DATACMNS-734 - Improved Querydsl predicate binding using formatters.

We now default to a FormattingConversionService to make sure comma-separated values are transformed into arrays correctly. Also, we now build up dedicated TypeDescriptor instances for the property or field about to be bound to potentially pick up formatting annotations on those.

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

@@ -15,6 +15,7 @@
  */
 package org.springframework.data.querydsl.binding;
 
+import java.beans.PropertyDescriptor;
 import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -24,8 +25,11 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 
+import org.springframework.beans.BeanUtils;
 import org.springframework.beans.PropertyValues;
 import org.springframework.core.convert.ConversionService;
+import org.springframework.core.convert.Property;
+import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.data.mapping.PropertyPath;
 import org.springframework.data.mapping.PropertyReferenceException;
 import org.springframework.data.querydsl.EntityPathResolver;
@@ -191,8 +195,8 @@ public class QuerydslPredicateBuilder {
 	 */
 	private Collection<Object> convertToPropertyPathSpecificType(List<String> source, PropertyPath path) {
 
-		Class<?> targetType = path.getLeafProperty().getOwningType().getProperty(path.getLeafProperty().getSegment())
-				.getType();
+		PropertyPath leafProperty = path.getLeafProperty();
+		Class<?> targetType = leafProperty.getOwningType().getProperty(leafProperty.getSegment()).getType();
 
 		if (source.isEmpty() || isSingleElementCollectionWithoutText(source)) {
 			return Collections.emptyList();
@@ -202,13 +206,36 @@ public class QuerydslPredicateBuilder {
 
 		for (String value : source) {
 
-			target.add(conversionService.canConvert(String.class, targetType) ? conversionService.convert(
-					targetType.isArray() ? value.split(",") : value, targetType) : value);
+			target.add(conversionService.canConvert(String.class, targetType)
+					? conversionService.convert(value, TypeDescriptor.forObject(value), getTargetTypeDescriptor(path)) : value);
 		}
 
 		return target;
 	}
 
+	/**
+	 * Returns the target {@link TypeDescriptor} for the given {@link PropertyPath} by either inspecting the field or
+	 * property (the latter preferred) to pick up annotations potentially defined for formatting purposes.
+	 * 
+	 * @param path must not be {@literal null}.
+	 * @return
+	 */
+	private static TypeDescriptor getTargetTypeDescriptor(PropertyPath path) {
+
+		PropertyPath leafProperty = path.getLeafProperty();
+		Class<?> owningType = leafProperty.getOwningType().getType();
+
+		PropertyDescriptor descriptor = BeanUtils.getPropertyDescriptor(owningType, leafProperty.getSegment());
+
+		if (descriptor == null) {
+			return TypeDescriptor.nested(ReflectionUtils.findField(owningType, leafProperty.getSegment()), 0);
+		}
+
+		return TypeDescriptor.nested(
+				new Property(owningType, descriptor.getReadMethod(), descriptor.getWriteMethod(), leafProperty.getSegment()),
+				0);
+	}
+
 	/**
 	 * Returns whether the given collection has exactly one element that doesn't contain any text. This is basically an
 	 * indicator that a request parameter has been submitted but no value for it.

src/test/java/org/springframework/data/querydsl/User.java

@@ -18,6 +18,9 @@ package org.springframework.data.querydsl;
 import java.util.Date;
 import java.util.List;
 
+import org.springframework.format.annotation.DateTimeFormat;
+import org.springframework.format.annotation.DateTimeFormat.ISO;
+
 import com.mysema.query.annotations.QueryEntity;
 
 /**
@@ -29,7 +32,7 @@ import com.mysema.query.annotations.QueryEntity;
 public class User {
 
 	public String firstname, lastname;
-	public Date dateOfBirth;
+	public @DateTimeFormat(iso = ISO.DATE) Date dateOfBirth;
 	public Address address;
 	public List<String> nickNames;
 	public Long inceptionYear;

src/test/java/org/springframework/data/querydsl/binding/QuerydslPredicateBuilderUnitTests.java

@@ -19,16 +19,20 @@ import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
 import static org.springframework.test.util.ReflectionTestUtils.*;
 
+import java.text.ParseException;
 import java.util.List;
 
+import org.joda.time.DateTime;
+import org.joda.time.format.DateTimeFormat;
+import org.joda.time.format.DateTimeFormatter;
 import org.junit.Before;
 import org.junit.Test;
-import org.springframework.core.convert.support.DefaultConversionService;
 import org.springframework.data.querydsl.QUser;
 import org.springframework.data.querydsl.SimpleEntityPathResolver;
 import org.springframework.data.querydsl.User;
 import org.springframework.data.querydsl.Users;
 import org.springframework.data.util.ClassTypeInformation;
+import org.springframework.format.support.DefaultFormattingConversionService;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 
@@ -53,7 +57,8 @@ public class QuerydslPredicateBuilderUnitTests {
 
 	@Before
 	public void setUp() {
-		this.builder = new QuerydslPredicateBuilder(new DefaultConversionService(), SimpleEntityPathResolver.INSTANCE);
+		this.builder = new QuerydslPredicateBuilder(new DefaultFormattingConversionService(),
+				SimpleEntityPathResolver.INSTANCE);
 		this.values = new LinkedMultiValueMap<String, String>();
 	}
 
@@ -185,4 +190,20 @@ public class QuerydslPredicateBuilderUnitTests {
 		assertThat(constant.getConstant(), instanceOf(String.class));
 		assertThat((String) (constant.getConstant()), equalTo("rivers,two"));
 	}
+
+	/**
+	 * @see DATACMNS-734
+	 */
+	@Test
+	public void bindsDateCorrectly() throws ParseException {
+
+		DateTimeFormatter format = DateTimeFormat.forPattern("yyyy-MM-dd");
+		String date = format.print(new DateTime());
+
+		values.add("dateOfBirth", format.print(new DateTime()));
+
+		Predicate predicate = builder.getPredicate(USER_TYPE, values, DEFAULT_BINDINGS);
+
+		assertThat(predicate, is((Predicate) QUser.user.dateOfBirth.eq(format.parseDateTime(date).toDate())));
+	}
 }