEntity(TypeInformation<T> information, Comparator<P> comparator) {
+	public BasicPersistentEntity(TypeInformation<T> information, Optional<Comparator<P>> comparator) {
 
 		Assert.notNull(information, "Information must not be null!");
 
 		this.information = information;
-		this.properties = new ArrayList<P>();
+		this.properties = new ArrayList<>();
 		this.comparator = comparator;
-		this.constructor = new PreferredConstructorDiscoverer<T, P>(information, this).getConstructor();
-		this.associations = comparator == null ? new HashSet<Association<P>>()
-				: new TreeSet<Association<P>>(new AssociationComparator<P>(comparator));
+		this.constructor = new PreferredConstructorDiscoverer<>(this).getConstructor();
+		this.associations = comparator.<Set<Association<P>>> map(it -> new TreeSet<>(new AssociationComparator<>(it)))
+				.orElse(new HashSet<>());
 
-		this.propertyCache = new HashMap<String, P>();
-		this.annotationCache = new HashMap<Class<? extends Annotation>, Annotation>();
+		this.propertyCache = new HashMap<>();
+		this.annotationCache = new HashMap<>();
 		this.propertyAccessorFactory = BeanWrapperPropertyAccessorFactory.INSTANCE;
+
+		this.typeAlias = Lazy
+				.of(() -> Optional.ofNullable(AnnotatedElementUtils.findMergedAnnotation(getType(), TypeAlias.class))//
+						.map(TypeAlias::value).filter(it -> StringUtils.hasText(it)));
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.PersistentEntity#getPersistenceConstructor()
 	 */
-	public PreferredConstructor<T, P> getPersistenceConstructor() {
+	public Optional<PreferredConstructor<T, P>> getPersistenceConstructor() {
 		return constructor;
 	}
 
@@ -123,7 +131,7 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 * @see org.springframework.data.mapping.PersistentEntity#isConstructorArgument(org.springframework.data.mapping.PersistentProperty)
 	 */
 	public boolean isConstructorArgument(PersistentProperty<?> property) {
-		return constructor == null ? false : constructor.isConstructorParameter(property);
+		return constructor.map(it -> it.isConstructorParameter(property)).orElse(false);
 	}
 
 	/*
@@ -131,7 +139,7 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 * @see org.springframework.data.mapping.PersistentEntity#isIdProperty(org.springframework.data.mapping.PersistentProperty)
 	 */
 	public boolean isIdProperty(PersistentProperty<?> property) {
-		return this.idProperty == null ? false : this.idProperty.equals(property);
+		return this.idProperty.map(it -> it.equals(property)).orElse(false);
 	}
 
 	/*
@@ -139,7 +147,7 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 * @see org.springframework.data.mapping.PersistentEntity#isVersionProperty(org.springframework.data.mapping.PersistentProperty)
 	 */
 	public boolean isVersionProperty(PersistentProperty<?> property) {
-		return this.versionProperty == null ? false : this.versionProperty.equals(property);
+		return this.versionProperty.map(it -> it.equals(property)).orElse(false);
 	}
 
 	/*
@@ -154,7 +162,7 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.PersistentEntity#getIdProperty()
 	 */
-	public P getIdProperty() {
+	public Optional<P> getIdProperty() {
 		return idProperty;
 	}
 
@@ -162,7 +170,7 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.PersistentEntity#getVersionProperty()
 	 */
-	public P getVersionProperty() {
+	public Optional<P> getVersionProperty() {
 		return versionProperty;
 	}
 
@@ -171,7 +179,7 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 * @see org.springframework.data.mapping.PersistentEntity#hasIdProperty()
 	 */
 	public boolean hasIdProperty() {
-		return idProperty != null;
+		return idProperty.isPresent();
 	}
 
 	/*
@@ -179,7 +187,7 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 * @see org.springframework.data.mapping.PersistentEntity#hasVersionProperty()
 	 */
 	public boolean hasVersionProperty() {
-		return versionProperty != null;
+		return versionProperty.isPresent();
 	}
 
 	/*
@@ -203,20 +211,19 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 		P candidate = returnPropertyIfBetterIdPropertyCandidateOrNull(property);
 
 		if (candidate != null) {
-			this.idProperty = candidate;
+			this.idProperty = Optional.of(candidate);
 		}
 
 		if (property.isVersionProperty()) {
 
-			if (this.versionProperty != null) {
-				throw new MappingException(
-						String.format(
-								"Attempt to add version property %s but already have property %s registered "
-										+ "as version. Check your mapping configuration!",
-								property.getField(), versionProperty.getField()));
-			}
+			this.versionProperty.ifPresent(it -> {
 
-			this.versionProperty = property;
+				throw new MappingException(
+						String.format("Attempt to add version property %s but already have property %s registered "
+								+ "as version. Check your mapping configuration!", property.getField(), it.getField()));
+			});
+
+			this.versionProperty = Optional.of(property);
 		}
 	}
 
@@ -232,10 +239,10 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 			return null;
 		}
 
-		if (this.idProperty != null) {
+		this.idProperty.ifPresent(it -> {
 			throw new MappingException(String.format("Attempt to add id property %s but already have property %s registered "
-					+ "as id. Check your mapping configuration!", property.getField(), idProperty.getField()));
-		}
+					+ "as id. Check your mapping configuration!", property.getField(), it.getField()));
+		});
 
 		return property;
 	}
@@ -260,8 +267,8 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.PersistentEntity#getPersistentProperty(java.lang.String)
 	 */
-	public P getPersistentProperty(String name) {
-		return propertyCache.get(name);
+	public Optional<P> getPersistentProperty(String name) {
+		return Optional.ofNullable(propertyCache.get(name));
 	}
 
 	/*
@@ -269,26 +276,20 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 * @see org.springframework.data.mapping.PersistentEntity#getPersistentProperty(java.lang.Class)
 	 */
 	@Override
-	public P getPersistentProperty(Class<? extends Annotation> annotationType) {
+	public Optional<P> getPersistentProperty(Class<? extends Annotation> annotationType) {
 
 		Assert.notNull(annotationType, "Annotation type must not be null!");
 
-		for (P property : properties) {
-			if (property.isAnnotationPresent(annotationType)) {
-				return property;
-			}
+		Optional<P> property = properties.stream()//
+				.filter(it -> it.isAnnotationPresent(annotationType))//
+				.findAny();
+
+		if (property.isPresent()) {
+			return property;
 		}
 
-		for (Association<P> association : associations) {
-
-			P property = association.getInverse();
-
-			if (property.isAnnotationPresent(annotationType)) {
-				return property;
-			}
-		}
-
-		return null;
+		return associations.stream().map(Association::getInverse)//
+				.filter(it -> it.isAnnotationPresent(annotationType)).findAny();
 	}
 
 	/*
@@ -303,10 +304,8 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.PersistentEntity#getTypeAlias()
 	 */
-	public Object getTypeAlias() {
-
-		TypeAlias alias = AnnotatedElementUtils.findMergedAnnotation(getType(), TypeAlias.class);
-		return alias == null ? null : StringUtils.hasText(alias.value()) ? alias.value() : null;
+	public Optional<? extends Object> getTypeAlias() {
+		return typeAlias.get();
 	}
 
 	/*
@@ -325,11 +324,9 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 
 		Assert.notNull(handler, "Handler must not be null!");
 
-		for (P property : properties) {
-			if (!property.isTransient() && !property.isAssociation()) {
-				handler.doWithPersistentProperty(property);
-			}
-		}
+		properties.stream()//
+				.filter(it -> !it.isTransient() && !it.isAssociation())//
+				.forEach(it -> handler.doWithPersistentProperty(it));
 	}
 
 	/*
@@ -341,11 +338,9 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 
 		Assert.notNull(handler, "Handler must not be null!");
 
-		for (PersistentProperty<?> property : properties) {
-			if (!property.isTransient() && !property.isAssociation()) {
-				handler.doWithPersistentProperty(property);
-			}
-		}
+		properties.stream()//
+				.filter(it -> !it.isTransient() && !it.isAssociation())//
+				.forEach(it -> handler.doWithPersistentProperty(it));
 	}
 
 	/*
@@ -380,16 +375,10 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 */
 	@Override
 	@SuppressWarnings("unchecked")
-	public <A extends Annotation> A findAnnotation(Class<A> annotationType) {
+	public <A extends Annotation> Optional<A> findAnnotation(Class<A> annotationType) {
 
-		if (annotationCache.containsKey(annotationType)) {
-			return (A) annotationCache.get(annotationType);
-		}
-
-		A annotation = AnnotatedElementUtils.findMergedAnnotation(getType(), annotationType);
-		annotationCache.put(annotationType, annotation);
-
-		return annotation;
+		return (Optional<A>) annotationCache.computeIfAbsent(annotationType,
+				it -> Optional.ofNullable(AnnotatedElementUtils.findMergedAnnotation(getType(), it)));
 	}
 
 	/*
@@ -397,10 +386,7 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 * @see org.springframework.data.mapping.MutablePersistentEntity#verify()
 	 */
 	public void verify() {
-
-		if (comparator != null) {
-			Collections.sort(properties, comparator);
-		}
+		comparator.ifPresent(it -> Collections.sort(properties, it));
 	}
 
 	/*
@@ -455,8 +441,8 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 		 * @see org.springframework.data.mapping.IdentifierAccessor#getIdentifier()
 		 */
 		@Override
-		public Object getIdentifier() {
-			return null;
+		public Optional<? extends Object> getIdentifier() {
+			return Optional.empty();
 		}
 	}
 

src/main/java/org/springframework/data/mapping/model/BeanWrapper.java

@@ -17,6 +17,7 @@ package org.springframework.data.mapping.model;
 
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
+import java.util.Optional;
 
 import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.PersistentPropertyAccessor;
@@ -45,9 +46,9 @@ class BeanWrapper<T> implements PersistentPropertyAccessor {
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.mapping.PersistentPropertyAccessor#setProperty(org.springframework.data.mapping.PersistentProperty, java.lang.Object)
+	 * @see org.springframework.data.mapping.PersistentPropertyAccessor#setProperty(org.springframework.data.mapping.PersistentProperty, java.util.Optional)
 	 */
-	public void setProperty(PersistentProperty<?> property, Object value) {
+	public void setProperty(PersistentProperty<?> property, Optional<? extends Object> value) {
 
 		Assert.notNull(property, "PersistentProperty must not be null!");
 
@@ -55,18 +56,20 @@ class BeanWrapper<T> implements PersistentPropertyAccessor {
 
 			if (!property.usePropertyAccess()) {
 
-				ReflectionUtils.makeAccessible(property.getField());
-				ReflectionUtils.setField(property.getField(), bean, value);
+				Field field = property.getField().get();
+
+				ReflectionUtils.makeAccessible(field);
+				ReflectionUtils.setField(field, bean, value.orElse(null));
 				return;
 			}
 
-			Method setter = property.getSetter();
+			Optional<Method> setter = property.getSetter();
 
-			if (property.usePropertyAccess() && setter != null) {
+			setter.ifPresent(it -> {
 
-				ReflectionUtils.makeAccessible(setter);
-				ReflectionUtils.invokeMethod(setter, bean, value);
-			}
+				ReflectionUtils.makeAccessible(it);
+				ReflectionUtils.invokeMethod(it, bean, value.orElse(null));
+			});
 
 		} catch (IllegalStateException e) {
 			throw new MappingException("Could not set object property!", e);
@@ -77,7 +80,7 @@ class BeanWrapper<T> implements PersistentPropertyAccessor {
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.PersistentPropertyAccessor#getProperty(org.springframework.data.mapping.PersistentProperty)
 	 */
-	public Object getProperty(PersistentProperty<?> property) {
+	public Optional<? extends Object> getProperty(PersistentProperty<?> property) {
 		return getProperty(property, property.getType());
 	}
 
@@ -91,7 +94,7 @@ class BeanWrapper<T> implements PersistentPropertyAccessor {
 	 * @throws MappingException in case an exception occured when accessing the property.
 	 */
 	@SuppressWarnings("unchecked")
-	public <S> S getProperty(PersistentProperty<?> property, Class<? extends S> type) {
+	public <S> Optional<S> getProperty(PersistentProperty<?> property, Class<? extends S> type) {
 
 		Assert.notNull(property, "PersistentProperty must not be null!");
 
@@ -99,20 +102,18 @@ class BeanWrapper<T> implements PersistentPropertyAccessor {
 
 			if (!property.usePropertyAccess()) {
 
-				Field field = property.getField();
+				Field field = property.getField().get();
 				ReflectionUtils.makeAccessible(field);
-				return (S) ReflectionUtils.getField(field, bean);
+				return Optional.ofNullable((S) ReflectionUtils.getField(field, bean));
 			}
 
-			Method getter = property.getGetter();
+			Optional<Method> getter = property.getGetter();
 
-			if (property.usePropertyAccess() && getter != null) {
+			return getter.map(it -> {
 
-				ReflectionUtils.makeAccessible(getter);
-				return (S) ReflectionUtils.invokeMethod(getter, bean);
-			}
-
-			return null;
+				ReflectionUtils.makeAccessible(it);
+				return (S) ReflectionUtils.invokeMethod(it, bean);
+			});
 
 		} catch (IllegalStateException e) {
 			throw new MappingException(

src/main/java/org/springframework/data/mapping/model/ClassGeneratingPropertyAccessorFactory.java

@@ -32,8 +32,10 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.stream.Collectors;
 
 import org.springframework.asm.ClassWriter;
 import org.springframework.asm.Label;
@@ -46,6 +48,7 @@ import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.PersistentPropertyAccessor;
 import org.springframework.data.mapping.SimpleAssociationHandler;
 import org.springframework.data.mapping.SimplePropertyHandler;
+import org.springframework.data.util.Optionals;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.Assert;
 import org.springframework.util.ReflectionUtils;
@@ -153,7 +156,7 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 
 		propertyAccessorClass = createAccessorClass(entity);
 
-		map = new HashMap<TypeInformation<?>, Class<PersistentPropertyAccessor>>(map);
+		map = new HashMap<>(map);
 		map.put(entity.getTypeInformation(), propertyAccessorClass);
 
 		this.propertyAccessorClasses = map;
@@ -256,6 +259,7 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 		private static final String JAVA_LANG_REFLECT_METHOD = "java/lang/reflect/Method";
 		private static final String JAVA_LANG_INVOKE_METHOD_HANDLE = "java/lang/invoke/MethodHandle";
 		private static final String JAVA_LANG_CLASS = "java/lang/Class";
+		private static final String JAVA_UTIL_OPTIONAL = "java/util/Optional";
 		private static final String BEAN_FIELD = "bean";
 		private static final String THIS_REF = "this";
 		private static final String PERSISTENT_PROPERTY = "org/springframework/data/mapping/PersistentProperty";
@@ -369,30 +373,23 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 
 			for (PersistentProperty<?> property : persistentProperties) {
 
-				Method setter = property.getSetter();
-
-				if (setter != null && generateMethodHandle(entity, setter)) {
+				property.getSetter().filter(it -> generateMethodHandle(entity, it)).ifPresent(it -> {
 					cw.visitField(ACC_PRIVATE + ACC_FINAL + ACC_STATIC, setterName(property),
 							referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE), null, null).visitEnd();
-				}
-
-				Method getter = property.getGetter();
-
-				if (getter != null && generateMethodHandle(entity, getter)) {
+				});
+				property.getGetter().filter(it -> generateMethodHandle(entity, it)).ifPresent(it -> {
 
 					cw.visitField(ACC_PRIVATE + ACC_FINAL + ACC_STATIC, getterName(property),
 							referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE), null, null).visitEnd();
-				}
+				});
 
-				Field field = property.getField();
-
-				if (field != null && generateSetterMethodHandle(entity, field)) {
+				property.getField().filter(it -> generateSetterMethodHandle(entity, it)).ifPresent(it -> {
 
 					cw.visitField(ACC_PRIVATE + ACC_FINAL + ACC_STATIC, fieldSetterName(property),
 							referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE), null, null).visitEnd();
 					cw.visitField(ACC_PRIVATE + ACC_FINAL + ACC_STATIC, fieldGetterName(property),
 							referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE), null, null).visitEnd();
-				}
+				});
 			}
 		}
 
@@ -513,18 +510,18 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 
 				if (property.usePropertyAccess()) {
 
-					if (property.getGetter() != null && generateMethodHandle(entity, property.getGetter())) {
+					property.getGetter().filter(it -> generateMethodHandle(entity, it)).ifPresent(it -> {
 						visitPropertyGetterInitializer(property, mv, entityClasses, internalClassName);
-					}
+					});
 
-					if (property.getSetter() != null && generateMethodHandle(entity, property.getSetter())) {
+					property.getSetter().filter(it -> generateMethodHandle(entity, it)).ifPresent(it -> {
 						visitPropertySetterInitializer(property, mv, entityClasses, internalClassName);
-					}
+					});
 				}
 
-				if (property.getField() != null && generateSetterMethodHandle(entity, property.getField())) {
+				property.getField().filter(it -> generateSetterMethodHandle(entity, it)).ifPresent(it -> {
 					visitFieldGetterSetterInitializer(property, mv, entityClasses, internalClassName);
-				}
+				});
 			}
 
 			mv.visitLabel(l1);
@@ -554,24 +551,13 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 		 */
 		private static List<Class<?>> getPropertyDeclaratingClasses(List<PersistentProperty<?>> persistentProperties) {
 
-			Set<Class<?>> entityClassesSet = new HashSet<Class<?>>();
+			return persistentProperties.stream().flatMap(property -> {
+				return Optionals.toStream(property.getField(), property.getGetter(), property.getSetter())
 
-			for (PersistentProperty<?> property : persistentProperties) {
+						.map(it -> it.getDeclaringClass());
 
-				if (property.getField() != null) {
-					entityClassesSet.add(property.getField().getDeclaringClass());
-				}
+			}).collect(Collectors.collectingAndThen(Collectors.toSet(), it -> new ArrayList<>(it)));
 
-				if (property.getGetter() != null) {
-					entityClassesSet.add(property.getGetter().getDeclaringClass());
-				}
-
-				if (property.getSetter() != null) {
-					entityClassesSet.add(property.getSetter().getDeclaringClass());
-				}
-			}
-
-			return new ArrayList<Class<?>>(entityClassesSet);
 		}
 
 		/**
@@ -586,11 +572,12 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 				List<Class<?>> entityClasses, String internalClassName) {
 
 			// getter = <entity>.class.getDeclaredMethod()
-			Method getter = property.getGetter();
+			Optional<Method> getter = property.getGetter();
 
-			if (getter != null) {
-				mv.visitVarInsn(ALOAD, classVariableIndex4(entityClasses, getter.getDeclaringClass()));
-				mv.visitLdcInsn(getter.getName());
+			getter.ifPresent(it -> {
+
+				mv.visitVarInsn(ALOAD, classVariableIndex4(entityClasses, it.getDeclaringClass()));
+				mv.visitLdcInsn(it.getName());
 				mv.visitInsn(ICONST_0);
 				mv.visitTypeInsn(ANEWARRAY, JAVA_LANG_CLASS);
 
@@ -608,7 +595,9 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 				mv.visitVarInsn(ALOAD, 3);
 				mv.visitMethodInsn(INVOKEVIRTUAL, JAVA_LANG_INVOKE_METHOD_HANDLES_LOOKUP, "unreflect", String.format("(%s)%s",
 						referenceName(JAVA_LANG_REFLECT_METHOD), referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE)), false);
-			} else {
+			});
+
+			if (!getter.isPresent()) {
 				mv.visitInsn(ACONST_NULL);
 			}
 
@@ -628,22 +617,22 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 				List<Class<?>> entityClasses, String internalClassName) {
 
 			// setter = <entity>.class.getDeclaredMethod()
-			Method setter = property.getSetter();
+			Optional<Method> setter = property.getSetter();
 
-			if (setter != null) {
+			setter.ifPresent(it -> {
 
-				mv.visitVarInsn(ALOAD, classVariableIndex4(entityClasses, setter.getDeclaringClass()));
-				mv.visitLdcInsn(setter.getName());
+				mv.visitVarInsn(ALOAD, classVariableIndex4(entityClasses, it.getDeclaringClass()));
+				mv.visitLdcInsn(it.getName());
 
 				mv.visitInsn(ICONST_1);
 				mv.visitTypeInsn(ANEWARRAY, JAVA_LANG_CLASS);
 				mv.visitInsn(DUP);
 				mv.visitInsn(ICONST_0);
 
-				Class<?> parameterType = setter.getParameterTypes()[0];
+				Class<?> parameterType = it.getParameterTypes()[0];
 
 				if (parameterType.isPrimitive()) {
-					mv.visitFieldInsn(GETSTATIC, Type.getInternalName(autoboxType(setter.getParameterTypes()[0])), "TYPE",
+					mv.visitFieldInsn(GETSTATIC, Type.getInternalName(autoboxType(it.getParameterTypes()[0])), "TYPE",
 							referenceName(JAVA_LANG_CLASS));
 				} else {
 					mv.visitLdcInsn(Type.getType(referenceName(parameterType)));
@@ -665,7 +654,9 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 				mv.visitVarInsn(ALOAD, 2);
 				mv.visitMethodInsn(INVOKEVIRTUAL, JAVA_LANG_INVOKE_METHOD_HANDLES_LOOKUP, "unreflect", String.format("(%s)%s",
 						referenceName(JAVA_LANG_REFLECT_METHOD), referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE)), false);
-			} else {
+			});
+
+			if (!setter.isPresent()) {
 				mv.visitInsn(ACONST_NULL);
 			}
 
@@ -685,33 +676,35 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 				List<Class<?>> entityClasses, String internalClassName) {
 
 			// field = <entity>.class.getDeclaredField()
-			Field field = property.getField();
-			mv.visitVarInsn(ALOAD, classVariableIndex4(entityClasses, field.getDeclaringClass()));
-			mv.visitLdcInsn(field.getName());
-			mv.visitMethodInsn(INVOKEVIRTUAL, JAVA_LANG_CLASS, "getDeclaredField",
-					String.format("(%s)%s", referenceName(JAVA_LANG_STRING), referenceName(JAVA_LANG_REFLECT_FIELD)), false);
-			mv.visitVarInsn(ASTORE, 1);
+			property.getField().ifPresent(it -> {
 
-			// field.setAccessible(true)
-			mv.visitVarInsn(ALOAD, 1);
-			mv.visitInsn(ICONST_1);
-			mv.visitMethodInsn(INVOKEVIRTUAL, JAVA_LANG_REFLECT_FIELD, SET_ACCESSIBLE, "(Z)V", false);
+				mv.visitVarInsn(ALOAD, classVariableIndex4(entityClasses, it.getDeclaringClass()));
+				mv.visitLdcInsn(it.getName());
+				mv.visitMethodInsn(INVOKEVIRTUAL, JAVA_LANG_CLASS, "getDeclaredField",
+						String.format("(%s)%s", referenceName(JAVA_LANG_STRING), referenceName(JAVA_LANG_REFLECT_FIELD)), false);
+				mv.visitVarInsn(ASTORE, 1);
 
-			// $fieldGetter = lookup.unreflectGetter(field)
-			mv.visitVarInsn(ALOAD, 0);
-			mv.visitVarInsn(ALOAD, 1);
-			mv.visitMethodInsn(INVOKEVIRTUAL, JAVA_LANG_INVOKE_METHOD_HANDLES_LOOKUP, "unreflectGetter", String.format(
-					"(%s)%s", referenceName(JAVA_LANG_REFLECT_FIELD), referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE)), false);
-			mv.visitFieldInsn(PUTSTATIC, internalClassName, fieldGetterName(property),
-					referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE));
+				// field.setAccessible(true)
+				mv.visitVarInsn(ALOAD, 1);
+				mv.visitInsn(ICONST_1);
+				mv.visitMethodInsn(INVOKEVIRTUAL, JAVA_LANG_REFLECT_FIELD, SET_ACCESSIBLE, "(Z)V", false);
 
-			// $fieldSetter = lookup.unreflectSetter(field)
-			mv.visitVarInsn(ALOAD, 0);
-			mv.visitVarInsn(ALOAD, 1);
-			mv.visitMethodInsn(INVOKEVIRTUAL, JAVA_LANG_INVOKE_METHOD_HANDLES_LOOKUP, "unreflectSetter", String.format(
-					"(%s)%s", referenceName(JAVA_LANG_REFLECT_FIELD), referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE)), false);
-			mv.visitFieldInsn(PUTSTATIC, internalClassName, fieldSetterName(property),
-					referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE));
+				// $fieldGetter = lookup.unreflectGetter(field)
+				mv.visitVarInsn(ALOAD, 0);
+				mv.visitVarInsn(ALOAD, 1);
+				mv.visitMethodInsn(INVOKEVIRTUAL, JAVA_LANG_INVOKE_METHOD_HANDLES_LOOKUP, "unreflectGetter", String.format(
+						"(%s)%s", referenceName(JAVA_LANG_REFLECT_FIELD), referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE)), false);
+				mv.visitFieldInsn(PUTSTATIC, internalClassName, fieldGetterName(property),
+						referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE));
+
+				// $fieldSetter = lookup.unreflectSetter(field)
+				mv.visitVarInsn(ALOAD, 0);
+				mv.visitVarInsn(ALOAD, 1);
+				mv.visitMethodInsn(INVOKEVIRTUAL, JAVA_LANG_INVOKE_METHOD_HANDLES_LOOKUP, "unreflectSetter", String.format(
+						"(%s)%s", referenceName(JAVA_LANG_REFLECT_FIELD), referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE)), false);
+				mv.visitFieldInsn(PUTSTATIC, internalClassName, fieldSetterName(property),
+						referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE));
+			});
 		}
 
 		private static void visitBeanGetter(PersistentEntity<?, ?> entity, String internalClassName, ClassWriter cw) {
@@ -851,7 +844,7 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 				mv.visitLabel(propertyStackMap.get(property.getName()).label);
 				mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
 
-				if (property.getGetter() != null || property.getField() != null) {
+				if (property.getGetter().isPresent() || property.getField().isPresent()) {
 					visitGetProperty0(entity, property, mv, internalClassName);
 				} else {
 					mv.visitJumpInsn(GOTO, dfltLabel);
@@ -875,10 +868,9 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 		private static void visitGetProperty0(PersistentEntity<?, ?> entity, PersistentProperty<?> property,
 				MethodVisitor mv, String internalClassName) {
 
-			Method getter = property.getGetter();
-			if (property.usePropertyAccess() && getter != null) {
+			property.getGetter().filter(it -> property.usePropertyAccess()).map(it -> {
 
-				if (generateMethodHandle(entity, getter)) {
+				if (generateMethodHandle(entity, it)) {
 					// $getter.invoke(bean)
 					mv.visitFieldInsn(GETSTATIC, internalClassName, getterName(property),
 							referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE));
@@ -890,35 +882,42 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 					mv.visitVarInsn(ALOAD, 2);
 
 					int invokeOpCode = INVOKEVIRTUAL;
-					Class<?> declaringClass = getter.getDeclaringClass();
+					Class<?> declaringClass = it.getDeclaringClass();
 					boolean interfaceDefinition = declaringClass.isInterface();
 
 					if (interfaceDefinition) {
 						invokeOpCode = INVOKEINTERFACE;
 					}
 
-					mv.visitMethodInsn(invokeOpCode, Type.getInternalName(declaringClass), getter.getName(),
-							String.format("()%s", signatureTypeName(getter.getReturnType())), interfaceDefinition);
-					autoboxIfNeeded(getter.getReturnType(), autoboxType(getter.getReturnType()), mv);
+					mv.visitMethodInsn(invokeOpCode, Type.getInternalName(declaringClass), it.getName(),
+							String.format("()%s", signatureTypeName(it.getReturnType())), interfaceDefinition);
+					autoboxIfNeeded(it.getReturnType(), autoboxType(it.getReturnType()), mv);
 				}
-			} else {
 
-				Field field = property.getField();
-				if (generateMethodHandle(entity, field)) {
-					// $fieldGetter.invoke(bean)
-					mv.visitFieldInsn(GETSTATIC, internalClassName, fieldGetterName(property),
-							referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE));
-					mv.visitVarInsn(ALOAD, 2);
-					mv.visitMethodInsn(INVOKEVIRTUAL, JAVA_LANG_INVOKE_METHOD_HANDLE, "invoke",
-							String.format("(%s)%s", referenceName(JAVA_LANG_OBJECT), referenceName(JAVA_LANG_OBJECT)), false);
-				} else {
-					// bean.field
-					mv.visitVarInsn(ALOAD, 2);
-					mv.visitFieldInsn(GETFIELD, Type.getInternalName(field.getDeclaringClass()), field.getName(),
-							signatureTypeName(field.getType()));
-					autoboxIfNeeded(field.getType(), autoboxType(field.getType()), mv);
-				}
-			}
+				return null;
+
+			}).orElseGet(() -> {
+
+				property.getField().ifPresent(it -> {
+
+					if (generateMethodHandle(entity, it)) {
+						// $fieldGetter.invoke(bean)
+						mv.visitFieldInsn(GETSTATIC, internalClassName, fieldGetterName(property),
+								referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE));
+						mv.visitVarInsn(ALOAD, 2);
+						mv.visitMethodInsn(INVOKEVIRTUAL, JAVA_LANG_INVOKE_METHOD_HANDLE, "invoke",
+								String.format("(%s)%s", referenceName(JAVA_LANG_OBJECT), referenceName(JAVA_LANG_OBJECT)), false);
+					} else {
+						// bean.field
+						mv.visitVarInsn(ALOAD, 2);
+						mv.visitFieldInsn(GETFIELD, Type.getInternalName(it.getDeclaringClass()), it.getName(),
+								signatureTypeName(it.getType()));
+						autoboxIfNeeded(it.getType(), autoboxType(it.getType()), mv);
+					}
+				});
+
+				return null;
+			});
 
 			mv.visitInsn(ARETURN);
 		}
@@ -1029,7 +1028,7 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 				mv.visitLabel(propertyStackMap.get(property.getName()).label);
 				mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
 
-				if (property.getSetter() != null || property.getField() != null) {
+				if (property.getSetter().isPresent() || property.getField().isPresent()) {
 					visitSetProperty0(entity, property, mv, internalClassName);
 				} else {
 					mv.visitJumpInsn(GOTO, dfltLabel);
@@ -1053,10 +1052,11 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 		private static void visitSetProperty0(PersistentEntity<?, ?> entity, PersistentProperty<?> property,
 				MethodVisitor mv, String internalClassName) {
 
-			Method setter = property.getSetter();
-			if (property.usePropertyAccess() && setter != null) {
+			Optional<Method> setter = property.getSetter();
 
-				if (generateMethodHandle(entity, setter)) {
+			setter.filter(it -> property.usePropertyAccess()).map(it -> {
+
+				if (generateMethodHandle(entity, it)) {
 					// $setter.invoke(bean)
 					mv.visitFieldInsn(GETSTATIC, internalClassName, setterName(property),
 							referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE));
@@ -1069,26 +1069,28 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 					mv.visitVarInsn(ALOAD, 3);
 					mv.visitVarInsn(ALOAD, 2);
 
-					Class<?> parameterType = setter.getParameterTypes()[0];
+					Class<?> parameterType = it.getParameterTypes()[0];
 					mv.visitTypeInsn(CHECKCAST, Type.getInternalName(autoboxType(parameterType)));
 					autoboxIfNeeded(autoboxType(parameterType), parameterType, mv);
 
 					int invokeOpCode = INVOKEVIRTUAL;
-					Class<?> declaringClass = setter.getDeclaringClass();
+					Class<?> declaringClass = it.getDeclaringClass();
 					boolean interfaceDefinition = declaringClass.isInterface();
 
 					if (interfaceDefinition) {
 						invokeOpCode = INVOKEINTERFACE;
 					}
 
-					mv.visitMethodInsn(invokeOpCode, Type.getInternalName(setter.getDeclaringClass()), setter.getName(),
+					mv.visitMethodInsn(invokeOpCode, Type.getInternalName(it.getDeclaringClass()), it.getName(),
 							String.format("(%s)V", signatureTypeName(parameterType)), interfaceDefinition);
 				}
-			} else {
 
-				Field field = property.getField();
-				if (field != null) {
-					if (generateSetterMethodHandle(entity, field)) {
+				return null;
+
+			}).orElseGet(() -> {
+
+				property.getField().ifPresent(it -> {
+					if (generateSetterMethodHandle(entity, it)) {
 						// $fieldSetter.invoke(bean, object)
 						mv.visitFieldInsn(GETSTATIC, internalClassName, fieldSetterName(property),
 								referenceName(JAVA_LANG_INVOKE_METHOD_HANDLE));
@@ -1101,15 +1103,17 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 						mv.visitVarInsn(ALOAD, 3);
 						mv.visitVarInsn(ALOAD, 2);
 
-						Class<?> fieldType = field.getType();
+						Class<?> fieldType = it.getType();
 
 						mv.visitTypeInsn(CHECKCAST, Type.getInternalName(autoboxType(fieldType)));
 						autoboxIfNeeded(autoboxType(fieldType), fieldType, mv);
-						mv.visitFieldInsn(PUTFIELD, Type.getInternalName(field.getDeclaringClass()), field.getName(),
+						mv.visitFieldInsn(PUTFIELD, Type.getInternalName(it.getDeclaringClass()), it.getName(),
 								signatureTypeName(fieldType));
 					}
-				}
-			}
+				});
+
+				return null;
+			});
 
 			mv.visitInsn(RETURN);
 		}
@@ -1197,7 +1201,7 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 			if (isAccessible(entity)) {
 
 				if (Modifier.isProtected(member.getModifiers()) || isDefault(member.getModifiers())) {
-					if (!member.getDeclaringClass().getPackage().equals(entity.getClass().getPackage())) {
+					if (!member.getDeclaringClass().getPackage().equals(entity.getType().getPackage())) {
 						return true;
 					}
 				}

src/main/java/org/springframework/data/mapping/model/ConvertingPropertyAccessor.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.mapping.model;
 
+import java.util.Optional;
+
 import org.springframework.core.convert.ConversionService;
 import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.PersistentPropertyAccessor;
@@ -54,7 +56,7 @@ public class ConvertingPropertyAccessor implements PersistentPropertyAccessor {
 	 * @see org.springframework.data.mapping.PersistentPropertyAccessor#setProperty(org.springframework.data.mapping.PersistentProperty, java.lang.Object)
 	 */
 	@Override
-	public void setProperty(PersistentProperty<?> property, Object value) {
+	public void setProperty(PersistentProperty<?> property, Optional<? extends Object> value) {
 		accessor.setProperty(property, convertIfNecessary(value, property.getType()));
 	}
 
@@ -63,7 +65,7 @@ public class ConvertingPropertyAccessor implements PersistentPropertyAccessor {
 	 * @see org.springframework.data.mapping.PersistentPropertyAccessor#getProperty(org.springframework.data.mapping.PersistentProperty)
 	 */
 	@Override
-	public Object getProperty(PersistentProperty<?> property) {
+	public Optional<? extends Object> getProperty(PersistentProperty<?> property) {
 		return accessor.getProperty(property);
 	}
 
@@ -74,7 +76,7 @@ public class ConvertingPropertyAccessor implements PersistentPropertyAccessor {
 	 * @param targetType must not be {@literal null}.
 	 * @return
 	 */
-	public <T> T getProperty(PersistentProperty<?> property, Class<T> targetType) {
+	public <T> Optional<T> getProperty(PersistentProperty<?> property, Class<T> targetType) {
 
 		Assert.notNull(property, "PersistentProperty must not be null!");
 		Assert.notNull(targetType, "Target type must not be null!");
@@ -100,8 +102,7 @@ public class ConvertingPropertyAccessor implements PersistentPropertyAccessor {
 	 * @return
 	 */
 	@SuppressWarnings("unchecked")
-	private <T> T convertIfNecessary(Object source, Class<T> type) {
-		return (T) (source == null ? source : type.isAssignableFrom(source.getClass()) ? source : conversionService
-				.convert(source, type));
+	private <T> Optional<T> convertIfNecessary(Optional<? extends Object> source, Class<T> type) {
+		return source.map(it -> type.isAssignableFrom(it.getClass()) ? (T) it : conversionService.convert(it, type));
 	}
 }

src/main/java/org/springframework/data/mapping/model/IdPropertyIdentifierAccessor.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.mapping.model;
 
+import java.util.Optional;
+
 import org.springframework.data.mapping.IdentifierAccessor;
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentProperty;
@@ -31,7 +33,7 @@ import org.springframework.util.Assert;
 public class IdPropertyIdentifierAccessor implements IdentifierAccessor {
 
 	private final PersistentPropertyAccessor accessor;
-	private final PersistentProperty<?> idProperty;
+	private final Optional<? extends PersistentProperty<?>> idProperty;
 
 	/**
 	 * Creates a new {@link IdPropertyIdentifierAccessor} for the given {@link PersistentEntity} and
@@ -54,7 +56,7 @@ public class IdPropertyIdentifierAccessor implements IdentifierAccessor {
 	 * (non-Javadoc)
 	 * @see org.springframework.data.keyvalue.core.IdentifierAccessor#getIdentifier()
 	 */
-	public Object getIdentifier() {
-		return accessor.getProperty(idProperty);
+	public Optional<? extends Object> getIdentifier() {
+		return idProperty.map(it -> accessor.getProperty(it));
 	}
 }

src/main/java/org/springframework/data/mapping/model/MappingInstantiationException.java

@@ -17,10 +17,12 @@ package org.springframework.data.mapping.model;
 
 import java.lang.reflect.Constructor;
 import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PreferredConstructor;
-import org.springframework.util.StringUtils;
 
 /**
  * Exception being thrown in case an entity could not be instantiated in the process of a to-object-mapping.
@@ -45,32 +47,33 @@ public class MappingInstantiationException extends RuntimeException {
 	 * @param arguments
 	 * @param cause
 	 */
-	public MappingInstantiationException(PersistentEntity<?, ?> entity, List<Object> arguments, Exception cause) {
+	public MappingInstantiationException(Optional<PersistentEntity<?, ?>> entity, List<Object> arguments,
+			Exception cause) {
 		this(entity, arguments, null, cause);
 	}
 
-	private MappingInstantiationException(PersistentEntity<?, ?> entity, List<Object> arguments, String message,
+	private MappingInstantiationException(Optional<PersistentEntity<?, ?>> entity, List<Object> arguments, String message,
 			Exception cause) {
 
-		super(buildExceptionMessage(entity, arguments, message), cause);
+		super(buildExceptionMessage(entity, arguments.stream(), message), cause);
 
-		this.entityType = entity == null ? null : entity.getType();
-		this.constructor = entity == null || entity.getPersistenceConstructor() == null ? null : entity
-				.getPersistenceConstructor().getConstructor();
+		this.entityType = entity.map(it -> it.getType()).orElse(null);
+		this.constructor = entity.flatMap(it -> it.getPersistenceConstructor()).map(c -> c.getConstructor()).orElse(null);
 		this.constructorArguments = arguments;
 	}
 
-	private static final String buildExceptionMessage(PersistentEntity<?, ?> entity, List<Object> arguments,
+	private static final String buildExceptionMessage(Optional<PersistentEntity<?, ?>> entity, Stream<Object> arguments,
 			String defaultMessage) {
 
-		if (entity == null) {
-			return defaultMessage;
-		}
+		return entity.map(it -> {
 
-		PreferredConstructor<?, ?> constructor = entity.getPersistenceConstructor();
+			Optional<? extends PreferredConstructor<?, ?>> constructor = it.getPersistenceConstructor();
 
-		return String.format(TEXT_TEMPLATE, entity.getType().getName(), constructor == null ? "NO_CONSTRUCTOR"
-				: constructor.getConstructor().toString(), StringUtils.collectionToCommaDelimitedString(arguments));
+			return String.format(TEXT_TEMPLATE, it.getType().getName(),
+					constructor.map(c -> c.getConstructor().toString()).orElse("NO_CONSTRUCTOR"),
+					String.join(",", arguments.map(Object::toString).collect(Collectors.toList())));
+
+		}).orElse(defaultMessage);
 	}
 
 	/**
@@ -78,8 +81,8 @@ public class MappingInstantiationException extends RuntimeException {
 	 * 
 	 * @return the entityType
 	 */
-	public Class<?> getEntityType() {
-		return entityType;
+	public Optional<Class<?>> getEntityType() {
+		return Optional.ofNullable(entityType);
 	}
 
 	/**
@@ -87,8 +90,8 @@ public class MappingInstantiationException extends RuntimeException {
 	 * 
 	 * @return the constructor
 	 */
-	public Constructor<?> getConstructor() {
-		return constructor;
+	public Optional<Constructor<?>> getConstructor() {
+		return Optional.ofNullable(constructor);
 	}
 
 	/**

src/main/java/org/springframework/data/mapping/model/ParameterValueProvider.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.mapping.model;
 
+import java.util.Optional;
+
 import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.PreferredConstructor.Parameter;
 
@@ -31,5 +33,5 @@ public interface ParameterValueProvider<P extends PersistentProperty<P>> {
 	 * @param parameter must not be {@literal null}.
 	 * @return
 	 */
-	<T> T getParameterValue(Parameter<T, P> parameter);
-}
+	<T> Optional<T> getParameterValue(Parameter<T, P> parameter);
+}

src/main/java/org/springframework/data/mapping/model/PersistentEntityParameterValueProvider.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.mapping.model;
 
+import java.util.Optional;
+
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.PreferredConstructor;
@@ -29,12 +31,12 @@ import org.springframework.util.Assert;
  * 
  * @author Oliver Gierke
  */
-public class PersistentEntityParameterValueProvider<P extends PersistentProperty<P>> implements
-		ParameterValueProvider<P> {
+public class PersistentEntityParameterValueProvider<P extends PersistentProperty<P>>
+		implements ParameterValueProvider<P> {
 
 	private final PersistentEntity<?, P> entity;
 	private final PropertyValueProvider<P> provider;
-	private final Object parent;
+	private final Optional<Object> parent;
 
 	/**
 	 * Creates a new {@link PersistentEntityParameterValueProvider} for the given {@link PersistentEntity} and
@@ -45,10 +47,11 @@ public class PersistentEntityParameterValueProvider<P extends PersistentProperty
 	 * @param parent the parent object being created currently, can be {@literal null}.
 	 */
 	public PersistentEntityParameterValueProvider(PersistentEntity<?, P> entity, PropertyValueProvider<P> provider,
-			Object parent) {
+			Optional<Object> parent) {
 
 		Assert.notNull(entity, "Entity must not be null!");
 		Assert.notNull(provider, "Provider must not be null!");
+		Assert.notNull(parent, "Parent must not be null!");
 
 		this.entity = entity;
 		this.provider = provider;
@@ -60,21 +63,18 @@ public class PersistentEntityParameterValueProvider<P extends PersistentProperty
 	 * @see org.springframework.data.mapping.model.ParameterValueProvider#getParameterValue(org.springframework.data.mapping.PreferredConstructor.Parameter)
 	 */
 	@SuppressWarnings("unchecked")
-	public <T> T getParameterValue(Parameter<T, P> parameter) {
+	public <T> Optional<T> getParameterValue(Parameter<T, P> parameter) {
 
-		PreferredConstructor<?, P> constructor = entity.getPersistenceConstructor();
+		PreferredConstructor<?, P> constructor = entity.getPersistenceConstructor().get();
 
 		if (constructor.isEnclosingClassParameter(parameter)) {
-			return (T) parent;
+			return (Optional<T>) parent;
 		}
 
-		P property = entity.getPersistentProperty(parameter.getName());
-
-		if (property == null) {
-			throw new MappingException(String.format("No property %s found on entity %s to bind constructor parameter to!",
-					parameter.getName(), entity.getType()));
-		}
-
-		return provider.getPropertyValue(property);
+		return provider.getPropertyValue(parameter.getName()//
+				.flatMap(it -> entity.getPersistentProperty(it))//
+				.orElseThrow(() -> new MappingException(
+						String.format("No property %s found on entity %s to bind constructor parameter to!", parameter.getName(),
+								entity.getType()))));
 	}
 }

src/main/java/org/springframework/data/mapping/model/PreferredConstructorDiscoverer.java

@@ -18,6 +18,7 @@ package org.springframework.data.mapping.model;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Constructor;
 import java.util.List;
+import java.util.Optional;
 
 import org.springframework.core.DefaultParameterNameDiscoverer;
 import org.springframework.core.ParameterNameDiscoverer;
@@ -37,7 +38,7 @@ public class PreferredConstructorDiscoverer<T, P extends PersistentProperty<P>>
 
 	private final ParameterNameDiscoverer discoverer = new DefaultParameterNameDiscoverer();
 
-	private PreferredConstructor<T, P> constructor;
+	private Optional<PreferredConstructor<T, P>> constructor;
 
 	/**
 	 * Creates a new {@link PreferredConstructorDiscoverer} for the given type.
@@ -54,7 +55,7 @@ public class PreferredConstructorDiscoverer<T, P extends PersistentProperty<P>>
 	 * @param entity must not be {@literal null}.
 	 */
 	public PreferredConstructorDiscoverer(PersistentEntity<T, P> entity) {
-		this(entity.getTypeInformation(), entity);
+		this(entity.getTypeInformation(), Optional.ofNullable(entity));
 	}
 
 	/**
@@ -63,7 +64,7 @@ public class PreferredConstructorDiscoverer<T, P extends PersistentProperty<P>>
 	 * @param type must not be {@literal null}.
 	 * @param entity
 	 */
-	protected PreferredConstructorDiscoverer(TypeInformation<T> type, PersistentEntity<T, P> entity) {
+	protected PreferredConstructorDiscoverer(TypeInformation<T> type, Optional<PersistentEntity<T, P>> entity) {
 
 		boolean noArgConstructorFound = false;
 		int numberOfArgConstructors = 0;
@@ -75,13 +76,13 @@ public class PreferredConstructorDiscoverer<T, P extends PersistentProperty<P>>
 
 			// Explicitly defined constructor trumps all
 			if (preferredConstructor.isExplicitlyAnnotated()) {
-				this.constructor = preferredConstructor;
+				this.constructor = Optional.of(preferredConstructor);
 				return;
 			}
 
 			// No-arg constructor trumps custom ones
 			if (this.constructor == null || preferredConstructor.isNoArgConstructor()) {
-				this.constructor = preferredConstructor;
+				this.constructor = Optional.of(preferredConstructor);
 			}
 
 			if (preferredConstructor.isNoArgConstructor()) {
@@ -92,13 +93,13 @@ public class PreferredConstructorDiscoverer<T, P extends PersistentProperty<P>>
 		}
 
 		if (!noArgConstructorFound && numberOfArgConstructors > 1) {
-			this.constructor = null;
+			this.constructor = Optional.empty();
 		}
 	}
 
 	@SuppressWarnings({ "unchecked", "rawtypes" })
 	private PreferredConstructor<T, P> buildPreferredConstructor(Constructor<?> constructor,
-			TypeInformation<T> typeInformation, PersistentEntity<T, P> entity) {
+			TypeInformation<T> typeInformation, Optional<PersistentEntity<T, P>> entity) {
 
 		List<TypeInformation<?>> parameterTypes = typeInformation.getParameterTypes(constructor);
 
@@ -113,7 +114,7 @@ public class PreferredConstructorDiscoverer<T, P extends PersistentProperty<P>>
 
 		for (int i = 0; i < parameterTypes.size(); i++) {
 
-			String name = parameterNames == null ? null : parameterNames[i];
+			Optional<String> name = Optional.ofNullable(parameterNames == null ? null : parameterNames[i]);
 			TypeInformation<?> type = parameterTypes.get(i);
 			Annotation[] annotations = parameterAnnotations[i];
 
@@ -128,7 +129,7 @@ public class PreferredConstructorDiscoverer<T, P extends PersistentProperty<P>>
 	 * 
 	 * @return
 	 */
-	public PreferredConstructor<T, P> getConstructor() {
+	public Optional<PreferredConstructor<T, P>> getConstructor() {
 		return constructor;
 	}
 }

src/main/java/org/springframework/data/mapping/model/PropertyValueProvider.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.mapping.model;
 
+import java.util.Optional;
+
 import org.springframework.data.mapping.PersistentProperty;
 
 /**
@@ -30,5 +32,5 @@ public interface PropertyValueProvider<P extends PersistentProperty<P>> {
 	 * @param property will never be {@literal null}.
 	 * @return
 	 */
-	<T> T getPropertyValue(P property);
+	<T> Optional<T> getPropertyValue(P property);
 }

src/main/java/org/springframework/data/mapping/model/SpELExpressionParameterValueProvider.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.mapping.model;
 
+import java.util.Optional;
+
 import org.springframework.core.convert.ConversionService;
 import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.PreferredConstructor.Parameter;
@@ -26,7 +28,8 @@ import org.springframework.util.Assert;
  * 
  * @author Oliver Gierke
  */
-public class SpELExpressionParameterValueProvider<P extends PersistentProperty<P>> implements ParameterValueProvider<P> {
+public class SpELExpressionParameterValueProvider<P extends PersistentProperty<P>>
+		implements ParameterValueProvider<P> {
 
 	private final SpELExpressionEvaluator evaluator;
 	private final ParameterValueProvider<P> delegate;
@@ -57,14 +60,15 @@ public class SpELExpressionParameterValueProvider<P extends PersistentProperty<P
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.model.ParameterValueProvider#getParameterValue(org.springframework.data.mapping.PreferredConstructor.Parameter)
 	 */
-	public <T> T getParameterValue(Parameter<T, P> parameter) {
+	public <T> Optional<T> getParameterValue(Parameter<T, P> parameter) {
 
 		if (!parameter.hasSpelExpression()) {
-			return delegate == null ? null : delegate.getParameterValue(parameter);
+			return delegate.getParameterValue(parameter);
 		}
 
-		Object object = evaluator.evaluate(parameter.getSpelExpression());
-		return object == null ? null : potentiallyConvertSpelValue(object, parameter);
+		Optional<Object> object = Optional.ofNullable(evaluator.evaluate(parameter.getSpelExpression().orElse(null)));
+
+		return object.map(it -> potentiallyConvertSpelValue(object, parameter));
 	}
 
 	/**

src/main/java/org/springframework/data/projection/DefaultProjectionInformation.java

@@ -47,7 +47,7 @@ class DefaultProjectionInformation implements ProjectionInformation {
 		Assert.notNull(type, "Projection type must not be null!");
 
 		this.projectionType = type;
-		this.properties = collectDescriptors(type);
+		this.properties = Arrays.asList(BeanUtils.getPropertyDescriptors(type));
 	}
 
 	/* 
@@ -66,7 +66,8 @@ class DefaultProjectionInformation implements ProjectionInformation {
 	public List<PropertyDescriptor> getInputProperties() {
 
 		return properties.stream()//
-				.filter(it -> isInputProperty(it))//
+				.filter(this::isInputProperty)//
+				.distinct()//
 				.collect(Collectors.toList());
 	}
 
@@ -91,30 +92,9 @@ class DefaultProjectionInformation implements ProjectionInformation {
 		return true;
 	}
 
-	/**
-	 * Collects {@link PropertyDescriptor}s for all properties exposed by the given type and all its super interfaces.
-	 * 
-	 * @param type must not be {@literal null}.
-	 * @return
-	 */
-	private static List<PropertyDescriptor> collectDescriptors(Class<?> type) {
-
-		List<PropertyDescriptor> result = new ArrayList<PropertyDescriptor>();
-
-		result.addAll(Arrays.stream(BeanUtils.getPropertyDescriptors(type))//
-				.filter(it -> !hasDefaultGetter(it))//
-				.collect(Collectors.toList()));
-
-		for (Class<?> interfaze : type.getInterfaces()) {
-			result.addAll(collectDescriptors(interfaze));
-		}
-
-		return result;
-	}
-
 	/**
 	 * Returns whether the given {@link PropertyDescriptor} has a getter that is a Java 8 default method.
-	 * 
+	 *
 	 * @param descriptor must not be {@literal null}.
 	 * @return
 	 */

src/main/java/org/springframework/data/querydsl/QuerydslRepositoryInvokerAdapter.java

@@ -17,7 +17,6 @@ package org.springframework.data.querydsl;
 
 import java.io.Serializable;
 import java.lang.reflect.Method;
-import java.util.Map;
 
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
@@ -130,15 +129,6 @@ public class QuerydslRepositoryInvokerAdapter implements RepositoryInvoker {
 		return delegate.invokeFindOne(id);
 	}
 
-	/* 
-	 * (non-Javadoc)
-	 * @see org.springframework.data.repository.support.RepositoryInvoker#invokeQueryMethod(java.lang.reflect.Method, java.util.Map, org.springframework.data.domain.Pageable, org.springframework.data.domain.Sort)
-	 */
-	@Override
-	public Object invokeQueryMethod(Method method, Map<String, String[]> parameters, Pageable pageable, Sort sort) {
-		return delegate.invokeQueryMethod(method, parameters, pageable, sort);
-	}
-
 	/* 
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.support.RepositoryInvoker#invokeQueryMethod(java.lang.reflect.Method, org.springframework.util.MultiValueMap, org.springframework.data.domain.Pageable, org.springframework.data.domain.Sort)

src/main/java/org/springframework/data/querydsl/binding/MultiValueBinding.java

@@ -16,6 +16,7 @@
 package org.springframework.data.querydsl.binding;
 
 import java.util.Collection;
+import java.util.Optional;
 
 import com.querydsl.core.types.Path;
 import com.querydsl.core.types.Predicate;
@@ -40,5 +41,5 @@ public interface MultiValueBinding<T extends Path<? extends S>, S> {
 	 * @return can be {@literal null}, in which case the binding will not be incorporated in the overall {@link Predicate}
 	 *         .
 	 */
-	Predicate bind(T path, Collection<? extends S> value);
+	Optional<Predicate> bind(T path, Collection<? extends S> value);
 }

src/main/java/org/springframework/data/querydsl/binding/OptionalValueBinding.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.querydsl.binding;
+
+import java.util.Optional;
+
+import com.querydsl.core.types.Path;
+import com.querydsl.core.types.Predicate;
+
+/**
+ * {@link OptionalValueBinding} creates a {@link Predicate} out of given {@link Path} and value. Used for specific
+ * parameter treatment in {@link QuerydslBindings}.
+ * 
+ * @author Christoph Strobl
+ * @author Oliver Gierke
+ * @since 1.11
+ */
+@FunctionalInterface
+public interface OptionalValueBinding<T extends Path<? extends S>, S> {
+
+	/**
+	 * Returns the predicate to be applied to the given {@link Path} for the given value. The given value will be the
+	 * first the first one provided for the given path and converted into the expected type.
+	 * 
+	 * @param path {@link Path} to the property. Will not be {@literal null}.
+	 * @param value the value that should be bound. Will not be {@literal null}.
+	 * @return can be {@literal null}, in which case the binding will not be incorporated in the overall {@link Predicate}
+	 *         .
+	 */
+	Optional<Predicate> bind(T path, Optional<? extends S> value);
+}

src/main/java/org/springframework/data/querydsl/binding/QuerydslBindings.java

@@ -15,8 +15,6 @@
  */
 package org.springframework.data.querydsl.binding;
 
-import static org.springframework.data.querydsl.QueryDslUtils.*;
-
 import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 import lombok.Value;
@@ -24,15 +22,16 @@ import lombok.Value;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 
 import org.springframework.data.mapping.PropertyPath;
 import org.springframework.data.mapping.PropertyReferenceException;
 import org.springframework.data.util.ClassTypeInformation;
+import org.springframework.data.util.Optionals;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
@@ -42,7 +41,7 @@ import com.querydsl.core.types.Predicate;
 
 /**
  * {@link QuerydslBindings} allows definition of path specific bindings.
- * 
+ *
  * <pre>
  * <code>
  * new QuerydslBindings() {
@@ -53,7 +52,7 @@ import com.querydsl.core.types.Predicate;
  * }
  * </code>
  * </pre>
- * 
+ *
  * The bindings can either handle a single - see {@link PathBinder#first(SingleValueBinding)} - (the first in case
  * multiple ones are supplied) or multiple - see {@link PathBinder#all(MultiValueBinding)} - value binding. If exactly
  * one path is deployed, an {@link AliasingPathBinder} is returned which - as the name suggests - allows aliasing of
@@ -61,7 +60,7 @@ import com.querydsl.core.types.Predicate;
  * <p>
  * {@link QuerydslBindings} are usually manipulated using a {@link QuerydslBinderCustomizer}, either implemented
  * directly or using a default method on a Spring Data repository.
- * 
+ *
  * @author Christoph Strobl
  * @author Oliver Gierke
  * @since 1.11
@@ -90,7 +89,7 @@ public class QuerydslBindings {
 
 	/**
 	 * Returns an {@link AliasingPathBinder} for the given {@link Path} to define bindings for them.
-	 * 
+	 *
 	 * @param path must not be {@literal null}.
 	 * @return
 	 */
@@ -100,17 +99,18 @@ public class QuerydslBindings {
 
 	/**
 	 * Returns a new {@link PathBinder} for the given {@link Path}s to define bindings for them.
-	 * 
+	 *
 	 * @param paths must not be {@literal null} or empty.
 	 * @return
 	 */
+	@SafeVarargs
 	public final <T extends Path<S>, S> PathBinder<T, S> bind(T... paths) {
 		return new PathBinder<T, S>(paths);
 	}
 
 	/**
 	 * Returns a new {@link TypeBinder} for the given type.
-	 * 
+	 *
 	 * @param type must not be {@literal null}.
 	 * @return
 	 */
@@ -121,7 +121,7 @@ public class QuerydslBindings {
 	/**
 	 * Exclude properties from binding. Exclusion of all properties of a nested type can be done by exclusion on a higher
 	 * level. E.g. {@code address} would exclude both {@code address.city} and {@code address.street}.
-	 * 
+	 *
 	 * @param paths must not be {@literal null} or empty.
 	 */
 	public final void excluding(Path<?>... paths) {
@@ -129,13 +129,13 @@ public class QuerydslBindings {
 		Assert.notEmpty(paths, "At least one path has to be provided!");
 
 		for (Path<?> path : paths) {
-			this.blackList.add(toDotPath(path));
+			this.blackList.add(toDotPath(Optional.of(path)));
 		}
 	}
 
 	/**
 	 * Include properties for binding. Include the property considered a binding candidate.
-	 * 
+	 *
 	 * @param properties must not be {@literal null} or empty.
 	 */
 	public final void including(Path<?>... paths) {
@@ -143,7 +143,7 @@ public class QuerydslBindings {
 		Assert.notEmpty(paths, "At least one path has to be provided!");
 
 		for (Path<?> path : paths) {
-			this.whiteList.add(toDotPath(path));
+			this.whiteList.add(toDotPath(Optional.of(path)));
 		}
 	}
 
@@ -151,7 +151,7 @@ public class QuerydslBindings {
 	 * Returns whether to exclude all properties for which no explicit binding has been defined or it has been explicitly
 	 * white-listed. This defaults to {@literal false} which means that for properties without an explicitly defined
 	 * binding a type specific default binding will be applied.
-	 * 
+	 *
 	 * @param excludeUnlistedProperties
 	 * @return
 	 * @see #including(String...)
@@ -165,7 +165,7 @@ public class QuerydslBindings {
 
 	/**
 	 * Returns whether the given path is available on the given type.
-	 * 
+	 *
 	 * @param path must not be {@literal null}.
 	 * @param type must not be {@literal null}.
 	 * @return
@@ -180,7 +180,7 @@ public class QuerydslBindings {
 
 	/**
 	 * Returns whether the given path is available on the given type.
-	 * 
+	 *
 	 * @param path must not be {@literal null}.
 	 * @param type
 	 * @return
@@ -196,12 +196,12 @@ public class QuerydslBindings {
 	/**
 	 * Returns the {@link SingleValueBinding} for the given {@link PropertyPath}. Prefers a path configured for the
 	 * specific path but falls back to the builder registered for a given type.
-	 * 
+	 *
 	 * @param path must not be {@literal null}.
 	 * @return can be {@literal null}.
 	 */
 	@SuppressWarnings("unchecked")
-	public <S extends Path<? extends T>, T> MultiValueBinding<S, T> getBindingForPath(PathInformation path) {
+	public <S extends Path<? extends T>, T> Optional<MultiValueBinding<S, T>> getBindingForPath(PathInformation path) {
 
 		Assert.notNull(path, "PropertyPath must not be null!");
 
@@ -209,30 +209,29 @@ public class QuerydslBindings {
 
 		if (pathAndBinding != null) {
 
-			MultiValueBinding<S, T> binding = pathAndBinding.getBinding();
+			Optional<MultiValueBinding<S, T>> binding = pathAndBinding.getBinding();
 
-			if (binding != null) {
-				return pathAndBinding.getBinding();
+			if (binding.isPresent()) {
+				return binding;
 			}
 		}
 
 		pathAndBinding = (PathAndBinding<S, T>) typeSpecs.get(path.getLeafType());
 
-		return pathAndBinding == null ? null : pathAndBinding.getBinding();
+		return pathAndBinding == null ? Optional.empty() : pathAndBinding.getBinding();
 	}
 
 	/**
 	 * Returns a {@link Path} for the {@link PropertyPath} instance.
-	 * 
+	 *
 	 * @param path must not be {@literal null}.
 	 * @return
 	 */
-	Path<?> getExistingPath(PathInformation path) {
+	Optional<Path<?>> getExistingPath(PathInformation path) {
 
 		Assert.notNull(path, "PropertyPath must not be null!");
 
-		PathAndBinding<?, ?> pathAndBuilder = pathSpecs.get(path.toDotPath());
-		return pathAndBuilder == null ? null : pathAndBuilder.getPath();
+		return Optional.ofNullable(pathSpecs.get(path.toDotPath())).flatMap(it -> it.getPath());
 	}
 
 	/**
@@ -252,7 +251,9 @@ public class QuerydslBindings {
 		}
 
 		if (pathSpecs.containsKey(path)) {
-			return QuerydslPathInformation.of(pathSpecs.get(path).getPath());
+			return pathSpecs.get(path).getPath()//
+					.map(it -> QuerydslPathInformation.of(it))//
+					.orElse(null);
 		}
 
 		try {
@@ -265,7 +266,7 @@ public class QuerydslBindings {
 
 	/**
 	 * Checks if a given {@link PropertyPath} should be visible for binding values.
-	 * 
+	 *
 	 * @param path
 	 * @return
 	 */
@@ -292,7 +293,7 @@ public class QuerydslBindings {
 	/**
 	 * Returns whether the given path is visible, which means either an alias and not explicitly blacklisted, explicitly
 	 * white listed or not on the black list if no white list configured.
-	 * 
+	 *
 	 * @param path must not be {@literal null}.
 	 * @return
 	 */
@@ -310,6 +311,17 @@ public class QuerydslBindings {
 		return whiteList.contains(path);
 	}
 
+	/**
+	 * Returns the property path for the given {@link Path}.
+	 *
+	 * @param path can be {@literal null}.
+	 * @return
+	 */
+	private static String toDotPath(Optional<Path<?>> path) {
+		return path.map(it -> it.toString().substring(it.getMetadata().getRootPath().getMetadata().getName().length() + 1))
+				.orElse("");
+	}
+
 	/**
 	 * A binder for {@link Path}s.
 	 *
@@ -321,9 +333,10 @@ public class QuerydslBindings {
 
 		/**
 		 * Creates a new {@link PathBinder} for the given {@link Path}s.
-		 * 
+		 *
 		 * @param paths must not be {@literal null} or empty.
 		 */
+		@SafeVarargs
 		PathBinder(P... paths) {
 
 			Assert.notEmpty(paths, "At least one path has to be provided!");
@@ -332,20 +345,26 @@ public class QuerydslBindings {
 
 		/**
 		 * Defines the given {@link SingleValueBinding} to be used for the paths.
-		 * 
+		 *
 		 * @param binding must not be {@literal null}.
 		 * @return
 		 */
-		public void first(SingleValueBinding<P, T> binding) {
+		public void firstOptional(OptionalValueBinding<P, T> binding) {
 
 			Assert.notNull(binding, "Binding must not be null!");
 
-			all(new MultiValueBindingAdapter<P, T>(binding));
+			all((path, value) -> binding.bind(path, Optionals.next(value.iterator())));
+		}
+
+		public void first(SingleValueBinding<P, T> binding) {
+
+			Assert.notNull(binding, "Binding must not be null!");
+			all((path, value) -> Optionals.next(value.iterator()).flatMap(t -> binding.bind(path, t)));
 		}
 
 		/**
 		 * Defines the given {@link MultiValueBinding} to be used for the paths.
-		 * 
+		 *
 		 * @param binding must not be {@literal null}.
 		 * @return
 		 */
@@ -353,9 +372,7 @@ public class QuerydslBindings {
 
 			Assert.notNull(binding, "Binding must not be null!");
 
-			for (P path : paths) {
-				registerBinding(new PathAndBinding<P, T>(path, binding));
-			}
+			paths.forEach(path -> registerBinding(PathAndBinding.withPath(path).with(binding)));
 		}
 
 		protected void registerBinding(PathAndBinding<P, T> binding) {
@@ -376,7 +393,7 @@ public class QuerydslBindings {
 
 		/**
 		 * Creates a new {@link AliasingPathBinder} for the given {@link Path}.
-		 * 
+		 *
 		 * @param paths must not be {@literal null}.
 		 */
 		AliasingPathBinder(P path) {
@@ -385,11 +402,10 @@ public class QuerydslBindings {
 
 		/**
 		 * Creates a new {@link AliasingPathBinder} using the given alias and {@link Path}.
-		 * 
+		 *
 		 * @param alias can be {@literal null}.
 		 * @param path must not be {@literal null}.
 		 */
-		@SuppressWarnings("unchecked")
 		private AliasingPathBinder(String alias, P path) {
 
 			super(path);
@@ -404,7 +420,7 @@ public class QuerydslBindings {
 		 * Aliases the current binding to be available under the given path. By default, the binding path will be
 		 * blacklisted so that aliasing effectively hides the original path. If you want to keep the original path around,
 		 * include it in an explicit whitelist.
-		 * 
+		 *
 		 * @param alias must not be {@literal null}.
 		 * @return will never be {@literal null}.
 		 */
@@ -418,10 +434,10 @@ public class QuerydslBindings {
 		 * Registers the current aliased binding to use the default binding.
 		 */
 		public void withDefaultBinding() {
-			registerBinding(new PathAndBinding<P, T>(path, null));
+			registerBinding(PathAndBinding.withPath(path));
 		}
 
-		/* 
+		/*
 		 * (non-Javadoc)
 		 * @see org.springframework.data.querydsl.binding.QuerydslBindings.PathBinder#registerBinding(org.springframework.data.querydsl.binding.QuerydslBindings.PathAndBinding)
 		 */
@@ -450,60 +466,69 @@ public class QuerydslBindings {
 
 		/**
 		 * Configures the given {@link SingleValueBinding} to be used for the current type.
-		 * 
+		 *
 		 * @param binding must not be {@literal null}.
 		 */
+		public <P extends Path<T>> void firstOptional(OptionalValueBinding<P, T> binding) {
+
+			Assert.notNull(binding, "Binding must not be null!");
+			all(new MultiValueBinding<P, T>() {
+
+				@Override
+				public Optional<Predicate> bind(P path, Collection<? extends T> value) {
+					return binding.bind(path, Optionals.next(value.iterator()));
+				}
+			});
+		}
+
 		public <P extends Path<T>> void first(SingleValueBinding<P, T> binding) {
 
 			Assert.notNull(binding, "Binding must not be null!");
-			all(new MultiValueBindingAdapter<P, T>(binding));
+			all(new MultiValueBinding<P, T>() {
+
+				@Override
+				public Optional<Predicate> bind(P path, Collection<? extends T> value) {
+					return Optionals.next(value.iterator()).flatMap(t -> binding.bind(path, t));
+				}
+			});
 		}
 
 		/**
 		 * Configures the given {@link MultiValueBinding} to be used for the current type.
-		 * 
+		 *
 		 * @param binding must not be {@literal null}.
 		 */
 		public <P extends Path<T>> void all(MultiValueBinding<P, T> binding) {
 
 			Assert.notNull(binding, "Binding must not be null!");
-			QuerydslBindings.this.typeSpecs.put(type, new PathAndBinding<P, T>(null, binding));
+
+			QuerydslBindings.this.typeSpecs.put(type, PathAndBinding.<T, P> withoutPath().with(binding));
 		}
 	}
 
 	/**
 	 * A pair of a {@link Path} and the registered {@link MultiValueBinding}.
-	 * 
+	 *
 	 * @author Christoph Strobl
 	 * @author Oliver Gierke
 	 * @since 1.11
 	 */
 	@Value
-	private static class PathAndBinding<S extends Path<? extends T>, T> {
+	private static class PathAndBinding<P extends Path<? extends T>, T> {
 
-		Path<?> path;
-		MultiValueBinding<S, T> binding;
-	}
+		@NonNull Optional<Path<?>> path;
+		@NonNull Optional<MultiValueBinding<P, T>> binding;
 
-	/**
-	 * {@link MultiValueBinding} that forwards the first value of the collection values to the delegate
-	 * {@link SingleValueBinding}.
-	 * 
-	 * @author Oliver Gierke
-	 */
-	@RequiredArgsConstructor
-	static class MultiValueBindingAdapter<P extends Path<? extends T>, T> implements MultiValueBinding<P, T> {
+		public static <T, P extends Path<? extends T>> PathAndBinding<P, T> withPath(P path) {
+			return new PathAndBinding<P, T>(Optional.of(path), Optional.empty());
+		}
 
-		private final @NonNull SingleValueBinding<P, T> delegate;
+		public static <T, S extends Path<? extends T>> PathAndBinding<S, T> withoutPath() {
+			return new PathAndBinding<S, T>(Optional.empty(), Optional.empty());
+		}
 
-		/* 
-		 * (non-Javadoc)
-		 * @see org.springframework.data.web.querydsl.MultiValueBinding#bind(com.mysema.query.types.Path, java.util.Collection)
-		 */
-		@Override
-		public Predicate bind(P path, Collection<? extends T> value) {
-			Iterator<? extends T> iterator = value.iterator();
-			return delegate.bind(path, iterator.hasNext() ? iterator.next() : null);
+		public PathAndBinding<P, T> with(MultiValueBinding<P, T> binding) {
+			return new PathAndBinding<P, T>(path, Optional.of(binding));
 		}
 	}
 }

src/main/java/org/springframework/data/querydsl/binding/QuerydslBindingsFactory.java

@@ -16,6 +16,7 @@
 package org.springframework.data.querydsl.binding;
 
 import java.util.Map;
+import java.util.Optional;
 
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.BeansException;
@@ -44,8 +45,8 @@ public class QuerydslBindingsFactory implements ApplicationContextAware {
 	private final EntityPathResolver entityPathResolver;
 	private final Map<TypeInformation<?>, EntityPath<?>> entityPaths;
 
-	private AutowireCapableBeanFactory beanFactory;
-	private Repositories repositories;
+	private Optional<AutowireCapableBeanFactory> beanFactory;
+	private Optional<Repositories> repositories;
 
 	/**
 	 * Creates a new {@link QuerydslBindingsFactory} using the given {@link EntityPathResolver}.
@@ -58,6 +59,8 @@ public class QuerydslBindingsFactory implements ApplicationContextAware {
 
 		this.entityPathResolver = entityPathResolver;
 		this.entityPaths = new ConcurrentReferenceHashMap<TypeInformation<?>, EntityPath<?>>();
+		this.beanFactory = Optional.empty();
+		this.repositories = Optional.empty();
 	}
 
 	/* 
@@ -67,8 +70,8 @@ public class QuerydslBindingsFactory implements ApplicationContextAware {
 	@Override
 	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
 
-		this.beanFactory = applicationContext.getAutowireCapableBeanFactory();
-		this.repositories = new Repositories(applicationContext);
+		this.beanFactory = Optional.of(applicationContext.getAutowireCapableBeanFactory());
+		this.repositories = Optional.of(new Repositories(applicationContext));
 	}
 
 	/**
@@ -84,14 +87,15 @@ public class QuerydslBindingsFactory implements ApplicationContextAware {
 	 * Creates the {@link QuerydslBindings} to be used using for the given domain type and a pre-defined
 	 * {@link QuerydslBinderCustomizer}. If no customizer is given, auto-detection will be applied.
 	 * 
-	 * @param customizer the {@link QuerydslBinderCustomizer} to use. If {@literal null} is given customizer detection for
-	 *          the given domain type will be applied.
 	 * @param domainType must not be {@literal null}.
+	 * @param customizer the {@link QuerydslBinderCustomizer} to use. If an empty {@link Optional} is given customizer
+	 *          detection for the given domain type will be applied.
 	 * @return
 	 */
-	public QuerydslBindings createBindingsFor(Class<? extends QuerydslBinderCustomizer<?>> customizer,
-			TypeInformation<?> domainType) {
+	public QuerydslBindings createBindingsFor(TypeInformation<?> domainType,
+			Optional<Class<? extends QuerydslBinderCustomizer<?>>> customizer) {
 
+		Assert.notNull(customizer, "Customizer must not be null!");
 		Assert.notNull(domainType, "Domain type must not be null!");
 
 		EntityPath<?> path = verifyEntityPathPresent(domainType);
@@ -111,23 +115,15 @@ public class QuerydslBindingsFactory implements ApplicationContextAware {
 	 */
 	private EntityPath<?> verifyEntityPathPresent(TypeInformation<?> candidate) {
 
-		EntityPath<?> path = entityPaths.get(candidate);
+		return entityPaths.computeIfAbsent(candidate, key -> {
 
-		if (path != null) {
-			return path;
-		}
-
-		Class<?> type = candidate.getType();
-
-		try {
-			path = entityPathResolver.createPath(type);
-		} catch (IllegalArgumentException o_O) {
-			throw new IllegalStateException(
-					String.format(INVALID_DOMAIN_TYPE, candidate.getType(), QuerydslPredicate.class.getSimpleName()), o_O);
-		}
-
-		entityPaths.put(candidate, path);
-		return path;
+			try {
+				return entityPathResolver.createPath(key.getType());
+			} catch (IllegalArgumentException o_O) {
+				throw new IllegalStateException(
+						String.format(INVALID_DOMAIN_TYPE, key.getType(), QuerydslPredicate.class.getSimpleName()), o_O);
+			}
+		});
 	}
 
 	/**
@@ -140,22 +136,16 @@ public class QuerydslBindingsFactory implements ApplicationContextAware {
 	 */
 	@SuppressWarnings({ "unchecked", "rawtypes" })
 	private QuerydslBinderCustomizer<EntityPath<?>> findCustomizerForDomainType(
-			Class<? extends QuerydslBinderCustomizer> customizer, Class<?> domainType) {
+			Optional<? extends Class<? extends QuerydslBinderCustomizer>> customizer, Class<?> domainType) {
 
-		if (customizer != null && !QuerydslBinderCustomizer.class.equals(customizer)) {
-			return createQuerydslBinderCustomizer(customizer);
-		}
+		return customizer//
+				.filter(it -> !QuerydslBinderCustomizer.class.equals(it))//
+				.map(it -> createQuerydslBinderCustomizer(it)).orElseGet(() -> {
 
-		if (repositories != null && repositories.hasRepositoryFor(domainType)) {
-
-			Object repository = repositories.getRepositoryFor(domainType);
-
-			if (repository instanceof QuerydslBinderCustomizer) {
-				return (QuerydslBinderCustomizer<EntityPath<?>>) repository;
-			}
-		}
-
-		return NoOpCustomizer.INSTANCE;
+					return repositories.flatMap(it -> it.getRepositoryFor(domainType))//
+							.map(it -> it instanceof QuerydslBinderCustomizer ? (QuerydslBinderCustomizer<EntityPath<?>>) it : null)//
+							.orElse(NoOpCustomizer.INSTANCE);
+				});
 	}
 
 	/**
@@ -171,15 +161,14 @@ public class QuerydslBindingsFactory implements ApplicationContextAware {
 	private QuerydslBinderCustomizer<EntityPath<?>> createQuerydslBinderCustomizer(
 			Class<? extends QuerydslBinderCustomizer> type) {
 
-		if (beanFactory == null) {
-			return BeanUtils.instantiateClass(type);
-		}
+		return beanFactory.map(it -> {
 
-		try {
-			return beanFactory.getBean(type);
-		} catch (NoSuchBeanDefinitionException e) {
-			return beanFactory.createBean(type);
-		}
+			try {
+				return it.getBean(type);
+			} catch (NoSuchBeanDefinitionException e) {
+				return it.createBean(type);
+			}
+		}).orElseGet(() -> BeanUtils.instantiateClass(type));
 	}
 
 	private static enum NoOpCustomizer implements QuerydslBinderCustomizer<EntityPath<?>> {

src/main/java/org/springframework/data/querydsl/binding/QuerydslDefaultBinding.java

@@ -16,6 +16,7 @@
 package org.springframework.data.querydsl.binding;
 
 import java.util.Collection;
+import java.util.Optional;
 
 import org.springframework.util.Assert;
 
@@ -46,13 +47,13 @@ class QuerydslDefaultBinding implements MultiValueBinding<Path<? extends Object>
 	 */
 	@Override
 	@SuppressWarnings({ "unchecked", "rawtypes" })
-	public Predicate bind(Path<?> path, Collection<? extends Object> value) {
+	public Optional<Predicate> bind(Path<?> path, Collection<? extends Object> value) {
 
 		Assert.notNull(path, "Path must not be null!");
 		Assert.notNull(value, "Value must not be null!");
 
 		if (value.isEmpty()) {
-			return null;
+			return Optional.empty();
 		}
 
 		if (path instanceof CollectionPathBase) {
@@ -63,16 +64,16 @@ class QuerydslDefaultBinding implements MultiValueBinding<Path<? extends Object>
 				builder.and(((CollectionPathBase) path).contains(element));
 			}
 
-			return builder.getValue();
+			return Optional.of(builder.getValue());
 		}
 
 		if (path instanceof SimpleExpression) {
 
 			if (value.size() > 1) {
-				return ((SimpleExpression) path).in(value);
+				return Optional.of(((SimpleExpression) path).in(value));
 			}
 
-			return ((SimpleExpression) path).eq(value.iterator().next());
+			return Optional.of(((SimpleExpression) path).eq(value.iterator().next()));
 		}
 
 		throw new IllegalArgumentException(

src/main/java/org/springframework/data/querydsl/binding/QuerydslPredicate.java

@@ -38,7 +38,7 @@ public @interface QuerydslPredicate {
 	 * 
 	 * @return
 	 */
-	Class<?>root() default Object.class;
+	Class<?> root() default Object.class;
 
 	/**
 	 * To customize the way individual properties' values should be bound to the predicate a
@@ -49,5 +49,5 @@ public @interface QuerydslPredicate {
 	 * @return
 	 */
 	@SuppressWarnings("rawtypes")
-	Class<? extends QuerydslBinderCustomizer>bindings() default QuerydslBinderCustomizer.class;
+	Class<? extends QuerydslBinderCustomizer> bindings() default QuerydslBinderCustomizer.class;
 }

src/main/java/org/springframework/data/querydsl/binding/QuerydslPredicateBuilder.java

@@ -23,6 +23,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Optional;
 
 import org.springframework.beans.PropertyValues;
 import org.springframework.core.convert.ConversionService;
@@ -50,7 +51,7 @@ import com.querydsl.core.types.Predicate;
 public class QuerydslPredicateBuilder {
 
 	private final ConversionService conversionService;
-	private final MultiValueBinding<?, ?> defaultBinding;
+	private final MultiValueBinding<Path<? extends Object>, Object> defaultBinding;
 	private final Map<PathInformation, Path<?>> paths;
 	private final EntityPathResolver resolver;
 
@@ -67,7 +68,7 @@ public class QuerydslPredicateBuilder {
 
 		this.defaultBinding = new QuerydslDefaultBinding();
 		this.conversionService = conversionService;
-		this.paths = new HashMap<PathInformation, Path<?>>();
+		this.paths = new HashMap<>();
 		this.resolver = resolver;
 	}
 
@@ -110,11 +111,9 @@ public class QuerydslPredicateBuilder {
 			}
 
 			Collection<Object> value = convertToPropertyPathSpecificType(entry.getValue(), propertyPath);
-			Predicate predicate = invokeBinding(propertyPath, bindings, value);
+			Optional<Predicate> predicate = invokeBinding(propertyPath, bindings, value);
 
-			if (predicate != null) {
-				builder.and(predicate);
-			}
+			predicate.ifPresent(it -> builder.and(it));
 		}
 
 		return builder.getValue();
@@ -128,15 +127,12 @@ public class QuerydslPredicateBuilder {
 	 * @param values must not be {@literal null}.
 	 * @return
 	 */
-	@SuppressWarnings({ "unchecked", "rawtypes" })
-	private Predicate invokeBinding(PathInformation dotPath, QuerydslBindings bindings, Collection<Object> values) {
+	private Optional<Predicate> invokeBinding(PathInformation dotPath, QuerydslBindings bindings,
+			Collection<Object> values) {
 
 		Path<?> path = getPath(dotPath, bindings);
 
-		MultiValueBinding binding = bindings.getBindingForPath(dotPath);
-		binding = binding == null ? defaultBinding : binding;
-
-		return binding.bind(path, values);
+		return bindings.getBindingForPath(dotPath).orElse(defaultBinding).bind(path, values);
 	}
 
 	/**
@@ -150,22 +146,9 @@ public class QuerydslPredicateBuilder {
 	 */
 	private Path<?> getPath(PathInformation path, QuerydslBindings bindings) {
 
-		Path<?> resolvedPath = bindings.getExistingPath(path);
+		Optional<Path<?>> resolvedPath = bindings.getExistingPath(path);
 
-		if (resolvedPath != null) {
-			return resolvedPath;
-		}
-
-		resolvedPath = paths.get(resolvedPath);
-
-		if (resolvedPath != null) {
-			return resolvedPath;
-		}
-
-		resolvedPath = path.reifyPath(resolver);
-		paths.put(path, resolvedPath);
-
-		return resolvedPath;
+		return resolvedPath.orElseGet(() -> paths.computeIfAbsent(path, it -> path.reifyPath(resolver)));
 	}
 
 	/**

src/main/java/org/springframework/data/querydsl/binding/SingleValueBinding.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.querydsl.binding;
 
+import java.util.Optional;
+
 import com.querydsl.core.types.Path;
 import com.querydsl.core.types.Predicate;
 
@@ -38,5 +40,5 @@ public interface SingleValueBinding<T extends Path<? extends S>, S> {
 	 * @return can be {@literal null}, in which case the binding will not be incorporated in the overall {@link Predicate}
 	 *         .
 	 */
-	Predicate bind(T path, S value);
+	Optional<Predicate> bind(T path, S value);
 }

src/main/java/org/springframework/data/repository/CrudRepository.java

@@ -16,6 +16,7 @@
 package org.springframework.data.repository;
 
 import java.io.Serializable;
+import java.util.Optional;
 
 /**
  * Interface for generic CRUD operations on a repository for a specific type.
@@ -51,7 +52,7 @@ public interface CrudRepository<T, ID extends Serializable> extends Repository<T
 	 * @return the entity with the given id or {@literal null} if none found
 	 * @throws IllegalArgumentException if {@code id} is {@literal null}
 	 */
-	T findOne(ID id);
+	Optional<T> findOne(ID id);
 
 	/**
 	 * Returns whether an entity with the given id exists.

src/main/java/org/springframework/data/repository/cdi/CdiRepositoryBean.java

@@ -22,7 +22,9 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Optional;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import javax.enterprise.context.ApplicationScoped;
 import javax.enterprise.context.spi.CreationalContext;
@@ -37,7 +39,6 @@ import javax.enterprise.inject.spi.PassivationCapable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.support.AbstractBeanDefinition;
-import org.springframework.core.type.filter.TypeFilter;
 import org.springframework.data.repository.config.CustomRepositoryImplementationDetector;
 import org.springframework.data.repository.config.DefaultRepositoryConfiguration;
 import org.springframework.util.Assert;
@@ -59,7 +60,7 @@ public abstract class CdiRepositoryBean<T> implements Bean<T>, PassivationCapabl
 
 	private final Set<Annotation> qualifiers;
 	private final Class<T> repositoryType;
-	private final CustomRepositoryImplementationDetector detector;
+	private final Optional<CustomRepositoryImplementationDetector> detector;
 	private final BeanManager beanManager;
 	private final String passivationId;
 
@@ -73,7 +74,7 @@ public abstract class CdiRepositoryBean<T> implements Bean<T>, PassivationCapabl
 	 * @param beanManager the CDI {@link BeanManager}, must not be {@literal null}.
 	 */
 	public CdiRepositoryBean(Set<Annotation> qualifiers, Class<T> repositoryType, BeanManager beanManager) {
-		this(qualifiers, repositoryType, beanManager, null);
+		this(qualifiers, repositoryType, beanManager, Optional.empty());
 	}
 
 	/**
@@ -86,7 +87,7 @@ public abstract class CdiRepositoryBean<T> implements Bean<T>, PassivationCapabl
 	 *          can be {@literal null}.
 	 */
 	public CdiRepositoryBean(Set<Annotation> qualifiers, Class<T> repositoryType, BeanManager beanManager,
-			CustomRepositoryImplementationDetector detector) {
+			Optional<CustomRepositoryImplementationDetector> detector) {
 
 		Assert.notNull(qualifiers, "Qualifiers must not be null!");
 		Assert.notNull(beanManager, "BeanManager must not be null!");
@@ -141,13 +142,13 @@ public abstract class CdiRepositoryBean<T> implements Bean<T>, PassivationCapabl
 	 * Returns an instance of an the given {@link Bean}.
 	 * 
 	 * @param bean the {@link Bean} about to create an instance for.
-	 * @param type the expected type of the componentn instance created for that {@link Bean}.
+	 * @param type the expected type of the component instance created for that {@link Bean}.
 	 * @return the actual component instance.
 	 */
 	@SuppressWarnings("unchecked")
-	protected <S> S getDependencyInstance(Bean<S> bean, Class<S> type) {
+	protected <S> S getDependencyInstance(Bean<S> bean) {
 		CreationalContext<S> creationalContext = beanManager.createCreationalContext(bean);
-		return (S) beanManager.getReference(bean, type, creationalContext);
+		return (S) beanManager.getReference(bean, bean.getBeanClass(), creationalContext);
 	}
 
 	/**
@@ -193,17 +194,11 @@ public abstract class CdiRepositoryBean<T> implements Bean<T>, PassivationCapabl
 	 * 
 	 * @return an available CdiRepositoryConfiguration instance or a default configuration.
 	 */
-	@SuppressWarnings("unchecked")
 	protected CdiRepositoryConfiguration lookupConfiguration(BeanManager beanManager, Set<Annotation> qualifiers) {
 
-		Set<Bean<?>> beans = beanManager.getBeans(CdiRepositoryConfiguration.class, getQualifiersArray(qualifiers));
-
-		if (beans.isEmpty()) {
-			return DEFAULT_CONFIGURATION;
-		}
-
-		Bean<CdiRepositoryConfiguration> bean = (Bean<CdiRepositoryConfiguration>) beans.iterator().next();
-		return getDependencyInstance(bean, (Class<CdiRepositoryConfiguration>) bean.getBeanClass());
+		return beanManager.getBeans(CdiRepositoryConfiguration.class, getQualifiersArray(qualifiers)).stream().findFirst()//
+				.map(it -> (CdiRepositoryConfiguration) getDependencyInstance(it)) //
+				.orElse(DEFAULT_CONFIGURATION);
 	}
 
 	/**
@@ -215,49 +210,42 @@ public abstract class CdiRepositoryBean<T> implements Bean<T>, PassivationCapabl
 	 * @param qualifiers
 	 * @return the custom implementation instance or null
 	 */
-	private Bean<?> getCustomImplementationBean(Class<?> repositoryType, BeanManager beanManager,
+	private Optional<Bean<?>> getCustomImplementationBean(Class<?> repositoryType, BeanManager beanManager,
 			Set<Annotation> qualifiers) {
 
-		if (detector == null) {
-			return null;
-		}
+		return detector.flatMap(it -> {
 
-		CdiRepositoryConfiguration cdiRepositoryConfiguration = lookupConfiguration(beanManager, qualifiers);
-		Class<?> customImplementationClass = getCustomImplementationClass(repositoryType, cdiRepositoryConfiguration);
+			CdiRepositoryConfiguration cdiRepositoryConfiguration = lookupConfiguration(beanManager, qualifiers);
 
-		if (customImplementationClass == null) {
-			return null;
-		}
-
-		Set<Bean<?>> beans = beanManager.getBeans(customImplementationClass, getQualifiersArray(qualifiers));
-		return beans.isEmpty() ? null : beans.iterator().next();
+			return getCustomImplementationClass(repositoryType, cdiRepositoryConfiguration, it)//
+					.flatMap(type -> beanManager.getBeans(type, getQualifiersArray(qualifiers)).stream().findFirst());
+		});
 	}
 
 	/**
 	 * Retrieves a custom repository interfaces from a repository type. This works for the whole class hierarchy and can
-	 * find also a custom repo which is inherieted over many levels.
+	 * find also a custom repository which is inherited over many levels.
 	 * 
 	 * @param repositoryType The class representing the repository.
 	 * @param cdiRepositoryConfiguration The configuration for CDI usage.
 	 * @return the interface class or {@literal null}.
 	 */
-	private Class<?> getCustomImplementationClass(Class<?> repositoryType,
-			CdiRepositoryConfiguration cdiRepositoryConfiguration) {
+	private Optional<Class<?>> getCustomImplementationClass(Class<?> repositoryType,
+			CdiRepositoryConfiguration cdiRepositoryConfiguration, CustomRepositoryImplementationDetector detector) {
 
 		String className = getCustomImplementationClassName(repositoryType, cdiRepositoryConfiguration);
-		AbstractBeanDefinition beanDefinition = detector.detectCustomImplementation(className,
-				Collections.singleton(repositoryType.getPackage().getName()), Collections.<TypeFilter> emptySet());
+		Optional<AbstractBeanDefinition> beanDefinition = detector.detectCustomImplementation(className,
+				Collections.singleton(repositoryType.getPackage().getName()), Collections.emptySet());
 
-		if (beanDefinition == null) {
-			return null;
-		}
+		return beanDefinition.map(it -> {
 
-		try {
-			return Class.forName(beanDefinition.getBeanClassName());
-		} catch (ClassNotFoundException e) {
-			throw new UnsatisfiedResolutionException(
-					String.format("Unable to resolve class for '%s'", beanDefinition.getBeanClassName()), e);
-		}
+			try {
+				return Class.forName(it.getBeanClassName());
+			} catch (ClassNotFoundException e) {
+				throw new UnsatisfiedResolutionException(
+						String.format("Unable to resolve class for '%s'", it.getBeanClassName()), e);
+			}
+		});
 	}
 
 	private String getCustomImplementationClassName(Class<?> repositoryType,
@@ -295,16 +283,10 @@ public abstract class CdiRepositoryBean<T> implements Bean<T>, PassivationCapabl
 	 */
 	public Set<Class<? extends Annotation>> getStereotypes() {
 
-		Set<Class<? extends Annotation>> stereotypes = new HashSet<Class<? extends Annotation>>();
-
-		for (Annotation annotation : repositoryType.getAnnotations()) {
-			Class<? extends Annotation> annotationType = annotation.annotationType();
-			if (annotationType.isAnnotationPresent(Stereotype.class)) {
-				stereotypes.add(annotationType);
-			}
-		}
-
-		return stereotypes;
+		return Arrays.stream(repositoryType.getAnnotations())//
+				.map(it -> it.annotationType())//
+				.filter(it -> it.isAnnotationPresent(Stereotype.class))//
+				.collect(Collectors.toSet());
 	}
 
 	/*
@@ -361,15 +343,12 @@ public abstract class CdiRepositoryBean<T> implements Bean<T>, PassivationCapabl
 	 * @param creationalContext will never be {@literal null}.
 	 * @param repositoryType will never be {@literal null}.
 	 * @return
-	 * @deprecated overide {@link #create(CreationalContext, Class, Object)} instead.
 	 */
-	@Deprecated
-	protected T create(CreationalContext<T> creationalContext, Class<T> repositoryType) {
+	private final T create(CreationalContext<T> creationalContext, Class<T> repositoryType) {
 
-		Bean<?> customImplementationBean = getCustomImplementationBean(repositoryType, beanManager, qualifiers);
-		Object customImplementation = customImplementationBean == null ? null
-				: beanManager.getReference(customImplementationBean, customImplementationBean.getBeanClass(),
-						beanManager.createCreationalContext(customImplementationBean));
+		Optional<Bean<?>> customImplementationBean = getCustomImplementationBean(repositoryType, beanManager, qualifiers);
+		Optional<Object> customImplementation = customImplementationBean
+				.map(it -> beanManager.getReference(it, it.getBeanClass(), beanManager.createCreationalContext(it)));
 
 		return create(creationalContext, repositoryType, customImplementation);
 	}
@@ -382,9 +361,11 @@ public abstract class CdiRepositoryBean<T> implements Bean<T>, PassivationCapabl
 	 * @param customImplementation can be {@literal null}.
 	 * @return
 	 */
-	protected T create(CreationalContext<T> creationalContext, Class<T> repositoryType, Object customImplementation) {
-		throw new UnsupportedOperationException("You have to implement create(CreationalContext<T>, Class<T>, Object) "
-				+ "in order to use custom repository implementations");
+	protected T create(CreationalContext<T> creationalContext, Class<T> repositoryType,
+			Optional<Object> customImplementation) {
+		throw new UnsupportedOperationException(
+				"You have to implement create(CreationalContext<T>, Class<T>, Optional<Object>) "
+						+ "in order to use custom repository implementations");
 	}
 
 	/*

src/main/java/org/springframework/data/repository/cdi/CdiRepositoryConfiguration.java

@@ -26,7 +26,7 @@ public interface CdiRepositoryConfiguration {
 	/**
 	 * Returns the configured postfix to be used for looking up custom implementation classes.
 	 *
-	 * @return the postfix to use or {@literal null} in case none is configured.
+	 * @return the postfix to use, must not be {@literal null}.
 	 */
 	String getRepositoryImplementationPostfix();
 }

src/main/java/org/springframework/data/repository/config/AnnotationRepositoryConfigurationSource.java

@@ -21,6 +21,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Optional;
 import java.util.Set;
 import java.util.regex.Pattern;
 
@@ -138,15 +139,15 @@ public class AnnotationRepositoryConfigurationSource extends RepositoryConfigura
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getQueryLookupStrategyKey()
 	 */
-	public Object getQueryLookupStrategyKey() {
-		return attributes.get(QUERY_LOOKUP_STRATEGY);
+	public Optional<Object> getQueryLookupStrategyKey() {
+		return Optional.ofNullable(attributes.get(QUERY_LOOKUP_STRATEGY));
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getNamedQueryLocation()
 	 */
-	public String getNamedQueryLocation() {
+	public Optional<String> getNamedQueryLocation() {
 		return getNullDefaultedAttribute(NAMED_QUERIES_LOCATION);
 	}
 
@@ -154,7 +155,7 @@ public class AnnotationRepositoryConfigurationSource extends RepositoryConfigura
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getRepositoryImplementationPostfix()
 	 */
-	public String getRepositoryImplementationPostfix() {
+	public Optional<String> getRepositoryImplementationPostfix() {
 		return getNullDefaultedAttribute(REPOSITORY_IMPLEMENTATION_POSTFIX);
 	}
 
@@ -197,14 +198,15 @@ public class AnnotationRepositoryConfigurationSource extends RepositoryConfigura
 	}
 
 	/**
-	 * Returns the {@link String} attribute with the given name and defaults it to {@literal null} in case it's empty.
+	 * Returns the {@link String} attribute with the given name and defaults it to {@literal Optional#empty()} in case
+	 * it's empty.
 	 * 
 	 * @param attributeName
 	 * @return
 	 */
-	private String getNullDefaultedAttribute(String attributeName) {
+	private Optional<String> getNullDefaultedAttribute(String attributeName) {
 		String attribute = attributes.getString(attributeName);
-		return StringUtils.hasText(attribute) ? attribute : null;
+		return StringUtils.hasText(attribute) ? Optional.of(attribute) : Optional.empty();
 	}
 
 	/* 
@@ -220,14 +222,15 @@ public class AnnotationRepositoryConfigurationSource extends RepositoryConfigura
 	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getRepositoryBaseClassName()
 	 */
 	@Override
-	public String getRepositoryBaseClassName() {
+	public Optional<String> getRepositoryBaseClassName() {
 
 		if (!attributes.containsKey(REPOSITORY_BASE_CLASS)) {
-			return null;
+			return Optional.empty();
 		}
 
 		Class<? extends Object> repositoryBaseClass = attributes.getClass(REPOSITORY_BASE_CLASS);
-		return DefaultRepositoryBaseClass.class.equals(repositoryBaseClass) ? null : repositoryBaseClass.getName();
+		return DefaultRepositoryBaseClass.class.equals(repositoryBaseClass) ? Optional.empty()
+				: Optional.of(repositoryBaseClass.getName());
 	}
 
 	/**
@@ -311,10 +314,10 @@ public class AnnotationRepositoryConfigurationSource extends RepositoryConfigura
 	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getAttribute(java.lang.String)
 	 */
 	@Override
-	public String getAttribute(String name) {
+	public Optional<String> getAttribute(String name) {
 
 		String attribute = attributes.getString(name);
-		return StringUtils.hasText(attribute) ? attribute : null;
+		return StringUtils.hasText(attribute) ? Optional.of(attribute) : Optional.empty();
 	}
 
 	/* 

src/main/java/org/springframework/data/repository/config/CustomRepositoryImplementationDetector.java

@@ -16,11 +16,14 @@
 
 package org.springframework.data.repository.config;
 
-import java.util.ArrayList;
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+
 import java.util.HashSet;
-import java.util.List;
+import java.util.Optional;
 import java.util.Set;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.support.AbstractBeanDefinition;
@@ -31,7 +34,6 @@ import org.springframework.core.type.classreading.MetadataReaderFactory;
 import org.springframework.core.type.filter.RegexPatternTypeFilter;
 import org.springframework.core.type.filter.TypeFilter;
 import org.springframework.util.Assert;
-import org.springframework.util.StringUtils;
 
 /**
  * Detects the custom implementation for a {@link org.springframework.data.repository.Repository}
@@ -40,34 +42,14 @@ import org.springframework.util.StringUtils;
  * @author Mark Paluch
  * @author Peter Rietzler
  */
+@RequiredArgsConstructor
 public class CustomRepositoryImplementationDetector {
 
 	private static final String CUSTOM_IMPLEMENTATION_RESOURCE_PATTERN = "**/*%s.class";
 
-	private final MetadataReaderFactory metadataReaderFactory;
-	private final Environment environment;
-	private final ResourceLoader resourceLoader;
-
-	/**
-	 * Creates a new {@link CustomRepositoryImplementationDetector} from the given
-	 * {@link org.springframework.core.type.classreading.MetadataReaderFactory},
-	 * {@link org.springframework.core.env.Environment} and {@link org.springframework.core.io.ResourceLoader}.
-	 *
-	 * @param metadataReaderFactory must not be {@literal null}.
-	 * @param environment must not be {@literal null}.
-	 * @param resourceLoader must not be {@literal null}.
-	 */
-	public CustomRepositoryImplementationDetector(MetadataReaderFactory metadataReaderFactory, Environment environment,
-			ResourceLoader resourceLoader) {
-
-		Assert.notNull(metadataReaderFactory, "MetadataReaderFactory must not be null!");
-		Assert.notNull(resourceLoader, "ResourceLoader must not be null!");
-		Assert.notNull(environment, "Environment must not be null!");
-
-		this.metadataReaderFactory = metadataReaderFactory;
-		this.environment = environment;
-		this.resourceLoader = resourceLoader;
-	}
+	private final @NonNull MetadataReaderFactory metadataReaderFactory;
+	private final @NonNull Environment environment;
+	private final @NonNull ResourceLoader resourceLoader;
 
 	/**
 	 * Tries to detect a custom implementation for a repository bean by classpath scanning.
@@ -75,7 +57,7 @@ public class CustomRepositoryImplementationDetector {
 	 * @param configuration the {@link RepositoryConfiguration} to consider.
 	 * @return the {@code AbstractBeanDefinition} of the custom implementation or {@literal null} if none found.
 	 */
-	public AbstractBeanDefinition detectCustomImplementation(RepositoryConfiguration<?> configuration) {
+	public Optional<AbstractBeanDefinition> detectCustomImplementation(RepositoryConfiguration<?> configuration) {
 
 		// TODO 2.0: Extract into dedicated interface for custom implementation lookup configuration.
 
@@ -91,7 +73,7 @@ public class CustomRepositoryImplementationDetector {
 	 * @param basePackages must not be {@literal null}.
 	 * @return the {@code AbstractBeanDefinition} of the custom implementation or {@literal null} if none found.
 	 */
-	public AbstractBeanDefinition detectCustomImplementation(String className, Iterable<String> basePackages,
+	public Optional<AbstractBeanDefinition> detectCustomImplementation(String className, Iterable<String> basePackages,
 			Iterable<TypeFilter> excludeFilters) {
 
 		Assert.notNull(className, "ClassName must not be null!");
@@ -119,20 +101,17 @@ public class CustomRepositoryImplementationDetector {
 		}
 
 		if (definitions.isEmpty()) {
-			return null;
+			return Optional.empty();
 		}
 
 		if (definitions.size() == 1) {
-			return (AbstractBeanDefinition) definitions.iterator().next();
-		}
-
-		List<String> implementationClassNames = new ArrayList<String>();
-		for (BeanDefinition bean : definitions) {
-			implementationClassNames.add(bean.getBeanClassName());
+			return Optional.of((AbstractBeanDefinition) definitions.iterator().next());
 		}
 
 		throw new IllegalStateException(
-				String.format("Ambiguous custom implementations detected! Found %s but expected a single implementation!",
-						StringUtils.collectionToCommaDelimitedString(implementationClassNames)));
+				String.format("Ambiguous custom implementations detected! Found %s but expected a single implementation!", //
+						definitions.stream()//
+								.map(it -> it.getBeanClassName())//
+								.collect(Collectors.joining(", "))));
 	}
 }

src/main/java/org/springframework/data/repository/config/DefaultRepositoryConfiguration.java

@@ -15,10 +15,14 @@
  */
 package org.springframework.data.repository.config;
 
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+
+import java.util.Optional;
+
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.core.type.filter.TypeFilter;
 import org.springframework.data.repository.query.QueryLookupStrategy.Key;
-import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
 
@@ -27,37 +31,23 @@ import org.springframework.util.StringUtils;
  * 
  * @author Oliver Gierke
  */
+@RequiredArgsConstructor
 public class DefaultRepositoryConfiguration<T extends RepositoryConfigurationSource>
 		implements RepositoryConfiguration<T> {
 
 	public static final String DEFAULT_REPOSITORY_IMPLEMENTATION_POSTFIX = "Impl";
 	private static final Key DEFAULT_QUERY_LOOKUP_STRATEGY = Key.CREATE_IF_NOT_FOUND;
 
-	private final T configurationSource;
-	private final BeanDefinition definition;
-
-	/**
-	 * Creates a new {@link DefaultRepositoryConfiguration} from the given {@link RepositoryConfigurationSource} and
-	 * source {@link BeanDefinition}.
-	 * 
-	 * @param configurationSource must not be {@literal null}.
-	 * @param definition must not be {@literal null}.
-	 */
-	public DefaultRepositoryConfiguration(T configurationSource, BeanDefinition definition) {
-
-		Assert.notNull(configurationSource, "ConfigurationSource must not be null!");
-		Assert.notNull(definition, "BeanDefinition must not be null!");
-
-		this.configurationSource = configurationSource;
-		this.definition = definition;
-	}
+	private final @NonNull T configurationSource;
+	private final @NonNull BeanDefinition definition;
 
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.config.RepositoryConfiguration#getBeanId()
 	 */
 	public String getBeanId() {
-		return StringUtils.uncapitalize(ClassUtils.getShortName(getRepositoryFactoryBeanName()));
+		return StringUtils.uncapitalize(ClassUtils.getShortName(getRepositoryBaseClassName().orElseThrow(
+				() -> new IllegalStateException("Can't create bean identifier without a repository base class defined!"))));
 	}
 
 	/*
@@ -65,9 +55,7 @@ public class DefaultRepositoryConfiguration<T extends RepositoryConfigurationSou
 	 * @see org.springframework.data.repository.config.RepositoryConfiguration#getQueryLookupStrategyKey()
 	 */
 	public Object getQueryLookupStrategyKey() {
-
-		Object configuredStrategy = configurationSource.getQueryLookupStrategyKey();
-		return configuredStrategy != null ? configuredStrategy : DEFAULT_QUERY_LOOKUP_STRATEGY;
+		return configurationSource.getQueryLookupStrategyKey().orElse(DEFAULT_QUERY_LOOKUP_STRATEGY);
 	}
 
 	/*
@@ -97,7 +85,7 @@ public class DefaultRepositoryConfiguration<T extends RepositoryConfigurationSou
 	/* (non-Javadoc)
 	 * @see org.springframework.data.repository.config.RepositoryConfiguration#getNamedQueryLocation()
 	 */
-	public String getNamedQueriesLocation() {
+	public Optional<String> getNamedQueriesLocation() {
 		return configurationSource.getNamedQueryLocation();
 	}
 
@@ -106,7 +94,8 @@ public class DefaultRepositoryConfiguration<T extends RepositoryConfigurationSou
 	 * @see org.springframework.data.repository.config.RepositoryConfiguration#getImplementationClassName()
 	 */
 	public String getImplementationClassName() {
-		return ClassUtils.getShortName(getRepositoryInterface()) + getImplementationPostfix();
+		return ClassUtils.getShortName(getRepositoryInterface()).concat(
+				configurationSource.getRepositoryImplementationPostfix().orElse(DEFAULT_REPOSITORY_IMPLEMENTATION_POSTFIX));
 	}
 
 	/* 
@@ -117,20 +106,11 @@ public class DefaultRepositoryConfiguration<T extends RepositoryConfigurationSou
 		return StringUtils.uncapitalize(getImplementationClassName());
 	}
 
-	/* 
-	 * (non-Javadoc)
-	 * @see org.springframework.data.repository.config.RepositoryConfiguration#getImplementationPostfix()
-	 */
-	public String getImplementationPostfix() {
-
-		String configuredPostfix = configurationSource.getRepositoryImplementationPostfix();
-		return StringUtils.hasText(configuredPostfix) ? configuredPostfix : DEFAULT_REPOSITORY_IMPLEMENTATION_POSTFIX;
-	}
-
 	/* 
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.config.RepositoryConfiguration#getSource()
 	 */
+	@Override
 	public Object getSource() {
 		return configurationSource.getSource();
 	}
@@ -139,24 +119,17 @@ public class DefaultRepositoryConfiguration<T extends RepositoryConfigurationSou
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.config.RepositoryConfiguration#getConfigurationSource()
 	 */
+	@Override
 	public T getConfigurationSource() {
 		return configurationSource;
 	}
 
-	/* 
-	 * (non-Javadoc)
-	 * @see org.springframework.data.repository.config.RepositoryConfiguration#getRepositoryFactoryBeanName()
-	 */
-	public String getRepositoryFactoryBeanName() {
-		return configurationSource.getRepositoryFactoryBeanName();
-	}
-
 	/* 
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.config.RepositoryConfiguration#getRepositoryBaseClassName()
 	 */
 	@Override
-	public String getRepositoryBaseClassName() {
+	public Optional<String> getRepositoryBaseClassName() {
 		return configurationSource.getRepositoryBaseClassName();
 	}
 

src/main/java/org/springframework/data/repository/config/RepositoryBeanDefinitionBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,6 +15,8 @@
  */
 package org.springframework.data.repository.config;
 
+import java.util.Optional;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.support.AbstractBeanDefinition;
@@ -27,7 +29,6 @@ import org.springframework.core.type.classreading.CachingMetadataReaderFactory;
 import org.springframework.core.type.classreading.MetadataReaderFactory;
 import org.springframework.data.repository.query.ExtensionAwareEvaluationContextProvider;
 import org.springframework.util.Assert;
-import org.springframework.util.StringUtils;
 
 /**
  * Builder to create {@link BeanDefinitionBuilder} instance to eventually create Spring Data repository instances.
@@ -44,7 +45,7 @@ class RepositoryBeanDefinitionBuilder {
 	private final ResourceLoader resourceLoader;
 
 	private final MetadataReaderFactory metadataReaderFactory;
-	private CustomRepositoryImplementationDetector implementationDetector;
+	private final CustomRepositoryImplementationDetector implementationDetector;
 
 	/**
 	 * Creates a new {@link RepositoryBeanDefinitionBuilder} from the given {@link BeanDefinitionRegistry},
@@ -82,11 +83,7 @@ class RepositoryBeanDefinitionBuilder {
 		Assert.notNull(registry, "BeanDefinitionRegistry must not be null!");
 		Assert.notNull(resourceLoader, "ResourceLoader must not be null!");
 
-		String factoryBeanName = configuration.getRepositoryFactoryBeanName();
-		factoryBeanName = StringUtils.hasText(factoryBeanName) ? factoryBeanName
-				: extension.getRepositoryFactoryClassName();
-
-		BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(factoryBeanName);
+		BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(extension.getRepositoryFactoryClassName());
 
 		builder.getRawBeanDefinition().setSource(configuration.getSource());
 		builder.addConstructorArgValue(configuration.getRepositoryInterface());
@@ -96,19 +93,16 @@ class RepositoryBeanDefinitionBuilder {
 
 		NamedQueriesBeanDefinitionBuilder definitionBuilder = new NamedQueriesBeanDefinitionBuilder(
 				extension.getDefaultNamedQueryLocation());
-
-		if (StringUtils.hasText(configuration.getNamedQueriesLocation())) {
-			definitionBuilder.setLocations(configuration.getNamedQueriesLocation());
-		}
+		configuration.getNamedQueriesLocation().ifPresent(it -> definitionBuilder.setLocations(it));
 
 		builder.addPropertyValue("namedQueries", definitionBuilder.build(configuration.getSource()));
 
-		String customImplementationBeanName = registerCustomImplementation(configuration);
+		Optional<String> customImplementationBeanName = registerCustomImplementation(configuration);
 
-		if (customImplementationBeanName != null) {
-			builder.addPropertyReference("customImplementation", customImplementationBeanName);
-			builder.addDependsOn(customImplementationBeanName);
-		}
+		customImplementationBeanName.ifPresent(it -> {
+			builder.addPropertyReference("customImplementation", it);
+			builder.addDependsOn(it);
+		});
 
 		RootBeanDefinition evaluationContextProviderDefinition = new RootBeanDefinition(
 				ExtensionAwareEvaluationContextProvider.class);
@@ -119,30 +113,30 @@ class RepositoryBeanDefinitionBuilder {
 		return builder;
 	}
 
-	private String registerCustomImplementation(RepositoryConfiguration<?> configuration) {
+	private Optional<String> registerCustomImplementation(RepositoryConfiguration<?> configuration) {
 
 		String beanName = configuration.getImplementationBeanName();
 
 		// Already a bean configured?
 		if (registry.containsBeanDefinition(beanName)) {
+			return Optional.of(beanName);
+		}
+
+		Optional<AbstractBeanDefinition> beanDefinition = implementationDetector.detectCustomImplementation(
+				configuration.getImplementationClassName(), configuration.getBasePackages(), configuration.getExcludeFilters());
+
+		return beanDefinition.map(it -> {
+
+			if (LOGGER.isDebugEnabled()) {
+				LOGGER.debug("Registering custom repository implementation: " + configuration.getImplementationBeanName() + " "
+						+ it.getBeanClassName());
+			}
+
+			it.setSource(configuration.getSource());
+
+			registry.registerBeanDefinition(beanName, it);
+
 			return beanName;
-		}
-
-		AbstractBeanDefinition beanDefinition = implementationDetector.detectCustomImplementation(configuration);
-
-		if (null == beanDefinition) {
-			return null;
-		}
-
-		if (LOGGER.isDebugEnabled()) {
-			LOGGER.debug("Registering custom repository implementation: " + configuration.getImplementationBeanName() + " "
-					+ beanDefinition.getBeanClassName());
-		}
-
-		beanDefinition.setSource(configuration.getSource());
-
-		registry.registerBeanDefinition(beanName, beanDefinition);
-
-		return beanName;
+		});
 	}
 }

src/main/java/org/springframework/data/repository/config/RepositoryBeanDefinitionParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2015 the original author or authors.
+ * Copyright 2008-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -65,7 +65,8 @@ public class RepositoryBeanDefinitionParser implements BeanDefinitionParser {
 			ResourceLoader resourceLoader = readerContext.getResourceLoader();
 			BeanDefinitionRegistry registry = parser.getRegistry();
 
-			XmlRepositoryConfigurationSource configSource = new XmlRepositoryConfigurationSource(element, parser, environment);
+			XmlRepositoryConfigurationSource configSource = new XmlRepositoryConfigurationSource(element, parser,
+					environment);
 			RepositoryConfigurationDelegate delegate = new RepositoryConfigurationDelegate(configSource, resourceLoader,
 					environment);
 

src/main/java/org/springframework/data/repository/config/RepositoryConfiguration.java

@@ -15,7 +15,8 @@
  */
 package org.springframework.data.repository.config;
 
-import org.springframework.beans.factory.FactoryBean;
+import java.util.Optional;
+
 import org.springframework.core.type.filter.TypeFilter;
 import org.springframework.data.repository.query.QueryLookupStrategy;
 
@@ -53,7 +54,7 @@ public interface RepositoryConfiguration<T extends RepositoryConfigurationSource
 	 * 
 	 * @return
 	 */
-	String getNamedQueriesLocation();
+	Optional<String> getNamedQueriesLocation();
 
 	/**
 	 * Returns the class name of the custom implementation.
@@ -69,15 +70,6 @@ public interface RepositoryConfiguration<T extends RepositoryConfigurationSource
 	 */
 	String getImplementationBeanName();
 
-	/**
-	 * Returns the name of the {@link FactoryBean} class to be used to create repository instances.
-	 * 
-	 * @return
-	 * @deprecated as of 1.11 in favor of a dedicated repository class name, see {@link #getRepositoryBaseClassName()}.
-	 */
-	@Deprecated
-	String getRepositoryFactoryBeanName();
-
 	/**
 	 * Returns the name of the repository base class to be used or {@literal null} if the store specific defaults shall be
 	 * applied.
@@ -85,7 +77,7 @@ public interface RepositoryConfiguration<T extends RepositoryConfigurationSource
 	 * @return
 	 * @since 1.11
 	 */
-	String getRepositoryBaseClassName();
+	Optional<String> getRepositoryBaseClassName();
 
 	/**
 	 * Returns the source of the {@link RepositoryConfiguration}.

src/main/java/org/springframework/data/repository/config/RepositoryConfigurationSource.java

@@ -16,8 +16,8 @@
 package org.springframework.data.repository.config;
 
 import java.util.Collection;
+import java.util.Optional;
 
-import org.springframework.beans.factory.FactoryBean;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.core.type.filter.TypeFilter;
@@ -52,29 +52,19 @@ public interface RepositoryConfigurationSource {
 	 * 
 	 * @return
 	 */
-	Object getQueryLookupStrategyKey();
+	Optional<Object> getQueryLookupStrategyKey();
 
 	/**
 	 * Returns the configured postfix to be used for looking up custom implementation classes.
 	 * 
 	 * @return the postfix to use or {@literal null} in case none is configured.
 	 */
-	String getRepositoryImplementationPostfix();
+	Optional<String> getRepositoryImplementationPostfix();
 
 	/**
 	 * @return
 	 */
-	String getNamedQueryLocation();
-
-	/**
-	 * Returns the name of the class of the {@link FactoryBean} to actually create repository instances.
-	 * 
-	 * @return
-	 * @deprecated as of 1.11 in favor of using a dedicated repository base class name, see
-	 *             {@link #getRepositoryBaseClassName()}.
-	 */
-	@Deprecated
-	String getRepositoryFactoryBeanName();
+	Optional<String> getNamedQueryLocation();
 
 	/**
 	 * Returns the name of the repository base class to be used or {@literal null} if the store specific defaults shall be
@@ -83,7 +73,7 @@ public interface RepositoryConfigurationSource {
 	 * @return
 	 * @since 1.11
 	 */
-	String getRepositoryBaseClassName();
+	Optional<String> getRepositoryBaseClassName();
 
 	/**
 	 * Returns the source {@link BeanDefinition}s of the repository interfaces to create repository instances for.
@@ -101,7 +91,7 @@ public interface RepositoryConfigurationSource {
 	 * @return the attribute with the given name or {@literal null} if not configured or empty.
 	 * @since 1.8
 	 */
-	String getAttribute(String name);
+	Optional<String> getAttribute(String name);
 
 	/**
 	 * Returns whether the configuration uses explicit filtering to scan for repository types.

src/main/java/org/springframework/data/repository/config/XmlRepositoryConfigurationSource.java

@@ -17,6 +17,7 @@ package org.springframework.data.repository.config;
 
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Optional;
 
 import org.springframework.beans.factory.xml.ParserContext;
 import org.springframework.core.env.Environment;
@@ -96,15 +97,15 @@ public class XmlRepositoryConfigurationSource extends RepositoryConfigurationSou
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getQueryLookupStrategyKey()
 	 */
-	public Object getQueryLookupStrategyKey() {
-		return QueryLookupStrategy.Key.create(getNullDefaultedAttribute(element, QUERY_LOOKUP_STRATEGY));
+	public Optional<Object> getQueryLookupStrategyKey() {
+		return getNullDefaultedAttribute(element, QUERY_LOOKUP_STRATEGY).map(it -> QueryLookupStrategy.Key.create(it));
 	}
 
 	/* 
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getNamedQueryLocation()
 	 */
-	public String getNamedQueryLocation() {
+	public Optional<String> getNamedQueryLocation() {
 		return getNullDefaultedAttribute(element, NAMED_QUERIES_LOCATION);
 	}
 
@@ -138,7 +139,7 @@ public class XmlRepositoryConfigurationSource extends RepositoryConfigurationSou
 	/* (non-Javadoc)
 	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getRepositoryImplementationPostfix()
 	 */
-	public String getRepositoryImplementationPostfix() {
+	public Optional<String> getRepositoryImplementationPostfix() {
 		return getNullDefaultedAttribute(element, REPOSITORY_IMPL_POSTFIX);
 	}
 
@@ -146,7 +147,7 @@ public class XmlRepositoryConfigurationSource extends RepositoryConfigurationSou
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getRepositoryFactoryBeanName()
 	 */
-	public String getRepositoryFactoryBeanName() {
+	public Optional<String> getRepositoryFactoryBeanName() {
 		return getNullDefaultedAttribute(element, REPOSITORY_FACTORY_BEAN_CLASS_NAME);
 	}
 
@@ -155,13 +156,14 @@ public class XmlRepositoryConfigurationSource extends RepositoryConfigurationSou
 	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getRepositoryBaseClassName()
 	 */
 	@Override
-	public String getRepositoryBaseClassName() {
+	public Optional<String> getRepositoryBaseClassName() {
 		return getNullDefaultedAttribute(element, REPOSITORY_BASE_CLASS_NAME);
 	}
 
-	private String getNullDefaultedAttribute(Element element, String attributeName) {
+	private Optional<String> getNullDefaultedAttribute(Element element, String attributeName) {
+
 		String attribute = element.getAttribute(attributeName);
-		return StringUtils.hasText(attribute) ? attribute : null;
+		return StringUtils.hasText(attribute) ? Optional.of(attribute) : Optional.empty();
 	}
 
 	/* 
@@ -171,8 +173,8 @@ public class XmlRepositoryConfigurationSource extends RepositoryConfigurationSou
 	@Override
 	public boolean shouldConsiderNestedRepositories() {
 
-		String attribute = getNullDefaultedAttribute(element, CONSIDER_NESTED_REPOSITORIES);
-		return attribute != null && Boolean.parseBoolean(attribute);
+		return getNullDefaultedAttribute(element, CONSIDER_NESTED_REPOSITORIES).map(it -> Boolean.parseBoolean(it))
+				.orElse(false);
 	}
 
 	/* 
@@ -180,12 +182,12 @@ public class XmlRepositoryConfigurationSource extends RepositoryConfigurationSou
 	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getAttribute(java.lang.String)
 	 */
 	@Override
-	public String getAttribute(String name) {
+	public Optional<String> getAttribute(String name) {
 
 		String xmlAttributeName = ParsingUtils.reconcatenateCamelCase(name, "-");
 		String attribute = element.getAttribute(xmlAttributeName);
 
-		return StringUtils.hasText(attribute) ? attribute : null;
+		return StringUtils.hasText(attribute) ? Optional.of(attribute) : Optional.empty();
 	}
 
 	/* 

src/main/java/org/springframework/data/repository/core/RepositoryInformation.java

@@ -17,6 +17,8 @@ package org.springframework.data.repository.core;
 
 import java.lang.reflect.Method;
 
+import org.springframework.data.util.Streamable;
+
 /**
  * Aditional repository specific information
  * 
@@ -69,7 +71,7 @@ public interface RepositoryInformation extends RepositoryMetadata {
 	 * 
 	 * @return
 	 */
-	Iterable<Method> getQueryMethods();
+	Streamable<Method> getQueryMethods();
 
 	/**
 	 * Returns the target class method that is backing the given method. This can be necessary if a repository interface
@@ -81,4 +83,8 @@ public interface RepositoryInformation extends RepositoryMetadata {
 	 * @return
 	 */
 	Method getTargetClassMethod(Method method);
+
+	default boolean hasQueryMethods() {
+		return getQueryMethods().iterator().hasNext();
+	}
 }

src/main/java/org/springframework/data/repository/core/support/DefaultCrudMethods.java

@@ -78,7 +78,6 @@ public class DefaultCrudMethods implements CrudMethods {
 	 * @param metadata must not be {@literal null}.
 	 * @return the most suitable method or {@literal null} if no method could be found.
 	 */
-	@SuppressWarnings("unchecked")
 	private Method selectMostSuitableSaveMethod(RepositoryMetadata metadata) {
 
 		for (Class<?> type : asList(metadata.getDomainType(), Object.class)) {
@@ -105,7 +104,6 @@ public class DefaultCrudMethods implements CrudMethods {
 	 * @param metadata must not be {@literal null}.
 	 * @return the most suitable method or {@literal null} if no method could be found.
 	 */
-	@SuppressWarnings("unchecked")
 	private Method selectMostSuitableDeleteMethod(RepositoryMetadata metadata) {
 
 		for (Class<?> type : asList(metadata.getDomainType(), metadata.getIdType(), Serializable.class, Iterable.class)) {
@@ -131,7 +129,6 @@ public class DefaultCrudMethods implements CrudMethods {
 	 * @param metadata must not be {@literal null}.
 	 * @return the most suitable method or {@literal null} if no method could be found.
 	 */
-	@SuppressWarnings("unchecked")
 	private Method selectMostSuitableFindAllMethod(RepositoryMetadata metadata) {
 
 		for (Class<?> type : asList(Pageable.class, Sort.class)) {
@@ -163,7 +160,6 @@ public class DefaultCrudMethods implements CrudMethods {
 	 * @param metadata must not be {@literal null}.
 	 * @return the most suitable method or {@literal null} if no method could be found.
 	 */
-	@SuppressWarnings("unchecked")
 	private Method selectMostSuitableFindOneMethod(RepositoryMetadata metadata) {
 
 		for (Class<?> type : asList(metadata.getIdType(), Serializable.class)) {

src/main/java/org/springframework/data/repository/core/support/DefaultRepositoryInformation.java

@@ -25,9 +25,11 @@ import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.lang.reflect.Type;
 import java.lang.reflect.TypeVariable;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
@@ -40,6 +42,7 @@ import org.springframework.data.repository.core.CrudMethods;
 import org.springframework.data.repository.core.RepositoryInformation;
 import org.springframework.data.repository.core.RepositoryMetadata;
 import org.springframework.data.util.ReflectionUtils;
+import org.springframework.data.util.Streamable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 
@@ -61,17 +64,17 @@ class DefaultRepositoryInformation implements RepositoryInformation {
 
 	private final RepositoryMetadata metadata;
 	private final Class<?> repositoryBaseClass;
-	private final Class<?> customImplementationClass;
+	private final Optional<Class<?>> customImplementationClass;
 
 	/**
 	 * Creates a new {@link DefaultRepositoryMetadata} for the given repository interface and repository base class.
 	 * 
 	 * @param metadata must not be {@literal null}.
 	 * @param repositoryBaseClass must not be {@literal null}.
-	 * @param customImplementationClass
+	 * @param customImplementationClass must not be {@literal null}.
 	 */
 	public DefaultRepositoryInformation(RepositoryMetadata metadata, Class<?> repositoryBaseClass,
-			Class<?> customImplementationClass) {
+			Optional<Class<?>> customImplementationClass) {
 
 		Assert.notNull(metadata, "Metadata must not be null!");
 		Assert.notNull(repositoryBaseClass, "RepositoryBaseClass must not be null!");
@@ -125,7 +128,7 @@ class DefaultRepositoryInformation implements RepositoryInformation {
 			return cacheAndReturn(method, result);
 		}
 
-		return cacheAndReturn(method, getTargetClassMethod(method, repositoryBaseClass));
+		return cacheAndReturn(method, getTargetClassMethod(method, Optional.of(repositoryBaseClass)));
 	}
 
 	private Method cacheAndReturn(Method key, Method value) {
@@ -144,19 +147,12 @@ class DefaultRepositoryInformation implements RepositoryInformation {
 	 * @param method
 	 * @return
 	 */
-	private boolean isTargetClassMethod(Method method, Class<?> targetType) {
+	private boolean isTargetClassMethod(Method method, Optional<Class<?>> targetType) {
 
 		Assert.notNull(method, "Method must not be null!");
 
-		if (targetType == null) {
-			return false;
-		}
-
-		if (method.getDeclaringClass().isAssignableFrom(targetType)) {
-			return true;
-		}
-
-		return !method.equals(getTargetClassMethod(method, targetType));
+		return targetType.map(it -> method.getDeclaringClass().isAssignableFrom(it)
+				|| !method.equals(getTargetClassMethod(method, targetType))).orElse(false);
 	}
 
 	/*
@@ -164,7 +160,7 @@ class DefaultRepositoryInformation implements RepositoryInformation {
 	 * @see org.springframework.data.repository.support.RepositoryInformation#getQueryMethods()
 	 */
 	@Override
-	public Set<Method> getQueryMethods() {
+	public Streamable<Method> getQueryMethods() {
 
 		Set<Method> result = new HashSet<Method>();
 
@@ -175,7 +171,7 @@ class DefaultRepositoryInformation implements RepositoryInformation {
 			}
 		}
 
-		return Collections.unmodifiableSet(result);
+		return Streamable.of(Collections.unmodifiableSet(result));
 	}
 
 	/**
@@ -217,7 +213,7 @@ class DefaultRepositoryInformation implements RepositoryInformation {
 	 */
 	@Override
 	public boolean isQueryMethod(Method method) {
-		return getQueryMethods().contains(method);
+		return getQueryMethods().stream().anyMatch(it -> it.equals(method));
 	}
 
 	/*
@@ -228,7 +224,7 @@ class DefaultRepositoryInformation implements RepositoryInformation {
 	public boolean isBaseClassMethod(Method method) {
 
 		Assert.notNull(method, "Method must not be null!");
-		return isTargetClassMethod(method, repositoryBaseClass);
+		return isTargetClassMethod(method, Optional.of(repositoryBaseClass));
 	}
 
 	/**
@@ -240,39 +236,16 @@ class DefaultRepositoryInformation implements RepositoryInformation {
 	 * @param baseClass
 	 * @return
 	 */
-	Method getTargetClassMethod(Method method, Class<?> baseClass) {
-
-		if (baseClass == null) {
-			return method;
-		}
-
-		Method result = findMethod(baseClass, method.getName(), method.getParameterTypes());
-
-		if (result != null) {
-			return result;
-		}
-
-		for (Method baseClassMethod : baseClass.getMethods()) {
-
-			// Wrong name
-			if (!method.getName().equals(baseClassMethod.getName())) {
-				continue;
-			}
-
-			// Wrong number of arguments
-			if (!(method.getParameterTypes().length == baseClassMethod.getParameterTypes().length)) {
-				continue;
-			}
-
-			// Check whether all parameters match
-			if (!parametersMatch(method, baseClassMethod)) {
-				continue;
-			}
-
-			return baseClassMethod;
-		}
-
-		return method;
+	Method getTargetClassMethod(Method method, Optional<Class<?>> baseClass) {
+		return baseClass.map(it -> {
+			return Optional.ofNullable(findMethod(it, method.getName(), method.getParameterTypes())).orElseGet(() -> {
+				return Arrays.stream(it.getMethods())//
+						.filter(baseClassMethod -> method.getName().equals(baseClassMethod.getName()))// Right name
+						.filter(baseClassMethod -> method.getParameterTypes().length == baseClassMethod.getParameterTypes().length)
+						.filter(baseClassMethod -> parametersMatch(method, baseClassMethod))// All parameters match
+						.findFirst().orElse(method);
+			});
+		}).orElse(method);
 	}
 
 	/*

src/main/java/org/springframework/data/repository/core/support/PersistentEntityInformation.java

@@ -48,7 +48,7 @@ public class PersistentEntityInformation<T, ID extends Serializable> extends Abs
 	 */
 	@Override
 	public ID getId(T entity) {
-		return (ID) persistentEntity.getIdentifierAccessor(entity).getIdentifier();
+		return (ID) persistentEntity.getIdentifierAccessor(entity).getIdentifier().orElse(null);
 	}
 
 	/* 
@@ -57,6 +57,6 @@ public class PersistentEntityInformation<T, ID extends Serializable> extends Abs
 	 */
 	@Override
 	public Class<ID> getIdType() {
-		return (Class<ID>) persistentEntity.getIdProperty().getType();
+		return (Class<ID>) persistentEntity.getIdProperty().map(it -> it.getType()).orElse(null);
 	}
 }

src/main/java/org/springframework/data/repository/core/support/ReactiveRepositoryInformation.java

@@ -23,6 +23,7 @@ import lombok.RequiredArgsConstructor;
 import java.lang.reflect.Method;
 import java.lang.reflect.Type;
 import java.util.Arrays;
+import java.util.Optional;
 import java.util.function.BiPredicate;
 
 import org.springframework.core.MethodParameter;
@@ -53,7 +54,7 @@ public class ReactiveRepositoryInformation extends DefaultRepositoryInformation
 	 * @param customImplementationClass can be {@literal null}.
 	 */
 	public ReactiveRepositoryInformation(RepositoryMetadata metadata, Class<?> repositoryBaseClass,
-			Class<?> customImplementationClass) {
+			Optional<Class<?>> customImplementationClass) {
 		super(metadata, repositoryBaseClass, customImplementationClass);
 	}
 
@@ -67,31 +68,31 @@ public class ReactiveRepositoryInformation extends DefaultRepositoryInformation
 	 * @return
 	 */
 	@Override
-	Method getTargetClassMethod(Method method, Class<?> baseClass) {
+	Method getTargetClassMethod(Method method, Optional<Class<?>> baseClass) {
 
-		if (baseClass == null) {
-			return method;
-		}
+		return baseClass.map(it -> {
 
-		if (usesParametersWithReactiveWrappers(method)) {
+			if (usesParametersWithReactiveWrappers(method)) {
 
-			Method candidate = getMethodCandidate(method, baseClass, new AssignableWrapperMatch(method.getParameterTypes()));
+				Method candidate = getMethodCandidate(method, it, new AssignableWrapperMatch(method.getParameterTypes()));
 
-			if (candidate != null) {
-				return candidate;
+				if (candidate != null) {
+					return candidate;
+				}
+
+				candidate = getMethodCandidate(method, it, WrapperConversionMatch.of(method.getParameterTypes()));
+
+				if (candidate != null) {
+					return candidate;
+				}
 			}
 
-			candidate = getMethodCandidate(method, baseClass, WrapperConversionMatch.of(method.getParameterTypes()));
+			Method candidate = getMethodCandidate(method, it,
+					MatchParameterOrComponentType.of(method, getRepositoryInterface()));
 
-			if (candidate != null) {
-				return candidate;
-			}
-		}
+			return candidate != null ? candidate : method;
 
-		Method candidate = getMethodCandidate(method, baseClass,
-				MatchParameterOrComponentType.of(method, getRepositoryInterface()));
-
-		return candidate != null ? candidate : method;
+		}).orElse(method);
 	}
 
 	/**

src/main/java/org/springframework/data/repository/core/support/RepositoryFactoryBeanSupport.java

@@ -17,6 +17,7 @@ package org.springframework.data.repository.core.support;
 
 import java.io.Serializable;
 import java.util.List;
+import java.util.Optional;
 
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanClassLoaderAware;
@@ -38,6 +39,7 @@ import org.springframework.data.repository.query.EvaluationContextProvider;
 import org.springframework.data.repository.query.QueryLookupStrategy;
 import org.springframework.data.repository.query.QueryLookupStrategy.Key;
 import org.springframework.data.repository.query.QueryMethod;
+import org.springframework.data.util.Lazy;
 import org.springframework.util.Assert;
 
 /**
@@ -54,19 +56,18 @@ public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>,
 
 	private final Class<? extends T> repositoryInterface;
 
-	private RepositoryFactorySupport factory;
 	private Key queryLookupStrategyKey;
-	private Class<?> repositoryBaseClass;
-	private Object customImplementation;
+	private Optional<Class<?>> repositoryBaseClass = Optional.empty();
+	private Optional<Object> customImplementation = Optional.empty();
 	private NamedQueries namedQueries;
-	private MappingContext<?, ?> mappingContext;
+	private Optional<MappingContext<?, ?>> mappingContext;
 	private ClassLoader classLoader;
 	private BeanFactory beanFactory;
 	private boolean lazyInit = false;
 	private EvaluationContextProvider evaluationContextProvider = DefaultEvaluationContextProvider.INSTANCE;
 	private ApplicationEventPublisher publisher;
 
-	private T repository;
+	private Lazy<T> repository;
 
 	private RepositoryMetadata repositoryMetadata;
 
@@ -88,7 +89,7 @@ public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>,
 	 * @since 1.11
 	 */
 	public void setRepositoryBaseClass(Class<?> repositoryBaseClass) {
-		this.repositoryBaseClass = repositoryBaseClass;
+		this.repositoryBaseClass = Optional.ofNullable(repositoryBaseClass);
 	}
 
 	/**
@@ -106,7 +107,7 @@ public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>,
 	 * @param customImplementation
 	 */
 	public void setCustomImplementation(Object customImplementation) {
-		this.customImplementation = customImplementation;
+		this.customImplementation = Optional.ofNullable(customImplementation);
 	}
 
 	/**
@@ -125,7 +126,7 @@ public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>,
 	 * @param mappingContext
 	 */
 	protected void setMappingContext(MappingContext<?, ?> mappingContext) {
-		this.mappingContext = mappingContext;
+		this.mappingContext = Optional.ofNullable(mappingContext);
 	}
 
 	/**
@@ -142,7 +143,7 @@ public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>,
 	/**
 	 * Configures whether to initialize the repository proxy lazily. This defaults to {@literal false}.
 	 * 
-	 * @param lazyInit whether to initialize the repository proxy lazily. This defaults to {@literal false}.
+	 * @param lazy whether to initialize the repository proxy lazily. This defaults to {@literal false}.
 	 */
 	public void setLazyInit(boolean lazy) {
 		this.lazyInit = lazy;
@@ -181,7 +182,6 @@ public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>,
 	 */
 	@SuppressWarnings("unchecked")
 	public EntityInformation<S, ID> getEntityInformation() {
-
 		return (EntityInformation<S, ID>) factory.getEntityInformation(repositoryMetadata.getDomainType());
 	}
 
@@ -190,9 +190,7 @@ public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>,
 	 * @see org.springframework.data.repository.core.support.RepositoryFactoryInformation#getRepositoryInformation()
 	 */
 	public RepositoryInformation getRepositoryInformation() {
-
-		return this.factory.getRepositoryInformation(repositoryMetadata,
-				customImplementation == null ? null : customImplementation.getClass());
+		return this.factory.getRepositoryInformation(repositoryMetadata, customImplementation.map(Object::getClass));
 	}
 
 	/* 
@@ -201,11 +199,9 @@ public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>,
 	 */
 	public PersistentEntity<?, ?> getPersistentEntity() {
 
-		if (mappingContext == null) {
-			return null;
-		}
-
-		return mappingContext.getPersistentEntity(repositoryMetadata.getDomainType());
+		return mappingContext//
+				.map(context -> context.getPersistentEntity(repositoryMetadata.getDomainType()))//
+				.orElseGet(null);
 	}
 
 	/* (non-Javadoc)
@@ -220,7 +216,7 @@ public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>,
 	 * @see org.springframework.beans.factory.FactoryBean#getObject()
 	 */
 	public T getObject() {
-		return initAndReturn();
+		return this.repository.get();
 	}
 
 	/*
@@ -249,7 +245,6 @@ public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>,
 		this.factory.setQueryLookupStrategyKey(queryLookupStrategyKey);
 		this.factory.setNamedQueries(namedQueries);
 		this.factory.setEvaluationContextProvider(evaluationContextProvider);
-		this.factory.setRepositoryBaseClass(repositoryBaseClass);
 		this.factory.setBeanClassLoader(classLoader);
 		this.factory.setBeanFactory(beanFactory);
 
@@ -257,29 +252,16 @@ public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>,
 			this.factory.addRepositoryProxyPostProcessor(new EventPublishingRepositoryProxyPostProcessor(publisher));
 		}
 
+		repositoryBaseClass.ifPresent(it -> this.factory.setRepositoryBaseClass(it));
+
 		this.repositoryMetadata = this.factory.getRepositoryMetadata(repositoryInterface);
+		this.repository = Lazy.of(() -> this.factory.getRepository(repositoryInterface, customImplementation));
 
 		if (!lazyInit) {
-			initAndReturn();
+			this.repository.get();
 		}
 	}
 
-	/**
-	 * Returns the previously initialized repository proxy or creates and returns the proxy if previously uninitialized.
-	 * 
-	 * @return
-	 */
-	private T initAndReturn() {
-
-		Assert.notNull(repositoryInterface, "Repository interface must not be null on initialization!");
-
-		if (this.repository == null) {
-			this.repository = this.factory.getRepository(repositoryInterface, customImplementation);
-		}
-
-		return this.repository;
-	}
-
 	/**
 	 * Create the actual {@link RepositoryFactorySupport} instance.
 	 * 

src/main/java/org/springframework/data/repository/core/support/RepositoryFactorySupport.java

@@ -15,14 +15,21 @@
  */
 package org.springframework.data.repository.core.support;
 
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
 import java.io.Serializable;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
+import java.util.Optional;
+import java.util.stream.Collectors;
 
 import org.aopalliance.intercept.MethodInterceptor;
 import org.aopalliance.intercept.MethodInvocation;
@@ -52,9 +59,9 @@ import org.springframework.data.repository.query.RepositoryQuery;
 import org.springframework.data.repository.util.ClassUtils;
 import org.springframework.data.repository.util.ReactiveWrapperConverters;
 import org.springframework.data.repository.util.ReactiveWrappers;
+import org.springframework.data.util.Pair;
 import org.springframework.data.util.ReflectionUtils;
 import org.springframework.util.Assert;
-import org.springframework.util.ObjectUtils;
 
 /**
  * Factory bean to create instances of a given repository interface. Creates a proxy implementing the configured
@@ -70,20 +77,29 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 			RepositoryFactorySupport.class.getClassLoader());
 	private static final Class<?> TRANSACTION_PROXY_TYPE = getTransactionProxyType();
 
-	private final Map<RepositoryInformationCacheKey, RepositoryInformation> repositoryInformationCache = new HashMap<RepositoryInformationCacheKey, RepositoryInformation>();
-	private final List<RepositoryProxyPostProcessor> postProcessors = new ArrayList<RepositoryProxyPostProcessor>();
+	private final Map<RepositoryInformationCacheKey, RepositoryInformation> repositoryInformationCache;
+	private final List<RepositoryProxyPostProcessor> postProcessors;
 
-	private Class<?> repositoryBaseClass;
+	private Optional<Class<?>> repositoryBaseClass;
 	private QueryLookupStrategy.Key queryLookupStrategyKey;
-	private List<QueryCreationListener<?>> queryPostProcessors = new ArrayList<QueryCreationListener<?>>();
-	private NamedQueries namedQueries = PropertiesBasedNamedQueries.EMPTY;
-	private ClassLoader classLoader = org.springframework.util.ClassUtils.getDefaultClassLoader();
-	private EvaluationContextProvider evaluationContextProvider = DefaultEvaluationContextProvider.INSTANCE;
+	private List<QueryCreationListener<?>> queryPostProcessors;
+	private NamedQueries namedQueries;
+	private ClassLoader classLoader;
+	private EvaluationContextProvider evaluationContextProvider;
 	private BeanFactory beanFactory;
 
 	private QueryCollectingQueryCreationListener collectingListener = new QueryCollectingQueryCreationListener();
 
 	public RepositoryFactorySupport() {
+
+		this.repositoryInformationCache = new HashMap<>();
+		this.postProcessors = new ArrayList<>();
+
+		this.repositoryBaseClass = Optional.empty();
+		this.namedQueries = PropertiesBasedNamedQueries.EMPTY;
+		this.classLoader = org.springframework.util.ClassUtils.getDefaultClassLoader();
+		this.evaluationContextProvider = DefaultEvaluationContextProvider.INSTANCE;
+		this.queryPostProcessors = new ArrayList<>();
 		this.queryPostProcessors.add(collectingListener);
 	}
 
@@ -142,7 +158,7 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 	 * @since 1.11
 	 */
 	public void setRepositoryBaseClass(Class<?> repositoryBaseClass) {
-		this.repositoryBaseClass = repositoryBaseClass;
+		this.repositoryBaseClass = Optional.ofNullable(repositoryBaseClass);
 	}
 
 	/**
@@ -178,7 +194,7 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 	 * @return
 	 */
 	public <T> T getRepository(Class<T> repositoryInterface) {
-		return getRepository(repositoryInterface, null);
+		return getRepository(repositoryInterface, Optional.empty());
 	}
 
 	/**
@@ -191,11 +207,10 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 	 * @return
 	 */
 	@SuppressWarnings({ "unchecked" })
-	public <T> T getRepository(Class<T> repositoryInterface, Object customImplementation) {
+	public <T> T getRepository(Class<T> repositoryInterface, Optional<Object> customImplementation) {
 
 		RepositoryMetadata metadata = getRepositoryMetadata(repositoryInterface);
-		Class<?> customImplementationClass = null == customImplementation ? null : customImplementation.getClass();
-		RepositoryInformation information = getRepositoryInformation(metadata, customImplementationClass);
+		RepositoryInformation information = getRepositoryInformation(metadata, customImplementation.map(Object::getClass));
 
 		validate(information, customImplementation);
 
@@ -213,9 +228,7 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 			result.addInterface(TRANSACTION_PROXY_TYPE);
 		}
 
-		for (RepositoryProxyPostProcessor processor : postProcessors) {
-			processor.postProcess(result, information);
-		}
+		postProcessors.forEach(processor -> processor.postProcess(result, information));
 
 		if (IS_JAVA_8) {
 			result.addAdvice(new DefaultMethodInvokingMethodInterceptor());
@@ -248,24 +261,19 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 	 * @return
 	 */
 	protected RepositoryInformation getRepositoryInformation(RepositoryMetadata metadata,
-			Class<?> customImplementationClass) {
+			Optional<Class<?>> customImplementationClass) {
 
 		RepositoryInformationCacheKey cacheKey = new RepositoryInformationCacheKey(metadata, customImplementationClass);
-		RepositoryInformation repositoryInformation = repositoryInformationCache.get(cacheKey);
 
-		if (repositoryInformation != null) {
-			return repositoryInformation;
-		}
-
-		Class<?> repositoryBaseClass = this.repositoryBaseClass == null ? getRepositoryBaseClass(metadata)
-				: this.repositoryBaseClass;
+		return repositoryInformationCache.computeIfAbsent(cacheKey, key -> new DefaultRepositoryInformation(metadata,
+				repositoryBaseClass.orElse(getRepositoryBaseClass(metadata)), customImplementationClass));
 
+		/*
 		repositoryInformation = metadata.isReactiveRepository()
-				? new ReactiveRepositoryInformation(metadata, repositoryBaseClass, customImplementationClass)
-				: new DefaultRepositoryInformation(metadata, repositoryBaseClass, customImplementationClass);
+						? new ReactiveRepositoryInformation(metadata, repositoryBaseClass, customImplementationClass)
+						: new DefaultRepositoryInformation(metadata, repositoryBaseClass, customImplementationClass);
+		*/
 
-		repositoryInformationCache.put(cacheKey, repositoryInformation);
-		return repositoryInformation;
 	}
 
 	protected List<QueryMethod> getQueryMethods() {
@@ -299,17 +307,6 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 	 */
 	protected abstract Class<?> getRepositoryBaseClass(RepositoryMetadata metadata);
 
-	/**
-	 * Returns the {@link QueryLookupStrategy} for the given {@link Key}.
-	 * 
-	 * @deprecated favor {@link #getQueryLookupStrategy(Key, EvaluationContextProvider)}
-	 * @param key can be {@literal null}
-	 * @return the {@link QueryLookupStrategy} to use or {@literal null} if no queries should be looked up.
-	 */
-	protected QueryLookupStrategy getQueryLookupStrategy(Key key) {
-		return null;
-	}
-
 	/**
 	 * Returns the {@link QueryLookupStrategy} for the given {@link Key} and {@link EvaluationContextProvider}.
 	 * 
@@ -318,8 +315,9 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 	 * @return the {@link QueryLookupStrategy} to use or {@literal null} if no queries should be looked up.
 	 * @since 1.9
 	 */
-	protected QueryLookupStrategy getQueryLookupStrategy(Key key, EvaluationContextProvider evaluationContextProvider) {
-		return null;
+	protected Optional<QueryLookupStrategy> getQueryLookupStrategy(Key key,
+			EvaluationContextProvider evaluationContextProvider) {
+		return Optional.empty();
 	}
 
 	/**
@@ -328,14 +326,18 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 	 * @param repositoryInformation
 	 * @param customImplementation
 	 */
-	private void validate(RepositoryInformation repositoryInformation, Object customImplementation) {
+	private void validate(RepositoryInformation repositoryInformation, Optional<Object> customImplementation) {
 
-		if (null == customImplementation && repositoryInformation.hasCustomMethod()) {
+		customImplementation.orElseGet(() -> {
+
+			if (!repositoryInformation.hasCustomMethod()) {
+				return null;
+			}
 
 			throw new IllegalArgumentException(
 					String.format("You have custom methods in %s but not provided a custom implementation!",
 							repositoryInformation.getRepositoryInterface()));
-		}
+		});
 
 		validate(repositoryInformation);
 	}
@@ -357,22 +359,14 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 			Object... constructorArguments) {
 
 		Class<?> baseClass = information.getRepositoryBaseClass();
-		Constructor<?> constructor = ReflectionUtils.findConstructor(baseClass, constructorArguments);
+		Optional<Constructor<?>> constructor = ReflectionUtils.findConstructor(baseClass, constructorArguments);
 
-		if (constructor == null) {
+		return constructor.map(it -> (R) BeanUtils.instantiateClass(it, constructorArguments)).orElseThrow(() -> {
 
-			List<Class<?>> argumentTypes = new ArrayList<Class<?>>(constructorArguments.length);
-
-			for (Object argument : constructorArguments) {
-				argumentTypes.add(argument.getClass());
-			}
-
-			throw new IllegalStateException(String.format(
+			return new IllegalStateException(String.format(
 					"No suitable constructor found on %s to match the given arguments: %s. Make sure you implement a constructor taking these",
-					baseClass, argumentTypes));
-		}
-
-		return (R) BeanUtils.instantiateClass(constructor, constructorArguments);
+					baseClass, Arrays.stream(constructorArguments).map(Object::getClass).collect(Collectors.toList())));
+		});
 	}
 
 	/**
@@ -399,8 +393,7 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 	 */
 	public class QueryExecutorMethodInterceptor implements MethodInterceptor {
 
-		private final Map<Method, RepositoryQuery> queries = new ConcurrentHashMap<Method, RepositoryQuery>();
-
+		private final Map<Method, RepositoryQuery> queries;
 		private final QueryExecutionResultHandler resultHandler;
 
 		/**
@@ -411,33 +404,28 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 
 			this.resultHandler = new QueryExecutionResultHandler();
 
-			QueryLookupStrategy lookupStrategy = getQueryLookupStrategy(queryLookupStrategyKey,
+			Optional<QueryLookupStrategy> lookupStrategy = getQueryLookupStrategy(queryLookupStrategyKey,
 					RepositoryFactorySupport.this.evaluationContextProvider);
-			lookupStrategy = lookupStrategy == null ? getQueryLookupStrategy(queryLookupStrategyKey) : lookupStrategy;
-			Iterable<Method> queryMethods = repositoryInformation.getQueryMethods();
 
-			if (lookupStrategy == null) {
+			if (!lookupStrategy.isPresent() && repositoryInformation.hasQueryMethods()) {
 
-				if (queryMethods.iterator().hasNext()) {
-					throw new IllegalStateException("You have defined query method in the repository but "
-							+ "you don't have any query lookup strategy defined. The "
-							+ "infrastructure apparently does not support query methods!");
-				}
-
-				return;
+				throw new IllegalStateException("You have defined query method in the repository but "
+						+ "you don't have any query lookup strategy defined. The "
+						+ "infrastructure apparently does not support query methods!");
 			}
 
-			SpelAwareProxyProjectionFactory factory = new SpelAwareProxyProjectionFactory();
-			factory.setBeanClassLoader(classLoader);
-			factory.setBeanFactory(beanFactory);
+			this.queries = lookupStrategy.map(it -> {
 
-			for (Method method : queryMethods) {
+				SpelAwareProxyProjectionFactory factory = new SpelAwareProxyProjectionFactory();
+				factory.setBeanClassLoader(classLoader);
+				factory.setBeanFactory(beanFactory);
 
-				RepositoryQuery query = lookupStrategy.resolveQuery(method, repositoryInformation, factory, namedQueries);
+				return repositoryInformation.getQueryMethods().stream()//
+						.map(method -> Pair.of(method, it.resolveQuery(method, repositoryInformation, factory, namedQueries)))//
+						.peek(pair -> invokeListeners(pair.getSecond()))//
+						.collect(Pair.toMap());
 
-				invokeListeners(query);
-				queries.put(method, query);
-			}
+			}).orElse(Collections.emptyMap());
 		}
 
 		@SuppressWarnings({ "rawtypes", "unchecked" })
@@ -496,28 +484,13 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 	 *
 	 * @author Mark Paluch
 	 */
+	@RequiredArgsConstructor
 	public class ImplementationMethodExecutionInterceptor implements MethodInterceptor {
 
-		private final Object customImplementation;
 		private final RepositoryInformation repositoryInformation;
+		private final Optional<Object> customImplementation;
 		private final Object target;
 
-		/**
-		 * Creates a new {@link QueryExecutorMethodInterceptor}. Builds a model of {@link QueryMethod}s to be invoked on
-		 * execution of repository interface methods.
-		 */
-		public ImplementationMethodExecutionInterceptor(RepositoryInformation repositoryInformation,
-				Object customImplementation, Object target) {
-
-			Assert.notNull(repositoryInformation, "RepositoryInformation must not be null!");
-			Assert.notNull(target, "Target must not be null!");
-
-			this.repositoryInformation = repositoryInformation;
-			this.customImplementation = customImplementation;
-			this.target = target;
-
-		}
-
 		/* (non-Javadoc)
 		 * @see org.aopalliance.intercept.MethodInterceptor#invoke(org.aopalliance.intercept.MethodInvocation)
 		 */
@@ -530,7 +503,7 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 			if (isCustomMethodInvocation(invocation)) {
 
 				Method actualMethod = repositoryInformation.getTargetClassMethod(method);
-				return executeMethodOn(customImplementation, actualMethod, arguments);
+				return executeMethodOn(customImplementation.get(), actualMethod, arguments);
 			}
 
 			// Lookup actual method as it might be redeclared in the interface
@@ -589,7 +562,7 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 		 * @param target
 		 */
 		public ConvertingImplementationMethodExecutionInterceptor(RepositoryInformation repositoryInformation,
-				Object customImplementation, Object target) {
+				Optional<Object> customImplementation, Object target) {
 
 			super(repositoryInformation, customImplementation, target);
 		}
@@ -641,18 +614,13 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 	 * 
 	 * @author Oliver Gierke
 	 */
+	@Getter
 	private static class QueryCollectingQueryCreationListener implements QueryCreationListener<RepositoryQuery> {
 
-		private List<QueryMethod> queryMethods = new ArrayList<QueryMethod>();
-
 		/**
-		 * Returns all {@link QueryMethod}s.
-		 * 
-		 * @return
+		 * All {@link QueryMethod}s.
 		 */
-		public List<QueryMethod> getQueryMethods() {
-			return queryMethods;
-		}
+		private List<QueryMethod> queryMethods = new ArrayList<QueryMethod>();
 
 		/* (non-Javadoc)
 		 * @see org.springframework.data.repository.core.support.QueryCreationListener#onCreation(org.springframework.data.repository.query.RepositoryQuery)
@@ -667,6 +635,7 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 	 * 
 	 * @author Oliver Gierke
 	 */
+	@EqualsAndHashCode
 	private static class RepositoryInformationCacheKey {
 
 		private final String repositoryInterfaceName;
@@ -679,40 +648,10 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 		 * @param repositoryInterfaceName must not be {@literal null}.
 		 * @param customImplementationClassName
 		 */
-		public RepositoryInformationCacheKey(RepositoryMetadata metadata, Class<?> customImplementationType) {
+		public RepositoryInformationCacheKey(RepositoryMetadata metadata, Optional<Class<?>> customImplementationType) {
+
 			this.repositoryInterfaceName = metadata.getRepositoryInterface().getName();
-			this.customImplementationClassName = customImplementationType == null ? null : customImplementationType.getName();
-		}
-
-		/* 
-		 * (non-Javadoc)
-		 * @see java.lang.Object#equals(java.lang.Object)
-		 */
-		@Override
-		public boolean equals(Object obj) {
-
-			if (!(obj instanceof RepositoryInformationCacheKey)) {
-				return false;
-			}
-
-			RepositoryInformationCacheKey that = (RepositoryInformationCacheKey) obj;
-			return this.repositoryInterfaceName.equals(that.repositoryInterfaceName)
-					&& ObjectUtils.nullSafeEquals(this.customImplementationClassName, that.customImplementationClassName);
-		}
-
-		/* 
-		 * (non-Javadoc)
-		 * @see java.lang.Object#hashCode()
-		 */
-		@Override
-		public int hashCode() {
-
-			int result = 31;
-
-			result += 17 * repositoryInterfaceName.hashCode();
-			result += 17 * ObjectUtils.nullSafeHashCode(customImplementationClassName);
-
-			return result;
+			this.customImplementationClassName = customImplementationType.map(Class::getName).orElse(null);
 		}
 	}
 }

src/main/java/org/springframework/data/repository/query/EvaluationContextExtensionInformation.java

@@ -15,6 +15,9 @@
  */
 package org.springframework.data.repository.query;
 
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
 import java.beans.PropertyDescriptor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
@@ -25,17 +28,17 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
-import java.util.Map.Entry;
+import java.util.Optional;
+import java.util.stream.Collectors;
 
 import org.springframework.beans.BeanUtils;
 import org.springframework.data.repository.query.EvaluationContextExtensionInformation.ExtensionTypeInformation.PublicMethodAndFieldFilter;
 import org.springframework.data.repository.query.spi.EvaluationContextExtension;
 import org.springframework.data.repository.query.spi.Function;
+import org.springframework.data.util.Streamable;
 import org.springframework.util.Assert;
 import org.springframework.util.ReflectionUtils;
-import org.springframework.util.ReflectionUtils.FieldCallback;
 import org.springframework.util.ReflectionUtils.FieldFilter;
-import org.springframework.util.ReflectionUtils.MethodCallback;
 import org.springframework.util.ReflectionUtils.MethodFilter;
 
 /**
@@ -53,7 +56,7 @@ import org.springframework.util.ReflectionUtils.MethodFilter;
 class EvaluationContextExtensionInformation {
 
 	private final ExtensionTypeInformation extensionTypeInformation;
-	private final RootObjectInformation rootObjectInformation;
+	private final Optional<RootObjectInformation> rootObjectInformation;
 
 	/**
 	 * Creates a new {@link EvaluationContextExtension} for the given extension type.
@@ -65,7 +68,8 @@ class EvaluationContextExtensionInformation {
 		Assert.notNull(type, "Extension type must not be null!");
 		Class<?> rootObjectType = getRootObjectMethod(type).getReturnType();
 
-		this.rootObjectInformation = Object.class.equals(rootObjectType) ? null : new RootObjectInformation(rootObjectType);
+		this.rootObjectInformation = Optional
+				.ofNullable(Object.class.equals(rootObjectType) ? null : new RootObjectInformation(rootObjectType));
 		this.extensionTypeInformation = new ExtensionTypeInformation(type);
 	}
 
@@ -85,9 +89,10 @@ class EvaluationContextExtensionInformation {
 	 * @param target
 	 * @return
 	 */
-	public RootObjectInformation getRootObjectInformation(Object target) {
-		return target == null ? RootObjectInformation.NONE : rootObjectInformation == null ? new RootObjectInformation(
-				target.getClass()) : rootObjectInformation;
+	public RootObjectInformation getRootObjectInformation(Optional<Object> target) {
+
+		return target.map(it -> rootObjectInformation.orElse(new RootObjectInformation(it.getClass())))
+				.orElse(RootObjectInformation.NONE);
 	}
 
 	private static Method getRootObjectMethod(Class<?> type) {
@@ -105,9 +110,21 @@ class EvaluationContextExtensionInformation {
 	 *
 	 * @author Oliver Gierke
 	 */
+	@Getter
 	public static class ExtensionTypeInformation {
 
+		/**
+		 * The statically defined properties of the extension type.
+		 * 
+		 * @return the properties will never be {@literal null}.
+		 */
 		private final Map<String, Object> properties;
+
+		/**
+		 * The statically exposed functions of the extension type.
+		 * 
+		 * @return the functions will never be {@literal null}.
+		 */
 		private final Map<String, Function> functions;
 
 		/**
@@ -120,44 +137,21 @@ class EvaluationContextExtensionInformation {
 			Assert.notNull(type, "Extension type must not be null!");
 
 			this.functions = discoverDeclaredFunctions(type);
-			this.properties = discoverDeclaredProperties(type, PublicMethodAndFieldFilter.STATIC);
-		}
-
-		/**
-		 * Returns the statically defined properties of the extension type.
-		 * 
-		 * @return the properties will never be {@literal null}.
-		 */
-		public Map<String, Object> getProperties() {
-			return properties;
-		}
-
-		/**
-		 * Returns the statically exposed functions of the extension type.
-		 * 
-		 * @return the functions will never be {@literal null}.
-		 */
-		public Map<String, Function> getFunctions() {
-			return functions;
+			this.properties = discoverDeclaredProperties(type);
 		}
 
 		private static Map<String, Function> discoverDeclaredFunctions(Class<?> type) {
 
-			final Map<String, Function> map = new HashMap<String, Function>();
+			Map<String, Function> map = new HashMap<String, Function>();
 
-			ReflectionUtils.doWithMethods(type, new MethodCallback() {
+			ReflectionUtils.doWithMethods(type, //
+					method -> map.put(method.getName(), new Function(method, null)), //
+					PublicMethodAndFieldFilter.STATIC);
 
-				@Override
-				public void doWith(Method method) throws IllegalArgumentException, IllegalAccessException {
-					if (Modifier.isPublic(method.getModifiers()) && Modifier.isStatic(method.getModifiers())) {
-						map.put(method.getName(), new Function(method, null));
-					}
-				}
-			});
-
-			return map.isEmpty() ? Collections.<String, Function> emptyMap() : Collections.unmodifiableMap(map);
+			return map.isEmpty() ? Collections.emptyMap() : Collections.unmodifiableMap(map);
 		}
 
+		@RequiredArgsConstructor
 		static class PublicMethodAndFieldFilter implements MethodFilter, FieldFilter {
 
 			public static final PublicMethodAndFieldFilter STATIC = new PublicMethodAndFieldFilter(true);
@@ -165,13 +159,6 @@ class EvaluationContextExtensionInformation {
 
 			private final boolean staticOnly;
 
-			/**
-			 * @param staticOnly
-			 */
-			public PublicMethodAndFieldFilter(boolean forStatic) {
-				this.staticOnly = forStatic;
-			}
-
 			/* 
 			 * (non-Javadoc)
 			 * @see org.springframework.util.ReflectionUtils.MethodFilter#matches(java.lang.reflect.Method)
@@ -235,30 +222,20 @@ class EvaluationContextExtensionInformation {
 				return;
 			}
 
-			final PropertyDescriptor[] descriptors = BeanUtils.getPropertyDescriptors(type);
+			Streamable<PropertyDescriptor> descriptors = Streamable.of(BeanUtils.getPropertyDescriptors(type));
 
-			ReflectionUtils.doWithMethods(type, new MethodCallback() {
+			ReflectionUtils.doWithMethods(type, method -> {
 
-				@Override
-				public void doWith(Method method) {
+				RootObjectInformation.this.methods.add(method);
 
-					RootObjectInformation.this.methods.add(method);
+				descriptors.stream()//
+						.filter(it -> method.equals(it.getReadMethod()))//
+						.forEach(it -> RootObjectInformation.this.accessors.put(it.getName(), method));
 
-					for (PropertyDescriptor descriptor : descriptors) {
-						if (method.equals(descriptor.getReadMethod())) {
-							RootObjectInformation.this.accessors.put(descriptor.getName(), method);
-						}
-					}
-				}
-			}, PublicMethodAndFieldFilter.NON_STATIC);
+			} , PublicMethodAndFieldFilter.NON_STATIC);
 
-			ReflectionUtils.doWithFields(type, new FieldCallback() {
-
-				@Override
-				public void doWith(Field field) {
-					RootObjectInformation.this.fields.add(field);
-				}
-			}, PublicMethodAndFieldFilter.NON_STATIC);
+			ReflectionUtils.doWithFields(type, field -> RootObjectInformation.this.fields.add(field),
+					PublicMethodAndFieldFilter.NON_STATIC);
 		}
 
 		/**
@@ -267,20 +244,13 @@ class EvaluationContextExtensionInformation {
 		 * @param target can be {@literal null}.
 		 * @return the methods
 		 */
-		public Map<String, Function> getFunctions(Object target) {
-
-			if (target == null) {
-				return Collections.emptyMap();
-			}
-
-			Map<String, Function> functions = new HashMap<String, Function>(methods.size());
-
-			for (Method method : methods) {
-				functions.put(method.getName(), new Function(method, target));
-			}
-
-			return Collections.unmodifiableMap(functions);
+		public Map<String, Function> getFunctions(Optional<Object> target) {
 
+			return target.map(it -> methods.stream()//
+					.collect(Collectors.toMap(//
+							Method::getName, //
+							method -> new Function(method, it))))
+					.orElse(Collections.emptyMap());
 		}
 
 		/**
@@ -289,38 +259,29 @@ class EvaluationContextExtensionInformation {
 		 * 
 		 * @return the properties
 		 */
-		public Map<String, Object> getProperties(Object target) {
+		public Map<String, Object> getProperties(Optional<Object> target) {
 
-			if (target == null) {
-				return Collections.emptyMap();
-			}
+			return target.map(it -> {
 
-			Map<String, Object> properties = new HashMap<String, Object>();
+				Map<String, Object> properties = new HashMap<String, Object>();
 
-			for (Entry<String, Method> method : accessors.entrySet()) {
-				properties.put(method.getKey(), new Function(method.getValue(), target));
-			}
+				accessors.entrySet().stream()
+						.forEach(method -> properties.put(method.getKey(), new Function(method.getValue(), it)));
+				fields.stream().forEach(field -> properties.put(field.getName(), ReflectionUtils.getField(field, it)));
 
-			for (Field field : fields) {
-				properties.put(field.getName(), ReflectionUtils.getField(field, target));
-			}
+				return Collections.unmodifiableMap(properties);
 
-			return Collections.unmodifiableMap(properties);
+			}).orElse(Collections.emptyMap());
 		}
 	}
 
-	private static Map<String, Object> discoverDeclaredProperties(Class<?> type, FieldFilter filter) {
+	private static Map<String, Object> discoverDeclaredProperties(Class<?> type) {
 
-		final Map<String, Object> map = new HashMap<String, Object>();
+		Map<String, Object> map = new HashMap<String, Object>();
 
-		ReflectionUtils.doWithFields(type, new FieldCallback() {
+		ReflectionUtils.doWithFields(type, field -> map.put(field.getName(), field.get(null)),
+				PublicMethodAndFieldFilter.STATIC);
 
-			@Override
-			public void doWith(Field field) throws IllegalAccessException {
-				map.put(field.getName(), field.get(null));
-			}
-		}, filter);
-
-		return map.isEmpty() ? Collections.<String, Object> emptyMap() : Collections.unmodifiableMap(map);
+		return map.isEmpty() ? Collections.emptyMap() : Collections.unmodifiableMap(map);
 	}
 }

src/main/java/org/springframework/data/repository/query/ExtensionAwareEvaluationContextProvider.java

@@ -15,12 +15,17 @@
  */
 package org.springframework.data.repository.query;
 
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Optional;
+import java.util.stream.Collectors;
 
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanFactory;
@@ -34,6 +39,7 @@ import org.springframework.data.repository.query.EvaluationContextExtensionInfor
 import org.springframework.data.repository.query.EvaluationContextExtensionInformation.RootObjectInformation;
 import org.springframework.data.repository.query.spi.EvaluationContextExtension;
 import org.springframework.data.repository.query.spi.Function;
+import org.springframework.data.util.Optionals;
 import org.springframework.expression.AccessException;
 import org.springframework.expression.EvaluationContext;
 import org.springframework.expression.MethodExecutor;
@@ -61,7 +67,7 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 	private final Map<Class<?>, EvaluationContextExtensionInformation> extensionInformationCache = new HashMap<Class<?>, EvaluationContextExtensionInformation>();
 
 	private List<? extends EvaluationContextExtension> extensions;
-	private ListableBeanFactory beanFactory;
+	private Optional<ListableBeanFactory> beanFactory = Optional.empty();
 
 	/**
 	 * Creates a new {@link ExtensionAwareEvaluationContextProvider}. Extensions are being looked up lazily from the
@@ -88,7 +94,7 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 	 */
 	@Override
 	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
-		this.beanFactory = applicationContext;
+		this.beanFactory = Optional.of(applicationContext);
 	}
 
 	/* (non-Javadoc)
@@ -100,9 +106,7 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 
 		StandardEvaluationContext ec = new StandardEvaluationContext();
 
-		if (beanFactory != null) {
-			ec.setBeanResolver(new BeanFactoryResolver(beanFactory));
-		}
+		beanFactory.ifPresent(it -> ec.setBeanResolver(new BeanFactoryResolver(it)));
 
 		ExtensionAwarePropertyAccessor accessor = new ExtensionAwarePropertyAccessor(getExtensions());
 
@@ -129,21 +133,17 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 
 		Map<String, Object> variables = new HashMap<String, Object>();
 
-		for (Parameter param : parameters) {
-			if (param.isSpecialParameter()) {
+		parameters.stream()//
+				.filter(Parameter::isSpecialParameter)//
+				.forEach(it -> variables.put(//
+						StringUtils.uncapitalize(it.getType().getSimpleName()), //
+						arguments[it.getIndex()]));
 
-				String key = StringUtils.uncapitalize(param.getType().getSimpleName());
-				Object value = arguments[param.getIndex()];
-
-				variables.put(key, value);
-			}
-		}
-
-		for (Parameter param : parameters) {
-			if (param.isNamedParameter()) {
-				variables.put(param.getName(), arguments[param.getIndex()]);
-			}
-		}
+		parameters.stream()//
+				.filter(Parameter::isNamedParameter)//
+				.forEach(it -> variables.put(//
+						it.getName().orElseThrow(() -> new IllegalStateException("Should never occur!")), //
+						arguments[it.getIndex()]));
 
 		return variables;
 	}
@@ -160,13 +160,12 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 			return this.extensions;
 		}
 
-		if (beanFactory == null) {
-			this.extensions = Collections.emptyList();
-			return this.extensions;
-		}
+		this.extensions = Collections.emptyList();
 
-		this.extensions = new ArrayList<EvaluationContextExtension>(beanFactory.getBeansOfType(
-				EvaluationContextExtension.class, true, false).values());
+		beanFactory.ifPresent(it -> {
+			this.extensions = new ArrayList<EvaluationContextExtension>(
+					it.getBeansOfType(EvaluationContextExtension.class, true, false).values());
+		});
 
 		return extensions;
 	}
@@ -181,15 +180,9 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 	private EvaluationContextExtensionInformation getOrCreateInformation(EvaluationContextExtension extension) {
 
 		Class<? extends EvaluationContextExtension> extensionType = extension.getClass();
-		EvaluationContextExtensionInformation information = extensionInformationCache.get(extensionType);
 
-		if (information != null) {
-			return information;
-		}
-
-		information = new EvaluationContextExtensionInformation(extensionType);
-		extensionInformationCache.put(extensionType, information);
-		return information;
+		return extensionInformationCache.computeIfAbsent(extensionType,
+				type -> new EvaluationContextExtensionInformation(extensionType));
 	}
 
 	/**
@@ -198,19 +191,12 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 	 * @param extensions
 	 * @return
 	 */
-	private List<EvaluationContextExtensionAdapter> toAdapters(Collection<? extends EvaluationContextExtension> extensions) {
+	private List<EvaluationContextExtensionAdapter> toAdapters(List<? extends EvaluationContextExtension> extensions) {
 
-		List<EvaluationContextExtension> extensionsToSet = new ArrayList<EvaluationContextExtension>(extensions);
-		Collections.sort(extensionsToSet, AnnotationAwareOrderComparator.INSTANCE);
-
-		List<EvaluationContextExtensionAdapter> adapters = new ArrayList<EvaluationContextExtensionAdapter>(
-				extensions.size());
-
-		for (EvaluationContextExtension extension : extensionsToSet) {
-			adapters.add(new EvaluationContextExtensionAdapter(extension, getOrCreateInformation(extension)));
-		}
-
-		return adapters;
+		return extensions.stream()//
+				.sorted(AnnotationAwareOrderComparator.INSTANCE)//
+				.map(it -> new EvaluationContextExtensionAdapter(it, getOrCreateInformation(it)))//
+				.collect(Collectors.toList());
 	}
 
 	/**
@@ -233,11 +219,8 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 			Assert.notNull(extensions, "Extensions must not be null!");
 
 			this.adapters = toAdapters(extensions);
-			this.adapterMap = new HashMap<String, EvaluationContextExtensionAdapter>(extensions.size());
-
-			for (EvaluationContextExtensionAdapter adapter : adapters) {
-				this.adapterMap.put(adapter.getExtensionId(), adapter);
-			}
+			this.adapterMap = adapters.stream()//
+					.collect(Collectors.toMap(it -> it.getExtensionId(), it -> it));
 
 			Collections.reverse(this.adapters);
 		}
@@ -257,13 +240,7 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 				return true;
 			}
 
-			for (EvaluationContextExtensionAdapter extension : adapters) {
-				if (extension.getProperties().containsKey(name)) {
-					return true;
-				}
-			}
-
-			return false;
+			return adapters.stream().anyMatch(it -> it.getProperties().containsKey(name));
 		}
 
 		/*
@@ -281,16 +258,10 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 				return new TypedValue(adapterMap.get(name));
 			}
 
-			for (EvaluationContextExtensionAdapter extension : adapters) {
-
-				Map<String, Object> properties = extension.getProperties();
-
-				if (properties.containsKey(name)) {
-					return lookupPropertyFrom(extension, name);
-				}
-			}
-
-			return null;
+			return adapters.stream()//
+					.filter(it -> it.getProperties().containsKey(name))//
+					.map(it -> lookupPropertyFrom(it, name))//
+					.findFirst().orElse(null);
 		}
 
 		/*
@@ -302,19 +273,12 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 				List<TypeDescriptor> argumentTypes) throws AccessException {
 
 			if (target instanceof EvaluationContextExtensionAdapter) {
-				return getMethodExecutor((EvaluationContextExtensionAdapter) target, name, argumentTypes);
+				return getMethodExecutor((EvaluationContextExtensionAdapter) target, name, argumentTypes).orElse(null);
 			}
 
-			for (EvaluationContextExtensionAdapter adapter : adapters) {
-
-				MethodExecutor executor = getMethodExecutor(adapter, name, argumentTypes);
-
-				if (executor != null) {
-					return executor;
-				}
-			}
-
-			return null;
+			return adapters.stream()//
+					.flatMap(it -> Optionals.toStream(getMethodExecutor(it, name, argumentTypes)))//
+					.findFirst().orElse(null);
 		}
 
 		/*
@@ -352,22 +316,12 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 		 * @param argumentTypes
 		 * @return
 		 */
-		private MethodExecutor getMethodExecutor(EvaluationContextExtensionAdapter adapter, String name,
+		private Optional<MethodExecutor> getMethodExecutor(EvaluationContextExtensionAdapter adapter, String name,
 				List<TypeDescriptor> argumentTypes) {
 
-			Map<String, Function> functions = adapter.getFunctions();
-
-			if (!functions.containsKey(name)) {
-				return null;
-			}
-
-			Function function = functions.get(name);
-
-			if (!function.supports(argumentTypes)) {
-				return null;
-			}
-
-			return new FunctionMethodExecutor(function);
+			return adapter.getFunctions().entrySet().stream()//
+					.filter(entry -> entry.getKey().equals(name))//
+					.findFirst().map(Entry::getValue).map(FunctionMethodExecutor::new);
 		}
 
 		/**
@@ -403,18 +357,10 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 	 * @author Oliver Gierke
 	 * @since 1.9
 	 */
+	@RequiredArgsConstructor
 	private static class FunctionMethodExecutor implements MethodExecutor {
 
-		private final Function function;
-
-		/**
-		 * Creates a new {@link FunctionMethodExecutor} for the given {@link Function}.
-		 * 
-		 * @param function must not be {@literal null}.
-		 */
-		public FunctionMethodExecutor(Function function) {
-			this.function = function;
-		}
+		private final @NonNull Function function;
 
 		/* 
 		 * (non-Javadoc)
@@ -460,7 +406,7 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 			Assert.notNull(extension, "Extenstion must not be null!");
 			Assert.notNull(information, "Extension information must not be null!");
 
-			Object target = extension.getRootObject();
+			Optional<Object> target = Optional.ofNullable(extension.getRootObject());
 			ExtensionTypeInformation extensionTypeInformation = information.getExtensionTypeInformation();
 			RootObjectInformation rootObjectInformation = information.getRootObjectInformation(target);
 

src/main/java/org/springframework/data/repository/query/Parameter.java

@@ -20,6 +20,7 @@ import static java.lang.String.*;
 import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Optional;
 
 import org.springframework.core.MethodParameter;
 import org.springframework.core.ResolvableType;
@@ -38,7 +39,7 @@ import org.springframework.util.Assert;
  */
 public class Parameter {
 
-	@SuppressWarnings("unchecked") static final List<Class<?>> TYPES = Arrays.asList(Pageable.class, Sort.class);
+	static final List<Class<?>> TYPES = Arrays.asList(Pageable.class, Sort.class);
 
 	private static final String NAMED_PARAMETER_TEMPLATE = ":%s";
 	private static final String POSITION_PARAMETER_TEMPLATE = "?%s";
@@ -97,7 +98,7 @@ public class Parameter {
 	public String getPlaceholder() {
 
 		if (isNamedParameter()) {
-			return format(NAMED_PARAMETER_TEMPLATE, getName());
+			return format(NAMED_PARAMETER_TEMPLATE, getName().get());
 		} else {
 			return format(POSITION_PARAMETER_TEMPLATE, getIndex());
 		}
@@ -118,18 +119,18 @@ public class Parameter {
 	 * @return
 	 */
 	public boolean isNamedParameter() {
-		return !isSpecialParameter() && getName() != null;
+		return !isSpecialParameter() && getName().isPresent();
 	}
 
 	/**
-	 * Returns the name of the parameter (through {@link Param} annotation) or null if none can be found.
+	 * Returns the name of the parameter (through {@link Param} annotation).
 	 * 
 	 * @return
 	 */
-	public String getName() {
+	public Optional<String> getName() {
 
 		Param annotation = parameter.getParameterAnnotation(Param.class);
-		return annotation == null ? parameter.getParameterName() : annotation.value();
+		return Optional.ofNullable(annotation == null ? parameter.getParameterName() : annotation.value());
 	}
 
 	/**

src/main/java/org/springframework/data/repository/query/Parameters.java

@@ -28,6 +28,7 @@ import org.springframework.core.MethodParameter;
 import org.springframework.core.ParameterNameDiscoverer;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
+import org.springframework.data.util.Streamable;
 import org.springframework.util.Assert;
 
 /**
@@ -35,9 +36,8 @@ import org.springframework.util.Assert;
  * 
  * @author Oliver Gierke
  */
-public abstract class Parameters<S extends Parameters<S, T>, T extends Parameter> implements Iterable<T> {
+public abstract class Parameters<S extends Parameters<S, T>, T extends Parameter> implements Streamable<T> {
 
-	@SuppressWarnings("unchecked") //
 	public static final List<Class<?>> TYPES = Arrays.asList(Pageable.class, Sort.class);
 
 	private static final String PARAM_ON_SPECIAL = format("You must not user @%s on a parameter typed %s or %s",

src/main/java/org/springframework/data/repository/query/ParametersParameterAccessor.java

@@ -15,9 +15,10 @@
  */
 package org.springframework.data.repository.query;
 
-import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Iterator;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
@@ -48,14 +49,9 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 		Assert.isTrue(parameters.getNumberOfParameters() == values.length, "Invalid number of parameters given!");
 
 		this.parameters = parameters;
-
-		List<Object> unwrapped = new ArrayList<Object>(values.length);
-
-		for (Object element : values.clone()) {
-			unwrapped.add(QueryExecutionConverters.unwrap(element));
-		}
-
-		this.values = unwrapped;
+		this.values = Arrays.stream(values)//
+				.map(QueryExecutionConverters::unwrap)//
+				.collect(Collectors.toList());
 	}
 
 	/**
@@ -131,13 +127,8 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 	 */
 	public boolean hasBindableNullValue() {
 
-		for (Parameter parameter : parameters.getBindableParameters()) {
-			if (values.get(parameter.getIndex()) == null) {
-				return true;
-			}
-		}
-
-		return false;
+		return parameters.getBindableParameters().stream()//
+				.anyMatch(it -> values.get(it.getIndex()) == null);
 	}
 
 	/*

src/main/java/org/springframework/data/repository/query/QueryMethod.java

@@ -29,6 +29,7 @@ import org.springframework.data.repository.core.EntityMetadata;
 import org.springframework.data.repository.core.RepositoryMetadata;
 import org.springframework.data.repository.util.QueryExecutionConverters;
 import org.springframework.data.util.ClassTypeInformation;
+import org.springframework.data.util.Lazy;
 import org.springframework.data.util.ReflectionUtils;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.Assert;
@@ -48,8 +49,7 @@ public class QueryMethod {
 	private final Class<?> unwrappedReturnType;
 	private final Parameters<?, ?> parameters;
 	private final ResultProcessor resultProcessor;
-
-	private Class<?> domainClass;
+	private final Lazy<Class<?>> domainClass;
 
 	/**
 	 * Creates a new {@link QueryMethod} from the given parameters. Looks up the correct query to use for following
@@ -65,12 +65,13 @@ public class QueryMethod {
 		Assert.notNull(metadata, "Repository metadata must not be null!");
 		Assert.notNull(factory, "ProjectionFactory must not be null!");
 
-		for (Class<?> type : Parameters.TYPES) {
-			if (getNumberOfOccurences(method, type) > 1) {
-				throw new IllegalStateException(String.format("Method must only one argument of type %s! Offending method: %s",
-						type.getSimpleName(), method.toString()));
-			}
-		}
+		Parameters.TYPES.stream()//
+				.filter(type -> getNumberOfOccurences(method, type) > 1)//
+				.findFirst().ifPresent(type -> {
+					throw new IllegalStateException(
+							String.format("Method must only one argument of type %s! Offending method: %s", type.getSimpleName(),
+									method.toString()));
+				});
 
 		this.method = method;
 		this.unwrappedReturnType = potentiallyUnwrapReturnTypeFor(method);
@@ -97,6 +98,15 @@ public class QueryMethod {
 					String.format("Paging query needs to have a Pageable parameter! Offending method %s", method.toString()));
 		}
 
+		this.domainClass = Lazy.of(() -> {
+
+			Class<?> repositoryDomainClass = metadata.getDomainType();
+			Class<?> methodDomainClass = metadata.getReturnedDomainClass(method);
+
+			return repositoryDomainClass == null || repositoryDomainClass.isAssignableFrom(methodDomainClass)
+					? methodDomainClass : repositoryDomainClass;
+		});
+
 		this.resultProcessor = new ResultProcessor(this, factory);
 	}
 
@@ -116,20 +126,12 @@ public class QueryMethod {
 	 * @return
 	 */
 	public String getName() {
-
 		return method.getName();
 	}
 
-	@SuppressWarnings("rawtypes")
+	@SuppressWarnings({ "rawtypes", "unchecked" })
 	public EntityMetadata<?> getEntityInformation() {
-
-		return new EntityMetadata() {
-
-			public Class<?> getJavaType() {
-
-				return getDomainClass();
-			}
-		};
+		return () -> (Class) getDomainClass();
 	}
 
 	/**
@@ -147,17 +149,7 @@ public class QueryMethod {
 	 * @return will never be {@literal null}.
 	 */
 	protected Class<?> getDomainClass() {
-
-		if (domainClass == null) {
-
-			Class<?> repositoryDomainClass = metadata.getDomainType();
-			Class<?> methodDomainClass = metadata.getReturnedDomainClass(method);
-
-			this.domainClass = repositoryDomainClass == null || repositoryDomainClass.isAssignableFrom(methodDomainClass)
-					? methodDomainClass : repositoryDomainClass;
-		}
-
-		return domainClass;
+		return domainClass.get();
 	}
 
 	/**
@@ -224,7 +216,7 @@ public class QueryMethod {
 	}
 
 	/**
-	 * Returns whether the query for theis method actually returns entities.
+	 * Returns whether the query for this method actually returns entities.
 	 * 
 	 * @return
 	 */
@@ -252,7 +244,7 @@ public class QueryMethod {
 	}
 
 	/**
-	 * Returns the {@link ResultProcessor} to be usedwith the query method.
+	 * Returns the {@link ResultProcessor} to be used with the query method.
 	 * 
 	 * @return the resultFactory
 	 */

src/main/java/org/springframework/data/repository/query/ResultProcessor.java

@@ -23,7 +23,6 @@ import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.function.Function;
 import java.util.stream.Stream;
 
 import org.springframework.core.CollectionFactory;
@@ -33,7 +32,6 @@ import org.springframework.core.convert.support.DefaultConversionService;
 import org.springframework.data.domain.Slice;
 import org.springframework.data.projection.ProjectionFactory;
 import org.springframework.data.repository.util.ReactiveWrapperConverters;
-import org.springframework.data.util.ReflectionUtils;
 import org.springframework.util.Assert;
 
 /**
@@ -135,8 +133,7 @@ public class ResultProcessor {
 
 		Assert.notNull(preparingConverter, "Preparing converter must not be null!");
 
-		final ChainingConverter converter = ChainingConverter.of(type.getReturnedType(), preparingConverter)
-				.and(this.converter);
+		ChainingConverter converter = ChainingConverter.of(type.getReturnedType(), preparingConverter).and(this.converter);
 
 		if (source instanceof Slice && method.isPageQuery() || method.isSliceQuery()) {
 			return (T) ((Slice<?>) source).map(converter);
@@ -154,8 +151,8 @@ public class ResultProcessor {
 			return (T) target;
 		}
 
-		if (ReflectionUtils.isJava8StreamType(source.getClass()) && method.isStreamQuery()) {
-			return (T) new StreamQueryResultHandler(type, converter).handle(source);
+		if (source instanceof Stream && method.isStreamQuery()) {
+			return (T) ((Stream<Object>) source).map(t -> type.isInstance(t) ? t : converter.convert(t));
 		}
 
 		if (ReactiveWrapperConverters.supports(source.getClass())) {
@@ -198,14 +195,10 @@ public class ResultProcessor {
 
 			Assert.notNull(converter, "Converter must not be null!");
 
-			return new ChainingConverter(targetType, new Converter<Object, Object>() {
+			return new ChainingConverter(targetType, source -> {
 
-				@Override
-				public Object convert(Object source) {
-
-					Object intermediate = ChainingConverter.this.convert(source);
-					return targetType.isInstance(intermediate) ? intermediate : converter.convert(intermediate);
-				}
+				Object intermediate = ChainingConverter.this.convert(source);
+				return targetType.isInstance(intermediate) ? intermediate : converter.convert(intermediate);
 			});
 		}
 
@@ -313,13 +306,8 @@ public class ResultProcessor {
 
 			Assert.isInstanceOf(Stream.class, source, "Source must not be null and an instance of Stream!");
 
-			return ((Stream<Object>) source).map(new Function<Object, Object>() {
-
-				@Override
-				public Object apply(Object element) {
-					return returnType.isInstance(element) ? element : converter.convert(element);
-				}
-			});
+			return ((Stream<Object>) source)
+					.map(element -> returnType.isInstance(element) ? element : converter.convert(element));
 		}
 	}
 }

src/main/java/org/springframework/data/repository/query/ReturnedType.java

@@ -26,11 +26,12 @@ import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.stream.Collectors;
 
-import org.springframework.data.mapping.PreferredConstructor;
 import org.springframework.data.mapping.model.PreferredConstructorDiscoverer;
 import org.springframework.data.projection.ProjectionFactory;
 import org.springframework.data.projection.ProjectionInformation;
+import org.springframework.data.util.Optionals;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 
@@ -208,7 +209,6 @@ public abstract class ReturnedType {
 	 */
 	private static final class ReturnedClass extends ReturnedType {
 
-		@SuppressWarnings("unchecked") //
 		private static final Set<Class<?>> VOID_TYPES = new HashSet<Class<?>>(Arrays.asList(Void.class, void.class));
 
 		private final Class<?> type;
@@ -284,19 +284,14 @@ public abstract class ReturnedType {
 			}
 
 			PreferredConstructorDiscoverer<?, ?> discoverer = new PreferredConstructorDiscoverer(type);
-			PreferredConstructor<?, ?> constructor = discoverer.getConstructor();
 
-			if (constructor == null) {
-				return Collections.emptyList();
-			}
+			return discoverer.getConstructor().map(it -> {
 
-			List<String> properties = new ArrayList<String>();
+				return it.getParameters().stream()//
+						.flatMap(parameter -> Optionals.toStream(parameter.getName()))//
+						.collect(Collectors.toList());
 
-			for (PreferredConstructor.Parameter<Object, ?> parameter : constructor.getParameters()) {
-				properties.add(parameter.getName());
-			}
-
-			return properties;
+			}).orElse(Collections.emptyList());
 		}
 
 		private boolean isDto() {

src/main/java/org/springframework/data/repository/query/parser/OrderBySource.java

@@ -19,6 +19,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Optional;
 import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -36,7 +37,7 @@ import org.springframework.util.StringUtils;
  * 
  * @author Oliver Gierke
  */
-public class OrderBySource {
+class OrderBySource {
 
 	private static final String BLOCK_SPLIT = "(?<=Asc|Desc)(?=\\p{Lu})";
 	private static final Pattern DIRECTION_SPLIT = Pattern.compile("(.+?)(Asc|Desc)?$");
@@ -109,10 +110,10 @@ public class OrderBySource {
 	/**
 	 * Returns the clause as {@link Sort}.
 	 * 
-	 * @return the {@link Sort} or null if no orders found.
+	 * @return the {@link Sort}.
 	 */
-	public Sort toSort() {
-		return this.orders.isEmpty() ? null : new Sort(this.orders);
+	public Optional<Sort> toSort() {
+		return this.orders.isEmpty() ? Optional.empty() : Optional.of(new Sort(this.orders));
 	}
 
 	/*

src/main/java/org/springframework/data/repository/query/parser/Part.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.repository.query.parser;
 
+import lombok.EqualsAndHashCode;
+
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -35,6 +37,7 @@ import org.springframework.util.StringUtils;
  * @author Oliver Gierke
  * @author Martin Baumgartner
  */
+@EqualsAndHashCode
 public class Part {
 
 	private static final Pattern IGNORE_CASE = Pattern.compile("Ignor(ing|e)Case");
@@ -69,9 +72,11 @@ public class Part {
 		Assert.notNull(clazz, "Type must not be null!");
 
 		String partToUse = detectAndSetIgnoreCase(source);
+
 		if (alwaysIgnoreCase && ignoreCase != IgnoreCaseType.ALWAYS) {
 			this.ignoreCase = IgnoreCaseType.WHEN_POSSIBLE;
 		}
+
 		this.type = Type.fromProperty(partToUse);
 		this.propertyPath = PropertyPath.from(type.extractProperty(partToUse), clazz);
 	}
@@ -89,8 +94,7 @@ public class Part {
 		return result;
 	}
 
-	public boolean getParameterRequired() {
-
+	boolean isParameterRequired() {
 		return getNumberOfArguments() > 0;
 	}
 
@@ -100,7 +104,6 @@ public class Part {
 	 * @return
 	 */
 	public int getNumberOfArguments() {
-
 		return type.getNumberOfArguments();
 	}
 
@@ -108,7 +111,6 @@ public class Part {
 	 * @return the propertyPath
 	 */
 	public PropertyPath getProperty() {
-
 		return propertyPath;
 	}
 
@@ -116,7 +118,6 @@ public class Part {
 	 * @return the type
 	 */
 	public Part.Type getType() {
-
 		return type;
 	}
 
@@ -126,50 +127,16 @@ public class Part {
 	 * @return
 	 */
 	public IgnoreCaseType shouldIgnoreCase() {
-
 		return ignoreCase;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see java.lang.Object#equals(java.lang.Object)
-	 */
-	@Override
-	public boolean equals(Object obj) {
-
-		if (obj == this) {
-			return true;
-		}
-
-		if (obj == null || !getClass().equals(obj.getClass())) {
-			return false;
-		}
-
-		Part that = (Part) obj;
-		return this.propertyPath.equals(that.propertyPath) && this.type.equals(that.type);
-	}
-
-	/*
-	 * (non-Javadoc)
-	 * @see java.lang.Object#hashCode()
-	 */
-	@Override
-	public int hashCode() {
-
-		int result = 37;
-		result += 17 * propertyPath.hashCode();
-		result += 17 * type.hashCode();
-		return result;
-	}
-
 	/*
 	 * (non-Javadoc)
 	 * @see java.lang.Object#toString()
 	 */
 	@Override
 	public String toString() {
-
-		return String.format("%s %s", propertyPath.getSegment(), type);
+		return String.format("%s %s %s", propertyPath.getSegment(), type, ignoreCase);
 	}
 
 	/**

src/main/java/org/springframework/data/repository/query/parser/PartTree.java

@@ -15,15 +15,20 @@
  */
 package org.springframework.data.repository.query.parser;
 
-import java.util.ArrayList;
+import lombok.Getter;
+
+import java.util.Arrays;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Optional;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
 import org.springframework.data.domain.Sort;
 import org.springframework.data.repository.query.parser.Part.Type;
 import org.springframework.data.repository.query.parser.PartTree.OrPart;
+import org.springframework.data.util.Streamable;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -38,7 +43,7 @@ import org.springframework.util.StringUtils;
  * @author Christoph Strobl
  * @author Mark Paluch
  */
-public class PartTree implements Iterable<OrPart> {
+public class PartTree implements Streamable<OrPart> {
 
 	/*
 	 * We look for a pattern of: keyword followed by
@@ -81,11 +86,12 @@ public class PartTree implements Iterable<OrPart> {
 		Assert.notNull(domainClass, "Domain class must not be null");
 
 		Matcher matcher = PREFIX_TEMPLATE.matcher(source);
+
 		if (!matcher.find()) {
-			this.subject = new Subject(null);
+			this.subject = new Subject(Optional.empty());
 			this.predicate = new Predicate(source, domainClass);
 		} else {
-			this.subject = new Subject(matcher.group(0));
+			this.subject = new Subject(Optional.of(matcher.group(0)));
 			this.predicate = new Predicate(source.substring(matcher.group().length()), domainClass);
 		}
 	}
@@ -104,9 +110,7 @@ public class PartTree implements Iterable<OrPart> {
 	 * @return the sort
 	 */
 	public Sort getSort() {
-
-		OrderBySource orderBySource = predicate.getOrderBySource();
-		return orderBySource == null ? null : orderBySource.toSort();
+		return predicate.getOrderBySource().flatMap(OrderBySource::toSort).orElse(null);
 	}
 
 	/**
@@ -123,7 +127,7 @@ public class PartTree implements Iterable<OrPart> {
 	 * 
 	 * @return
 	 */
-	public Boolean isCountProjection() {
+	public boolean isCountProjection() {
 		return subject.isCountProjection();
 	}
 
@@ -143,7 +147,7 @@ public class PartTree implements Iterable<OrPart> {
 	 * @return
 	 * @since 1.8
 	 */
-	public Boolean isDelete() {
+	public boolean isDelete() {
 		return subject.isDelete();
 	}
 
@@ -164,7 +168,7 @@ public class PartTree implements Iterable<OrPart> {
 	 * @since 1.9
 	 */
 	public Integer getMaxResults() {
-		return subject.getMaxResults();
+		return subject.getMaxResults().orElse(null);
 	}
 
 	/**
@@ -172,15 +176,8 @@ public class PartTree implements Iterable<OrPart> {
 	 * 
 	 * @return the iterable {@link Part}s
 	 */
-	public Iterable<Part> getParts() {
-
-		List<Part> result = new ArrayList<Part>();
-		for (OrPart orPart : this) {
-			for (Part part : orPart) {
-				result.add(part);
-			}
-		}
-		return result;
+	public Streamable<Part> getParts() {
+		return Streamable.of(this.stream().flatMap(OrPart::stream).collect(Collectors.toList()));
 	}
 
 	/**
@@ -189,25 +186,19 @@ public class PartTree implements Iterable<OrPart> {
 	 * @param type
 	 * @return
 	 */
-	public Iterable<Part> getParts(Type type) {
+	public Streamable<Part> getParts(Type type) {
 
-		List<Part> result = new ArrayList<Part>();
-
-		for (Part part : getParts()) {
-			if (part.getType().equals(type)) {
-				result.add(part);
-			}
-		}
-
-		return result;
+		return Streamable.of(getParts().stream()//
+				.filter(part -> part.getType().equals(type))//
+				.collect(Collectors.toList()));
 	}
 
 	@Override
 	public String toString() {
 
-		OrderBySource orderBySource = predicate.getOrderBySource();
+		Optional<OrderBySource> orderBySource = predicate.getOrderBySource();
 		return String.format("%s%s", StringUtils.collectionToDelimitedString(predicate.nodes, " or "),
-				orderBySource == null ? "" : " " + orderBySource);
+				orderBySource.map(it -> " ".concat(it.toString())).orElse(""));
 	}
 
 	/**
@@ -228,9 +219,9 @@ public class PartTree implements Iterable<OrPart> {
 	 * A part of the parsed source that results from splitting up the resource around {@literal Or} keywords. Consists of
 	 * {@link Part}s that have to be concatenated by {@literal And}.
 	 */
-	public static class OrPart implements Iterable<Part> {
+	public static class OrPart implements Streamable<Part> {
 
-		private final List<Part> children = new ArrayList<Part>();
+		private final List<Part> children;
 
 		/**
 		 * Creates a new {@link OrPart}.
@@ -242,21 +233,19 @@ public class PartTree implements Iterable<OrPart> {
 		OrPart(String source, Class<?> domainClass, boolean alwaysIgnoreCase) {
 
 			String[] split = split(source, "And");
-			for (String part : split) {
-				if (StringUtils.hasText(part)) {
-					children.add(new Part(part, domainClass, alwaysIgnoreCase));
-				}
-			}
+
+			this.children = Arrays.stream(split)//
+					.filter(part -> StringUtils.hasText(part))//
+					.map(part -> new Part(part, domainClass, alwaysIgnoreCase))//
+					.collect(Collectors.toList());
 		}
 
 		public Iterator<Part> iterator() {
-
 			return children.iterator();
 		}
 
 		@Override
 		public String toString() {
-
 			return StringUtils.collectionToDelimitedString(children, " and ");
 		}
 	}
@@ -277,18 +266,18 @@ public class PartTree implements Iterable<OrPart> {
 		private static final Pattern EXISTS_BY_TEMPLATE = Pattern.compile("^(" + EXISTS_PATTERN + ")(\\p{Lu}.*?)??By");
 		private static final Pattern DELETE_BY_TEMPLATE = Pattern.compile("^(" + DELETE_PATTERN + ")(\\p{Lu}.*?)??By");
 		private static final String LIMITING_QUERY_PATTERN = "(First|Top)(\\d*)?";
-		private static final Pattern LIMITED_QUERY_TEMPLATE = Pattern.compile("^(" + QUERY_PATTERN + ")(" + DISTINCT + ")?"
-				+ LIMITING_QUERY_PATTERN + "(\\p{Lu}.*?)??By");
+		private static final Pattern LIMITED_QUERY_TEMPLATE = Pattern
+				.compile("^(" + QUERY_PATTERN + ")(" + DISTINCT + ")?" + LIMITING_QUERY_PATTERN + "(\\p{Lu}.*?)??By");
 
 		private final boolean distinct;
 		private final boolean count;
 		private final boolean exists;
 		private final boolean delete;
-		private final Integer maxResults;
+		private final Optional<Integer> maxResults;
 
-		public Subject(String subject) {
+		public Subject(Optional<String> subject) {
 
-			this.distinct = subject == null ? false : subject.contains(DISTINCT);
+			this.distinct = subject.map(it -> it.contains(DISTINCT)).orElse(false);
 			this.count = matches(subject, COUNT_BY_TEMPLATE);
 			this.exists = matches(subject, EXISTS_BY_TEMPLATE);
 			this.delete = matches(subject, DELETE_BY_TEMPLATE);
@@ -300,19 +289,19 @@ public class PartTree implements Iterable<OrPart> {
 		 * @return
 		 * @since 1.9
 		 */
-		private Integer returnMaxResultsIfFirstKSubjectOrNull(String subject) {
+		private Optional<Integer> returnMaxResultsIfFirstKSubjectOrNull(Optional<String> subject) {
 
-			if (subject == null) {
-				return null;
-			}
+			return subject.map(it -> {
 
-			Matcher grp = LIMITED_QUERY_TEMPLATE.matcher(subject);
+				Matcher grp = LIMITED_QUERY_TEMPLATE.matcher(it);
 
-			if (!grp.find()) {
-				return null;
-			}
+				if (!grp.find()) {
+					return null;
+				}
+
+				return StringUtils.hasText(grp.group(4)) ? Integer.valueOf(grp.group(4)) : 1;
+			});
 
-			return StringUtils.hasText(grp.group(4)) ? Integer.valueOf(grp.group(4)) : 1;
 		}
 
 		/**
@@ -321,7 +310,7 @@ public class PartTree implements Iterable<OrPart> {
 		 * @return
 		 * @since 1.8
 		 */
-		public Boolean isDelete() {
+		public boolean isDelete() {
 			return delete;
 		}
 
@@ -343,12 +332,12 @@ public class PartTree implements Iterable<OrPart> {
 			return distinct;
 		}
 
-		public Integer getMaxResults() {
+		public Optional<Integer> getMaxResults() {
 			return maxResults;
 		}
 
-		private final boolean matches(String subject, Pattern pattern) {
-			return subject == null ? false : pattern.matcher(subject).find();
+		private final boolean matches(Optional<String> subject, Pattern pattern) {
+			return subject.map(it -> pattern.matcher(it).find()).orElse(false);
 		}
 	}
 
@@ -358,13 +347,13 @@ public class PartTree implements Iterable<OrPart> {
 	 * @author Oliver Gierke
 	 * @author Phil Webb
 	 */
-	private static class Predicate {
+	private static class Predicate implements Iterable<OrPart> {
 
 		private static final Pattern ALL_IGNORE_CASE = Pattern.compile("AllIgnor(ing|e)Case");
 		private static final String ORDER_BY = "OrderBy";
 
-		private final List<OrPart> nodes = new ArrayList<OrPart>();
-		private final OrderBySource orderBySource;
+		private final List<OrPart> nodes;
+		private final @Getter Optional<OrderBySource> orderBySource;
 		private boolean alwaysIgnoreCase;
 
 		public Predicate(String predicate, Class<?> domainClass) {
@@ -375,8 +364,11 @@ public class PartTree implements Iterable<OrPart> {
 				throw new IllegalArgumentException("OrderBy must not be used more than once in a method name!");
 			}
 
-			buildTree(parts[0], domainClass);
-			this.orderBySource = parts.length == 2 ? new OrderBySource(parts[1], domainClass) : null;
+			this.nodes = Arrays.stream(split(parts[0], "Or"))//
+					.map(part -> new OrPart(part, domainClass, alwaysIgnoreCase))//
+					.collect(Collectors.toList());
+
+			this.orderBySource = Optional.ofNullable(parts.length == 2 ? new OrderBySource(parts[1], domainClass) : null);
 		}
 
 		private String detectAndSetAllIgnoreCase(String predicate) {
@@ -391,20 +383,13 @@ public class PartTree implements Iterable<OrPart> {
 			return predicate;
 		}
 
-		private void buildTree(String source, Class<?> domainClass) {
-
-			String[] split = split(source, "Or");
-			for (String part : split) {
-				nodes.add(new OrPart(part, domainClass, alwaysIgnoreCase));
-			}
-		}
-
+		/* 
+		 * (non-Javadoc)
+		 * @see java.lang.Iterable#iterator()
+		 */
+		@Override
 		public Iterator<OrPart> iterator() {
 			return nodes.iterator();
 		}
-
-		public OrderBySource getOrderBySource() {
-			return orderBySource;
-		}
 	}
 }

src/main/java/org/springframework/data/repository/support/AnnotationAttribute.java

@@ -15,8 +15,12 @@
  */
 package org.springframework.data.repository.support;
 
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+
 import java.lang.annotation.Annotation;
 import java.lang.reflect.AnnotatedElement;
+import java.util.Optional;
 
 import org.springframework.core.MethodParameter;
 import org.springframework.core.annotation.AnnotationUtils;
@@ -28,10 +32,11 @@ import org.springframework.util.Assert;
  * @author Oliver Gierke
  * @since 1.10
  */
+@RequiredArgsConstructor
 class AnnotationAttribute {
 
-	private final Class<? extends Annotation> annotationType;
-	private final String attributeName;
+	private final @NonNull Class<? extends Annotation> annotationType;
+	private final @NonNull Optional<String> attributeName;
 
 	/**
 	 * Creates a new {@link AnnotationAttribute} to the {@code value} attribute of the given {@link Annotation} type.
@@ -39,21 +44,7 @@ class AnnotationAttribute {
 	 * @param annotationType must not be {@literal null}.
 	 */
 	public AnnotationAttribute(Class<? extends Annotation> annotationType) {
-		this(annotationType, null);
-	}
-
-	/**
-	 * Creates a new {@link AnnotationAttribute} for the given {@link Annotation} type and annotation attribute name.
-	 * 
-	 * @param annotationType must not be {@literal null}.
-	 * @param attributeName can be {@literal null}, defaults to {@code value}.
-	 */
-	public AnnotationAttribute(Class<? extends Annotation> annotationType, String attributeName) {
-
-		Assert.notNull(annotationType, "AnnotationType must not be null!");
-
-		this.annotationType = annotationType;
-		this.attributeName = attributeName;
+		this(annotationType, Optional.empty());
 	}
 
 	/**
@@ -71,11 +62,12 @@ class AnnotationAttribute {
 	 * @param parameter must not be {@literal null}.
 	 * @return
 	 */
-	public Object getValueFrom(MethodParameter parameter) {
+	public Optional<Object> getValueFrom(MethodParameter parameter) {
 
 		Assert.notNull(parameter, "MethodParameter must not be null!");
 		Annotation annotation = parameter.getParameterAnnotation(annotationType);
-		return annotation == null ? null : getValueFrom(annotation);
+
+		return Optional.ofNullable(annotation).map(it -> getValueFrom(it));
 	}
 
 	/**
@@ -84,11 +76,12 @@ class AnnotationAttribute {
 	 * @param annotatedElement must not be {@literal null}.
 	 * @return
 	 */
-	public Object getValueFrom(AnnotatedElement annotatedElement) {
+	public Optional<Object> getValueFrom(AnnotatedElement annotatedElement) {
 
 		Assert.notNull(annotatedElement, "Annotated element must not be null!");
 		Annotation annotation = annotatedElement.getAnnotation(annotationType);
-		return annotation == null ? null : getValueFrom(annotation);
+
+		return Optional.ofNullable(annotation).map(it -> getValueFrom(annotation));
 	}
 
 	/**
@@ -100,7 +93,7 @@ class AnnotationAttribute {
 	public Object getValueFrom(Annotation annotation) {
 
 		Assert.notNull(annotation, "Annotation must not be null!");
-		return (String) (attributeName == null ? AnnotationUtils.getValue(annotation) : AnnotationUtils.getValue(
-				annotation, attributeName));
+		return (String) attributeName.map(it -> AnnotationUtils.getValue(annotation, it))
+				.orElseGet(() -> AnnotationUtils.getValue(annotation));
 	}
 }

src/main/java/org/springframework/data/repository/support/DefaultRepositoryInvokerFactory.java

@@ -73,17 +73,7 @@ public class DefaultRepositoryInvokerFactory implements RepositoryInvokerFactory
 	 */
 	@Override
 	public RepositoryInvoker getInvokerFor(Class<?> domainType) {
-
-		RepositoryInvoker invoker = invokers.get(domainType);
-
-		if (invoker != null) {
-			return invoker;
-		}
-
-		invoker = prepareInvokers(domainType);
-		invokers.put(domainType, invoker);
-
-		return invoker;
+		return invokers.computeIfAbsent(domainType, type -> prepareInvokers(type));
 	}
 
 	/**

src/main/java/org/springframework/data/repository/support/ReflectionRepositoryInvoker.java

@@ -19,8 +19,6 @@ import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
 
 import org.springframework.core.MethodParameter;
 import org.springframework.core.convert.ConversionException;
@@ -33,7 +31,6 @@ import org.springframework.data.repository.core.RepositoryMetadata;
 import org.springframework.data.repository.query.Param;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
-import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
@@ -170,25 +167,6 @@ class ReflectionRepositoryInvoker implements RepositoryInvoker {
 		}
 	}
 
-	/* 
-	 * (non-Javadoc)
-	 * @see org.springframework.data.repository.support.RepositoryInvoker#invokeQueryMethod(java.lang.reflect.Method, java.util.Map, org.springframework.data.domain.Pageable, org.springframework.data.domain.Sort)
-	 */
-	@Override
-	public Object invokeQueryMethod(Method method, Map<String, String[]> parameters, Pageable pageable, Sort sort) {
-
-		Assert.notNull(method, "Method must not be null!");
-		Assert.notNull(parameters, "Parameters must not be null!");
-
-		MultiValueMap<String, String> forward = new LinkedMultiValueMap<String, String>(parameters.size());
-
-		for (Entry<String, String[]> entry : parameters.entrySet()) {
-			forward.put(entry.getKey(), Arrays.asList(entry.getValue()));
-		}
-
-		return invokeQueryMethod(method, forward, pageable, sort);
-	}
-
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.rest.core.invoke.RepositoryInvoker#invokeQueryMethod(java.lang.reflect.Method, java.util.Map, org.springframework.data.domain.Pageable, org.springframework.data.domain.Sort)

src/main/java/org/springframework/data/repository/support/Repositories.java

@@ -22,6 +22,7 @@ import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 
 import org.springframework.beans.factory.BeanFactory;
@@ -50,7 +51,7 @@ public class Repositories implements Iterable<Class<?>> {
 	private static final RepositoryFactoryInformation<Object, Serializable> EMPTY_REPOSITORY_FACTORY_INFO = EmptyRepositoryFactoryInformation.INSTANCE;
 	private static final String DOMAIN_TYPE_MUST_NOT_BE_NULL = "Domain type must not be null!";
 
-	private final BeanFactory beanFactory;
+	private final Optional<BeanFactory> beanFactory;
 	private final Map<Class<?>, String> repositoryBeanNames;
 	private final Map<Class<?>, RepositoryFactoryInformation<Object, Serializable>> repositoryFactoryInfos;
 
@@ -59,9 +60,9 @@ public class Repositories implements Iterable<Class<?>> {
 	 */
 	private Repositories() {
 
-		this.beanFactory = null;
-		this.repositoryBeanNames = Collections.<Class<?>, String> emptyMap();
-		this.repositoryFactoryInfos = Collections.<Class<?>, RepositoryFactoryInformation<Object, Serializable>> emptyMap();
+		this.beanFactory = Optional.empty();
+		this.repositoryBeanNames = Collections.emptyMap();
+		this.repositoryFactoryInfos = Collections.emptyMap();
 	}
 
 	/**
@@ -74,7 +75,7 @@ public class Repositories implements Iterable<Class<?>> {
 
 		Assert.notNull(factory, "Factory must not be null!");
 
-		this.beanFactory = factory;
+		this.beanFactory = Optional.of(factory);
 		this.repositoryFactoryInfos = new HashMap<Class<?>, RepositoryFactoryInformation<Object, Serializable>>();
 		this.repositoryBeanNames = new HashMap<Class<?>, String>();
 
@@ -92,7 +93,7 @@ public class Repositories implements Iterable<Class<?>> {
 	@SuppressWarnings({ "rawtypes", "unchecked" })
 	private synchronized void cacheRepositoryFactory(String name) {
 
-		RepositoryFactoryInformation repositoryFactoryInformation = beanFactory.getBean(name,
+		RepositoryFactoryInformation repositoryFactoryInformation = beanFactory.get().getBean(name,
 				RepositoryFactoryInformation.class);
 		Class<?> domainType = ClassUtils
 				.getUserClass(repositoryFactoryInformation.getRepositoryInformation().getDomainType());
@@ -130,12 +131,12 @@ public class Repositories implements Iterable<Class<?>> {
 	 * @param domainClass must not be {@literal null}.
 	 * @return
 	 */
-	public Object getRepositoryFor(Class<?> domainClass) {
+	public Optional<Object> getRepositoryFor(Class<?> domainClass) {
 
 		Assert.notNull(domainClass, DOMAIN_TYPE_MUST_NOT_BE_NULL);
 
-		String repositoryBeanName = repositoryBeanNames.get(domainClass);
-		return repositoryBeanName == null || beanFactory == null ? null : beanFactory.getBean(repositoryBeanName);
+		Optional<String> repositoryBeanName = Optional.ofNullable(repositoryBeanNames.get(domainClass));
+		return beanFactory.flatMap(it -> repositoryBeanName.map(name -> it.getBean(name)));
 	}
 
 	/**
@@ -201,18 +202,12 @@ public class Repositories implements Iterable<Class<?>> {
 	 *         repository instance registered for the given interface.
 	 * @since 1.12
 	 */
-	public RepositoryInformation getRepositoryInformation(Class<?> repositoryInterface) {
+	public Optional<RepositoryInformation> getRepositoryInformation(Class<?> repositoryInterface) {
 
-		for (RepositoryFactoryInformation<Object, Serializable> factoryInformation : repositoryFactoryInfos.values()) {
-
-			RepositoryInformation information = factoryInformation.getRepositoryInformation();
-
-			if (information.getRepositoryInterface().equals(repositoryInterface)) {
-				return information;
-			}
-		}
-
-		return null;
+		return repositoryFactoryInfos.values().stream()//
+				.map(RepositoryFactoryInformation::getRepositoryInformation)//
+				.filter(information -> information.getRepositoryInterface().equals(repositoryInterface))//
+				.findFirst();
 	}
 
 	/**

src/main/java/org/springframework/data/repository/support/RepositoryInvoker.java

@@ -17,7 +17,6 @@ package org.springframework.data.repository.support;
 
 import java.io.Serializable;
 import java.lang.reflect.Method;
-import java.util.Map;
 
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
@@ -88,20 +87,6 @@ public interface RepositoryInvoker extends RepositoryInvocationInformation {
 	 */
 	void invokeDelete(Serializable id);
 
-	/**
-	 * Invokes the query method backed by the given {@link Method} using the given parameters, {@link Pageable} and
-	 * {@link Sort}.
-	 * 
-	 * @param method must not be {@literal null}.
-	 * @param parameters must not be {@literal null}.
-	 * @param pageable can be {@literal null}.
-	 * @param sort can be {@literal null}.
-	 * @return the result of the invoked query method.
-	 * @deprecated use {@link #invokeQueryMethod(Method, MultiValueMap, Pageable, Sort)} instead.
-	 */
-	@Deprecated
-	Object invokeQueryMethod(Method method, Map<String, String[]> parameters, Pageable pageable, Sort sort);
-
 	/**
 	 * Invokes the query method backed by the given {@link Method} using the given parameters, {@link Pageable} and
 	 * {@link Sort}.

src/main/java/org/springframework/data/support/IsNewStrategy.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.support;
 
+import java.util.Optional;
+
 /**
  * Strategy interface to determine whether a given entity is to be considered new.
  * 
@@ -29,5 +31,5 @@ public interface IsNewStrategy {
 	 * @param entity can be {@literal null}.
 	 * @return
 	 */
-	boolean isNew(Object entity);
+	boolean isNew(Optional<? extends Object> entity);
 }

src/main/java/org/springframework/data/support/PersistableIsNewStrategy.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.support;
 
+import java.util.Optional;
+
 import org.springframework.data.domain.Persistable;
 
 /**
@@ -26,17 +28,21 @@ public enum PersistableIsNewStrategy implements IsNewStrategy {
 
 	INSTANCE;
 
-	/* 
+	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.mapping.model.IsNewStrategy#isNew(java.lang.Object)
+	 * @see org.springframework.data.support.IsNewStrategy#isNew(java.util.Optional)
 	 */
-	public boolean isNew(Object entity) {
+	public boolean isNew(Optional<? extends Object> entity) {
 
-		if (!(entity instanceof Persistable)) {
-			throw new IllegalArgumentException(String.format("Given object of type %s does not implement %s!",
-					entity.getClass(), Persistable.class));
-		}
+		return entity.map(it -> {
 
-		return ((Persistable<?>) entity).isNew();
+			if (!(it instanceof Persistable)) {
+				throw new IllegalArgumentException(
+						String.format("Given object of type %s does not implement %s!", it.getClass(), Persistable.class));
+			}
+
+			return ((Persistable<?>) it).isNew();
+
+		}).orElse(false);
 	}
 }

src/main/java/org/springframework/data/util/AnnotatedTypeScanner.java

@@ -48,6 +48,7 @@ public class AnnotatedTypeScanner implements ResourceLoaderAware, EnvironmentAwa
 	 * 
 	 * @param annotationTypes the annotation types to scan for.
 	 */
+	@SafeVarargs
 	public AnnotatedTypeScanner(Class<? extends Annotation>... annotationTypes) {
 		this(true, annotationTypes);
 	}
@@ -58,6 +59,7 @@ public class AnnotatedTypeScanner implements ResourceLoaderAware, EnvironmentAwa
 	 * @param considerInterfaces whether to consider interfaces as well.
 	 * @param annotationTypes the annotations to scan for.
 	 */
+	@SafeVarargs
 	public AnnotatedTypeScanner(boolean considerInterfaces, Class<? extends Annotation>... annotationTypes) {
 
 		this.annotationTypess = Arrays.asList(annotationTypes);

src/main/java/org/springframework/data/util/Lazy.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.util;
+
+import lombok.EqualsAndHashCode;
+import lombok.RequiredArgsConstructor;
+
+import java.util.Optional;
+import java.util.function.Supplier;
+
+/**
+ * @author Oliver Gierke
+ */
+@RequiredArgsConstructor
+@EqualsAndHashCode
+public class Lazy<T> {
+
+	private final Supplier<T> supplier;
+	private Optional<T> value;
+
+	public static <T> Lazy<T> of(Supplier<T> supplier) {
+		return new Lazy<T>(supplier);
+	}
+
+	/**
+	 * Returns the value created by the configured {@link Supplier}.
+	 * 
+	 * @return
+	 */
+	public T get() {
+
+		if (value == null) {
+			this.value = Optional.ofNullable(supplier.get());
+		}
+
+		return value.orElse(null);
+	}
+}

src/main/java/org/springframework/data/util/Optionals.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.util;
+
+import lombok.experimental.UtilityClass;
+
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.Optional;
+import java.util.stream.Stream;
+
+import org.springframework.util.Assert;
+
+/**
+ * Utility methods to work with {@link Optional}s.
+ * 
+ * @author Oliver Gierke
+ */
+@UtilityClass
+public class Optionals {
+
+	/**
+	 * Returns whether any of the given {@link Optional}s is present.
+	 * 
+	 * @param optionals must not be {@literal null}.
+	 * @return
+	 */
+	public static boolean isAnyPresent(Optional<?>... optionals) {
+
+		Assert.notNull(optionals, "Optionals must not be null!");
+
+		return Arrays.stream(optionals).anyMatch(Optional::isPresent);
+	}
+
+	/**
+	 * Turns the given {@link Optional} into a one-element {@link Stream} or an empty one if not present.
+	 * 
+	 * @param optionals must not be {@literal null}.
+	 * @return
+	 */
+	@SafeVarargs
+	public static <T> Stream<T> toStream(Optional<? extends T>... optionals) {
+
+		Assert.notNull(optionals, "Optional must not be null!");
+
+		return Arrays.asList(optionals).stream().flatMap(it -> it.map(Stream::of).orElse(Stream.empty()));
+	}
+
+	public static <T> Optional<T> next(Iterator<T> iterator) {
+		return iterator.hasNext() ? Optional.of(iterator.next()) : Optional.empty();
+	}
+}

src/main/java/org/springframework/data/util/Pair.java

@@ -21,6 +21,10 @@ import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 
+import java.util.Map;
+import java.util.stream.Collector;
+import java.util.stream.Collectors;
+
 /**
  * A tuple of things.
  * 
@@ -66,4 +70,8 @@ public final class Pair<S, T> {
 	public T getSecond() {
 		return second;
 	}
+
+	public static <S, T> Collector<Pair<S, T>, ?, Map<S, T>> toMap() {
+		return Collectors.toMap(Pair::getFirst, Pair::getSecond);
+	}
 }

src/main/java/org/springframework/data/util/ReflectionUtils.java

@@ -15,12 +15,16 @@
  */
 package org.springframework.data.util;
 
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.util.Arrays;
+import java.util.Optional;
 import java.util.stream.Stream;
 
 import org.springframework.beans.BeanUtils;
@@ -105,18 +109,10 @@ public abstract class ReflectionUtils {
 	 * 
 	 * @author Oliver Gierke
 	 */
+	@RequiredArgsConstructor
 	public static class AnnotationFieldFilter implements DescribedFieldFilter {
 
-		private final Class<? extends Annotation> annotationType;
-
-		/**
-		 * Creates a new {@link AnnotationFieldFilter} for the given annotation type.
-		 */
-		public AnnotationFieldFilter(Class<? extends Annotation> annotationType) {
-
-			Assert.notNull(annotationType, "Annotation type must not be null!");
-			this.annotationType = annotationType;
-		}
+		private final @NonNull Class<? extends Annotation> annotationType;
 
 		/* 
 		 * (non-Javadoc)
@@ -242,27 +238,20 @@ public abstract class ReflectionUtils {
 	}
 
 	/**
-	 * Finds a constructoron the given type that matches the given constructor arguments.
+	 * Finds a constructor on the given type that matches the given constructor arguments.
 	 * 
 	 * @param type must not be {@literal null}.
 	 * @param constructorArguments must not be {@literal null}.
-	 * @return a {@link Constructor} that is compatible with the given arguments or {@literal null} if none found.
+	 * @return a {@link Constructor} that is compatible with the given arguments.
 	 */
-	public static Constructor<?> findConstructor(Class<?> type, Object... constructorArguments) {
+	public static Optional<Constructor<?>> findConstructor(Class<?> type, Object... constructorArguments) {
 
 		Assert.notNull(type, "Target type must not be null!");
 		Assert.notNull(constructorArguments, "Constructor arguments must not be null!");
 
-		for (Constructor<?> candidate : type.getDeclaredConstructors()) {
-
-			Class<?>[] parameterTypes = candidate.getParameterTypes();
-
-			if (argumentsMatch(parameterTypes, constructorArguments)) {
-				return candidate;
-			}
-		}
-
-		return null;
+		return Arrays.stream(type.getDeclaredConstructors())//
+				.filter(constructor -> argumentsMatch(constructor.getParameterTypes(), constructorArguments))//
+				.findFirst();
 	}
 
 	/**

src/main/java/org/springframework/data/util/Streamable.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.util;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
+
+import org.springframework.util.Assert;
+
+/**
+ * Simple interface to ease streamability of {@link Iterable}s.
+ * 
+ * @author Oliver Gierke
+ */
+public interface Streamable<T> extends Iterable<T> {
+
+	/**
+	 * Creates a non-parallel {@link Stream} of the underlying {@link Iterable}.
+	 * 
+	 * @return will never be {@literal null}.
+	 */
+	default Stream<T> stream() {
+		return StreamSupport.stream(spliterator(), false);
+	}
+
+	public static <T> Streamable<T> empty() {
+		return () -> Collections.emptyIterator();
+	}
+
+	@SafeVarargs
+	public static <T> Streamable<T> of(T... t) {
+		return () -> Arrays.asList(t).iterator();
+	}
+
+	/**
+	 * Returns a {@link Streamable} for the given {@link Iterable}.
+	 * 
+	 * @param iterable must not be {@literal null}.
+	 * @return
+	 */
+	public static <T> Streamable<T> of(Iterable<T> iterable) {
+
+		Assert.notNull(iterable, "Iterable must not be null!");
+
+		return () -> iterable.iterator();
+	}
+}

src/main/java/org/springframework/data/web/config/HateoasAwareSpringDataWebConfiguration.java

@@ -17,8 +17,12 @@ package org.springframework.data.web.config;
 
 import java.util.List;
 
+import org.springframework.beans.factory.ObjectFactory;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.convert.ConversionService;
 import org.springframework.data.web.HateoasPageableHandlerMethodArgumentResolver;
 import org.springframework.data.web.HateoasSortHandlerMethodArgumentResolver;
 import org.springframework.data.web.PagedResourcesAssembler;
@@ -36,6 +40,15 @@ import org.springframework.web.method.support.HandlerMethodArgumentResolver;
 @Configuration
 public class HateoasAwareSpringDataWebConfiguration extends SpringDataWebConfiguration {
 
+	/**
+	 * @param context must not be {@literal null}.
+	 * @param conversionService must not be {@literal null}.
+	 */
+	public HateoasAwareSpringDataWebConfiguration(ApplicationContext context,
+			@Qualifier("mvcConversionService") ObjectFactory<ConversionService> conversionService) {
+		super(context, conversionService);
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.web.config.SpringDataWebConfiguration#pageableResolver()

src/main/java/org/springframework/data/web/config/QuerydslWebConfiguration.java

@@ -16,6 +16,7 @@
 package org.springframework.data.web.config;
 
 import java.util.List;
+import java.util.Optional;
 
 import org.springframework.beans.factory.ObjectFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -54,7 +55,7 @@ public class QuerydslWebConfiguration extends WebMvcConfigurerAdapter {
 	@Lazy
 	@Bean
 	public QuerydslPredicateArgumentResolver querydslPredicateArgumentResolver() {
-		return new QuerydslPredicateArgumentResolver(querydslBindingsFactory(), conversionService.getObject());
+		return new QuerydslPredicateArgumentResolver(querydslBindingsFactory(), Optional.of(conversionService.getObject()));
 	}
 
 	@Lazy

src/main/java/org/springframework/data/web/config/SpringDataWebConfiguration.java

@@ -18,7 +18,6 @@ package org.springframework.data.web.config;
 import java.util.List;
 
 import org.springframework.beans.factory.ObjectFactory;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
@@ -52,8 +51,15 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 @Configuration
 public class SpringDataWebConfiguration extends WebMvcConfigurerAdapter {
 
-	@Autowired private ApplicationContext context;
-	@Autowired @Qualifier("mvcConversionService") ObjectFactory<ConversionService> conversionService;
+	private final ApplicationContext context;
+	private final ObjectFactory<ConversionService> conversionService;
+
+	public SpringDataWebConfiguration(ApplicationContext context,
+			@Qualifier("mvcConversionService") ObjectFactory<ConversionService> conversionService) {
+
+		this.context = context;
+		this.conversionService = conversionService;
+	}
 
 	/*
 	 * (non-Javadoc)

src/main/java/org/springframework/data/web/querydsl/QuerydslPredicateArgumentResolver.java

@@ -17,6 +17,7 @@ package org.springframework.data.web.querydsl;
 
 import java.util.Arrays;
 import java.util.Map.Entry;
+import java.util.Optional;
 
 import org.springframework.core.MethodParameter;
 import org.springframework.core.convert.ConversionService;
@@ -56,11 +57,11 @@ public class QuerydslPredicateArgumentResolver implements HandlerMethodArgumentR
 	 * @param factory
 	 * @param conversionService defaults to {@link DefaultConversionService} if {@literal null}.
 	 */
-	public QuerydslPredicateArgumentResolver(QuerydslBindingsFactory factory, ConversionService conversionService) {
+	public QuerydslPredicateArgumentResolver(QuerydslBindingsFactory factory,
+			Optional<ConversionService> conversionService) {
 
 		this.bindingsFactory = factory;
-		this.predicateBuilder = new QuerydslPredicateBuilder(
-				conversionService == null ? new DefaultConversionService() : conversionService,
+		this.predicateBuilder = new QuerydslPredicateBuilder(conversionService.orElse(new DefaultConversionService()),
 				factory.getEntityPathResolver());
 	}
 
@@ -88,7 +89,7 @@ public class QuerydslPredicateArgumentResolver implements HandlerMethodArgumentR
 	 * @see org.springframework.web.method.support.HandlerMethodArgumentResolver#resolveArgument(org.springframework.core.MethodParameter, org.springframework.web.method.support.ModelAndViewContainer, org.springframework.web.context.request.NativeWebRequest, org.springframework.web.bind.support.WebDataBinderFactory)
 	 */
 	@Override
-	@SuppressWarnings("unchecked")
+	@SuppressWarnings({ "unchecked", "rawtypes" })
 	public Predicate resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer,
 			NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
 
@@ -98,12 +99,15 @@ public class QuerydslPredicateArgumentResolver implements HandlerMethodArgumentR
 			parameters.put(entry.getKey(), Arrays.asList(entry.getValue()));
 		}
 
-		QuerydslPredicate annotation = parameter.getParameterAnnotation(QuerydslPredicate.class);
+		Optional<QuerydslPredicate> annotation = Optional
+				.ofNullable(parameter.getParameterAnnotation(QuerydslPredicate.class));
 		TypeInformation<?> domainType = extractTypeInfo(parameter).getActualType();
 
-		Class<? extends QuerydslBinderCustomizer<?>> customizer = (Class<? extends QuerydslBinderCustomizer<?>>) (annotation == null
-				? null : annotation.bindings());
-		QuerydslBindings bindings = bindingsFactory.createBindingsFor(customizer, domainType);
+		Optional<? extends Class<? extends QuerydslBinderCustomizer>> map = annotation
+				.<Class<? extends QuerydslBinderCustomizer>> map(it -> it.bindings());
+
+		QuerydslBindings bindings = bindingsFactory.createBindingsFor(domainType,
+				(Optional<Class<? extends QuerydslBinderCustomizer<?>>>) map);
 
 		return predicateBuilder.getPredicate(domainType, parameters, bindings);
 	}
@@ -117,13 +121,12 @@ public class QuerydslPredicateArgumentResolver implements HandlerMethodArgumentR
 	 */
 	static TypeInformation<?> extractTypeInfo(MethodParameter parameter) {
 
-		QuerydslPredicate annotation = parameter.getParameterAnnotation(QuerydslPredicate.class);
+		Optional<QuerydslPredicate> annotation = Optional
+				.ofNullable(parameter.getParameterAnnotation(QuerydslPredicate.class));
 
-		if (annotation != null && !Object.class.equals(annotation.root())) {
-			return ClassTypeInformation.from(annotation.root());
-		}
-
-		return detectDomainType(ClassTypeInformation.fromReturnTypeOf(parameter.getMethod()));
+		return annotation.filter(it -> !Object.class.equals(it.root()))//
+				.<TypeInformation<?>> map(it -> ClassTypeInformation.from(it.root()))//
+				.orElseGet(() -> detectDomainType(ClassTypeInformation.fromReturnTypeOf(parameter.getMethod())));
 	}
 
 	private static TypeInformation<?> detectDomainType(TypeInformation<?> source) {