DATAJPA-141 - JpaMetamodelEntityInformation now works with MappedSuperclasses as well.

We now call Metamodel.managedClass(…) instead of Metamodel.entityType(…) to be able to detect ids in @MappedSuperclass types as well. Unfortunately this currently still fails with Hibernate as theit Metamodel implementation only considers entities. See [0] for further details.

[0] https://hibernate.onjira.com/browse/HHH-6896

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

@@ -20,7 +20,8 @@ import java.lang.reflect.Field;
 import java.lang.reflect.Member;
 import java.lang.reflect.Method;
 
-import javax.persistence.metamodel.EntityType;
+import javax.persistence.metamodel.IdentifiableType;
+import javax.persistence.metamodel.ManagedType;
 import javax.persistence.metamodel.Metamodel;
 import javax.persistence.metamodel.SingularAttribute;
 
@@ -49,13 +50,18 @@ public class JpaMetamodelEntityInformation<T, ID extends Serializable> extends J
 		super(domainClass);
 
 		Assert.notNull(metamodel);
-		EntityType<T> type = metamodel.entity(domainClass);
+		ManagedType<T> type = metamodel.managedType(domainClass);
 
 		if (type == null) {
 			throw new IllegalArgumentException("The given domain class can not be found in the given Metamodel!");
 		}
 
-		this.attribute = type.getId(type.getIdType().getJavaType());
+		if (!(type instanceof IdentifiableType)) {
+			throw new IllegalArgumentException("The given domain class does not contain an id attribute!");
+		}
+
+		IdentifiableType<T> identifiableType = (IdentifiableType<T>) type;
+		this.attribute = identifiableType.getId(identifiableType.getIdType().getJavaType());
 	}
 
 	/*

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

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2011 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jpa.repository.support;
+
+import static org.hamcrest.Matchers.*;
+import static org.junit.Assert.*;
+
+import java.io.Serializable;
+
+import javax.persistence.EntityManager;
+import javax.persistence.MappedSuperclass;
+import javax.persistence.PersistenceContext;
+import javax.persistence.metamodel.Metamodel;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.data.jpa.domain.AbstractPersistable;
+import org.springframework.data.jpa.domain.sample.User;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+/**
+ * Integration tests for {@link JpaMetamodelEntityInformation}. Has to run with OpenJPA as Hibernate does not implement
+ * {@link Metamodel#managedType(Class)} correctly (does not consider {@link MappedSuperclass}es correctly).
+ * 
+ * @see https://hibernate.onjira.com/browse/HHH-6896
+ * @author Oliver Gierke
+ */
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration({ "classpath:infrastructure.xml", "classpath:openjpa.xml" })
+public class JpaMetamodelEntityInformationIntegrationTests {
+
+	@PersistenceContext
+	EntityManager em;
+
+	@Test
+	public void detectsIdTypeForEntity() {
+
+		JpaEntityInformation<User, ?> information = JpaEntityInformationSupport.getMetadata(User.class, em);
+		assertThat(information.getIdType(), is(typeCompatibleWith(Integer.class)));
+	}
+
+	/**
+	 * @see DATAJPA-141
+	 */
+	@Test
+	public void detectsIdTypeForMappedSuperclass() {
+
+		JpaEntityInformation<?, ?> information = JpaEntityInformationSupport.getMetadata(AbstractPersistable.class, em);
+		assertEquals(Serializable.class, information.getIdType());
+	}
+}

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

@@ -53,7 +53,7 @@ public class JpaPersistableEntityInformationUnitTests {
 	@SuppressWarnings("unchecked")
 	public void setUp() {
 
-		when(metamodel.entity(Foo.class)).thenReturn(type);
+		when(metamodel.managedType(Foo.class)).thenReturn(type);
 		when(type.getIdType()).thenReturn(idType);
 	}