HHH-7610 Add an option to initialize empty components when all the pr…

hibernate-core/src/main/java/org/hibernate/cfg/AvailableSettings.java

@@ -711,4 +711,11 @@ public interface AvailableSettings {
 
 	String AUTO_SESSION_EVENTS_LISTENER = "hibernate.session.events.auto";
 
+	/**
+	 * Enable instantiation of composite/embedded objects when all of its attribute values are {@code null}.
+	 * The default (and historical) behavior is that a {@code null} reference will be used to represent the
+	 * composite when all of its attributes are {@code null}.
+	 */
+	String CREATE_EMPTY_COMPOSITES_ENABLED = "hibernate.create_empty_composites.enabled";
+
 }

hibernate-core/src/main/java/org/hibernate/tuple/component/ComponentMetamodel.java

@@ -31,6 +31,8 @@
 
 import org.hibernate.EntityMode;
 import org.hibernate.HibernateException;
+import org.hibernate.cfg.Environment;
+import org.hibernate.internal.util.config.ConfigurationHelper;
 import org.hibernate.mapping.Component;
 import org.hibernate.mapping.Property;
 import org.hibernate.tuple.PropertyFactory;
@@ -56,6 +58,7 @@ public class ComponentMetamodel implements Serializable {
 	// cached for efficiency...
 	private final int propertySpan;
 	private final Map propertyIndexes = new HashMap();
+	private final boolean createEmptyCompositesEnabled;
 
 //	public ComponentMetamodel(Component component, SessionFactoryImplementor sessionFactory) {
 	public ComponentMetamodel(Component component) {
@@ -82,6 +85,12 @@ public ComponentMetamodel(Component component) {
 				entityMode,
 				component
 		) : componentTuplizerFactory.constructTuplizer( tuplizerClassName, component );
+
+		this.createEmptyCompositesEnabled = ConfigurationHelper.getBoolean(
+				Environment.CREATE_EMPTY_COMPOSITES_ENABLED,
+				component.getMappings().getConfigurationProperties(),
+				false
+		);
 	}
 
 	public boolean isKey() {
@@ -123,4 +132,8 @@ public ComponentTuplizer getComponentTuplizer() {
 		return componentTuplizer;
 	}
 
+	public boolean isCreateEmptyCompositesEnabled() {
+		return createEmptyCompositesEnabled;
+	}
+
 }

hibernate-core/src/main/java/org/hibernate/type/ComponentType.java

@@ -67,6 +67,7 @@ public class ComponentType extends AbstractType implements CompositeType, Proced
 	private final FetchMode[] joinedFetch;
 	private final boolean isKey;
 	private boolean hasNotNullProperty;
+	private final boolean createEmptyCompositesEnabled;
 
 	protected final EntityMode entityMode;
 	protected final ComponentTuplizer componentTuplizer;
@@ -96,6 +97,7 @@ public ComponentType(TypeFactory.TypeScope typeScope, ComponentMetamodel metamod
 
 		this.entityMode = metamodel.getEntityMode();
 		this.componentTuplizer = metamodel.getComponentTuplizer();
+		this.createEmptyCompositesEnabled = metamodel.isCreateEmptyCompositesEnabled();
 	}
 
 	public boolean isKey() {
@@ -668,6 +670,9 @@ public Object resolve(Object value, SessionImplementor session, Object owner)
 			setPropertyValues( result, resolvedValues, entityMode );
 			return result;
 		}
+		else if ( isCreateEmptyCompositesEnabled() ) {
+			return instantiate( owner, session );
+		}
 		else {
 			return null;
 		}
@@ -813,4 +818,8 @@ public Object extract(CallableStatement statement, String[] paramNames, SessionI
 	public boolean hasNotNullProperty() {
 		return hasNotNullProperty;
 	}
+
+	private boolean isCreateEmptyCompositesEnabled() {
+		return createEmptyCompositesEnabled;
+	}
 }

hibernate-core/src/test/java/org/hibernate/test/component/empty/ComponentEmptyEmbedded.java

@@ -0,0 +1,28 @@
+package org.hibernate.test.component.empty;
+
+import javax.persistence.Embeddable;
+
+@Embeddable
+public class ComponentEmptyEmbedded {
+
+	private String field1;
+
+	private String field2;
+
+	public String getField1() {
+		return field1;
+	}
+
+	public void setField1(String field1) {
+		this.field1 = field1;
+	}
+
+	public String getField2() {
+		return field2;
+	}
+
+	public void setField2(String field2) {
+		this.field2 = field2;
+	}
+
+}

hibernate-core/src/test/java/org/hibernate/test/component/empty/ComponentEmptyEmbeddedOwner.java

@@ -0,0 +1,32 @@
+package org.hibernate.test.component.empty;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+@Entity
+public class ComponentEmptyEmbeddedOwner {
+
+	@Id
+	@GeneratedValue
+	private Integer id;
+
+	private ComponentEmptyEmbedded embedded;
+
+	public Integer getId() {
+		return id;
+	}
+
+	public void setId(Integer id) {
+		this.id = id;
+	}
+
+	public ComponentEmptyEmbedded getEmbedded() {
+		return embedded;
+	}
+
+	public void setEmbedded(ComponentEmptyEmbedded embedded) {
+		this.embedded = embedded;
+	}
+
+}

hibernate-core/src/test/java/org/hibernate/test/component/empty/EmptyCompositesDirtynessTest.java

@@ -0,0 +1,80 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * Copyright (c) 2014, Red Hat Middleware LLC or third-party contributors as
+ * indicated by the @author tags or express copyright attribution
+ * statements applied by the authors.  All third-party contributions are
+ * distributed under license by Red Hat Middleware LLC.
+ *
+ * This copyrighted material is made available to anyone wishing to use, modify,
+ * copy, or redistribute it subject to the terms and conditions of the GNU
+ * Lesser General Public License, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this distribution; if not, write to:
+ * Free Software Foundation, Inc.
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA  02110-1301  USA
+ */
+package org.hibernate.test.component.empty;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+
+import org.hibernate.Session;
+import org.hibernate.cfg.Configuration;
+import org.hibernate.cfg.Environment;
+import org.hibernate.testing.TestForIssue;
+import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
+import org.junit.Test;
+
+/**
+ * Test class for empty embedded dirtiness computation.
+ *
+ * @author Laurent Almeras
+ */
+public class EmptyCompositesDirtynessTest extends BaseCoreFunctionalTestCase {
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class[] { ComponentEmptyEmbeddedOwner.class, ComponentEmptyEmbedded.class };
+	}
+
+	@Override
+	protected void configure(Configuration configuration) {
+		super.configure( configuration );
+		configuration.getProperties().put( Environment.CREATE_EMPTY_COMPOSITES_ENABLED, Boolean.valueOf( false ) );
+	}
+
+	/**
+	 * Test for dirtyness computation consistency when a property is an empty composite.
+	 */
+	@Test
+	@TestForIssue(jiraKey = "HHH-7610")
+	public void testCompositesEmpty() {
+		Session s = openSession();
+		s.getTransaction().begin();
+
+		ComponentEmptyEmbeddedOwner owner = new ComponentEmptyEmbeddedOwner();
+		s.persist( owner );
+
+		s.flush();
+		s.getTransaction().commit();
+
+		s.clear();
+		s.getTransaction().begin();
+		owner = (ComponentEmptyEmbeddedOwner) s.get( ComponentEmptyEmbeddedOwner.class, owner.getId() );
+		assertNull( owner.getEmbedded() );
+		owner.setEmbedded( new ComponentEmptyEmbedded() );
+
+		// technically, as all properties are null, update may not be necessary
+		assertFalse( session.isDirty() ); // must be false to avoid unnecessary updates
+
+		s.getTransaction().rollback();
+	}
+}

hibernate-core/src/test/java/org/hibernate/test/component/empty/EmptyInitializedCompositesDirtynessTest.java

@@ -0,0 +1,78 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * Copyright (c) 2014, Red Hat Middleware LLC or third-party contributors as
+ * indicated by the @author tags or express copyright attribution
+ * statements applied by the authors.  All third-party contributions are
+ * distributed under license by Red Hat Middleware LLC.
+ *
+ * This copyrighted material is made available to anyone wishing to use, modify,
+ * copy, or redistribute it subject to the terms and conditions of the GNU
+ * Lesser General Public License, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this distribution; if not, write to:
+ * Free Software Foundation, Inc.
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA  02110-1301  USA
+ */
+package org.hibernate.test.component.empty;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+
+import org.hibernate.Session;
+import org.hibernate.cfg.Configuration;
+import org.hibernate.cfg.Environment;
+import org.hibernate.testing.TestForIssue;
+import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
+import org.junit.Test;
+
+/**
+ * Test class for empty embedded dirtiness computation.
+ *
+ * @author Laurent Almeras
+ */
+public class EmptyInitializedCompositesDirtynessTest extends BaseCoreFunctionalTestCase {
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class[] { ComponentEmptyEmbeddedOwner.class, ComponentEmptyEmbedded.class };
+	}
+
+	@Override
+	protected void configure(Configuration configuration) {
+		super.configure( configuration );
+		configuration.getProperties().put( Environment.CREATE_EMPTY_COMPOSITES_ENABLED, Boolean.valueOf( true ) );
+	}
+
+	/**
+	 * Test for dirtyness computation consistency when a property is an empty composite and that empty composite
+	 * initialization is set.
+	 */
+	@Test
+	@TestForIssue(jiraKey = "HHH-7610")
+	public void testInitializedCompositesEmpty() {
+		Session s = openSession();
+		s.getTransaction().begin();
+
+		ComponentEmptyEmbeddedOwner owner = new ComponentEmptyEmbeddedOwner();
+		s.persist( owner );
+
+		s.flush();
+		s.getTransaction().commit();
+
+		s.clear();
+		s.getTransaction().begin();
+		owner = (ComponentEmptyEmbeddedOwner) s.get( ComponentEmptyEmbeddedOwner.class, owner.getId() );
+		assertNotNull( owner.getEmbedded() );
+		assertFalse( s.isDirty() );
+
+		s.getTransaction().rollback();
+	}
+}

hibernate-core/src/test/java/org/hibernate/test/component/empty/EmptyInitializedCompositesTest.java

@@ -0,0 +1,80 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * Copyright (c) 2014, Red Hat Middleware LLC or third-party contributors as
+ * indicated by the @author tags or express copyright attribution
+ * statements applied by the authors.  All third-party contributions are
+ * distributed under license by Red Hat Middleware LLC.
+ *
+ * This copyrighted material is made available to anyone wishing to use, modify,
+ * copy, or redistribute it subject to the terms and conditions of the GNU
+ * Lesser General Public License, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this distribution; if not, write to:
+ * Free Software Foundation, Inc.
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA  02110-1301  USA
+ */
+package org.hibernate.test.component.empty;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+
+import org.hibernate.Session;
+import org.hibernate.cfg.Configuration;
+import org.hibernate.cfg.Environment;
+import org.hibernate.testing.TestForIssue;
+import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
+import org.junit.Test;
+
+/**
+ * Test class for empty embedded dirtiness computation.
+ *
+ * @author Laurent Almeras
+ */
+public class EmptyInitializedCompositesTest extends BaseCoreFunctionalTestCase {
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class[] { ComponentEmptyEmbeddedOwner.class, ComponentEmptyEmbedded.class };
+	}
+
+	@Override
+	protected void configure(Configuration configuration) {
+		super.configure( configuration );
+		configuration.getProperties().put( Environment.CREATE_EMPTY_COMPOSITES_ENABLED, Boolean.valueOf( true ) );
+	}
+
+	/**
+	 * Test empty composite initialization.
+	 */
+	@Test
+	@TestForIssue(jiraKey = "HHH-7610")
+	public void testCompositesEmpty() {
+		Session s = openSession();
+		s.getTransaction().begin();
+
+		ComponentEmptyEmbeddedOwner owner = new ComponentEmptyEmbeddedOwner();
+		s.persist( owner );
+
+		s.flush();
+		s.getTransaction().commit();
+
+		s.clear();
+		s.getTransaction().begin();
+		owner = (ComponentEmptyEmbeddedOwner) s.get( ComponentEmptyEmbeddedOwner.class, owner.getId() );
+		assertNotNull( owner.getEmbedded() );
+		assertFalse( s.isDirty() );
+
+		owner.setEmbedded( null );
+		assertFalse( s.isDirty() ); // must be false to avoid unnecessary updates
+
+		s.getTransaction().rollback();
+	}
+}