HHH-10013 - Adjust default for hibernate.id.new_generator_mappings to true

documentation/src/main/docbook/mapping/en-US/chapters/id/Identifiers.xml

@@ -191,8 +191,8 @@
                 The discussions below assume that the application is using Hibernate's "new generator mappings" as
                 indicated by the <literal>hibernate.id.new_generator_mappings</literal> setting or
                 <methodname>MetadataBuilder.enableNewIdentifierGeneratorSupport</methodname> method during bootstrap.
-                For legacy reasons the default value for this setting is currently false, however we anticipate it
+                This is set to true by default, however if applications set this to false the resolutions discussed
-                becoming true at some point.  The rest of the discussion here assumes this setting is enabled (true).
+                here will be very different.  The rest of the discussion here assumes this setting is enabled (true).
             </para>
         </note>
 

hibernate-core/src/main/java/org/hibernate/boot/internal/MetadataBuilderImpl.java

@@ -686,7 +686,7 @@ public class MetadataBuilderImpl implements MetadataBuilderImplementor, TypeCont
 			final boolean useNewIdentifierGenerators = configService.getSetting(
 					AvailableSettings.USE_NEW_ID_GENERATOR_MAPPINGS,
 					StandardConverters.BOOLEAN,
-					false
+					true
 			);
 			if ( useNewIdentifierGenerators ) {
 				idGenerationTypeInterpreter.disableLegacyFallback();

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

@@ -256,7 +256,9 @@ public interface AvailableSettings {
 	/**
 	 * Setting which indicates whether or not the new {@link org.hibernate.id.IdentifierGenerator} are used
 	 * for AUTO, TABLE and SEQUENCE.
-	 * Default to false to keep backward compatibility.
+	 * <p/>
+	 * Default is {@code true}.  Existing applications may want to disable this (set it {@code false}) for
+	 * upgrade compatibility.
 	 *
 	 * @see MetadataBuilder#enableNewIdentifierGeneratorSupport
 	 */

hibernate-core/src/main/java/org/hibernate/dialect/Dialect.java

@@ -731,9 +731,6 @@ public abstract class Dialect implements ConversionContext {
 		if ( supportsIdentityColumns() ) {
 			return IdentityGenerator.class;
 		}
-		else if ( supportsSequences() ) {
-			return SequenceGenerator.class;
-		}
 		else {
 			return SequenceStyleGenerator.class;
 		}

hibernate-core/src/main/java/org/hibernate/dialect/PostgreSQL81Dialect.java

@@ -28,6 +28,7 @@ import org.hibernate.hql.spi.id.MultiTableBulkIdStrategy;
 import org.hibernate.hql.spi.id.local.AfterUseAction;
 import org.hibernate.hql.spi.id.local.LocalTemporaryTableBulkIdStrategy;
 import org.hibernate.id.SequenceGenerator;
+import org.hibernate.id.enhanced.SequenceStyleGenerator;
 import org.hibernate.internal.util.JdbcExceptionHelper;
 import org.hibernate.procedure.internal.PostgresCallableStatementSupport;
 import org.hibernate.procedure.spi.CallableStatementSupport;
@@ -313,7 +314,7 @@ public class PostgreSQL81Dialect extends Dialect {
 
 	@Override
 	public Class getNativeIdentifierGeneratorClass() {
-		return SequenceGenerator.class;
+		return SequenceStyleGenerator.class;
 	}
 
 	@Override

hibernate-core/src/main/java/org/hibernate/id/factory/internal/DefaultIdentifierGeneratorFactory.java

@@ -65,7 +65,7 @@ public class DefaultIdentifierGeneratorFactory
 		register( "assigned", Assigned.class );
 		register( "identity", IdentityGenerator.class );
 		register( "select", SelectGenerator.class );
-		register( "sequence", SequenceGenerator.class );
+		register( "sequence", SequenceStyleGenerator.class );
 		register( "seqhilo", SequenceHiLoGenerator.class );
 		register( "increment", IncrementGenerator.class );
 		register( "foreign", ForeignGenerator.class );

hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/join/AbstractHHH3949TestTask.java

@@ -22,6 +22,14 @@ public abstract class AbstractHHH3949TestTask extends AbstractEnhancerTestTask {
 		Session session = getFactory().openSession();
 		Transaction tx = session.beginTransaction();
 
+		// it is important that the data associations remain as follows:
+		//		* Johnny <-> Volkswagen Golf
+		//		* Ricky <-> Subaru Impreza
+		//		* Rosy -> none
+		//		* none <- Renault Truck
+		//
+		// see #shouldHaveVehicle and #shouldHaveDriver
+
 		Person person1 = new Person( "Johnny" );
 		Person person2 = new Person( "Ricky" );
 		Person person3 = new Person( "Rosy" );
@@ -46,6 +54,16 @@ public abstract class AbstractHHH3949TestTask extends AbstractEnhancerTestTask {
 		session.close();
 	}
 
+	protected boolean shouldHaveVehicle(Person person) {
+		return "Johnny".equals( person.getName() )
+				|| "Ricky".equals( person.getName() );
+	}
+
+	protected boolean shouldHaveDriver(Vehicle vehicle) {
+		return "Volkswagen Golf".equals( vehicle.getName() )
+				|| "Subaru Impreza".equals( vehicle.getName() );
+	}
+
 	protected void cleanup() {
 	}
 

hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/join/HHH3949TestTask1.java

@@ -28,7 +28,7 @@ public class HHH3949TestTask1 extends AbstractHHH3949TestTask {
 		// 4) verify the results
 		for ( Person person : persons ) {
 			assertTrue( Hibernate.isInitialized( person ) );
-			if ( person.getId() < 3 ) {
+			if ( shouldHaveVehicle( person ) ) {
 				assertNotNull( person.getVehicle() );
 				assertTrue( Hibernate.isInitialized( person.getVehicle() ) );
 				assertNotNull( person.getVehicle().getDriver() );

hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/join/HHH3949TestTask2.java

@@ -24,7 +24,7 @@ public class HHH3949TestTask2 extends AbstractHHH3949TestTask {
 
 		// 4) verify the results
 		for ( Vehicle vehicle : vehicles ) {
-			if ( vehicle.getId() < 3 ) {
+			if ( shouldHaveDriver( vehicle ) ) {
 				Assert.assertNotNull( vehicle.getDriver() );
 				Assert.assertNotNull( vehicle.getDriver().getVehicle() );
 			}

hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/join/HHH3949TestTask3.java

@@ -16,7 +16,7 @@ public class HHH3949TestTask3 extends AbstractHHH3949TestTask {
 				.setFetchMode( "vehicle", FetchMode.JOIN )
 				.list();
 		for ( Person person : persons ) {
-			if ( person.getId() < 3 ) {
+			if ( shouldHaveVehicle( person ) ) {
 				Assert.assertNotNull( person.getVehicle() );
 				Assert.assertNotNull( person.getVehicle().getDriver() );
 			}

hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/join/HHH3949TestTask4.java

@@ -18,7 +18,7 @@ public class HHH3949TestTask4 extends AbstractHHH3949TestTask {
 		session.close();
 
 		for ( Vehicle vehicle : vehicles ) {
-			if ( vehicle.getId() < 3 ) {
+			if ( shouldHaveDriver( vehicle ) ) {
 				Assert.assertNotNull( vehicle.getDriver() );
 				Assert.assertNotNull( vehicle.getDriver().getVehicle() );
 			}

working-5.0-migration-guide.md

@@ -38,6 +38,8 @@ Working list of changes for 5.0
 * For EnumType mappings defined in hbm.xml where the user wants name-mapping (`javax.persistence.EnumType#STRING`) 
     the configuration must explicitly state that using either the `useNamed` (true) setting or by specifying the `type`
     setting set to the value 12 (VARCHAR JDBC type code).
+* Default value for `hibernate.id.new_generator_mappings` setting changed to true for 5.0.  See 
+    `org.hibernate.cfg.AvailableSettings#USE_NEW_ID_GENERATOR_MAPPINGS` javadocs. 
     
 
 TODOs