Polish configuration property bean classes

Refactor the `org.springframework.boot.actuate.context` package
with the following changes:

- Deprecate several classes which would ideally be internal

- Replace `ConfigurationBeanFactoryMetadata` with a new
  `ConfigurationPropertiesBean` class to better reflect that we no
  longer maintain meta-data directly.

- Use constructor injection and final fields whenever possible

- Rename `ConfiguraionPropertiesBeanDefinition` to
  `ConfigurationPropertiesValueObjectBeanDefinition` to align
  with the binder changes made in commit 0b3015e4ff

- Add additional tests

Closes gh-16903

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/context/properties/ConfigurationPropertiesReportEndpoint.java

@@ -49,8 +49,8 @@ import org.springframework.beans.BeansException;
 import org.springframework.boot.actuate.endpoint.Sanitizer;
 import org.springframework.boot.actuate.endpoint.annotation.Endpoint;
 import org.springframework.boot.actuate.endpoint.annotation.ReadOperation;
-import org.springframework.boot.context.properties.ConfigurationBeanFactoryMetadata;
 import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.boot.context.properties.ConfigurationPropertiesBean;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
 import org.springframework.util.ClassUtils;
@@ -108,36 +108,17 @@ public class ConfigurationPropertiesReportEndpoint implements ApplicationContext
 
 	private ContextConfigurationProperties describeConfigurationProperties(ApplicationContext context,
 			ObjectMapper mapper) {
-		ConfigurationBeanFactoryMetadata beanFactoryMetadata = getBeanFactoryMetadata(context);
-		Map<String, Object> beans = getConfigurationPropertiesBeans(context, beanFactoryMetadata);
-		Map<String, ConfigurationPropertiesBeanDescriptor> beanDescriptors = new HashMap<>();
+		Map<String, ConfigurationPropertiesBean> beans = ConfigurationPropertiesBean.getAll(context);
+		Map<String, ConfigurationPropertiesBeanDescriptor> descriptors = new HashMap<>();
 		beans.forEach((beanName, bean) -> {
-			String prefix = extractPrefix(context, beanFactoryMetadata, beanName);
-			beanDescriptors.put(beanName, new ConfigurationPropertiesBeanDescriptor(prefix,
-					sanitize(prefix, safeSerialize(mapper, bean, prefix))));
+			String prefix = bean.getAnnotation().prefix();
+			descriptors.put(beanName, new ConfigurationPropertiesBeanDescriptor(prefix,
+					sanitize(prefix, safeSerialize(mapper, bean.getInstance(), prefix))));
 		});
-		return new ContextConfigurationProperties(beanDescriptors,
+		return new ContextConfigurationProperties(descriptors,
 				(context.getParent() != null) ? context.getParent().getId() : null);
 	}
 
-	private ConfigurationBeanFactoryMetadata getBeanFactoryMetadata(ApplicationContext context) {
-		Map<String, ConfigurationBeanFactoryMetadata> beans = context
-				.getBeansOfType(ConfigurationBeanFactoryMetadata.class);
-		if (beans.size() == 1) {
-			return beans.values().iterator().next();
-		}
-		return null;
-	}
-
-	private Map<String, Object> getConfigurationPropertiesBeans(ApplicationContext context,
-			ConfigurationBeanFactoryMetadata beanFactoryMetadata) {
-		Map<String, Object> beans = new HashMap<>(context.getBeansWithAnnotation(ConfigurationProperties.class));
-		if (beanFactoryMetadata != null) {
-			beans.putAll(beanFactoryMetadata.getBeansWithFactoryAnnotation(ConfigurationProperties.class));
-		}
-		return beans;
-	}
-
 	/**
 	 * Cautiously serialize the bean to a map (returning a map with an error message
 	 * instead of throwing an exception if there is a problem).
@@ -197,30 +178,6 @@ public class ConfigurationPropertiesReportEndpoint implements ApplicationContext
 				new SimpleFilterProvider().setDefaultFilter(new ConfigurationPropertiesPropertyFilter()));
 	}
 
-	/**
-	 * Extract configuration prefix from
-	 * {@link ConfigurationProperties @ConfigurationProperties} annotation.
-	 * @param context the application context
-	 * @param beanFactoryMetaData the bean factory meta-data
-	 * @param beanName the bean name
-	 * @return the prefix
-	 */
-	private String extractPrefix(ApplicationContext context, ConfigurationBeanFactoryMetadata beanFactoryMetaData,
-			String beanName) {
-		ConfigurationProperties annotation = context.findAnnotationOnBean(beanName, ConfigurationProperties.class);
-		if (beanFactoryMetaData != null) {
-			ConfigurationProperties override = beanFactoryMetaData.findFactoryAnnotation(beanName,
-					ConfigurationProperties.class);
-			if (override != null) {
-				// The @Bean-level @ConfigurationProperties overrides the one at type
-				// level when binding. Arguably we should render them both, but this one
-				// might be the most relevant for a starting point.
-				annotation = override;
-			}
-		}
-		return annotation.prefix();
-	}
-
 	/**
 	 * Sanitize all unwanted configuration properties to avoid leaking of sensitive
 	 * information.

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationBeanFactoryMetadata.java

@@ -24,6 +24,8 @@ import java.util.Map;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.GenericBeanDefinition;
 import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
@@ -31,12 +33,14 @@ import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.core.annotation.AnnotationUtils;
 
 /**
- * Utility class to memorize {@code @Bean} definition meta data during initialization of
+ * Utility class to memorize {@code @Bean} definition metadata during initialization of
  * the bean factory.
  *
  * @author Dave Syer
  * @since 1.1.0
+ * @deprecated since 2.2.0 in favor of {@link ConfigurationPropertiesBean}
  */
+@Deprecated
 public class ConfigurationBeanFactoryMetadata implements ApplicationContextAware {
 
 	/**
@@ -77,4 +81,13 @@ public class ConfigurationBeanFactoryMetadata implements ApplicationContextAware
 		this.applicationContext = (ConfigurableApplicationContext) applicationContext;
 	}
 
+	static void register(BeanDefinitionRegistry registry) {
+		if (!registry.containsBeanDefinition(BEAN_NAME)) {
+			GenericBeanDefinition definition = new GenericBeanDefinition();
+			definition.setBeanClass(ConfigurationBeanFactoryMetadata.class);
+			definition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
+			registry.registerBeanDefinition(ConfigurationBeanFactoryMetadata.BEAN_NAME, definition);
+		}
+	}
+
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBean.java

@@ -0,0 +1,205 @@
+/*
+ * Copyright 2012-2019 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
+ *
+ *      https://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.boot.context.properties;
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Method;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.springframework.aop.support.AopUtils;
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.boot.context.properties.bind.Bindable;
+import org.springframework.boot.context.properties.bind.Binder;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.core.ResolvableType;
+import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.util.Assert;
+import org.springframework.validation.annotation.Validated;
+
+/**
+ * Provides access to {@link ConfigurationProperties} beans from an
+ * {@link ApplicationContext}.
+ *
+ * @author Phillip Webb
+ * @since 2.0.0
+ * @see #get(ApplicationContext, Object, String)
+ * @see #getAll(ApplicationContext)
+ */
+public final class ConfigurationPropertiesBean {
+
+	private final String name;
+
+	private final Object instance;
+
+	private final ConfigurationProperties annotation;
+
+	private final Bindable<?> bindTarget;
+
+	private ConfigurationPropertiesBean(String name, Object instance, ConfigurationProperties annotation,
+			Bindable<?> bindTarget) {
+		this.name = name;
+		this.instance = instance;
+		this.annotation = annotation;
+		this.bindTarget = bindTarget;
+	}
+
+	/**
+	 * Return the name of the Spring bean.
+	 * @return the bean name
+	 */
+	public String getName() {
+		return this.name;
+	}
+
+	/**
+	 * Return the actual Spring bean instance.
+	 * @return the bean instance
+	 */
+	public Object getInstance() {
+		return this.instance;
+	}
+
+	/**
+	 * Return the {@link ConfigurationProperties} annotation for the bean. The annotation
+	 * may be defined on the bean itself or from the factory method that create the bean
+	 * (usually a {@link Bean @Bean} method).
+	 * @return the configuration properties annotation
+	 */
+	public ConfigurationProperties getAnnotation() {
+		return this.annotation;
+	}
+
+	/**
+	 * Return a {@link Bindable} instance suitable that can be used as a target for the
+	 * {@link Binder}.
+	 * @return a bind target for use with the {@link Binder}
+	 */
+	public Bindable<?> asBindTarget() {
+		return this.bindTarget;
+	}
+
+	/**
+	 * Return all {@link ConfigurationProperties @ConfigurationProperties} beans contained
+	 * in the given application context. Both directly annotated beans, as well as beans
+	 * that have {@link ConfigurationProperties @ConfigurationProperties} annotated
+	 * factory methods are included.
+	 * @param applicationContext the source application context
+	 * @return a map of all configuration properties beans keyed by the bean name
+	 */
+	public static Map<String, ConfigurationPropertiesBean> getAll(ApplicationContext applicationContext) {
+		Assert.notNull(applicationContext, "ApplicationContext must not be null");
+		if (applicationContext instanceof ConfigurableApplicationContext) {
+			return getAll((ConfigurableApplicationContext) applicationContext);
+		}
+		Map<String, ConfigurationPropertiesBean> propertiesBeans = new LinkedHashMap<>();
+		applicationContext.getBeansWithAnnotation(ConfigurationProperties.class)
+				.forEach((beanName, bean) -> propertiesBeans.put(beanName, get(applicationContext, bean, beanName)));
+		return propertiesBeans;
+	}
+
+	private static Map<String, ConfigurationPropertiesBean> getAll(ConfigurableApplicationContext applicationContext) {
+		Map<String, ConfigurationPropertiesBean> propertiesBeans = new LinkedHashMap<>();
+		ConfigurableListableBeanFactory beanFactory = applicationContext.getBeanFactory();
+		Iterator<String> beanNames = beanFactory.getBeanNamesIterator();
+		while (beanNames.hasNext()) {
+			String beanName = beanNames.next();
+			try {
+				Object bean = beanFactory.getBean(beanName);
+				ConfigurationPropertiesBean propertiesBean = get(applicationContext, bean, beanName);
+				if (propertiesBean != null) {
+					propertiesBeans.put(beanName, propertiesBean);
+				}
+			}
+			catch (NoSuchBeanDefinitionException ex) {
+			}
+		}
+		return propertiesBeans;
+	}
+
+	/**
+	 * Return a {@link ConfigurationPropertiesBean @ConfigurationPropertiesBean} instance
+	 * for the given bean details or {@code null} if the bean is not a
+	 * {@link ConfigurationProperties @ConfigurationProperties} object. Annotations are
+	 * considered both on the bean itself, as well as any factory method (for example a
+	 * {@link Bean @Bean} method).
+	 * @param applicationContext the source application context
+	 * @param bean the bean to consider
+	 * @param beanName the bean name
+	 * @return a configuration properties bean or {@code null} if the neither the bean or
+	 * factory method are annotated with
+	 * {@link ConfigurationProperties @ConfigurationProperties}
+	 */
+	public static ConfigurationPropertiesBean get(ApplicationContext applicationContext, Object bean, String beanName) {
+		Method factoryMethod = findFactoryMethod(applicationContext, beanName);
+		ConfigurationProperties annotation = getAnnotation(applicationContext, bean, beanName, factoryMethod,
+				ConfigurationProperties.class);
+		if (annotation == null) {
+			return null;
+		}
+		ResolvableType type = (factoryMethod != null) ? ResolvableType.forMethodReturnType(factoryMethod)
+				: ResolvableType.forClass(bean.getClass());
+		Validated validated = getAnnotation(applicationContext, bean, beanName, factoryMethod, Validated.class);
+		Annotation[] annotations = (validated != null) ? new Annotation[] { annotation, validated }
+				: new Annotation[] { annotation };
+		Bindable<?> bindTarget = Bindable.of(type).withAnnotations(annotations).withExistingValue(bean);
+		return new ConfigurationPropertiesBean(beanName, bean, annotation, bindTarget);
+	}
+
+	private static Method findFactoryMethod(ApplicationContext applicationContext, String beanName) {
+		if (applicationContext instanceof ConfigurableApplicationContext) {
+			return findFactoryMethod((ConfigurableApplicationContext) applicationContext, beanName);
+		}
+		return null;
+	}
+
+	private static Method findFactoryMethod(ConfigurableApplicationContext applicationContext, String beanName) {
+		ConfigurableListableBeanFactory beanFactory = applicationContext.getBeanFactory();
+		if (beanFactory.containsBeanDefinition(beanName)) {
+			BeanDefinition beanDefinition = beanFactory.getMergedBeanDefinition(beanName);
+			if (beanDefinition instanceof RootBeanDefinition) {
+				return ((RootBeanDefinition) beanDefinition).getResolvedFactoryMethod();
+			}
+		}
+		return null;
+	}
+
+	private static <A extends Annotation> A getAnnotation(ApplicationContext applicationContext, Object bean,
+			String beanName, Method factoryMethod, Class<A> annotationType) {
+		if (factoryMethod != null) {
+			A annotation = AnnotationUtils.findAnnotation(factoryMethod, annotationType);
+			if (annotation != null) {
+				return annotation;
+			}
+		}
+		A annotation = AnnotationUtils.findAnnotation(bean.getClass(), annotationType);
+		if (annotation != null) {
+			return annotation;
+		}
+		if (AopUtils.isAopProxy(bean)) {
+			return AnnotationUtils.findAnnotation(AopUtils.getTargetClass(bean), annotationType);
+		}
+		return null;
+	}
+
+}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBeanDefinition.java

@@ -1,70 +0,0 @@
-/*
- * Copyright 2012-2019 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
- *
- *      https://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.boot.context.properties;
-
-import java.lang.annotation.Annotation;
-import java.util.function.Supplier;
-
-import org.springframework.beans.factory.config.BeanDefinition;
-import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
-import org.springframework.beans.factory.support.GenericBeanDefinition;
-import org.springframework.boot.context.properties.bind.Bindable;
-import org.springframework.core.annotation.AnnotationUtils;
-import org.springframework.validation.annotation.Validated;
-
-/**
- * {@link BeanDefinition} that is used for registering
- * {@link ConfigurationProperties @ConfigurationProperties} beans that are bound at
- * creation time.
- *
- * @author Stephane Nicoll
- * @author Madhura Bhave
- */
-final class ConfigurationPropertiesBeanDefinition extends GenericBeanDefinition {
-
-	static ConfigurationPropertiesBeanDefinition from(ConfigurableListableBeanFactory beanFactory, String beanName,
-			Class<?> type) {
-		ConfigurationPropertiesBeanDefinition beanDefinition = new ConfigurationPropertiesBeanDefinition();
-		beanDefinition.setBeanClass(type);
-		beanDefinition.setInstanceSupplier(createBean(beanFactory, beanName, type));
-		return beanDefinition;
-	}
-
-	private static <T> Supplier<T> createBean(ConfigurableListableBeanFactory beanFactory, String beanName,
-			Class<T> type) {
-		return () -> {
-			ConfigurationProperties annotation = getAnnotation(type, ConfigurationProperties.class);
-			Validated validated = getAnnotation(type, Validated.class);
-			Annotation[] annotations = (validated != null) ? new Annotation[] { annotation, validated }
-					: new Annotation[] { annotation };
-			Bindable<T> bindable = Bindable.of(type).withAnnotations(annotations);
-			ConfigurationPropertiesBinder binder = beanFactory.getBean(ConfigurationPropertiesBinder.BEAN_NAME,
-					ConfigurationPropertiesBinder.class);
-			try {
-				return binder.bindOrCreate(bindable);
-			}
-			catch (Exception ex) {
-				throw new ConfigurationPropertiesBindException(beanName, type, annotation, ex);
-			}
-		};
-	}
-
-	private static <A extends Annotation> A getAnnotation(Class<?> type, Class<A> annotationType) {
-		return AnnotationUtils.findAnnotation(type, annotationType);
-	}
-
-}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBeanDefinitionRegistrar.java

@@ -1,112 +0,0 @@
-/*
- * Copyright 2012-2019 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
- *
- *      https://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.boot.context.properties;
-
-import java.lang.reflect.Constructor;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-
-import org.springframework.beans.BeanUtils;
-import org.springframework.beans.factory.BeanFactory;
-import org.springframework.beans.factory.config.BeanDefinition;
-import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
-import org.springframework.beans.factory.support.BeanDefinitionRegistry;
-import org.springframework.beans.factory.support.GenericBeanDefinition;
-import org.springframework.core.KotlinDetector;
-import org.springframework.core.annotation.MergedAnnotation;
-import org.springframework.core.annotation.MergedAnnotations;
-import org.springframework.core.annotation.MergedAnnotations.SearchStrategy;
-import org.springframework.util.Assert;
-import org.springframework.util.StringUtils;
-
-/**
- * Registers a bean definition for a type annotated with
- * {@link ConfigurationProperties @ConfigurationProperties} using the prefix of the
- * annotation in the bean name.
- *
- * @author Madhura Bhave
- */
-final class ConfigurationPropertiesBeanDefinitionRegistrar {
-
-	private static final boolean KOTLIN_PRESENT = KotlinDetector.isKotlinPresent();
-
-	private ConfigurationPropertiesBeanDefinitionRegistrar() {
-	}
-
-	static void register(BeanDefinitionRegistry registry, ConfigurableListableBeanFactory beanFactory, Class<?> type) {
-		MergedAnnotation<ConfigurationProperties> annotation = MergedAnnotations
-				.from(type, SearchStrategy.TYPE_HIERARCHY).get(ConfigurationProperties.class);
-		String name = getName(type, annotation);
-		if (!containsBeanDefinition(beanFactory, name)) {
-			registerBeanDefinition(registry, beanFactory, name, type, annotation);
-		}
-	}
-
-	private static String getName(Class<?> type, MergedAnnotation<ConfigurationProperties> annotation) {
-		String prefix = annotation.isPresent() ? annotation.getString("prefix") : "";
-		return (StringUtils.hasText(prefix) ? prefix + "-" + type.getName() : type.getName());
-	}
-
-	private static boolean containsBeanDefinition(ConfigurableListableBeanFactory beanFactory, String name) {
-		if (beanFactory.containsBeanDefinition(name)) {
-			return true;
-		}
-		BeanFactory parent = beanFactory.getParentBeanFactory();
-		if (parent instanceof ConfigurableListableBeanFactory) {
-			return containsBeanDefinition((ConfigurableListableBeanFactory) parent, name);
-		}
-		return false;
-	}
-
-	private static void registerBeanDefinition(BeanDefinitionRegistry registry,
-			ConfigurableListableBeanFactory beanFactory, String name, Class<?> type,
-			MergedAnnotation<ConfigurationProperties> annotation) {
-		Assert.isTrue(annotation.isPresent(), () -> "No " + ConfigurationProperties.class.getSimpleName()
-				+ " annotation found on  '" + type.getName() + "'.");
-		registry.registerBeanDefinition(name, createBeanDefinition(beanFactory, name, type));
-	}
-
-	private static BeanDefinition createBeanDefinition(ConfigurableListableBeanFactory beanFactory, String name,
-			Class<?> type) {
-		if (canBindAtCreationTime(type)) {
-			return ConfigurationPropertiesBeanDefinition.from(beanFactory, name, type);
-		}
-		GenericBeanDefinition definition = new GenericBeanDefinition();
-		definition.setBeanClass(type);
-		return definition;
-	}
-
-	private static boolean canBindAtCreationTime(Class<?> type) {
-		List<Constructor<?>> constructors = determineConstructors(type);
-		return (constructors.size() == 1 && constructors.get(0).getParameterCount() > 0);
-	}
-
-	private static List<Constructor<?>> determineConstructors(Class<?> type) {
-		List<Constructor<?>> constructors = new ArrayList<>();
-		if (KOTLIN_PRESENT && KotlinDetector.isKotlinType(type)) {
-			Constructor<?> primaryConstructor = BeanUtils.findPrimaryConstructor(type);
-			if (primaryConstructor != null) {
-				constructors.add(primaryConstructor);
-			}
-		}
-		else {
-			constructors.addAll(Arrays.asList(type.getDeclaredConstructors()));
-		}
-		return constructors;
-	}
-
-}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBeanRegistrar.java

@@ -13,45 +13,101 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package org.springframework.boot.context.properties;
 
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-import java.util.stream.Collectors;
+import java.lang.reflect.Constructor;
 
-import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.beans.BeanUtils;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.HierarchicalBeanFactory;
+import org.springframework.beans.factory.ListableBeanFactory;
+import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
-import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
-import org.springframework.core.type.AnnotationMetadata;
-import org.springframework.util.MultiValueMap;
+import org.springframework.beans.factory.support.GenericBeanDefinition;
+import org.springframework.core.KotlinDetector;
+import org.springframework.core.annotation.MergedAnnotation;
+import org.springframework.core.annotation.MergedAnnotations;
+import org.springframework.core.annotation.MergedAnnotations.SearchStrategy;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
 
 /**
- * {@link ImportBeanDefinitionRegistrar} for configuration properties support.
+ * Delegate used by {@link EnableConfigurationPropertiesRegistrar} and
+ * {@link ConfigurationPropertiesScanRegistrar} to register a bean definition for a
+ * {@link ConfigurationProperties @ConfigurationProperties} class.
  *
- * @author Dave Syer
- * @author Christian Dupuis
- * @author Stephane Nicoll
+ * @author Madhura Bhave
+ * @author Phillip Webb
  */
-class ConfigurationPropertiesBeanRegistrar implements ImportBeanDefinitionRegistrar {
+final class ConfigurationPropertiesBeanRegistrar {
 
-	@Override
-	public void registerBeanDefinitions(AnnotationMetadata metadata, BeanDefinitionRegistry registry) {
-		ConfigurableListableBeanFactory beanFactory = (ConfigurableListableBeanFactory) registry;
-		getTypes(metadata).forEach(
-				(type) -> ConfigurationPropertiesBeanDefinitionRegistrar.register(registry, beanFactory, type));
+	private final BeanDefinitionRegistry registry;
+
+	private final BeanFactory beanFactory;
+
+	ConfigurationPropertiesBeanRegistrar(BeanDefinitionRegistry registry) {
+		this.registry = registry;
+		this.beanFactory = (BeanFactory) this.registry;
 	}
 
-	private List<Class<?>> getTypes(AnnotationMetadata metadata) {
-		MultiValueMap<String, Object> attributes = metadata
-				.getAllAnnotationAttributes(EnableConfigurationProperties.class.getName(), false);
-		return collectClasses((attributes != null) ? attributes.get("value") : Collections.emptyList());
+	void register(Class<?> type) {
+		MergedAnnotation<ConfigurationProperties> annotation = MergedAnnotations
+				.from(type, SearchStrategy.TYPE_HIERARCHY).get(ConfigurationProperties.class);
+		register(type, annotation);
 	}
 
-	private List<Class<?>> collectClasses(List<?> values) {
-		return values.stream().flatMap((value) -> Arrays.stream((Class<?>[]) value))
-				.filter((type) -> void.class != type).collect(Collectors.toList());
+	void register(Class<?> type, MergedAnnotation<ConfigurationProperties> annotation) {
+		String name = getName(type, annotation);
+		if (!containsBeanDefinition(name)) {
+			registerBeanDefinition(name, type, annotation);
+		}
+	}
+
+	private String getName(Class<?> type, MergedAnnotation<ConfigurationProperties> annotation) {
+		String prefix = annotation.isPresent() ? annotation.getString("prefix") : "";
+		return (StringUtils.hasText(prefix) ? prefix + "-" + type.getName() : type.getName());
+	}
+
+	private boolean containsBeanDefinition(String name) {
+		return containsBeanDefinition(this.beanFactory, name);
+	}
+
+	private boolean containsBeanDefinition(BeanFactory beanFactory, String name) {
+		if (beanFactory instanceof ListableBeanFactory
+				&& ((ListableBeanFactory) beanFactory).containsBeanDefinition(name)) {
+			return true;
+		}
+		if (beanFactory instanceof HierarchicalBeanFactory) {
+			return containsBeanDefinition(((HierarchicalBeanFactory) beanFactory).getParentBeanFactory(), name);
+		}
+		return false;
+	}
+
+	private void registerBeanDefinition(String beanName, Class<?> type,
+			MergedAnnotation<ConfigurationProperties> annotation) {
+		Assert.state(annotation.isPresent(), () -> "No " + ConfigurationProperties.class.getSimpleName()
+				+ " annotation found on  '" + type.getName() + "'.");
+		this.registry.registerBeanDefinition(beanName, createBeanDefinition(beanName, type));
+	}
+
+	private BeanDefinition createBeanDefinition(String beanName, Class<?> type) {
+		if (isValueObject(type)) {
+			return new ConfigurationPropertiesValueObjectBeanDefinition(this.beanFactory, beanName, type);
+		}
+		GenericBeanDefinition definition = new GenericBeanDefinition();
+		definition.setBeanClass(type);
+		return definition;
+	}
+
+	private boolean isValueObject(Class<?> type) {
+		if (KotlinDetector.isKotlinPresent() && KotlinDetector.isKotlinType(type)) {
+			Constructor<?> primaryConstructor = BeanUtils.findPrimaryConstructor(type);
+			if (primaryConstructor != null) {
+				return primaryConstructor.getParameterCount() > 0;
+			}
+		}
+		Constructor<?>[] constructors = type.getDeclaredConstructors();
+		return constructors.length == 1 && constructors[0].getParameterCount() > 0;
 	}
 
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBindException.java

@@ -33,6 +33,10 @@ public class ConfigurationPropertiesBindException extends BeanCreationException
 
 	private final ConfigurationProperties annotation;
 
+	ConfigurationPropertiesBindException(ConfigurationPropertiesBean bean, Exception cause) {
+		this(bean.getName(), bean.getInstance().getClass(), bean.getAnnotation(), cause);
+	}
+
 	ConfigurationPropertiesBindException(String beanName, Class<?> beanType, ConfigurationProperties annotation,
 			Exception cause) {
 		super(beanName, getMessage(beanType, annotation), cause);

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBinder.java

@@ -23,6 +23,11 @@ import java.util.stream.Collectors;
 
 import org.springframework.beans.BeansException;
 import org.springframework.beans.PropertyEditorRegistry;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.GenericBeanDefinition;
 import org.springframework.boot.context.properties.bind.BindHandler;
 import org.springframework.boot.context.properties.bind.BindResult;
 import org.springframework.boot.context.properties.bind.Bindable;
@@ -45,43 +50,36 @@ import org.springframework.validation.Validator;
 import org.springframework.validation.annotation.Validated;
 
 /**
- * Internal class by the {@link ConfigurationPropertiesBindingPostProcessor} to handle the
- * actual {@link ConfigurationProperties @ConfigurationProperties} binding.
+ * Internal class used by the {@link ConfigurationPropertiesBindingPostProcessor} to
+ * handle the actual {@link ConfigurationProperties @ConfigurationProperties} binding.
  *
  * @author Stephane Nicoll
  * @author Phillip Webb
  */
-class ConfigurationPropertiesBinder implements ApplicationContextAware {
+class ConfigurationPropertiesBinder {
 
-	/**
-	 * The bean name that this binder is registered with.
-	 */
-	static final String BEAN_NAME = "org.springframework.boot.context.internalConfigurationPropertiesBinder";
+	private static final String BEAN_NAME = "org.springframework.boot.context.internalConfigurationPropertiesBinder";
 
-	private final String validatorBeanName;
+	private static final String FACTORY_BEAN_NAME = "org.springframework.boot.context.internalConfigurationPropertiesBinderFactory";
 
-	private ApplicationContext applicationContext;
+	private static final String VALIDATOR_BEAN_NAME = EnableConfigurationProperties.VALIDATOR_BEAN_NAME;
 
-	private PropertySources propertySources;
+	private final ApplicationContext applicationContext;
 
-	private Validator configurationPropertiesValidator;
+	private final PropertySources propertySources;
 
-	private boolean jsr303Present;
+	private final Validator configurationPropertiesValidator;
+
+	private final boolean jsr303Present;
 
 	private volatile Validator jsr303Validator;
 
 	private volatile Binder binder;
 
-	ConfigurationPropertiesBinder(String validatorBeanName) {
-		this.validatorBeanName = validatorBeanName;
-	}
-
-	@Override
-	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
+	ConfigurationPropertiesBinder(ApplicationContext applicationContext) {
 		this.applicationContext = applicationContext;
 		this.propertySources = new PropertySourcesDeducer(applicationContext).getPropertySources();
-		this.configurationPropertiesValidator = getConfigurationPropertiesValidator(applicationContext,
-				this.validatorBeanName);
+		this.configurationPropertiesValidator = getConfigurationPropertiesValidator(applicationContext);
 		this.jsr303Present = ConfigurationPropertiesJsr303Validator.isJsr303Present(applicationContext);
 	}
 
@@ -103,10 +101,9 @@ class ConfigurationPropertiesBinder implements ApplicationContextAware {
 		return annotation;
 	}
 
-	private Validator getConfigurationPropertiesValidator(ApplicationContext applicationContext,
-			String validatorBeanName) {
-		if (applicationContext.containsBean(validatorBeanName)) {
-			return applicationContext.getBean(validatorBeanName, Validator.class);
+	private Validator getConfigurationPropertiesValidator(ApplicationContext applicationContext) {
+		if (applicationContext.containsBean(VALIDATOR_BEAN_NAME)) {
+			return applicationContext.getBean(VALIDATOR_BEAN_NAME, Validator.class);
 		}
 		return null;
 	}
@@ -183,4 +180,46 @@ class ConfigurationPropertiesBinder implements ApplicationContextAware {
 		return null;
 	}
 
+	static void register(BeanDefinitionRegistry registry) {
+		if (!registry.containsBeanDefinition(FACTORY_BEAN_NAME)) {
+			GenericBeanDefinition definition = new GenericBeanDefinition();
+			definition.setBeanClass(ConfigurationPropertiesBinder.Factory.class);
+			definition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
+			registry.registerBeanDefinition(ConfigurationPropertiesBinder.FACTORY_BEAN_NAME, definition);
+		}
+		if (!registry.containsBeanDefinition(BEAN_NAME)) {
+			GenericBeanDefinition definition = new GenericBeanDefinition();
+			definition.setBeanClass(ConfigurationPropertiesBinder.class);
+			definition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
+			definition.setFactoryBeanName(FACTORY_BEAN_NAME);
+			definition.setFactoryMethodName("create");
+			registry.registerBeanDefinition(ConfigurationPropertiesBinder.BEAN_NAME, definition);
+		}
+	}
+
+	static ConfigurationPropertiesBinder get(BeanFactory beanFactory) {
+		return beanFactory.getBean(BEAN_NAME, ConfigurationPropertiesBinder.class);
+	}
+
+	/**
+	 * Factory bean used to create the {@link ConfigurationPropertiesBinder}. The bean
+	 * needs to be {@link ApplicationContextAware} since we can't directly inject an
+	 * {@link ApplicationContext} into the constructor without causing eager
+	 * {@link FactoryBean} initialization.
+	 */
+	static class Factory implements ApplicationContextAware {
+
+		private ApplicationContext applicationContext;
+
+		@Override
+		public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
+			this.applicationContext = applicationContext;
+		}
+
+		ConfigurationPropertiesBinder create() {
+			return new ConfigurationPropertiesBinder(this.applicationContext);
+		}
+
+	}
+
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBindingPostProcessor.java

@@ -16,23 +16,18 @@
 
 package org.springframework.boot.context.properties;
 
-import java.lang.annotation.Annotation;
-import java.lang.reflect.Method;
-
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
-import org.springframework.boot.context.properties.bind.Bindable;
+import org.springframework.beans.factory.support.GenericBeanDefinition;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
 import org.springframework.core.Ordered;
 import org.springframework.core.PriorityOrdered;
-import org.springframework.core.ResolvableType;
-import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.core.env.PropertySources;
-import org.springframework.validation.annotation.Validated;
+import org.springframework.util.Assert;
 
 /**
  * {@link BeanPostProcessor} to bind {@link PropertySources} to beans annotated with
@@ -56,16 +51,26 @@ public class ConfigurationPropertiesBindingPostProcessor
 	/**
 	 * The bean name of the configuration properties validator.
 	 * @deprecated since 2.2.0 in favor of
-	 * {@link ConfigurationPropertiesBindingPostProcessorRegistrar#VALIDATOR_BEAN_NAME}
+	 * {@link EnableConfigurationProperties#VALIDATOR_BEAN_NAME}
 	 */
 	@Deprecated
-	public static final String VALIDATOR_BEAN_NAME = ConfigurationPropertiesBindingPostProcessorRegistrar.VALIDATOR_BEAN_NAME;
-
-	private ConfigurationBeanFactoryMetadata beanFactoryMetadata;
+	public static final String VALIDATOR_BEAN_NAME = EnableConfigurationProperties.VALIDATOR_BEAN_NAME;
 
 	private ApplicationContext applicationContext;
 
-	private ConfigurationPropertiesBinder configurationPropertiesBinder;
+	private BeanDefinitionRegistry registry;
+
+	private ConfigurationPropertiesBinder binder;
+
+	/**
+	 * Create a new {@link ConfigurationPropertiesBindingPostProcessor} instance.
+	 * @deprecated since 2.2.0 in favor of
+	 * {@link EnableConfigurationProperties @EnableConfigurationProperties} or
+	 * {@link ConfigurationPropertiesBindingPostProcessor#register(BeanDefinitionRegistry)}
+	 */
+	@Deprecated
+	public ConfigurationPropertiesBindingPostProcessor() {
+	}
 
 	@Override
 	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
@@ -76,10 +81,8 @@ public class ConfigurationPropertiesBindingPostProcessor
 	public void afterPropertiesSet() throws Exception {
 		// We can't use constructor injection of the application context because
 		// it causes eager factory bean initialization
-		this.beanFactoryMetadata = this.applicationContext.getBean(ConfigurationBeanFactoryMetadata.BEAN_NAME,
-				ConfigurationBeanFactoryMetadata.class);
-		this.configurationPropertiesBinder = this.applicationContext.getBean(ConfigurationPropertiesBinder.BEAN_NAME,
-				ConfigurationPropertiesBinder.class);
+		this.registry = (BeanDefinitionRegistry) this.applicationContext.getAutowireCapableBeanFactory();
+		this.binder = ConfigurationPropertiesBinder.get(this.applicationContext);
 	}
 
 	@Override
@@ -89,51 +92,39 @@ public class ConfigurationPropertiesBindingPostProcessor
 
 	@Override
 	public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
-		ConfigurationProperties annotation = getAnnotation(bean, beanName, ConfigurationProperties.class);
-		if (annotation != null && !hasBeenBound(beanName)) {
-			bind(bean, beanName, annotation);
+		ConfigurationPropertiesBean configurationPropertiesBean = ConfigurationPropertiesBean
+				.get(this.applicationContext, bean, beanName);
+		if (configurationPropertiesBean != null && !hasBoundValueObject(beanName)) {
+			try {
+				this.binder.bind(configurationPropertiesBean.asBindTarget());
+			}
+			catch (Exception ex) {
+				throw new ConfigurationPropertiesBindException(configurationPropertiesBean, ex);
+			}
 		}
 		return bean;
 	}
 
-	private boolean hasBeenBound(String beanName) {
-		BeanDefinitionRegistry registry = (BeanDefinitionRegistry) this.applicationContext
-				.getAutowireCapableBeanFactory();
-		if (registry.containsBeanDefinition(beanName)) {
-			BeanDefinition beanDefinition = registry.getBeanDefinition(beanName);
-			return beanDefinition instanceof ConfigurationPropertiesBeanDefinition;
-		}
-		return false;
+	private boolean hasBoundValueObject(String beanName) {
+		return this.registry.containsBeanDefinition(beanName) && this.registry
+				.getBeanDefinition(beanName) instanceof ConfigurationPropertiesValueObjectBeanDefinition;
 	}
 
-	private void bind(Object bean, String beanName, ConfigurationProperties annotation) {
-		ResolvableType type = getBeanType(bean, beanName);
-		Validated validated = getAnnotation(bean, beanName, Validated.class);
-		Annotation[] annotations = (validated != null) ? new Annotation[] { annotation, validated }
-				: new Annotation[] { annotation };
-		Bindable<?> target = Bindable.of(type).withExistingValue(bean).withAnnotations(annotations);
-		try {
-			this.configurationPropertiesBinder.bind(target);
+	/**
+	 * Register a {@link ConfigurationPropertiesBindingPostProcessor} bean if one is not
+	 * already registered.
+	 * @param registry the bean definition registry
+	 * @since 2.2.0
+	 */
+	public static void register(BeanDefinitionRegistry registry) {
+		Assert.notNull(registry, "Registry must not be null");
+		if (!registry.containsBeanDefinition(BEAN_NAME)) {
+			GenericBeanDefinition definition = new GenericBeanDefinition();
+			definition.setBeanClass(ConfigurationPropertiesBindingPostProcessor.class);
+			definition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
+			registry.registerBeanDefinition(BEAN_NAME, definition);
 		}
-		catch (Exception ex) {
-			throw new ConfigurationPropertiesBindException(beanName, bean.getClass(), annotation, ex);
-		}
-	}
-
-	private ResolvableType getBeanType(Object bean, String beanName) {
-		Method factoryMethod = this.beanFactoryMetadata.findFactoryMethod(beanName);
-		if (factoryMethod != null) {
-			return ResolvableType.forMethodReturnType(factoryMethod);
-		}
-		return ResolvableType.forClass(bean.getClass());
-	}
-
-	private <A extends Annotation> A getAnnotation(Object bean, String beanName, Class<A> type) {
-		A annotation = this.beanFactoryMetadata.findFactoryAnnotation(beanName, type);
-		if (annotation == null) {
-			annotation = AnnotationUtils.findAnnotation(bean.getClass(), type);
-		}
-		return annotation;
+		ConfigurationPropertiesBinder.register(registry);
 	}
 
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBindingPostProcessorRegistrar.java

@@ -16,9 +16,7 @@
 
 package org.springframework.boot.context.properties;
 
-import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
-import org.springframework.beans.factory.support.GenericBeanDefinition;
 import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
 import org.springframework.core.type.AnnotationMetadata;
 
@@ -29,45 +27,20 @@ import org.springframework.core.type.AnnotationMetadata;
  * @author Dave Syer
  * @author Phillip Webb
  * @since 1.0.0
+ * @deprecated since 2.2.0 in favor of
+ * {@link EnableConfigurationProperties @EnableConfigurationProperties}
  */
+@Deprecated
 public class ConfigurationPropertiesBindingPostProcessorRegistrar implements ImportBeanDefinitionRegistrar {
 
-	/**
-	 * The bean name of the configuration properties validator.
-	 */
-	public static final String VALIDATOR_BEAN_NAME = "configurationPropertiesValidator";
-
 	@Override
 	public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
-		if (!registry.containsBeanDefinition(ConfigurationPropertiesBinder.BEAN_NAME)) {
-			registerConfigurationPropertiesBinder(registry);
+		// Spring Cloud Function may call this with a null importingClassMetadata
+		if (importingClassMetadata == null) {
+			EnableConfigurationPropertiesRegistrar.registerInfrastructureBeans(registry);
+			return;
 		}
-		if (!registry.containsBeanDefinition(ConfigurationPropertiesBindingPostProcessor.BEAN_NAME)) {
-			registerConfigurationPropertiesBindingPostProcessor(registry);
-			registerConfigurationBeanFactoryMetadata(registry);
-		}
-	}
-
-	private void registerConfigurationPropertiesBinder(BeanDefinitionRegistry registry) {
-		GenericBeanDefinition definition = new GenericBeanDefinition();
-		definition.setBeanClass(ConfigurationPropertiesBinder.class);
-		definition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
-		definition.getConstructorArgumentValues().addIndexedArgumentValue(0, VALIDATOR_BEAN_NAME);
-		registry.registerBeanDefinition(ConfigurationPropertiesBinder.BEAN_NAME, definition);
-	}
-
-	private void registerConfigurationPropertiesBindingPostProcessor(BeanDefinitionRegistry registry) {
-		GenericBeanDefinition definition = new GenericBeanDefinition();
-		definition.setBeanClass(ConfigurationPropertiesBindingPostProcessor.class);
-		definition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
-		registry.registerBeanDefinition(ConfigurationPropertiesBindingPostProcessor.BEAN_NAME, definition);
-	}
-
-	private void registerConfigurationBeanFactoryMetadata(BeanDefinitionRegistry registry) {
-		GenericBeanDefinition definition = new GenericBeanDefinition();
-		definition.setBeanClass(ConfigurationBeanFactoryMetadata.class);
-		definition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
-		registry.registerBeanDefinition(ConfigurationBeanFactoryMetadata.BEAN_NAME, definition);
+		new EnableConfigurationPropertiesRegistrar().registerBeanDefinitions(importingClassMetadata, registry);
 	}
 
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesScan.java

@@ -23,6 +23,7 @@ import java.lang.annotation.Target;
 
 import org.springframework.context.annotation.Import;
 import org.springframework.core.annotation.AliasFor;
+import org.springframework.stereotype.Component;
 
 /**
  * Configures the base packages used when scanning for
@@ -30,6 +31,9 @@ import org.springframework.core.annotation.AliasFor;
  * {@link #basePackageClasses()}, {@link #basePackages()} or its alias {@link #value()}
  * may be specified to define specific packages to scan. If specific packages are not
  * defined scanning will occur from the package of the class with this annotation.
+ * <p>
+ * Note: Classes annotated or meta-annotated with {@link Component @Component} will not be
+ * picked up by this annotation.
  *
  * @author Madhura Bhave
  * @since 2.2.0
@@ -37,7 +41,8 @@ import org.springframework.core.annotation.AliasFor;
 @Target(ElementType.TYPE)
 @Retention(RetentionPolicy.RUNTIME)
 @Documented
-@Import({ ConfigurationPropertiesScanRegistrar.class, ConfigurationPropertiesBindingPostProcessorRegistrar.class })
+@Import({ ConfigurationPropertiesScanRegistrar.class })
+@EnableConfigurationProperties
 public @interface ConfigurationPropertiesScan {
 
 	/**

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesScanRegistrar.java

@@ -19,12 +19,10 @@ import java.util.Arrays;
 import java.util.LinkedHashSet;
 import java.util.Set;
 
+import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.config.BeanDefinition;
-import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.boot.context.TypeExcludeFilter;
-import org.springframework.context.EnvironmentAware;
-import org.springframework.context.ResourceLoaderAware;
 import org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider;
 import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
 import org.springframework.core.annotation.AnnotationAttributes;
@@ -43,18 +41,23 @@ import org.springframework.util.StringUtils;
  * {@link ConfigurationProperties @ConfigurationProperties} bean definitions via scanning.
  *
  * @author Madhura Bhave
+ * @author Phillip Webb
  */
-class ConfigurationPropertiesScanRegistrar
-		implements ImportBeanDefinitionRegistrar, EnvironmentAware, ResourceLoaderAware {
+class ConfigurationPropertiesScanRegistrar implements ImportBeanDefinitionRegistrar {
 
-	private Environment environment;
+	private final Environment environment;
 
-	private ResourceLoader resourceLoader;
+	private final ResourceLoader resourceLoader;
+
+	ConfigurationPropertiesScanRegistrar(Environment environment, ResourceLoader resourceLoader) {
+		this.environment = environment;
+		this.resourceLoader = resourceLoader;
+	}
 
 	@Override
 	public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
 		Set<String> packagesToScan = getPackagesToScan(importingClassMetadata);
-		register(registry, (ConfigurableListableBeanFactory) registry, packagesToScan);
+		scan(registry, packagesToScan);
 	}
 
 	private Set<String> getPackagesToScan(AnnotationMetadata metadata) {
@@ -69,43 +72,43 @@ class ConfigurationPropertiesScanRegistrar
 		if (packagesToScan.isEmpty()) {
 			packagesToScan.add(ClassUtils.getPackageName(metadata.getClassName()));
 		}
+		packagesToScan.removeIf((candidate) -> !StringUtils.hasText(candidate));
 		return packagesToScan;
 	}
 
-	protected void register(BeanDefinitionRegistry registry, ConfigurableListableBeanFactory beanFactory,
-			Set<String> packagesToScan) {
-		scan(packagesToScan, beanFactory, registry);
+	private void scan(BeanDefinitionRegistry registry, Set<String> packages) {
+		ConfigurationPropertiesBeanRegistrar registrar = new ConfigurationPropertiesBeanRegistrar(registry);
+		ClassPathScanningCandidateComponentProvider scanner = getScanner(registry);
+		for (String basePackage : packages) {
+			for (BeanDefinition candidate : scanner.findCandidateComponents(basePackage)) {
+				register(registrar, candidate.getBeanClassName());
+			}
+		}
 	}
 
-	protected void scan(Set<String> packages, ConfigurableListableBeanFactory beanFactory,
-			BeanDefinitionRegistry registry) {
+	private ClassPathScanningCandidateComponentProvider getScanner(BeanDefinitionRegistry registry) {
 		ClassPathScanningCandidateComponentProvider scanner = new ClassPathScanningCandidateComponentProvider(false);
 		scanner.setEnvironment(this.environment);
 		scanner.setResourceLoader(this.resourceLoader);
 		scanner.addIncludeFilter(new AnnotationTypeFilter(ConfigurationProperties.class));
 		TypeExcludeFilter typeExcludeFilter = new TypeExcludeFilter();
-		typeExcludeFilter.setBeanFactory(beanFactory);
+		typeExcludeFilter.setBeanFactory((BeanFactory) registry);
 		scanner.addExcludeFilter(typeExcludeFilter);
-		for (String basePackage : packages) {
-			if (StringUtils.hasText(basePackage)) {
-				scan(beanFactory, registry, scanner, basePackage);
-			}
+		return scanner;
+	}
+
+	private void register(ConfigurationPropertiesBeanRegistrar registrar, String className) throws LinkageError {
+		try {
+			register(registrar, ClassUtils.forName(className, null));
+		}
+		catch (ClassNotFoundException ex) {
+			// Ignore
 		}
 	}
 
-	private void scan(ConfigurableListableBeanFactory beanFactory, BeanDefinitionRegistry registry,
-			ClassPathScanningCandidateComponentProvider scanner, String basePackage) throws LinkageError {
-		for (BeanDefinition candidate : scanner.findCandidateComponents(basePackage)) {
-			String beanClassName = candidate.getBeanClassName();
-			try {
-				Class<?> type = ClassUtils.forName(beanClassName, null);
-				if (!isComponent(type)) {
-					ConfigurationPropertiesBeanDefinitionRegistrar.register(registry, beanFactory, type);
-				}
-			}
-			catch (ClassNotFoundException ex) {
-				// Ignore
-			}
+	private void register(ConfigurationPropertiesBeanRegistrar registrar, Class<?> type) {
+		if (!isComponent(type)) {
+			registrar.register(type);
 		}
 	}
 
@@ -113,14 +116,4 @@ class ConfigurationPropertiesScanRegistrar
 		return MergedAnnotations.from(type, SearchStrategy.TYPE_HIERARCHY).isPresent(Component.class);
 	}
 
-	@Override
-	public void setEnvironment(Environment environment) {
-		this.environment = environment;
-	}
-
-	@Override
-	public void setResourceLoader(ResourceLoader resourceLoader) {
-		this.resourceLoader = resourceLoader;
-	}
-
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesValueObjectBeanDefinition.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2012-2019 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
+ *
+ *      https://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.boot.context.properties;
+
+import java.lang.annotation.Annotation;
+
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.support.GenericBeanDefinition;
+import org.springframework.boot.context.properties.bind.Bindable;
+import org.springframework.core.ResolvableType;
+import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.validation.annotation.Validated;
+
+/**
+ * {@link BeanDefinition} that is used for registering
+ * {@link ConfigurationProperties @ConfigurationProperties} value object beans that are
+ * bound at creation time.
+ *
+ * @author Stephane Nicoll
+ * @author Madhura Bhave
+ */
+final class ConfigurationPropertiesValueObjectBeanDefinition extends GenericBeanDefinition {
+
+	private final BeanFactory beanFactory;
+
+	private final String beanName;
+
+	ConfigurationPropertiesValueObjectBeanDefinition(BeanFactory beanFactory, String beanName, Class<?> beanClass) {
+		this.beanFactory = beanFactory;
+		this.beanName = beanName;
+		setBeanClass(beanClass);
+		setInstanceSupplier(this::createBean);
+	}
+
+	private Object createBean() {
+		ConfigurationPropertiesBinder binder = ConfigurationPropertiesBinder.get(this.beanFactory);
+		ResolvableType type = ResolvableType.forClass(getBeanClass());
+		ConfigurationProperties annotation = AnnotationUtils.findAnnotation(getBeanClass(),
+				ConfigurationProperties.class);
+		Validated validated = AnnotationUtils.findAnnotation(getBeanClass(), Validated.class);
+		Annotation[] annotations = (validated != null) ? new Annotation[] { annotation, validated }
+				: new Annotation[] { annotation };
+		Bindable<Object> bindTarget = Bindable.of(type).withAnnotations(annotations);
+		try {
+			return binder.bindOrCreate(bindTarget);
+		}
+		catch (Exception ex) {
+			throw new ConfigurationPropertiesBindException(this.beanName, getBeanClass(), annotation, ex);
+		}
+	}
+
+}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/EnableConfigurationProperties.java

@@ -37,9 +37,15 @@ import org.springframework.context.annotation.Import;
 @Target(ElementType.TYPE)
 @Retention(RetentionPolicy.RUNTIME)
 @Documented
-@Import({ ConfigurationPropertiesBeanRegistrar.class, ConfigurationPropertiesBindingPostProcessorRegistrar.class })
+@Import(EnableConfigurationPropertiesRegistrar.class)
 public @interface EnableConfigurationProperties {
 
+	/**
+	 * The bean name of the configuration properties validator.
+	 * @since 2.2.0
+	 */
+	String VALIDATOR_BEAN_NAME = "configurationPropertiesValidator";
+
 	/**
 	 * Convenient way to quickly register
 	 * {@link ConfigurationProperties @ConfigurationProperties} annotated beans with

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/EnableConfigurationPropertiesRegistrar.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2012-2019 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
+ *
+ *      https://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.boot.context.properties;
+
+import java.util.Arrays;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
+import org.springframework.core.annotation.MergedAnnotation;
+import org.springframework.core.type.AnnotationMetadata;
+
+/**
+ * {@link ImportBeanDefinitionRegistrar} for
+ * {@link EnableConfigurationProperties @EnableConfigurationProperties}.
+ *
+ * @author Phillip Webb
+ */
+class EnableConfigurationPropertiesRegistrar implements ImportBeanDefinitionRegistrar {
+
+	@Override
+	public void registerBeanDefinitions(AnnotationMetadata metadata, BeanDefinitionRegistry registry) {
+		registerInfrastructureBeans(registry);
+		ConfigurationPropertiesBeanRegistrar beanRegistrar = new ConfigurationPropertiesBeanRegistrar(registry);
+		getTypes(metadata).forEach(beanRegistrar::register);
+	}
+
+	private Set<Class<?>> getTypes(AnnotationMetadata metadata) {
+		return metadata.getAnnotations().stream(EnableConfigurationProperties.class)
+				.flatMap((annotation) -> Arrays.stream(annotation.getClassArray(MergedAnnotation.VALUE)))
+				.filter((type) -> void.class != type).collect(Collectors.toSet());
+	}
+
+	@SuppressWarnings("deprecation")
+	static void registerInfrastructureBeans(BeanDefinitionRegistry registry) {
+		ConfigurationPropertiesBindingPostProcessor.register(registry);
+		ConfigurationBeanFactoryMetadata.register(registry);
+	}
+
+}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/PropertySourcesDeducer.java

@@ -27,6 +27,7 @@ import org.springframework.core.env.ConfigurableEnvironment;
 import org.springframework.core.env.Environment;
 import org.springframework.core.env.MutablePropertySources;
 import org.springframework.core.env.PropertySources;
+import org.springframework.util.Assert;
 
 /**
  * Utility to deduce the {@link PropertySources} to use for configuration binding.
@@ -49,19 +50,9 @@ class PropertySourcesDeducer {
 			return configurer.getAppliedPropertySources();
 		}
 		MutablePropertySources sources = extractEnvironmentPropertySources();
-		if (sources != null) {
-			return sources;
-		}
-		throw new IllegalStateException(
+		Assert.state(sources != null,
 				"Unable to obtain PropertySources from PropertySourcesPlaceholderConfigurer or Environment");
-	}
-
-	private MutablePropertySources extractEnvironmentPropertySources() {
-		Environment environment = this.applicationContext.getEnvironment();
-		if (environment instanceof ConfigurableEnvironment) {
-			return ((ConfigurableEnvironment) environment).getPropertySources();
-		}
-		return null;
+		return sources;
 	}
 
 	private PropertySourcesPlaceholderConfigurer getSinglePropertySourcesPlaceholderConfigurer() {
@@ -78,4 +69,12 @@ class PropertySourcesDeducer {
 		return null;
 	}
 
+	private MutablePropertySources extractEnvironmentPropertySources() {
+		Environment environment = this.applicationContext.getEnvironment();
+		if (environment instanceof ConfigurableEnvironment) {
+			return ((ConfigurableEnvironment) environment).getPropertySources();
+		}
+		return null;
+	}
+
 }

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/ConfigurationPropertiesBeanRegistrarTests.java

@@ -13,130 +13,98 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.boot.context.properties;
 
-import java.io.IOException;
+package org.springframework.boot.context.properties;
 
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.beans.factory.support.GenericBeanDefinition;
-import org.springframework.core.type.AnnotationMetadata;
-import org.springframework.core.type.classreading.SimpleMetadataReaderFactory;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.verifyZeroInteractions;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
  * Tests for {@link ConfigurationPropertiesBeanRegistrar}.
  *
  * @author Madhura Bhave
  * @author Stephane Nicoll
+ * @author Phillip Webb
  */
 class ConfigurationPropertiesBeanRegistrarTests {
 
-	private final ConfigurationPropertiesBeanRegistrar registrar = new ConfigurationPropertiesBeanRegistrar();
+	private BeanDefinitionRegistry registry = new DefaultListableBeanFactory();
 
-	private final DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();
+	private ConfigurationPropertiesBeanRegistrar registrar = new ConfigurationPropertiesBeanRegistrar(this.registry);
 
 	@Test
-	void typeWithDefaultConstructorShouldRegisterGenericBeanDefinition() throws Exception {
-		this.registrar.registerBeanDefinitions(getAnnotationMetadata(TestConfiguration.class), this.beanFactory);
-		BeanDefinition beanDefinition = this.beanFactory.getBeanDefinition(
-				"foo-org.springframework.boot.context.properties.ConfigurationPropertiesBeanRegistrarTests$FooProperties");
-		assertThat(beanDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
+	void registerWhenNotAlreadyRegisteredAddBeanDefinition() {
+		String beanName = "beancp-" + BeanConfigurationProperties.class.getName();
+		this.registrar.register(BeanConfigurationProperties.class);
+		BeanDefinition definition = this.registry.getBeanDefinition(beanName);
+		assertThat(definition).isNotNull();
+		assertThat(definition.getBeanClassName()).isEqualTo(BeanConfigurationProperties.class.getName());
 	}
 
 	@Test
-	void typeWithOneConstructorWithParametersShouldRegisterConfigurationPropertiesBeanDefinition() throws Exception {
-		this.registrar.registerBeanDefinitions(getAnnotationMetadata(TestConfiguration.class), this.beanFactory);
-		BeanDefinition beanDefinition = this.beanFactory.getBeanDefinition(
-				"bar-org.springframework.boot.context.properties.ConfigurationPropertiesBeanRegistrarTests$BarProperties");
-		assertThat(beanDefinition).isExactlyInstanceOf(ConfigurationPropertiesBeanDefinition.class);
+	void registerWhenAlreadyContainsNameDoesNotReplace() {
+		String beanName = "beancp-" + BeanConfigurationProperties.class.getName();
+		this.registry.registerBeanDefinition(beanName, new GenericBeanDefinition());
+		this.registrar.register(BeanConfigurationProperties.class);
+		BeanDefinition definition = this.registry.getBeanDefinition(beanName);
+		assertThat(definition).isNotNull();
+		assertThat(definition.getBeanClassName()).isNull();
 	}
 
 	@Test
-	void typeWithMultipleConstructorsShouldRegisterGenericBeanDefinition() throws Exception {
-		this.registrar.registerBeanDefinitions(getAnnotationMetadata(TestConfiguration.class), this.beanFactory);
-		BeanDefinition beanDefinition = this.beanFactory.getBeanDefinition(
-				"bing-org.springframework.boot.context.properties.ConfigurationPropertiesBeanRegistrarTests$BingProperties");
-		assertThat(beanDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
+	void registerWhenNoAnnotationThrowsException() {
+		assertThatIllegalStateException()
+				.isThrownBy(() -> this.registrar.register(NoAnnotationConfigurationProperties.class))
+				.withMessageContaining("No ConfigurationProperties annotation found");
 	}
 
 	@Test
-	void typeWithNoAnnotationShouldFail() {
-		assertThatIllegalArgumentException()
-				.isThrownBy(() -> this.registrar
-						.registerBeanDefinitions(getAnnotationMetadata(InvalidConfiguration.class), this.beanFactory))
-				.withMessageContaining("No ConfigurationProperties annotation found")
-				.withMessageContaining(ConfigurationPropertiesBeanRegistrar.class.getName());
+	void registerWhenValueObjectRegistersValueObjectBeanDefinition() {
+		String beanName = "valuecp-" + ValueObjectConfigurationProperties.class.getName();
+		this.registrar.register(ValueObjectConfigurationProperties.class);
+		BeanDefinition definition = this.registry.getBeanDefinition(beanName);
+		assertThat(definition).isInstanceOf(ConfigurationPropertiesValueObjectBeanDefinition.class);
 	}
 
 	@Test
-	void registrationWithDuplicatedTypeShouldRegisterSingleBeanDefinition() throws IOException {
-		DefaultListableBeanFactory factory = spy(this.beanFactory);
-		this.registrar.registerBeanDefinitions(getAnnotationMetadata(DuplicateConfiguration.class), factory);
-		verify(factory, times(1)).registerBeanDefinition(anyString(), any());
+	void registerWhenNotValueObjectRegistersGenericBeanDefinition() {
+		String beanName = MultiConstructorBeanConfigurationProperties.class.getName();
+		this.registrar.register(MultiConstructorBeanConfigurationProperties.class);
+		BeanDefinition definition = this.registry.getBeanDefinition(beanName);
+		assertThat(definition).isInstanceOf(GenericBeanDefinition.class);
 	}
 
-	@Test
-	void registrationWithNoTypeShouldNotRegisterAnything() throws IOException {
-		DefaultListableBeanFactory factory = spy(this.beanFactory);
-		this.registrar.registerBeanDefinitions(getAnnotationMetadata(EmptyConfiguration.class), factory);
-		verifyZeroInteractions(factory);
-	}
-
-	private AnnotationMetadata getAnnotationMetadata(Class<?> source) throws IOException {
-		return new SimpleMetadataReaderFactory().getMetadataReader(source.getName()).getAnnotationMetadata();
-	}
-
-	@EnableConfigurationProperties({ FooProperties.class, BarProperties.class, BingProperties.class })
-	static class TestConfiguration {
+	@ConfigurationProperties(prefix = "beancp")
+	static class BeanConfigurationProperties {
 
 	}
 
-	@EnableConfigurationProperties(ConfigurationPropertiesBeanRegistrarTests.class)
-	static class InvalidConfiguration {
+	static class NoAnnotationConfigurationProperties {
 
 	}
 
-	@EnableConfigurationProperties({ FooProperties.class, FooProperties.class })
-	static class DuplicateConfiguration {
+	@ConfigurationProperties(prefix = "valuecp")
+	static class ValueObjectConfigurationProperties {
 
-	}
-
-	@EnableConfigurationProperties
-	static class EmptyConfiguration {
-
-	}
-
-	@ConfigurationProperties(prefix = "foo")
-	static class FooProperties {
-
-	}
-
-	@ConfigurationProperties(prefix = "bar")
-	static class BarProperties {
-
-		BarProperties(String foo) {
+		ValueObjectConfigurationProperties(String name) {
 		}
 
 	}
 
-	@ConfigurationProperties(prefix = "bing")
-	static class BingProperties {
+	@ConfigurationProperties
+	static class MultiConstructorBeanConfigurationProperties {
 
-		BingProperties() {
+		MultiConstructorBeanConfigurationProperties() {
 		}
 
-		BingProperties(String foo) {
+		MultiConstructorBeanConfigurationProperties(String name) {
 		}
 
 	}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/ConfigurationPropertiesBeanTests.java

@@ -0,0 +1,272 @@
+/*
+ * Copyright 2012-2019 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
+ *
+ *      https://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.boot.context.properties;
+
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.function.ThrowingConsumer;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.ResolvableType;
+import org.springframework.stereotype.Component;
+import org.springframework.validation.annotation.Validated;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link ConfigurationPropertiesBean}.
+ *
+ * @author Phillip Webb
+ */
+class ConfigurationPropertiesBeanTests {
+
+	@Test
+	void getAllReturnsAll() {
+		try (AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(
+				NonAnnotatedComponent.class, AnnotatedComponent.class, AnnotatedBeanConfiguration.class)) {
+			Map<String, ConfigurationPropertiesBean> all = ConfigurationPropertiesBean.getAll(context);
+			assertThat(all).containsOnlyKeys("annotatedComponent", "annotatedBean");
+			ConfigurationPropertiesBean component = all.get("annotatedComponent");
+			assertThat(component.getName()).isEqualTo("annotatedComponent");
+			assertThat(component.getInstance()).isInstanceOf(AnnotatedComponent.class);
+			assertThat(component.getAnnotation()).isNotNull();
+			ConfigurationPropertiesBean bean = all.get("annotatedBean");
+			assertThat(bean.getName()).isEqualTo("annotatedBean");
+			assertThat(bean.getInstance()).isInstanceOf(AnnotatedBean.class);
+			assertThat(bean.getAnnotation()).isNotNull();
+		}
+	}
+
+	@Test
+	void getWhenNotAnnotatedReturnsNull() throws Throwable {
+		get(NonAnnotatedComponent.class, "nonAnnotatedComponent",
+				(propertiesBean) -> assertThat(propertiesBean).isNull());
+	}
+
+	@Test
+	void getWhenBeanIsAnnotatedReturnsBean() throws Throwable {
+		get(AnnotatedComponent.class, "annotatedComponent", (propertiesBean) -> {
+			assertThat(propertiesBean).isNotNull();
+			assertThat(propertiesBean.getName()).isEqualTo("annotatedComponent");
+			assertThat(propertiesBean.getInstance()).isInstanceOf(AnnotatedComponent.class);
+			assertThat(propertiesBean.getAnnotation().prefix()).isEqualTo("prefix");
+		});
+	}
+
+	@Test
+	void getWhenFactoryMethodIsAnnotatedReturnsBean() throws Throwable {
+		get(NonAnnotatedBeanConfiguration.class, "nonAnnotatedBean", (propertiesBean) -> {
+			assertThat(propertiesBean).isNotNull();
+			assertThat(propertiesBean.getName()).isEqualTo("nonAnnotatedBean");
+			assertThat(propertiesBean.getInstance()).isInstanceOf(NonAnnotatedBean.class);
+			assertThat(propertiesBean.getAnnotation().prefix()).isEqualTo("prefix");
+		});
+	}
+
+	@Test
+	void getWhenHasFactoryMethodBindsUsingMethodReturnType() throws Throwable {
+		get(NonAnnotatedGenericBeanConfiguration.class, "nonAnnotatedGenericBean", (propertiesBean) -> {
+			ResolvableType type = propertiesBean.asBindTarget().getType();
+			assertThat(type.resolve()).isEqualTo(NonAnnotatedGenericBean.class);
+			assertThat(type.resolveGeneric(0)).isEqualTo(String.class);
+		});
+	}
+
+	@Test
+	void getWhenHasFactoryMethodWithoutAnnotationBindsUsingMethodType() throws Throwable {
+		get(AnnotatedGenericBeanConfiguration.class, "annotatedGenericBean", (propertiesBean) -> {
+			ResolvableType type = propertiesBean.asBindTarget().getType();
+			assertThat(type.resolve()).isEqualTo(AnnotatedGenericBean.class);
+			assertThat(type.resolveGeneric(0)).isEqualTo(String.class);
+		});
+	}
+
+	@Test
+	void getWhenHasNoFactoryMethodBindsUsingObjectType() throws Throwable {
+		get(AnnotatedGenericComponent.class, "annotatedGenericComponent", (propertiesBean) -> {
+			ResolvableType type = propertiesBean.asBindTarget().getType();
+			assertThat(type.resolve()).isEqualTo(AnnotatedGenericComponent.class);
+			assertThat(type.getGeneric(0).resolve()).isNull();
+		});
+	}
+
+	@Test
+	void getWhenHasFactoryMethodAndBeanAnnotationFavorsFactoryMethod() throws Throwable {
+		get(AnnotatedBeanConfiguration.class, "annotatedBean",
+				(propertiesBean) -> assertThat(propertiesBean.getAnnotation().prefix()).isEqualTo("factory"));
+	}
+
+	@Test
+	void getWhenHasValidatedBeanBindsWithBeanAnnotation() throws Throwable {
+		get(ValidatedBeanConfiguration.class, "validatedBean", (propertiesBean) -> {
+			Validated validated = propertiesBean.asBindTarget().getAnnotation(Validated.class);
+			assertThat(validated.value()).containsExactly(BeanGroup.class);
+		});
+	}
+
+	@Test
+	void getWhenHasValidatedFactoryMethodBindsWithFactoryMethodAnnotation() throws Throwable {
+		get(ValidatedMethodConfiguration.class, "annotatedBean", (propertiesBean) -> {
+			Validated validated = propertiesBean.asBindTarget().getAnnotation(Validated.class);
+			assertThat(validated.value()).containsExactly(FactoryMethodGroup.class);
+		});
+	}
+
+	@Test
+	void getWhenHasValidatedBeanAndFactoryMethodBindsWithFactoryMethodAnnotation() throws Throwable {
+		get(ValidatedMethodAndBeanConfiguration.class, "validatedBean", (propertiesBean) -> {
+			Validated validated = propertiesBean.asBindTarget().getAnnotation(Validated.class);
+			assertThat(validated.value()).containsExactly(FactoryMethodGroup.class);
+		});
+	}
+
+	private void get(Class<?> configuration, String beanName, ThrowingConsumer<ConfigurationPropertiesBean> consumer)
+			throws Throwable {
+		try (AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(configuration)) {
+			Object bean = context.getBean(beanName);
+			consumer.accept(ConfigurationPropertiesBean.get(context, bean, beanName));
+		}
+	}
+
+	@Component("nonAnnotatedComponent")
+	static class NonAnnotatedComponent {
+
+	}
+
+	@Component("annotatedComponent")
+	@ConfigurationProperties(prefix = "prefix")
+	static class AnnotatedComponent {
+
+	}
+
+	@ConfigurationProperties(prefix = "prefix")
+	static class AnnotatedBean {
+
+	}
+
+	static class NonAnnotatedBean {
+
+	}
+
+	static class NonAnnotatedGenericBean<T> {
+
+	}
+
+	@ConfigurationProperties
+	static class AnnotatedGenericBean<T> {
+
+	}
+
+	@Component("annotatedGenericComponent")
+	@ConfigurationProperties
+	static class AnnotatedGenericComponent<T> {
+
+	}
+
+	@Validated(BeanGroup.class)
+	@ConfigurationProperties
+	static class ValidatedBean {
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class NonAnnotatedBeanConfiguration {
+
+		@Bean
+		@ConfigurationProperties(prefix = "prefix")
+		NonAnnotatedBean nonAnnotatedBean() {
+			return new NonAnnotatedBean();
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class NonAnnotatedGenericBeanConfiguration {
+
+		@Bean
+		@ConfigurationProperties
+		NonAnnotatedGenericBean<String> nonAnnotatedGenericBean() {
+			return new NonAnnotatedGenericBean<>();
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class AnnotatedGenericBeanConfiguration {
+
+		@Bean
+		AnnotatedGenericBean<String> annotatedGenericBean() {
+			return new AnnotatedGenericBean<>();
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class AnnotatedBeanConfiguration {
+
+		@Bean
+		@ConfigurationProperties(prefix = "factory")
+		AnnotatedBean annotatedBean() {
+			return new AnnotatedBean();
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class ValidatedBeanConfiguration {
+
+		@Bean
+		ValidatedBean validatedBean() {
+			return new ValidatedBean();
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class ValidatedMethodConfiguration {
+
+		@Bean
+		@Validated(FactoryMethodGroup.class)
+		AnnotatedBean annotatedBean() {
+			return new AnnotatedBean();
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class ValidatedMethodAndBeanConfiguration {
+
+		@Bean
+		@Validated(FactoryMethodGroup.class)
+		ValidatedBean validatedBean() {
+			return new ValidatedBean();
+		}
+
+	}
+
+	static class BeanGroup {
+
+	}
+
+	static class FactoryMethodGroup {
+
+	}
+
+}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/ConfigurationPropertiesBindExceptionTests.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2012-2019 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
+ *
+ *      https://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.boot.context.properties;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.stereotype.Component;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link ConfigurationPropertiesBindException}.
+ *
+ * @author Phillip Webb
+ */
+class ConfigurationPropertiesBindExceptionTests {
+
+	@Test
+	void createFromBeanHasDetails() {
+		ApplicationContext applicationContext = new AnnotationConfigApplicationContext(Example.class);
+		ConfigurationPropertiesBean bean = ConfigurationPropertiesBean.get(applicationContext,
+				applicationContext.getBean(Example.class), "example");
+		ConfigurationPropertiesBindException exception = new ConfigurationPropertiesBindException(bean,
+				new IllegalStateException());
+		assertThat(exception.getMessage()).isEqualTo("Error creating bean with name 'example': "
+				+ "Could not bind properties to 'ConfigurationPropertiesBindExceptionTests.Example' : "
+				+ "prefix=, ignoreInvalidFields=false, ignoreUnknownFields=true; "
+				+ "nested exception is java.lang.IllegalStateException");
+		assertThat(exception.getBeanType()).isEqualTo(Example.class);
+		assertThat(exception.getBeanName()).isEqualTo("example");
+		assertThat(exception.getAnnotation()).isInstanceOf(ConfigurationProperties.class);
+		assertThat(exception.getCause()).isInstanceOf(IllegalStateException.class);
+	}
+
+	@Test
+	void createFromItemsHasDetails() {
+		Example example = new Example();
+		ConfigurationProperties annotation = example.getClass().getDeclaredAnnotation(ConfigurationProperties.class);
+		ConfigurationPropertiesBindException exception = new ConfigurationPropertiesBindException("example",
+				Example.class, annotation, new IllegalStateException());
+		assertThat(exception.getMessage()).isEqualTo("Error creating bean with name 'example': "
+				+ "Could not bind properties to 'ConfigurationPropertiesBindExceptionTests.Example' : "
+				+ "prefix=, ignoreInvalidFields=false, ignoreUnknownFields=true; "
+				+ "nested exception is java.lang.IllegalStateException");
+		assertThat(exception.getBeanType()).isEqualTo(Example.class);
+		assertThat(exception.getBeanName()).isEqualTo("example");
+		assertThat(exception.getAnnotation()).isInstanceOf(ConfigurationProperties.class);
+		assertThat(exception.getCause()).isInstanceOf(IllegalStateException.class);
+	}
+
+	@Component("example")
+	@ConfigurationProperties
+	static class Example {
+
+	}
+
+}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/ConfigurationPropertiesScanRegistrarTests.java

@@ -17,7 +17,6 @@ package org.springframework.boot.context.properties;
 
 import java.io.IOException;
 
-import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.config.BeanDefinition;
@@ -39,14 +38,10 @@ import static org.assertj.core.api.Assertions.assertThat;
  */
 class ConfigurationPropertiesScanRegistrarTests {
 
-	private final ConfigurationPropertiesScanRegistrar registrar = new ConfigurationPropertiesScanRegistrar();
-
 	private final DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();
 
-	@BeforeEach
-	void setup() {
-		this.registrar.setEnvironment(new MockEnvironment());
-	}
+	private final ConfigurationPropertiesScanRegistrar registrar = new ConfigurationPropertiesScanRegistrar(
+			new MockEnvironment(), null);
 
 	@Test
 	void registerBeanDefintionsShouldScanForConfigurationProperties() throws IOException {
@@ -60,7 +55,7 @@ class ConfigurationPropertiesScanRegistrarTests {
 				"bar-org.springframework.boot.context.properties.scan.valid.ConfigurationPropertiesScanConfiguration$BarProperties");
 		assertThat(bingDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
 		assertThat(fooDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
-		assertThat(barDefinition).isExactlyInstanceOf(ConfigurationPropertiesBeanDefinition.class);
+		assertThat(barDefinition).isExactlyInstanceOf(ConfigurationPropertiesValueObjectBeanDefinition.class);
 	}
 
 	@Test
@@ -92,7 +87,7 @@ class ConfigurationPropertiesScanRegistrarTests {
 				"b.second-org.springframework.boot.context.properties.scan.valid.b.BScanConfiguration$BSecondProperties");
 		assertThat(aDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
 		// Constructor injection
-		assertThat(bFirstDefinition).isExactlyInstanceOf(ConfigurationPropertiesBeanDefinition.class);
+		assertThat(bFirstDefinition).isExactlyInstanceOf(ConfigurationPropertiesValueObjectBeanDefinition.class);
 		// Post-processing injection
 		assertThat(bSecondDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
 	}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/ConfigurationPropertiesTests.java

@@ -82,7 +82,7 @@ import org.springframework.validation.annotation.Validated;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
-import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 import static org.assertj.core.api.Assertions.entry;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
@@ -216,7 +216,7 @@ class ConfigurationPropertiesTests {
 
 	@Test
 	void loadWhenBindingWithoutAndAnnotationShouldFail() {
-		assertThatIllegalArgumentException().isThrownBy(() -> load(WithoutAndAnnotationConfiguration.class, "name:foo"))
+		assertThatIllegalStateException().isThrownBy(() -> load(WithoutAndAnnotationConfiguration.class, "name:foo"))
 				.withMessageContaining("No ConfigurationProperties annotation found");
 	}
 
@@ -776,6 +776,7 @@ class ConfigurationPropertiesTests {
 	}
 
 	@Test
+	@SuppressWarnings("deprecation")
 	void loadWhenBindingOnBeanWithoutBeanDefinitionShouldBind() {
 		load(BasicConfiguration.class, "name=test");
 		BasicProperties bean = this.context.getBean(BasicProperties.class);
@@ -1119,7 +1120,7 @@ class ConfigurationPropertiesTests {
 	@EnableConfigurationProperties(WithCustomValidatorProperties.class)
 	static class WithCustomValidatorConfiguration {
 
-		@Bean(name = ConfigurationPropertiesBindingPostProcessorRegistrar.VALIDATOR_BEAN_NAME)
+		@Bean(name = EnableConfigurationProperties.VALIDATOR_BEAN_NAME)
 		CustomPropertiesValidator validator() {
 			return new CustomPropertiesValidator();
 		}
@@ -1130,7 +1131,7 @@ class ConfigurationPropertiesTests {
 	@EnableConfigurationProperties(WithSetterThatThrowsValidationExceptionProperties.class)
 	static class WithUnsupportedCustomValidatorConfiguration {
 
-		@Bean(name = ConfigurationPropertiesBindingPostProcessorRegistrar.VALIDATOR_BEAN_NAME)
+		@Bean(name = EnableConfigurationProperties.VALIDATOR_BEAN_NAME)
 		CustomPropertiesValidator validator() {
 			return new CustomPropertiesValidator();
 		}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/ConversionServiceDeducerTests.java

@@ -0,0 +1,106 @@
+/*
+ * Copyright 2012-2019 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
+ *
+ *      https://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.boot.context.properties;
+
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.convert.ApplicationConversionService;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.convert.ConversionService;
+import org.springframework.core.convert.converter.Converter;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link ConversionServiceDeducer}.
+ *
+ * @author Phillip Webb
+ */
+class ConversionServiceDeducerTests {
+
+	@Test
+	void getConversionServiceWhenHasConversionServiceBeanReturnsBean() {
+		ApplicationContext applicationContext = new AnnotationConfigApplicationContext(
+				CustomConverterServiceConfiguration.class);
+		ConversionServiceDeducer deducer = new ConversionServiceDeducer(applicationContext);
+		assertThat(deducer.getConversionService()).isInstanceOf(TestApplicationConversionService.class);
+	}
+
+	@Test
+	void getConversionServiceWhenHasNoConversionServiceBeanAndNoQualifiedBeansReturnsSharedInstance() {
+		ApplicationContext applicationContext = new AnnotationConfigApplicationContext(EmptyConfiguration.class);
+		ConversionServiceDeducer deducer = new ConversionServiceDeducer(applicationContext);
+		assertThat(deducer.getConversionService()).isSameAs(ApplicationConversionService.getSharedInstance());
+	}
+
+	@Test
+	void getConversionServiceWhenHasQualifiedConverterBeansReturnsNewInstance() {
+		ApplicationContext applicationContext = new AnnotationConfigApplicationContext(
+				CustomConverterConfiguration.class);
+		ConversionServiceDeducer deducer = new ConversionServiceDeducer(applicationContext);
+		ConversionService conversionService = deducer.getConversionService();
+		assertThat(conversionService).isNotSameAs(ApplicationConversionService.getSharedInstance());
+		assertThat(conversionService.canConvert(InputStream.class, OutputStream.class)).isTrue();
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class CustomConverterServiceConfiguration {
+
+		@Bean(ConfigurableApplicationContext.CONVERSION_SERVICE_BEAN_NAME)
+		TestApplicationConversionService conversionService() {
+			return new TestApplicationConversionService();
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class EmptyConfiguration {
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class CustomConverterConfiguration {
+
+		@Bean
+		@ConfigurationPropertiesBinding
+		TestConveter testConveter() {
+			return new TestConveter();
+		}
+
+	}
+
+	private static class TestApplicationConversionService extends ApplicationConversionService {
+
+	}
+
+	private static class TestConveter implements Converter<InputStream, OutputStream> {
+
+		@Override
+		public OutputStream convert(InputStream source) {
+			throw new UnsupportedOperationException();
+		}
+
+	}
+
+}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/EnableConfigurationPropertiesRegistrarTests.java

@@ -0,0 +1,150 @@
+/*
+ * Copyright 2012-2019 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
+ *
+ *      https://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.boot.context.properties;
+
+import java.io.IOException;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.support.DefaultListableBeanFactory;
+import org.springframework.beans.factory.support.GenericBeanDefinition;
+import org.springframework.core.type.AnnotationMetadata;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+/**
+ * Tests for {@link EnableConfigurationPropertiesRegistrar}.
+ *
+ * @author Madhura Bhave
+ * @author Stephane Nicoll
+ */
+class EnableConfigurationPropertiesRegistrarTests {
+
+	private DefaultListableBeanFactory beanFactory;
+
+	private EnableConfigurationPropertiesRegistrar registrar;
+
+	@BeforeEach
+	void setup() {
+		this.beanFactory = spy(new DefaultListableBeanFactory());
+		this.registrar = new EnableConfigurationPropertiesRegistrar();
+	}
+
+	@Test
+	void typeWithDefaultConstructorShouldRegisterGenericBeanDefinition() throws Exception {
+		register(TestConfiguration.class);
+		BeanDefinition beanDefinition = this.beanFactory
+				.getBeanDefinition("foo-" + getClass().getName() + "$FooProperties");
+		assertThat(beanDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
+	}
+
+	@Test
+	void typeWithOneConstructorWithParametersShouldRegisterConfigurationPropertiesBeanDefinition() throws Exception {
+		register(TestConfiguration.class);
+		BeanDefinition beanDefinition = this.beanFactory
+				.getBeanDefinition("bar-" + getClass().getName() + "$BarProperties");
+		assertThat(beanDefinition).isExactlyInstanceOf(ConfigurationPropertiesValueObjectBeanDefinition.class);
+	}
+
+	@Test
+	void typeWithMultipleConstructorsShouldRegisterGenericBeanDefinition() throws Exception {
+		register(TestConfiguration.class);
+		BeanDefinition beanDefinition = this.beanFactory
+				.getBeanDefinition("bing-" + getClass().getName() + "$BingProperties");
+		assertThat(beanDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
+	}
+
+	@Test
+	void typeWithNoAnnotationShouldFail() {
+		assertThatIllegalStateException().isThrownBy(() -> register(InvalidConfiguration.class))
+				.withMessageContaining("No ConfigurationProperties annotation found")
+				.withMessageContaining(EnableConfigurationPropertiesRegistrar.class.getName());
+	}
+
+	@Test
+	void registrationWithDuplicatedTypeShouldRegisterSingleBeanDefinition() throws IOException {
+		register(DuplicateConfiguration.class);
+		String name = "foo-" + getClass().getName() + "$FooProperties";
+		verify(this.beanFactory, times(1)).registerBeanDefinition(eq(name), any());
+	}
+
+	@Test
+	void registrationWithNoTypeShouldNotRegisterAnything() throws IOException {
+		register(EmptyConfiguration.class);
+		String[] names = this.beanFactory.getBeanNamesForType(Object.class);
+		for (String name : names) {
+			assertThat(name).doesNotContain("-");
+		}
+	}
+
+	private void register(Class<?> configuration) {
+		AnnotationMetadata metadata = AnnotationMetadata.introspect(configuration);
+		this.registrar.registerBeanDefinitions(metadata, this.beanFactory);
+	}
+
+	@EnableConfigurationProperties({ FooProperties.class, BarProperties.class, BingProperties.class })
+	static class TestConfiguration {
+
+	}
+
+	@EnableConfigurationProperties(EnableConfigurationPropertiesRegistrarTests.class)
+	static class InvalidConfiguration {
+
+	}
+
+	@EnableConfigurationProperties({ FooProperties.class, FooProperties.class })
+	static class DuplicateConfiguration {
+
+	}
+
+	@EnableConfigurationProperties
+	static class EmptyConfiguration {
+
+	}
+
+	@ConfigurationProperties(prefix = "foo")
+	static class FooProperties {
+
+	}
+
+	@ConfigurationProperties(prefix = "bar")
+	static class BarProperties {
+
+		BarProperties(String foo) {
+		}
+
+	}
+
+	@ConfigurationProperties(prefix = "bing")
+	static class BingProperties {
+
+		BingProperties() {
+		}
+
+		BingProperties(String foo) {
+		}
+
+	}
+
+}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/PropertySourcesDeducerTests.java

@@ -0,0 +1,128 @@
+/*
+ * Copyright 2012-2019 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
+ *
+ *      https://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.boot.context.properties;
+
+import java.util.Collections;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.env.Environment;
+import org.springframework.core.env.MapPropertySource;
+import org.springframework.core.env.MutablePropertySources;
+import org.springframework.core.env.PropertySources;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link PropertySourcesDeducer}.
+ *
+ * @author Phillip Webb
+ */
+class PropertySourcesDeducerTests {
+
+	@Test
+	void getPropertySourcesWhenHasSinglePropertySourcesPlaceholderConfigurerReturnsBean() {
+		ApplicationContext applicationContext = new AnnotationConfigApplicationContext(
+				PropertySourcesPlaceholderConfigurerConfiguration.class);
+		PropertySourcesDeducer deducer = new PropertySourcesDeducer(applicationContext);
+		PropertySources propertySources = deducer.getPropertySources();
+		assertThat(propertySources.get("test")).isInstanceOf(TestPropertySource.class);
+	}
+
+	@Test
+	void getPropertySourcesWhenHasNoPropertySourcesPlaceholderConfigurerReturnsEnvironmentSources() {
+		ApplicationContext applicationContext = new AnnotationConfigApplicationContext(EmptyConfiguration.class);
+		ConfigurableEnvironment environment = (ConfigurableEnvironment) applicationContext.getEnvironment();
+		environment.getPropertySources().addFirst(new TestPropertySource());
+		PropertySourcesDeducer deducer = new PropertySourcesDeducer(applicationContext);
+		PropertySources propertySources = deducer.getPropertySources();
+		assertThat(propertySources.get("test")).isInstanceOf(TestPropertySource.class);
+	}
+
+	@Test
+	void getPropertySourcesWhenHasMultiplePropertySourcesPlaceholderConfigurerReturnsEnvironmentSources() {
+		ApplicationContext applicationContext = new AnnotationConfigApplicationContext(
+				MultiplePropertySourcesPlaceholderConfigurerConfiguration.class);
+		ConfigurableEnvironment environment = (ConfigurableEnvironment) applicationContext.getEnvironment();
+		environment.getPropertySources().addFirst(new TestPropertySource());
+		PropertySourcesDeducer deducer = new PropertySourcesDeducer(applicationContext);
+		PropertySources propertySources = deducer.getPropertySources();
+		assertThat(propertySources.get("test")).isInstanceOf(TestPropertySource.class);
+	}
+
+	@Test
+	void getPropertySourcesWhenUnavailableThrowsException() {
+		ApplicationContext applicationContext = mock(ApplicationContext.class);
+		Environment environment = mock(Environment.class);
+		given(applicationContext.getEnvironment()).willReturn(environment);
+		PropertySourcesDeducer deducer = new PropertySourcesDeducer(applicationContext);
+		assertThatIllegalStateException().isThrownBy(() -> deducer.getPropertySources()).withMessage(
+				"Unable to obtain PropertySources from PropertySourcesPlaceholderConfigurer or Environment");
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class PropertySourcesPlaceholderConfigurerConfiguration {
+
+		@Bean
+		PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
+			PropertySourcesPlaceholderConfigurer configurer = new PropertySourcesPlaceholderConfigurer();
+			MutablePropertySources propertySources = new MutablePropertySources();
+			propertySources.addFirst(new TestPropertySource());
+			configurer.setPropertySources(propertySources);
+			return configurer;
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class EmptyConfiguration {
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class MultiplePropertySourcesPlaceholderConfigurerConfiguration {
+
+		@Bean
+		PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer1() {
+			return new PropertySourcesPlaceholderConfigurer();
+		}
+
+		@Bean
+		PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer2() {
+			return new PropertySourcesPlaceholderConfigurer();
+		}
+
+	}
+
+	private static class TestPropertySource extends MapPropertySource {
+
+		TestPropertySource() {
+			super("test", Collections.emptyMap());
+		}
+
+	}
+
+}

spring-boot-project/spring-boot/src/test/kotlin/org/springframework/boot/context/properties/KotlinConfigurationPropertiesBeanRegistrarTests.kt

@@ -15,14 +15,13 @@ import org.springframework.core.type.classreading.SimpleMetadataReaderFactory
 @Suppress("unused")
 class KotlinConfigurationPropertiesBeanRegistrarTests {
 
-	private val registrar = ConfigurationPropertiesBeanRegistrar()
-
 	private val beanFactory = DefaultListableBeanFactory()
 
+	private val registrar = ConfigurationPropertiesBeanRegistrar(beanFactory)
+
 	@Test
 	fun `type with default constructor should register generic bean definition`() {
-		this.registrar.registerBeanDefinitions(
-				getAnnotationMetadata(TestConfiguration::class.java), this.beanFactory)
+		this.registrar.register(FooProperties::class.java)
 		val beanDefinition = this.beanFactory.getBeanDefinition(
 				"foo-org.springframework.boot.context.properties.KotlinConfigurationPropertiesBeanRegistrarTests\$FooProperties")
 		assertThat(beanDefinition).isExactlyInstanceOf(GenericBeanDefinition::class.java)
@@ -30,33 +29,21 @@ class KotlinConfigurationPropertiesBeanRegistrarTests {
 
 	@Test
 	fun `type with primary constructor and no autowired should register configuration properties bean definition`() {
-		this.registrar.registerBeanDefinitions(
-				getAnnotationMetadata(TestConfiguration::class.java), this.beanFactory)
+		this.registrar.register(BarProperties::class.java)
 		val beanDefinition = this.beanFactory.getBeanDefinition(
 				"bar-org.springframework.boot.context.properties.KotlinConfigurationPropertiesBeanRegistrarTests\$BarProperties")
 		assertThat(beanDefinition).isExactlyInstanceOf(
-				ConfigurationPropertiesBeanDefinition::class.java)
+				ConfigurationPropertiesValueObjectBeanDefinition::class.java)
 	}
 
 	@Test
 	fun `type with no primary constructor should register generic bean definition`() {
-		this.registrar.registerBeanDefinitions(
-				getAnnotationMetadata(TestConfiguration::class.java), this.beanFactory)
+		this.registrar.register(BingProperties::class.java)
 		val beanDefinition = this.beanFactory.getBeanDefinition(
 				"bing-org.springframework.boot.context.properties.KotlinConfigurationPropertiesBeanRegistrarTests\$BingProperties")
 		assertThat(beanDefinition).isExactlyInstanceOf(GenericBeanDefinition::class.java)
 	}
 
-	private fun getAnnotationMetadata(source: Class<*>): AnnotationMetadata {
-		return SimpleMetadataReaderFactory().getMetadataReader(source.name)
-				.annotationMetadata
-	}
-
-
-	@EnableConfigurationProperties(FooProperties::class, BarProperties::class,
-			BingProperties::class)
-	class TestConfiguration
-
 	@ConfigurationProperties(prefix = "foo")
 	class FooProperties