DATAJPA-1416 - Unwrap proxies in JpaMetamodelEntityInformation.

Previously, when JpaMetamodelEntityInfortmation operated on a proxy class it failed to detect it as an entity. This problem is now solved by unwrapping the potential proxy before passing it into JpaMetamodelEntityInformation.

Original pull request: #293.

src/main/java/org/springframework/data/jpa/repository/support/JpaMetamodelEntityInformation.java

@@ -39,6 +39,7 @@ import org.springframework.data.jpa.util.JpaMetamodel;
 import org.springframework.data.util.DirectFieldAccessFallbackBeanWrapper;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 
 /**
  * Implementation of {@link org.springframework.data.repository.core.EntityInformation} that uses JPA {@link Metamodel}
@@ -343,8 +344,8 @@ public class JpaMetamodelEntityInformation<T, ID> extends JpaEntityInformationSu
 
 			// Derive the identifier from the nested entity that is part of the composite key.
 			@SuppressWarnings("rawtypes")
-			JpaMetamodelEntityInformation nestedEntityInformation = new JpaMetamodelEntityInformation(value.getClass(),
-					this.metamodel);
+			JpaMetamodelEntityInformation nestedEntityInformation = new JpaMetamodelEntityInformation(
+					ClassUtils.getUserClass(value), this.metamodel);
 
 			if (!nestedEntityInformation.getJavaType().isAnnotationPresent(IdClass.class)) {
 
@@ -413,7 +414,7 @@ public class JpaMetamodelEntityInformation<T, ID> extends JpaEntityInformationSu
 			}
 
 			try {
-				ManagedType<? extends Object> managedType = this.metamodel.managedType(value.getClass());
+				ManagedType<? extends Object> managedType = this.metamodel.managedType(ClassUtils.getUserClass(value));
 				return managedType != null && managedType.getPersistenceType() == PersistenceType.ENTITY;
 			} catch (IllegalArgumentException iae) {
 				// no mapped type

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

@@ -0,0 +1,45 @@
+package org.springframework.data.jpa.domain.sample;
+
+import lombok.Data;
+
+import java.io.Serializable;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.IdClass;
+import javax.persistence.ManyToOne;
+
+/**
+ * Sample class for integration testing
+ * {@link org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation}.
+ *
+ * @author Jens Schauder
+ */
+@Entity
+@IdClass(SampleWithIdClassIncludingEntity.SampleWithIdClassPK.class)
+@Data
+public class SampleWithIdClassIncludingEntity {
+
+	@Id Long first;
+	@ManyToOne @Id OtherEntity second;
+
+	@Data
+	@SuppressWarnings("serial")
+	public static class SampleWithIdClassPK implements Serializable {
+
+		Long first;
+		Long second;
+	}
+
+	@Entity
+	@Data
+	public static class OtherEntity {
+		@Id Long otherId;
+	}
+
+	/**
+	 * This class emulates a proxy at is returned from Hibernate.
+	 */
+	public static class OtherEntity$$PsudoProxy extends OtherEntity {}
+
+}

src/test/java/org/springframework/data/jpa/repository/support/EclipseLinkJpaMetamodelEntityInformationIntegrationTests.java

@@ -71,13 +71,28 @@ public class EclipseLinkJpaMetamodelEntityInformationIntegrationTests
 	}
 
 	/**
-	 * Ignored due to https://bugs.eclipse.org/bugs/show_bug.cgi?id=531528 EclipseLink doesn't support
-	 * {@link javax.persistence.IdClass} referencing inner classes.
+	 * This test fails due to https://bugs.eclipse.org/bugs/show_bug.cgi?id=531528 IdentifiableType.hasSingleIdAttribute()
+	 * returns true when IdClass references an inner class. This bug is supposedly fixed, but the test still fails.
 	 */
 	@Ignore
 	@Test
 	@Override
-	public void correctlyDeterminesIdValueForNestedIdClassesWithNonPrimitiveNonManagedType() {}
+	public void correctlyDeterminesIdValueForNestedIdClassesWithNonPrimitiveNonManagedType() {
+		super.correctlyDeterminesIdValueForNestedIdClassesWithNonPrimitiveNonManagedType();
+	}
+
+	/**
+	 * This test fails due to https://bugs.eclipse.org/bugs/show_bug.cgi?id=531528 IdentifiableType.hasSingleIdAttribute()
+	 * returns true when IdClass references an inner class. This bug is supposedly fixed, but the test still fails.
+	 */
+	@Ignore
+	@Test
+	@Override
+	public void proxiedIdClassElement() {
+		super.proxiedIdClassElement();
+	}
+
+
 
 	@Override
 	protected String getMetadadataPersitenceUnitName() {

src/test/java/org/springframework/data/jpa/repository/support/JpaMetamodelEntityInformationIntegrationTests.java

@@ -281,6 +281,28 @@ public class JpaMetamodelEntityInformationIntegrationTests {
 		assertThat(id, is(notNullValue()));
 	}
 
+	@Test // DATAJPA-1416
+	public void proxiedIdClassElement() {
+
+		JpaEntityInformation<SampleWithIdClassIncludingEntity, ?> information = getEntityInformation(
+				SampleWithIdClassIncludingEntity.class, em);
+
+		SampleWithIdClassIncludingEntity entity = new SampleWithIdClassIncludingEntity();
+		entity.setFirst(23L);
+		SampleWithIdClassIncludingEntity.OtherEntity$$PsudoProxy inner = new SampleWithIdClassIncludingEntity.OtherEntity$$PsudoProxy();
+		inner.setOtherId(42L);
+		entity.setSecond(inner);
+
+		Object id = information.getId(entity);
+
+		assertTrue(id instanceof SampleWithIdClassIncludingEntity.SampleWithIdClassPK);
+
+		SampleWithIdClassIncludingEntity.SampleWithIdClassPK pk = (SampleWithIdClassIncludingEntity.SampleWithIdClassPK) id;
+
+		assertThat(pk.getFirst(), equalTo(23L));
+		assertThat(pk.getSecond(), equalTo(42L));
+	}
+
 	protected String getMetadadataPersitenceUnitName() {
 		return "metadata";
 	}

src/test/resources/META-INF/persistence.xml

@@ -42,6 +42,8 @@
 		<class>org.springframework.data.jpa.domain.sample.User</class>
 		<class>org.springframework.data.jpa.domain.sample.VersionedUser</class>
 		<class>org.springframework.data.jpa.domain.sample.Dummy</class>
+		<class>org.springframework.data.jpa.domain.sample.SampleWithIdClassIncludingEntity</class>
+		<class>org.springframework.data.jpa.domain.sample.SampleWithIdClassIncludingEntity$OtherEntity</class>
 		<exclude-unlisted-classes>true</exclude-unlisted-classes>
 	</persistence-unit>
 	<persistence-unit name="querydsl">