DATAJPA-119 - JpaMetamodelEntityInformation now considers @Version.

If a JPA entity class has an @Version attribute we now consider this to determine whether it is new or not. So even if an id is set we'll consider it new as long as the version attribute is null.

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

@@ -46,6 +46,7 @@ import org.springframework.util.ReflectionUtils;
 public class JpaMetamodelEntityInformation<T, ID extends Serializable> extends JpaEntityInformationSupport<T, ID> {
 
 	private final IdMetadata<T> idMetadata;
+	private final SingularAttribute<? super T, ?> versionAttribute;
 
 	/**
 	 * Creates a new {@link JpaMetamodelEntityInformation} for the given domain class and {@link Metamodel}.
@@ -69,6 +70,26 @@ public class JpaMetamodelEntityInformation<T, ID extends Serializable> extends J
 		}
 
 		this.idMetadata = new IdMetadata<T>((IdentifiableType<T>) type);
+		this.versionAttribute = findVersionAttribute(type);
+	}
+
+	/**
+	 * Returns the version attribute of the given {@link ManagedType} or {@literal null} if none available.
+	 * 
+	 * @param type must not be {@literal null}.
+	 * @return
+	 */
+	private static <T> SingularAttribute<? super T, ?> findVersionAttribute(ManagedType<T> type) {
+
+		Set<SingularAttribute<? super T, ?>> attributes = type.getSingularAttributes();
+
+		for (SingularAttribute<? super T, ?> attribute : attributes) {
+			if (attribute.isVersion()) {
+				return attribute;
+			}
+		}
+
+		return null;
 	}
 
 	/*
@@ -153,6 +174,20 @@ public class JpaMetamodelEntityInformation<T, ID extends Serializable> extends J
 		return new DirectFieldAccessFallbackBeanWrapper(id).getPropertyValue(idAttribute);
 	}
 
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.core.support.AbstractEntityInformation#isNew(java.lang.Object)
+	 */
+	@Override
+	public boolean isNew(T entity) {
+
+		if (versionAttribute == null) {
+			return super.isNew(entity);
+		}
+
+		return new DirectFieldAccessFallbackBeanWrapper(entity).getPropertyValue(versionAttribute.getName()) == null;
+	}
+
 	/**
 	 * Simple value object to encapsulate id specific metadata.
 	 * 

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

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2013 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.domain.sample;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.Version;
+
+/**
+ * @author Oliver Gierke
+ */
+@Entity
+public class VersionedUser {
+
+	@Id
+	@GeneratedValue
+	private Long id;
+
+	@Version
+	private Long version;
+
+	/**
+	 * @return the id
+	 */
+	public Long getId() {
+		return id;
+	}
+
+	/**
+	 * @param id the id to set
+	 */
+	public void setId(Long id) {
+		this.id = id;
+	}
+
+	/**
+	 * @return the version
+	 */
+	public Long getVersion() {
+		return version;
+	}
+
+	/**
+	 * @param version the version to set
+	 */
+	public void setVersion(Long version) {
+		this.version = version;
+	}
+}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2012 the original author or authors.
+ * Copyright 2011-2013 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.
@@ -31,6 +31,7 @@ import org.springframework.data.jpa.domain.AbstractPersistable;
 import org.springframework.data.jpa.domain.sample.SampleWithIdClass;
 import org.springframework.data.jpa.domain.sample.SampleWithIdClassPK;
 import org.springframework.data.jpa.domain.sample.User;
+import org.springframework.data.jpa.domain.sample.VersionedUser;
 import org.springframework.data.repository.core.EntityInformation;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
@@ -92,4 +93,23 @@ public class JpaMetamodelEntityInformationIntegrationTests {
 		assertThat(id, is(instanceOf(SampleWithIdClassPK.class)));
 		assertThat(id, is((Object) new SampleWithIdClassPK(2L, 4L)));
 	}
+
+	/**
+	 * @see DATAJPA-119
+	 */
+	@Test
+	public void favoursVersionAnnotationIfPresent() {
+
+		EntityInformation<VersionedUser, Long> information = new JpaMetamodelEntityInformation<VersionedUser, Long>(
+				VersionedUser.class, em.getMetamodel());
+
+		VersionedUser entity = new VersionedUser();
+		assertThat(information.isNew(entity), is(true));
+		entity.setId(1L);
+		assertThat(information.isNew(entity), is(true));
+		entity.setVersion(1L);
+		assertThat(information.isNew(entity), is(false));
+		entity.setId(null);
+		assertThat(information.isNew(entity), is(false));
+	}
 }

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

@@ -14,6 +14,7 @@
 		<class>org.springframework.data.jpa.domain.sample.SampleEntity</class>
 		<class>org.springframework.data.jpa.domain.sample.SampleEntityPK</class>
 		<class>org.springframework.data.jpa.domain.sample.SampleWithIdClass</class>
+		<class>org.springframework.data.jpa.domain.sample.VersionedUser</class>
 		<exclude-unlisted-classes>true</exclude-unlisted-classes>
 	</persistence-unit>
 	<persistence-unit name="querydsl">