DATAJPA-496 - Fixed join creation for element collection attributes.

QueryUtils.toExpressionRecursively(…) now also creates joins for attributes mapped to an @ElementCollection.

Original pull request: #68.

src/main/java/org/springframework/data/jpa/repository/query/QueryUtils.java

@@ -118,6 +118,7 @@ public abstract class QueryUtils {
 		persistentAttributeTypes.put(ONE_TO_MANY, null);
 		persistentAttributeTypes.put(MANY_TO_ONE, ManyToOne.class);
 		persistentAttributeTypes.put(MANY_TO_MANY, null);
+		persistentAttributeTypes.put(ELEMENT_COLLECTION, null);
 
 		ASSOCIATION_TYPES = Collections.unmodifiableMap(persistentAttributeTypes);
 	}

src/test/java/org/springframework/data/jpa/domain/sample/User.java

@@ -21,6 +21,7 @@ import java.util.Set;
 
 import javax.persistence.CascadeType;
 import javax.persistence.Column;
+import javax.persistence.ElementCollection;
 import javax.persistence.Embedded;
 import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
@@ -63,6 +64,8 @@ public class User {
 
 	@Lob private byte[] binaryData;
 
+	@ElementCollection private Set<String> attributes;
+
 	/**
 	 * Creates a new empty instance of {@code User}.
 	 */
@@ -85,6 +88,7 @@ public class User {
 		this.active = true;
 		this.roles = new HashSet<Role>();
 		this.colleagues = new HashSet<User>();
+		this.attributes = new HashSet<String>();
 		this.createdAt = new Date();
 	}
 
@@ -329,6 +333,20 @@ public class User {
 		return this.getId().equals(that.getId());
 	}
 
+	/**
+	 * @return the attributes
+	 */
+	public Set<String> getAttributes() {
+		return attributes;
+	}
+
+	/**
+	 * @param attributes the attributes to set
+	 */
+	public void setAttributes(Set<String> attributes) {
+		this.attributes = attributes;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * 

src/test/java/org/springframework/data/jpa/repository/EclipseLinkNamespaceUserRepositoryTests.java

@@ -22,6 +22,7 @@ import org.springframework.test.context.ContextConfiguration;
  * Testcase to run {@link UserRepository} integration tests on top of EclipseLink.
  * 
  * @author Oliver Gierke
+ * @author Thomas Darimont
  */
 @ContextConfiguration(value = "classpath:eclipselink.xml")
 public class EclipseLinkNamespaceUserRepositoryTests extends NamespaceUserRepositoryTests {
@@ -67,4 +68,10 @@ public class EclipseLinkNamespaceUserRepositoryTests extends NamespaceUserReposi
 	 */
 	@Override
 	public void sortByAssociationPropertyInPageableShouldUseLeftOuterJoin() {}
+
+	/**
+	 * Ignored until https://bugs.eclipse.org/bugs/show_bug.cgi?id=349477 is resolved.
+	 */
+	@Override
+	public void findByElementCollectionAttribute() {}
 }

src/test/java/org/springframework/data/jpa/repository/UserRepositoryTests.java

@@ -1280,6 +1280,24 @@ public class UserRepositoryTests {
 		assertThat(page.getContent().get(3), is(firstUser));
 	}
 
+	/**
+	 * @see DATAJPA-496
+	 */
+	@Test
+	public void findByElementCollectionAttribute() {
+
+		firstUser.getAttributes().add("cool");
+		secondUser.getAttributes().add("hip");
+		thirdUser.getAttributes().add("rockstar");
+
+		flushTestUsers();
+
+		List<User> result = repository.findByAttributesIn(new HashSet<String>(Arrays.asList("cool", "hip")));
+
+		assertThat(result, hasSize(2));
+		assertThat(result, hasItems(firstUser, secondUser));
+	}
+
 	private Page<User> executeSpecWithSort(Sort sort) {
 
 		flushTestUsers();

src/test/java/org/springframework/data/jpa/repository/sample/UserRepository.java

@@ -18,6 +18,7 @@ package org.springframework.data.jpa.repository.sample;
 import java.util.Collection;
 import java.util.Date;
 import java.util.List;
+import java.util.Set;
 
 import javax.persistence.QueryHint;
 
@@ -311,4 +312,9 @@ public interface UserRepository extends JpaRepository<User, Integer>, JpaSpecifi
 	 * @see DATAJPA-486
 	 */
 	Slice<User> findSliceByLastname(String lastname, Pageable pageable);
+
+	/**
+	 * @see DATAJPA-496
+	 */
+	List<User> findByAttributesIn(Set<String> attributes);
 }