HHH-11152: Added BytecodeProvider based on Byte Buddy

build.gradle

@@ -154,6 +154,7 @@ subprojects { subProject ->
 
 		testRuntime( libraries.log4j )
 		testRuntime( libraries.javassist )
+		testRuntime( libraries.byteBuddy )
 		testRuntime( libraries.woodstox )
 
 		//Databases

documentation/src/main/asciidoc/quickstart/tutorials/osgi/unmanaged-native/pom.xml

@@ -76,7 +76,7 @@
               org.hibernate.cfg,
               org.hibernate.service,
               javax.persistence;version="[1.0.0,2.1.0]",
-              <!-- Needed for proxying's Javassist enhancement during runtime -->
+              <!-- Needed for proxy enhancement during runtime -->
               org.hibernate.proxy,
               javassist.util.proxy,
               *

hibernate-core/hibernate-core.gradle

@@ -23,6 +23,7 @@ configurations {
 dependencies {
     compile( libraries.jpa )
     compile( libraries.javassist )
+    compile( libraries.byteBuddy )
     compile( libraries.antlr )
     compile( libraries.jta )
     compile( libraries.jandex )
@@ -95,6 +96,7 @@ dependencies {
     testRuntime( libraries.expression_language_impl )
     testRuntime( 'jaxen:jaxen:1.1' )
     testRuntime( libraries.javassist )
+    testRuntime( libraries.byteBuddy )
 
     testCompile( project( ':hibernate-jpamodelgen' ) )
 

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/bytebuddy/BiDirectionalAssociationHandler.java

@@ -0,0 +1,330 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.bytebuddy;
+
+import java.util.Collection;
+import java.util.Map;
+import javax.persistence.Access;
+import javax.persistence.AccessType;
+import javax.persistence.ManyToMany;
+import javax.persistence.ManyToOne;
+import javax.persistence.OneToMany;
+import javax.persistence.OneToOne;
+
+import org.hibernate.bytecode.enhance.spi.EnhancementException;
+import org.hibernate.bytecode.enhance.spi.EnhancerConstants;
+import org.hibernate.internal.CoreLogging;
+import org.hibernate.internal.CoreMessageLogger;
+
+import net.bytebuddy.asm.Advice;
+import net.bytebuddy.description.annotation.AnnotationDescription;
+import net.bytebuddy.description.annotation.AnnotationValue;
+import net.bytebuddy.description.field.FieldDescription;
+import net.bytebuddy.description.method.MethodDescription;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.dynamic.scaffold.FieldLocator;
+import net.bytebuddy.dynamic.scaffold.InstrumentedType;
+import net.bytebuddy.implementation.Implementation;
+import net.bytebuddy.implementation.bytecode.ByteCodeAppender;
+import net.bytebuddy.jar.asm.MethodVisitor;
+import net.bytebuddy.jar.asm.Opcodes;
+import net.bytebuddy.jar.asm.Type;
+
+class BiDirectionalAssociationHandler implements Implementation {
+
+	private static final CoreMessageLogger log = CoreLogging.messageLogger( BiDirectionalAssociationHandler.class );
+
+	static Implementation wrap(
+			TypeDescription managedCtClass,
+			ByteBuddyEnhancementContext enhancementContext,
+			FieldDescription persistentField,
+			Implementation implementation) {
+		if ( !enhancementContext.doBiDirectionalAssociationManagement( persistentField ) ) {
+			return implementation;
+		}
+
+		TypeDescription targetEntity = getTargetEntityClass( managedCtClass, persistentField );
+		if ( targetEntity == null ) {
+			return implementation;
+		}
+		String mappedBy = getMappedBy( persistentField, targetEntity, enhancementContext );
+		if ( mappedBy == null || mappedBy.isEmpty() ) {
+			log.infof(
+					"Could not find bi-directional association for field [%s#%s]",
+					managedCtClass.getName(),
+					persistentField.getName()
+			);
+			return implementation;
+		}
+
+		TypeDescription targetType = FieldLocator.ForClassHierarchy.Factory.INSTANCE.make( targetEntity )
+				.locate( mappedBy )
+				.getField()
+				.getType()
+				.asErasure();
+
+		if ( EnhancerImpl.isAnnotationPresent( persistentField, OneToOne.class ) ) {
+			implementation = Advice.withCustomMapping()
+					.bind( CodeTemplates.FieldValue.class, persistentField )
+					.bind( CodeTemplates.MappedBy.class, mappedBy )
+					.to( CodeTemplates.OneToOneHandler.class )
+					.wrap( implementation );
+		}
+
+		if ( EnhancerImpl.isAnnotationPresent( persistentField, OneToMany.class ) ) {
+			implementation = Advice.withCustomMapping()
+					.bind( CodeTemplates.FieldValue.class, persistentField )
+					.bind( CodeTemplates.MappedBy.class, mappedBy )
+					.to( persistentField.getType().asErasure().isAssignableTo( Map.class )
+								? CodeTemplates.OneToManyOnMapHandler.class
+								: CodeTemplates.OneToManyOnCollectionHandler.class )
+					.wrap( implementation );
+		}
+
+		if ( EnhancerImpl.isAnnotationPresent( persistentField, ManyToOne.class ) ) {
+			implementation = Advice.withCustomMapping()
+					.bind( CodeTemplates.FieldValue.class, persistentField )
+					.bind( CodeTemplates.MappedBy.class, mappedBy )
+					.to( CodeTemplates.ManyToOneHandler.class )
+					.wrap( implementation );
+		}
+
+		if ( EnhancerImpl.isAnnotationPresent( persistentField, ManyToMany.class ) ) {
+
+			if ( persistentField.getType().asErasure().isAssignableTo( Map.class ) || targetType.isAssignableTo( Map.class ) ) {
+				log.infof(
+						"Bi-directional association for field [%s#%s] not managed: @ManyToMany in java.util.Map attribute not supported ",
+						managedCtClass.getName(),
+						persistentField.getName()
+				);
+				return implementation;
+			}
+
+			implementation = Advice.withCustomMapping()
+					.bind( CodeTemplates.FieldValue.class, persistentField )
+					.bind( CodeTemplates.MappedBy.class, mappedBy )
+					.to( CodeTemplates.ManyToManyHandler.class )
+					.wrap( implementation );
+		}
+
+		return new BiDirectionalAssociationHandler( implementation, targetEntity, targetType, mappedBy );
+	}
+
+	public static TypeDescription getTargetEntityClass(TypeDescription managedCtClass, FieldDescription persistentField) {
+		try {
+			AnnotationDescription.Loadable<OneToOne> oto = EnhancerImpl.getAnnotation( persistentField, OneToOne.class );
+			AnnotationDescription.Loadable<OneToMany> otm = EnhancerImpl.getAnnotation( persistentField, OneToMany.class );
+			AnnotationDescription.Loadable<ManyToOne> mto = EnhancerImpl.getAnnotation( persistentField, ManyToOne.class );
+			AnnotationDescription.Loadable<ManyToMany> mtm = EnhancerImpl.getAnnotation( persistentField, ManyToMany.class );
+
+			if ( oto == null && otm == null && mto == null && mtm == null ) {
+				return null;
+			}
+
+			AnnotationValue<?, ?> targetClass = null;
+			if ( oto != null ) {
+				targetClass = oto.getValue( new MethodDescription.ForLoadedMethod( OneToOne.class.getDeclaredMethod( "targetEntity" ) ) );
+			}
+			if ( otm != null ) {
+				targetClass = otm.getValue( new MethodDescription.ForLoadedMethod( OneToMany.class.getDeclaredMethod( "targetEntity" ) ) );
+			}
+			if ( mto != null ) {
+				targetClass = mto.getValue( new MethodDescription.ForLoadedMethod( ManyToOne.class.getDeclaredMethod( "targetEntity" ) ) );
+			}
+			if ( mtm != null ) {
+				targetClass = mtm.getValue( new MethodDescription.ForLoadedMethod( ManyToMany.class.getDeclaredMethod( "targetEntity" ) ) );
+			}
+
+			if ( targetClass == null ) {
+				log.infof(
+						"Could not find type of bi-directional association for field [%s#%s]",
+						managedCtClass.getName(),
+						persistentField.getName()
+				);
+				return null;
+			}
+			else if ( !targetClass.resolve( TypeDescription.class ).represents( void.class ) ) {
+				return targetClass.resolve( TypeDescription.class );
+			}
+		}
+		catch (NoSuchMethodException ignored) {
+		}
+
+		return entityType( target( persistentField ) );
+	}
+
+	private static TypeDescription.Generic target(FieldDescription persistentField) {
+		AnnotationDescription.Loadable<Access> access = persistentField.getDeclaringType().asErasure().getDeclaredAnnotations().ofType( Access.class );
+		if ( access != null && access.loadSilent().value() == AccessType.FIELD ) {
+			return persistentField.getType();
+		}
+		else {
+			MethodDescription getter = EnhancerImpl.getterOf( persistentField );
+			if ( getter == null ) {
+				return persistentField.getType();
+			}
+			else {
+				return getter.getReturnType();
+			}
+		}
+	}
+
+	private static String getMappedBy(FieldDescription target, TypeDescription targetEntity, ByteBuddyEnhancementContext context) {
+		String mappedBy = getMappedByNotManyToMany( target );
+		if ( mappedBy == null || mappedBy.isEmpty() ) {
+			return getMappedByManyToMany( target, targetEntity, context );
+		}
+		else {
+			return mappedBy;
+		}
+	}
+
+	private static String getMappedByNotManyToMany(FieldDescription target) {
+		try {
+			AnnotationDescription.Loadable<OneToOne> oto = EnhancerImpl.getAnnotation( target, OneToOne.class );
+			if ( oto != null ) {
+				return oto.getValue( new MethodDescription.ForLoadedMethod( OneToOne.class.getDeclaredMethod( "mappedBy" ) ) ).resolve( String.class );
+			}
+
+			AnnotationDescription.Loadable<OneToMany> otm = EnhancerImpl.getAnnotation( target, OneToMany.class );
+			if ( otm != null ) {
+				return otm.getValue( new MethodDescription.ForLoadedMethod( OneToMany.class.getDeclaredMethod( "mappedBy" ) ) ).resolve( String.class );
+			}
+
+			AnnotationDescription.Loadable<ManyToMany> mtm = EnhancerImpl.getAnnotation( target, ManyToMany.class );
+			if ( mtm != null ) {
+				return mtm.getValue( new MethodDescription.ForLoadedMethod( ManyToMany.class.getDeclaredMethod( "mappedBy" ) ) ).resolve( String.class );
+			}
+		}
+		catch (NoSuchMethodException ignored) {
+		}
+
+		return null;
+	}
+
+	private static String getMappedByManyToMany(FieldDescription target, TypeDescription targetEntity, ByteBuddyEnhancementContext context) {
+		for ( FieldDescription f : targetEntity.getDeclaredFields() ) {
+			if ( context.isPersistentField( f )
+					&& target.getName().equals( getMappedByNotManyToMany( f ) )
+					&& target.getDeclaringType().asErasure().isAssignableTo( entityType( f.getType() ) ) ) {
+				log.debugf(
+						"mappedBy association for field [%s#%s] is [%s#%s]",
+						target.getDeclaringType().asErasure().getName(),
+						target.getName(),
+						targetEntity.getName(),
+						f.getName()
+				);
+				return f.getName();
+			}
+		}
+		return null;
+	}
+
+	private static TypeDescription entityType(TypeDescription.Generic type) {
+		if ( type.getSort().isParameterized() ) {
+			if ( type.asErasure().isAssignableTo( Collection.class ) ) {
+				return type.getTypeArguments().get( 0 ).asErasure();
+			}
+			if ( type.asErasure().isAssignableTo( Map.class ) ) {
+				return type.getTypeArguments().get( 1 ).asErasure();
+			}
+		}
+
+		return type.asErasure();
+	}
+
+	private final Implementation delegate;
+
+	private final TypeDescription targetEntity;
+
+	private final TypeDescription targetType;
+
+	private final String mappedBy;
+
+	private BiDirectionalAssociationHandler(
+			Implementation delegate,
+			TypeDescription targetEntity,
+			TypeDescription targetType,
+			String mappedBy) {
+		this.delegate = delegate;
+		this.targetEntity = targetEntity;
+		this.targetType = targetType;
+		this.mappedBy = mappedBy;
+	}
+
+	@Override
+	public ByteCodeAppender appender(Target implementationTarget) {
+		return new WrappingAppender( delegate.appender( implementationTarget ) );
+	}
+
+	@Override
+	public InstrumentedType prepare(InstrumentedType instrumentedType) {
+		return delegate.prepare( instrumentedType );
+	}
+
+	private class WrappingAppender implements ByteCodeAppender {
+
+		private final ByteCodeAppender delegate;
+
+		private WrappingAppender(ByteCodeAppender delegate) {
+			this.delegate = delegate;
+		}
+
+		@Override
+		public Size apply(
+				MethodVisitor methodVisitor, Context implementationContext, MethodDescription instrumentedMethod) {
+			return delegate.apply( new MethodVisitor( Opcodes.ASM5, methodVisitor ) {
+
+				@Override
+				public void visitMethodInsn(int opcode, String owner, String name, String desc, boolean itf) {
+					if ( owner.startsWith( Type.getInternalName( CodeTemplates.class ) ) ) {
+						if ( name.equals( "getter" ) ) {
+							super.visitTypeInsn( Opcodes.CHECKCAST, targetEntity.getInternalName() );
+							super.visitMethodInsn(
+									Opcodes.INVOKEVIRTUAL,
+									targetEntity.getInternalName(),
+									EnhancerConstants.PERSISTENT_FIELD_READER_PREFIX + mappedBy,
+									Type.getMethodDescriptor( Type.getType( targetType.getDescriptor() ) ),
+									false
+							);
+						}
+						else if ( name.equals( "setterSelf" ) ) {
+							super.visitInsn( Opcodes.POP );
+							super.visitTypeInsn( Opcodes.CHECKCAST, targetEntity.getInternalName() );
+							super.visitVarInsn( Opcodes.ALOAD, 0 );
+							super.visitMethodInsn(
+									Opcodes.INVOKEVIRTUAL,
+									targetEntity.getInternalName(),
+									EnhancerConstants.PERSISTENT_FIELD_WRITER_PREFIX + mappedBy,
+									Type.getMethodDescriptor( Type.getType( void.class ), Type.getType( targetType.getDescriptor() ) ),
+									false
+							);
+						}
+						else if ( name.equals( "setterNull" ) ) {
+							super.visitInsn( Opcodes.POP );
+							super.visitTypeInsn( Opcodes.CHECKCAST, targetEntity.getInternalName() );
+							super.visitInsn( Opcodes.ACONST_NULL );
+							super.visitMethodInsn(
+									Opcodes.INVOKEVIRTUAL,
+									targetEntity.getInternalName(),
+									EnhancerConstants.PERSISTENT_FIELD_WRITER_PREFIX + mappedBy,
+									Type.getMethodDescriptor( Type.getType( void.class ), Type.getType( targetType.getDescriptor() ) ),
+									false
+							);
+						}
+						else {
+							throw new EnhancementException( "Unknown template method: " + name );
+						}
+					}
+					else {
+						super.visitMethodInsn( opcode, owner, name, desc, itf );
+					}
+				}
+			}, implementationContext, instrumentedMethod );
+		}
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/bytebuddy/ByteBuddyEnhancementContext.java

@@ -0,0 +1,79 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.bytebuddy;
+
+import org.hibernate.bytecode.enhance.spi.EnhancementContext;
+import org.hibernate.bytecode.enhance.spi.UnloadedField;
+
+import net.bytebuddy.description.field.FieldDescription;
+import net.bytebuddy.description.type.TypeDescription;
+
+class ByteBuddyEnhancementContext {
+
+	private final EnhancementContext enhancementContext;
+
+	ByteBuddyEnhancementContext(EnhancementContext enhancementContext) {
+		this.enhancementContext = enhancementContext;
+	}
+
+	public ClassLoader getLoadingClassLoader() {
+		return enhancementContext.getLoadingClassLoader();
+	}
+
+	public boolean isEntityClass(TypeDescription classDescriptor) {
+		return enhancementContext.isEntityClass( new UnloadedTypeDescription( classDescriptor ) );
+	}
+
+	public boolean isCompositeClass(TypeDescription classDescriptor) {
+		return enhancementContext.isCompositeClass( new UnloadedTypeDescription( classDescriptor ) );
+	}
+
+	public boolean isMappedSuperclassClass(TypeDescription classDescriptor) {
+		return enhancementContext.isMappedSuperclassClass( new UnloadedTypeDescription( classDescriptor ) );
+	}
+
+	public boolean doBiDirectionalAssociationManagement(FieldDescription field) {
+		return enhancementContext.doBiDirectionalAssociationManagement( new UnloadedFieldDescription( field ) );
+	}
+
+	public boolean doDirtyCheckingInline(TypeDescription classDescriptor) {
+		return enhancementContext.doDirtyCheckingInline( new UnloadedTypeDescription( classDescriptor ) );
+	}
+
+	public boolean doExtendedEnhancement(TypeDescription classDescriptor) {
+		return enhancementContext.doExtendedEnhancement( new UnloadedTypeDescription( classDescriptor ) );
+	}
+
+	public boolean hasLazyLoadableAttributes(TypeDescription classDescriptor) {
+		return enhancementContext.hasLazyLoadableAttributes( new UnloadedTypeDescription( classDescriptor ) );
+	}
+
+	public boolean isPersistentField(FieldDescription ctField) {
+		return enhancementContext.isPersistentField( new UnloadedFieldDescription( ctField ) );
+	}
+
+	public FieldDescription[] order(FieldDescription[] persistentFields) {
+		UnloadedField[] unloadedFields = new UnloadedField[persistentFields.length];
+		for ( int i = 0; i < unloadedFields.length; i++ ) {
+			unloadedFields[i] = new UnloadedFieldDescription( persistentFields[i] );
+		}
+		UnloadedField[] ordered = enhancementContext.order( unloadedFields );
+		FieldDescription[] orderedFields = new FieldDescription[persistentFields.length];
+		for ( int i = 0; i < orderedFields.length; i++ ) {
+			orderedFields[i] = ( (UnloadedFieldDescription) ordered[i] ).fieldDescription;
+		}
+		return orderedFields;
+	}
+
+	public boolean isLazyLoadable(FieldDescription field) {
+		return enhancementContext.isLazyLoadable( new UnloadedFieldDescription( field ) );
+	}
+
+	public boolean isMappedCollection(FieldDescription field) {
+		return enhancementContext.isMappedCollection( new UnloadedFieldDescription( field ) );
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/bytebuddy/CodeTemplates.java

@@ -0,0 +1,476 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.bytebuddy;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.util.Collection;
+import java.util.Map;
+
+import org.hibernate.Hibernate;
+import org.hibernate.bytecode.enhance.internal.tracker.CompositeOwnerTracker;
+import org.hibernate.bytecode.enhance.internal.tracker.DirtyTracker;
+import org.hibernate.bytecode.enhance.internal.tracker.SimpleCollectionTracker;
+import org.hibernate.bytecode.enhance.internal.tracker.SimpleFieldTracker;
+import org.hibernate.bytecode.enhance.spi.CollectionTracker;
+import org.hibernate.bytecode.enhance.spi.EnhancerConstants;
+import org.hibernate.bytecode.enhance.spi.interceptor.LazyAttributeLoadingInterceptor;
+import org.hibernate.engine.spi.ExtendedSelfDirtinessTracker;
+import org.hibernate.engine.spi.CompositeOwner;
+import org.hibernate.engine.spi.CompositeTracker;
+
+import net.bytebuddy.asm.Advice;
+
+class CodeTemplates {
+
+	static class SetOwner {
+		@Advice.OnMethodEnter
+		static void $$_hibernate_setOwner(
+				@Advice.Argument(0) String name,
+				@Advice.Argument(1) CompositeOwner tracker,
+				@Advice.FieldValue(value = EnhancerConstants.TRACKER_COMPOSITE_FIELD_NAME, readOnly = false) CompositeOwnerTracker $$_hibernate_compositeOwners) {
+			if ( $$_hibernate_compositeOwners == null ) {
+				$$_hibernate_compositeOwners = new CompositeOwnerTracker();
+			}
+			$$_hibernate_compositeOwners.add( name, tracker );
+		}
+	}
+
+	static class ClearOwner {
+		@Advice.OnMethodEnter
+		static void $$_hibernate_setOwner(
+				@Advice.Argument(0) String name,
+				@Advice.FieldValue(value = EnhancerConstants.TRACKER_COMPOSITE_FIELD_NAME, readOnly = false) CompositeOwnerTracker $$_hibernate_compositeOwners) {
+			if ( $$_hibernate_compositeOwners != null ) {
+				$$_hibernate_compositeOwners.removeOwner( name );
+			}
+		}
+	}
+
+	static class TrackChange {
+		@Advice.OnMethodEnter
+		static void $$_hibernate_trackChange(
+				@Advice.Argument(0) String name,
+				@Advice.FieldValue(value = EnhancerConstants.TRACKER_FIELD_NAME, readOnly = false) DirtyTracker $$_hibernate_tracker) {
+			if ( $$_hibernate_tracker == null ) {
+				$$_hibernate_tracker = new SimpleFieldTracker();
+			}
+			$$_hibernate_tracker.add( name );
+		}
+	}
+
+	static class GetDirtyAttributes {
+		@Advice.OnMethodExit
+		static void $$_hibernate_getDirtyAttributes(
+				@Advice.This ExtendedSelfDirtinessTracker self,
+				@Advice.Return(readOnly = false) String[] returned,
+				@Advice.FieldValue(value = EnhancerConstants.TRACKER_FIELD_NAME, readOnly = false) DirtyTracker $$_hibernate_tracker,
+				@Advice.FieldValue(value = EnhancerConstants.TRACKER_COLLECTION_NAME, readOnly = false) CollectionTracker $$_hibernate_collectionTracker) {
+			if ( $$_hibernate_collectionTracker == null ) {
+				returned = ( $$_hibernate_tracker == null ) ? new String[0] : $$_hibernate_tracker.get();
+			}
+			else {
+				if ( $$_hibernate_tracker == null ) {
+					$$_hibernate_tracker = new SimpleFieldTracker();
+				}
+				self.$$_hibernate_getCollectionFieldDirtyNames( $$_hibernate_tracker );
+				returned = $$_hibernate_tracker.get();
+			}
+		}
+	}
+
+	static class AreCollectionFieldsDirty {
+		@Advice.OnMethodExit
+		static void $$_hibernate_hasDirtyAttributes(
+				@Advice.This ExtendedSelfDirtinessTracker self,
+				@Advice.Return(readOnly = false) boolean returned,
+				@Advice.FieldValue(value = EnhancerConstants.TRACKER_FIELD_NAME, readOnly = false) DirtyTracker $$_hibernate_tracker) {
+			returned = ( $$_hibernate_tracker != null && !$$_hibernate_tracker.isEmpty() ) || self.$$_hibernate_areCollectionFieldsDirty();
+		}
+	}
+
+	static class ClearDirtyAttributes {
+		@Advice.OnMethodEnter
+		static void $$_hibernate_clearDirtyAttributes(
+				@Advice.This ExtendedSelfDirtinessTracker self,
+				@Advice.FieldValue(value = EnhancerConstants.TRACKER_FIELD_NAME, readOnly = false) DirtyTracker $$_hibernate_tracker) {
+			if ( $$_hibernate_tracker != null ) {
+				$$_hibernate_tracker.clear();
+			}
+			self.$$_hibernate_clearDirtyCollectionNames();
+		}
+	}
+
+	static class SuspendDirtyTracking {
+		@Advice.OnMethodEnter
+		static void $$_hibernate_suspendDirtyTracking(
+				@Advice.Argument(0) boolean suspend,
+				@Advice.FieldValue(value = EnhancerConstants.TRACKER_FIELD_NAME, readOnly = false) DirtyTracker $$_hibernate_tracker) {
+			if ( $$_hibernate_tracker == null ) {
+				$$_hibernate_tracker = new SimpleFieldTracker();
+			}
+			$$_hibernate_tracker.suspend( suspend );
+		}
+	}
+
+	static class CollectionAreCollectionFieldsDirty {
+		@Advice.OnMethodExit
+		static void $$_hibernate_areCollectionFieldsDirty(
+				@Advice.Return(readOnly = false) boolean returned,
+				@FieldName String fieldName,
+				@FieldValue Collection<?> collection,
+				@Advice.FieldValue(EnhancerConstants.TRACKER_COLLECTION_NAME) CollectionTracker $$_hibernate_collectionTracker) {
+			if ( !returned && $$_hibernate_collectionTracker != null ) {
+				if ( collection == null && $$_hibernate_collectionTracker.getSize( fieldName ) != -1 ) {
+					returned = true;
+				}
+				else if ( collection != null && $$_hibernate_collectionTracker.getSize( fieldName ) != collection.size() ) {
+					returned = true;
+				}
+			}
+		}
+	}
+
+	static class MapAreCollectionFieldsDirty {
+		@Advice.OnMethodExit
+		static void $$_hibernate_areCollectionFieldsDirty(
+				@Advice.Return(readOnly = false) boolean returned,
+				@FieldName String fieldName,
+				@FieldValue Map<?, ?> map,
+				@Advice.FieldValue(EnhancerConstants.TRACKER_COLLECTION_NAME) CollectionTracker $$_hibernate_collectionTracker) {
+			if ( !returned && $$_hibernate_collectionTracker != null ) {
+				if ( map == null && $$_hibernate_collectionTracker.getSize( fieldName ) != -1 ) {
+					returned = true;
+				}
+				else if ( map != null && $$_hibernate_collectionTracker.getSize( fieldName ) != map.size() ) {
+					returned = true;
+				}
+			}
+		}
+	}
+
+	static class CollectionGetCollectionFieldDirtyNames {
+		@Advice.OnMethodExit
+		static void $$_hibernate_areCollectionFieldsDirty(
+				@FieldName String fieldName,
+				@FieldValue Collection<?> collection,
+				@Advice.Argument(0) DirtyTracker tracker,
+				@Advice.FieldValue(EnhancerConstants.TRACKER_COLLECTION_NAME) CollectionTracker $$_hibernate_collectionTracker) {
+			if ( $$_hibernate_collectionTracker != null ) {
+				if ( collection == null && $$_hibernate_collectionTracker.getSize( fieldName ) != -1 ) {
+					tracker.add( fieldName );
+				}
+				else if ( collection != null && $$_hibernate_collectionTracker.getSize( fieldName ) != collection.size() ) {
+					tracker.add( fieldName );
+				}
+			}
+		}
+	}
+
+	static class MapGetCollectionFieldDirtyNames {
+		@Advice.OnMethodExit
+		static void $$_hibernate_areCollectionFieldsDirty(
+				@FieldName String fieldName,
+				@FieldValue Map<?, ?> map,
+				@Advice.Argument(0) DirtyTracker tracker,
+				@Advice.FieldValue(EnhancerConstants.TRACKER_COLLECTION_NAME) CollectionTracker $$_hibernate_collectionTracker) {
+			if ( $$_hibernate_collectionTracker != null ) {
+				if ( map == null && $$_hibernate_collectionTracker.getSize( fieldName ) != -1 ) {
+					tracker.add( fieldName );
+				}
+				else if ( map != null && $$_hibernate_collectionTracker.getSize( fieldName ) != map.size() ) {
+					tracker.add( fieldName );
+				}
+			}
+		}
+	}
+
+	static class CollectionGetCollectionClearDirtyNames {
+		@Advice.OnMethodExit
+		static void $$_hibernate_clearDirtyCollectionNames(
+				@FieldName String fieldName,
+				@FieldValue Collection<?> collection,
+				@Advice.Argument(0) LazyAttributeLoadingInterceptor lazyInterceptor,
+				@Advice.FieldValue(EnhancerConstants.TRACKER_COLLECTION_NAME) CollectionTracker $$_hibernate_collectionTracker) {
+			if ( lazyInterceptor == null || lazyInterceptor.isAttributeLoaded( fieldName ) ) {
+				if ( collection == null ) {
+					$$_hibernate_collectionTracker.add( fieldName, -1 );
+				}
+				else {
+					$$_hibernate_collectionTracker.add( fieldName, collection.size() );
+				}
+			}
+		}
+	}
+
+	static class MapGetCollectionClearDirtyNames {
+		@Advice.OnMethodExit
+		static void $$_hibernate_clearDirtyCollectionNames(
+				@FieldName String fieldName,
+				@FieldValue Map<?, ?> map,
+				@Advice.Argument(0) LazyAttributeLoadingInterceptor lazyInterceptor,
+				@Advice.FieldValue(EnhancerConstants.TRACKER_COLLECTION_NAME) CollectionTracker $$_hibernate_collectionTracker) {
+			if ( lazyInterceptor == null || lazyInterceptor.isAttributeLoaded( fieldName ) ) {
+				if ( map == null ) {
+					$$_hibernate_collectionTracker.add( fieldName, -1 );
+				}
+				else {
+					$$_hibernate_collectionTracker.add( fieldName, map.size() );
+				}
+			}
+		}
+	}
+
+	static class ClearDirtyCollectionNames {
+		@Advice.OnMethodEnter
+		static void $$_hibernate_clearDirtyCollectionNames(
+				@Advice.This ExtendedSelfDirtinessTracker self,
+				@Advice.FieldValue(value = EnhancerConstants.TRACKER_COLLECTION_NAME, readOnly = false) CollectionTracker $$_hibernate_collectionTracker) {
+			if ( $$_hibernate_collectionTracker == null ) {
+				$$_hibernate_collectionTracker = new SimpleCollectionTracker();
+			}
+			self.$$_hibernate_removeDirtyFields( null );
+		}
+	}
+
+	static class InitializeLazyAttributeLoadingInterceptor {
+		@Advice.OnMethodEnter
+		static void $$_hibernate_removeDirtyFields(
+				@Advice.Argument(value = 0, readOnly = false) LazyAttributeLoadingInterceptor lazyInterceptor,
+				@Advice.FieldValue(EnhancerConstants.TRACKER_COLLECTION_NAME) Object $$_hibernate_attributeInterceptor) {
+			if ( $$_hibernate_attributeInterceptor instanceof LazyAttributeLoadingInterceptor ) {
+				lazyInterceptor = (LazyAttributeLoadingInterceptor) $$_hibernate_attributeInterceptor;
+			}
+		}
+	}
+
+	static class CompositeFieldDirtyCheckingHandler {
+		@Advice.OnMethodEnter
+		static void enter(@FieldName String fieldName, @FieldValue Object field) {
+			if ( field != null ) {
+				( (CompositeTracker) field ).$$_hibernate_clearOwner( fieldName );
+			}
+		}
+
+		@Advice.OnMethodExit
+		static void exit(@Advice.This CompositeOwner self, @FieldName String fieldName, @FieldValue Object field) {
+			if ( field != null ) {
+				( (CompositeTracker) field ).$$_hibernate_setOwner( fieldName, self );
+			}
+			self.$$_hibernate_trackChange( fieldName );
+		}
+	}
+
+	static class CompositeDirtyCheckingHandler {
+		@Advice.OnMethodEnter
+		static void enter(@Advice.FieldValue(EnhancerConstants.TRACKER_COMPOSITE_FIELD_NAME) CompositeOwnerTracker $$_hibernate_compositeOwners) {
+			if ( $$_hibernate_compositeOwners != null ) {
+				$$_hibernate_compositeOwners.callOwner( "" );
+			}
+		}
+	}
+
+	static class CompositeOwnerDirtyCheckingHandler {
+		@Advice.OnMethodEnter
+		static void $$_hibernate_trackChange(
+				@Advice.Argument(0) String name,
+				@Advice.FieldValue(EnhancerConstants.TRACKER_COMPOSITE_FIELD_NAME) CompositeOwnerTracker $$_hibernate_compositeOwners) {
+			if ( $$_hibernate_compositeOwners != null ) {
+				$$_hibernate_compositeOwners.callOwner( "." + name );
+			}
+		}
+	}
+
+	static class OneToOneHandler {
+		@Advice.OnMethodEnter
+		static void enter(@FieldValue Object field, @Advice.Argument(0) Object argument, @MappedBy String mappedBy) {
+			if ( field != null && Hibernate.isPropertyInitialized( field, mappedBy ) && argument != null ) {
+				setterNull( field, null );
+			}
+		}
+
+		@Advice.OnMethodExit
+		static void exit(@Advice.This Object self, @Advice.Argument(0) Object argument, @MappedBy String mappedBy) {
+			if ( argument != null && Hibernate.isPropertyInitialized( argument, mappedBy ) && getter( argument ) != self ) {
+				setterSelf( argument, self );
+			}
+		}
+
+		static Object getter(Object target) {
+			// is replaced by the actual method call
+			throw new AssertionError();
+		}
+
+		static void setterNull(Object target, Object argument) {
+			// is replaced by the actual method call
+			throw new AssertionError();
+		}
+
+		static void setterSelf(Object target, Object argument) {
+			// is replaced by the actual method call
+			throw new AssertionError();
+		}
+	}
+
+	static class OneToManyOnCollectionHandler {
+		@Advice.OnMethodEnter
+		static void enter(@FieldValue Collection<?> field, @Advice.Argument(0) Collection<?> argument, @MappedBy String mappedBy) {
+			if ( field != null && Hibernate.isPropertyInitialized( field, mappedBy ) ) {
+				Object[] array = field.toArray();
+				for ( int i = 0; i < array.length; i++ ) {
+					if ( argument == null || !argument.contains( array[i] ) ) {
+						setterNull( array[i], null );
+					}
+				}
+			}
+		}
+
+		@Advice.OnMethodExit
+		static void exit(@Advice.This Object self, @Advice.Argument(0) Collection<?> argument, @MappedBy String mappedBy) {
+			if ( argument != null && Hibernate.isPropertyInitialized( argument, mappedBy ) ) {
+				Object[] array = argument.toArray();
+				for ( int i = 0; i < array.length; i++ ) {
+					if ( Hibernate.isPropertyInitialized( array[i], mappedBy ) && getter( array[i] ) != self ) {
+						setterSelf( array[i], self );
+					}
+				}
+			}
+		}
+
+		static Object getter(Object target) {
+			// is replaced by the actual method call
+			throw new AssertionError();
+		}
+
+		static void setterNull(Object target, Object argument) {
+			// is replaced by the actual method call
+			throw new AssertionError();
+		}
+
+		static void setterSelf(Object target, Object argument) {
+			// is replaced by the actual method call
+			throw new AssertionError();
+		}
+	}
+
+	static class OneToManyOnMapHandler {
+		@Advice.OnMethodEnter
+		static void enter(@FieldValue Map<?, ?> field, @Advice.Argument(0) Map<?, ?> argument, @MappedBy String mappedBy) {
+			if ( field != null && Hibernate.isPropertyInitialized( field, mappedBy ) ) {
+				Object[] array = field.values().toArray();
+				for ( int i = 0; i < array.length; i++ ) {
+					if ( argument == null || !argument.values().contains( array[i] ) ) {
+						setterNull( array[i], null );
+					}
+				}
+			}
+		}
+
+		@Advice.OnMethodExit
+		static void exit(@Advice.This Object self, @Advice.Argument(0) Map<?, ?> argument, @MappedBy String mappedBy) {
+			if ( argument != null && Hibernate.isPropertyInitialized( argument, mappedBy ) ) {
+				Object[] array = argument.values().toArray();
+				for ( int i = 0; i < array.length; i++ ) {
+					if ( Hibernate.isPropertyInitialized( array[i], mappedBy ) && getter( array[i] ) != self ) {
+						setterSelf( array[i], self );
+					}
+				}
+			}
+		}
+
+		static Object getter(Object target) {
+			// is replaced with the actual getter call during instrumentation.
+			throw new AssertionError();
+		}
+
+		static void setterNull(Object target, Object argument) {
+			// is replaced with the actual setter call during instrumentation.
+			throw new AssertionError();
+		}
+
+		static void setterSelf(Object target, Object argument) {
+			// is replaced with the actual setter call during instrumentation.
+			throw new AssertionError();
+		}
+	}
+
+	static class ManyToOneHandler {
+		@Advice.OnMethodEnter
+		static void enter(@Advice.This Object self, @FieldValue Object field, @MappedBy String mappedBy) {
+			if ( field != null && Hibernate.isPropertyInitialized( field, mappedBy ) ) {
+				Collection<?> c = getter( field );
+				if ( c != null ) {
+					c.remove( self );
+				}
+			}
+		}
+
+		@Advice.OnMethodExit
+		static void exit(@Advice.This Object self, @Advice.Argument(0) Object argument, @MappedBy String mappedBy) {
+			if ( argument != null && Hibernate.isPropertyInitialized( argument, mappedBy ) ) {
+				Collection<Object> c = getter( argument );
+				if ( c != null && !c.contains( self ) ) {
+					c.add( self );
+				}
+			}
+		}
+
+		static Collection<Object> getter(Object target) {
+			// is replaced by the actual method call
+			throw new AssertionError();
+		}
+	}
+
+	static class ManyToManyHandler {
+		@Advice.OnMethodEnter
+		static void enter(@Advice.This Object self, @FieldValue Collection<?> field, @Advice.Argument(0) Collection<?> argument, @MappedBy String mappedBy) {
+			if ( field != null && Hibernate.isPropertyInitialized( field, mappedBy ) ) {
+				Object[] array = field.toArray();
+				for ( int i = 0; i < array.length; i++ ) {
+					if ( argument == null || !argument.contains( array[i] ) ) {
+						getter( array[i] ).remove( self );
+					}
+				}
+			}
+		}
+
+		@Advice.OnMethodExit
+		static void exit(@Advice.This Object self, @Advice.Argument(0) Collection<?> argument, @MappedBy String mappedBy) {
+			if ( argument != null && Hibernate.isPropertyInitialized( argument, mappedBy ) ) {
+				Object[] array = argument.toArray();
+				for ( int i = 0; i < array.length; i++ ) {
+					if ( Hibernate.isPropertyInitialized( array[i], mappedBy ) ) {
+						Collection<Object> c = getter( array[i] );
+						if ( c != self && c != null ) {
+							c.add( self );
+						}
+					}
+				}
+			}
+		}
+
+		static Collection<Object> getter(Object self) {
+			// is replaced by the actual method call
+			throw new AssertionError();
+		}
+	}
+
+	@Retention(RetentionPolicy.RUNTIME)
+	@interface FieldName {
+
+	}
+
+	@Retention(RetentionPolicy.RUNTIME)
+	@interface FieldValue {
+
+	}
+
+	@Retention(RetentionPolicy.RUNTIME)
+	@interface MappedBy {
+
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/bytebuddy/EnhancerImpl.java

@@ -0,0 +1,443 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.bytebuddy;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import javax.persistence.Access;
+import javax.persistence.AccessType;
+import javax.persistence.Transient;
+
+import org.hibernate.bytecode.enhance.internal.tracker.CompositeOwnerTracker;
+import org.hibernate.bytecode.enhance.internal.tracker.DirtyTracker;
+import org.hibernate.bytecode.enhance.spi.CollectionTracker;
+import org.hibernate.bytecode.enhance.spi.EnhancementContext;
+import org.hibernate.bytecode.enhance.spi.EnhancementException;
+import org.hibernate.bytecode.enhance.spi.Enhancer;
+import org.hibernate.bytecode.enhance.spi.EnhancerConstants;
+import org.hibernate.bytecode.enhance.spi.interceptor.LazyAttributeLoadingInterceptor;
+import org.hibernate.engine.spi.ExtendedSelfDirtinessTracker;
+import org.hibernate.engine.spi.CompositeOwner;
+import org.hibernate.engine.spi.CompositeTracker;
+import org.hibernate.engine.spi.EntityEntry;
+import org.hibernate.engine.spi.Managed;
+import org.hibernate.engine.spi.ManagedComposite;
+import org.hibernate.engine.spi.ManagedEntity;
+import org.hibernate.engine.spi.ManagedMappedSuperclass;
+import org.hibernate.engine.spi.PersistentAttributeInterceptable;
+import org.hibernate.engine.spi.PersistentAttributeInterceptor;
+import org.hibernate.internal.CoreLogging;
+import org.hibernate.internal.CoreMessageLogger;
+
+import net.bytebuddy.ByteBuddy;
+import net.bytebuddy.asm.Advice;
+import net.bytebuddy.description.annotation.AnnotationDescription;
+import net.bytebuddy.description.field.FieldDescription;
+import net.bytebuddy.description.method.MethodDescription;
+import net.bytebuddy.description.method.MethodList;
+import net.bytebuddy.description.modifier.FieldManifestation;
+import net.bytebuddy.description.modifier.Visibility;
+import net.bytebuddy.description.type.TypeDefinition;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.dynamic.ClassFileLocator;
+import net.bytebuddy.dynamic.DynamicType;
+import net.bytebuddy.dynamic.scaffold.MethodGraph;
+import net.bytebuddy.dynamic.scaffold.TypeValidation;
+import net.bytebuddy.implementation.FieldAccessor;
+import net.bytebuddy.implementation.FixedValue;
+import net.bytebuddy.implementation.Implementation;
+import net.bytebuddy.implementation.StubMethod;
+import net.bytebuddy.pool.TypePool;
+import net.bytebuddy.utility.StreamDrainer;
+
+import static net.bytebuddy.matcher.ElementMatchers.isGetter;
+import static net.bytebuddy.matcher.ElementMatchers.named;
+
+public class EnhancerImpl implements Enhancer {
+
+	private static final CoreMessageLogger log = CoreLogging.messageLogger( Enhancer.class );
+
+	protected final ByteBuddyEnhancementContext enhancementContext;
+
+	private final TypePool classPool;
+
+	/**
+	 * Constructs the Enhancer, using the given context.
+	 *
+	 * @param enhancementContext Describes the context in which enhancement will occur so as to give access
+	 * to contextual/environmental information.
+	 */
+	public EnhancerImpl(EnhancementContext enhancementContext) {
+		this.enhancementContext = new ByteBuddyEnhancementContext( enhancementContext );
+		classPool = buildClassPool( this.enhancementContext );
+	}
+
+	/**
+	 * Performs the enhancement.
+	 *
+	 * @param className The name of the class whose bytecode is being enhanced.
+	 * @param originalBytes The class's original (pre-enhancement) byte code
+	 *
+	 * @return The enhanced bytecode. Could be the same as the original bytecode if the original was
+	 * already enhanced or we could not enhance it for some reason.
+	 *
+	 * @throws EnhancementException Indicates a problem performing the enhancement
+	 */
+	@Override
+	public synchronized byte[] enhance(String className, byte[] originalBytes) throws EnhancementException {
+		try {
+			final TypeDescription managedCtClass = classPool.describe( className ).resolve();
+			DynamicType.Builder<?> builder = doEnhance(
+					new ByteBuddy().with( TypeValidation.DISABLED ).redefine( managedCtClass, ClassFileLocator.Simple.of( className, originalBytes ) ),
+					managedCtClass
+			);
+			if ( builder == null ) {
+				return null;
+			}
+			else {
+				return builder.make().getBytes();
+			}
+		}
+		catch (RuntimeException e) {
+			e.printStackTrace();
+			log.unableToBuildEnhancementMetamodel( className );
+			return null;
+		}
+	}
+
+	@Override
+	public byte[] enhance(File javaClassFile) throws EnhancementException, IOException {
+		String name = javaClassFile.getName().substring( 0, javaClassFile.getName().length() - ".class".length() );
+		InputStream inputStream = new FileInputStream( javaClassFile );
+		try {
+			return enhance( name, StreamDrainer.DEFAULT.drain( inputStream ) );
+		}
+		finally {
+			inputStream.close();
+		}
+	}
+
+	private TypePool buildClassPool(final ByteBuddyEnhancementContext enhancementContext) {
+		return TypePool.Default.WithLazyResolution.of( enhancementContext.getLoadingClassLoader() );
+	}
+
+	private DynamicType.Builder<?> doEnhance(DynamicType.Builder<?> builder, TypeDescription managedCtClass) {
+		// can't effectively enhance interfaces
+		if ( managedCtClass.isInterface() ) {
+			log.debugf( "Skipping enhancement of [%s]: it's an interface!", managedCtClass.getName() );
+			return null;
+		}
+		// skip already enhanced classes
+		if ( alreadyEnhanced( managedCtClass ) ) {
+			log.debugf( "Skipping enhancement of [%s]: already enhanced", managedCtClass.getName() );
+			return null;
+		}
+
+		PersistentAttributeTransformer transformer = PersistentAttributeTransformer.collectPersistentFields( managedCtClass, enhancementContext, classPool );
+
+		if ( enhancementContext.isEntityClass( managedCtClass ) ) {
+			log.infof( "Enhancing [%s] as Entity", managedCtClass.getName() );
+			builder = builder.implement( ManagedEntity.class )
+					.defineMethod( EnhancerConstants.ENTITY_INSTANCE_GETTER_NAME, Object.class, Visibility.PUBLIC )
+					.intercept( FixedValue.self() );
+
+			builder = addFieldWithGetterAndSetter(
+					builder,
+					EntityEntry.class,
+					EnhancerConstants.ENTITY_ENTRY_FIELD_NAME,
+					EnhancerConstants.ENTITY_ENTRY_GETTER_NAME,
+					EnhancerConstants.ENTITY_ENTRY_SETTER_NAME
+			);
+			builder = addFieldWithGetterAndSetter(
+					builder,
+					ManagedEntity.class,
+					EnhancerConstants.PREVIOUS_FIELD_NAME,
+					EnhancerConstants.PREVIOUS_GETTER_NAME,
+					EnhancerConstants.PREVIOUS_SETTER_NAME
+			);
+			builder = addFieldWithGetterAndSetter(
+					builder,
+					ManagedEntity.class,
+					EnhancerConstants.NEXT_FIELD_NAME,
+					EnhancerConstants.NEXT_GETTER_NAME,
+					EnhancerConstants.NEXT_SETTER_NAME
+			);
+
+			builder = addInterceptorHandling( builder, managedCtClass );
+
+			if ( enhancementContext.doDirtyCheckingInline( managedCtClass ) ) {
+				builder = builder.implement( ExtendedSelfDirtinessTracker.class )
+						.defineField( EnhancerConstants.TRACKER_FIELD_NAME, DirtyTracker.class, FieldManifestation.TRANSIENT, Visibility.PRIVATE )
+						.annotateField( AnnotationDescription.Builder.ofType( Transient.class ).build() )
+						.defineField( EnhancerConstants.TRACKER_COLLECTION_NAME, CollectionTracker.class, FieldManifestation.TRANSIENT, Visibility.PRIVATE )
+						.annotateField( AnnotationDescription.Builder.ofType( Transient.class ).build() )
+						.defineMethod( EnhancerConstants.TRACKER_CHANGER_NAME, void.class, Visibility.PUBLIC )
+						.withParameters( String.class )
+						.intercept( Advice.to( CodeTemplates.TrackChange.class ).wrap( StubMethod.INSTANCE ) )
+						.defineMethod( EnhancerConstants.TRACKER_GET_NAME, String[].class, Visibility.PUBLIC )
+						.intercept( Advice.to( CodeTemplates.GetDirtyAttributes.class ).wrap( StubMethod.INSTANCE ) )
+						.defineMethod( EnhancerConstants.TRACKER_HAS_CHANGED_NAME, boolean.class, Visibility.PUBLIC )
+						.intercept( Advice.to( CodeTemplates.AreCollectionFieldsDirty.class ).wrap( StubMethod.INSTANCE ) )
+						.defineMethod( EnhancerConstants.TRACKER_CLEAR_NAME, void.class, Visibility.PUBLIC )
+						.intercept( Advice.to( CodeTemplates.ClearDirtyAttributes.class ).wrap( StubMethod.INSTANCE ) )
+						.defineMethod( EnhancerConstants.TRACKER_SUSPEND_NAME, void.class, Visibility.PUBLIC )
+						.withParameters( boolean.class )
+						.intercept( Advice.to( CodeTemplates.SuspendDirtyTracking.class ).wrap( StubMethod.INSTANCE ) )
+						.defineMethod( EnhancerConstants.TRACKER_COLLECTION_GET_NAME, CollectionTracker.class, Visibility.PUBLIC )
+						.intercept( FieldAccessor.ofField( EnhancerConstants.TRACKER_COLLECTION_NAME ) );
+
+				Implementation isDirty = StubMethod.INSTANCE, getDirtyNames = StubMethod.INSTANCE, clearDirtyNames = StubMethod.INSTANCE;
+				for ( FieldDescription collectionField : collectCollectionFields( managedCtClass ) ) {
+					if ( !enhancementContext.isMappedCollection( collectionField ) ) {
+						if ( collectionField.getType().asErasure().isAssignableTo( Map.class ) ) {
+							isDirty = Advice.withCustomMapping()
+									.bind( CodeTemplates.FieldName.class, collectionField.getName() )
+									.bind( CodeTemplates.FieldValue.class, collectionField )
+									.to( CodeTemplates.MapAreCollectionFieldsDirty.class )
+									.wrap( isDirty );
+							getDirtyNames = Advice.withCustomMapping()
+									.bind( CodeTemplates.FieldName.class, collectionField.getName() )
+									.bind( CodeTemplates.FieldValue.class, collectionField )
+									.to( CodeTemplates.MapGetCollectionFieldDirtyNames.class )
+									.wrap( getDirtyNames );
+							clearDirtyNames = Advice.withCustomMapping()
+									.bind( CodeTemplates.FieldName.class, collectionField.getName() )
+									.bind( CodeTemplates.FieldValue.class, collectionField )
+									.to( CodeTemplates.MapGetCollectionClearDirtyNames.class )
+									.wrap( clearDirtyNames );
+						}
+						else {
+							isDirty = Advice.withCustomMapping()
+									.bind( CodeTemplates.FieldName.class, collectionField.getName() )
+									.bind( CodeTemplates.FieldValue.class, collectionField )
+									.to( CodeTemplates.CollectionAreCollectionFieldsDirty.class )
+									.wrap( isDirty );
+							getDirtyNames = Advice.withCustomMapping()
+									.bind( CodeTemplates.FieldName.class, collectionField.getName() )
+									.bind( CodeTemplates.FieldValue.class, collectionField )
+									.to( CodeTemplates.CollectionGetCollectionFieldDirtyNames.class )
+									.wrap( getDirtyNames );
+							clearDirtyNames = Advice.withCustomMapping()
+									.bind( CodeTemplates.FieldName.class, collectionField.getName() )
+									.bind( CodeTemplates.FieldValue.class, collectionField )
+									.to( CodeTemplates.CollectionGetCollectionClearDirtyNames.class )
+									.wrap( clearDirtyNames );
+						}
+					}
+				}
+
+				if ( enhancementContext.hasLazyLoadableAttributes( managedCtClass ) ) {
+					clearDirtyNames = Advice.to( CodeTemplates.InitializeLazyAttributeLoadingInterceptor.class ).wrap( clearDirtyNames );
+				}
+
+				builder = builder.defineMethod( EnhancerConstants.TRACKER_COLLECTION_CHANGED_NAME, boolean.class, Visibility.PUBLIC )
+						.intercept( isDirty )
+						.defineMethod( EnhancerConstants.TRACKER_COLLECTION_CHANGED_FIELD_NAME, void.class, Visibility.PUBLIC )
+						.withParameters( DirtyTracker.class )
+						.intercept( getDirtyNames )
+						.defineMethod( EnhancerConstants.TRACKER_COLLECTION_CLEAR_NAME, void.class, Visibility.PUBLIC )
+						.intercept( Advice.withCustomMapping().to( CodeTemplates.ClearDirtyCollectionNames.class ).wrap( StubMethod.INSTANCE ) )
+						.defineMethod( ExtendedSelfDirtinessTracker.REMOVE_DIRTY_FIELDS_NAME, void.class, Visibility.PUBLIC )
+						.withParameters( LazyAttributeLoadingInterceptor.class )
+						.intercept( clearDirtyNames );
+			}
+
+			return transformer.applyTo( builder, false );
+		}
+		else if ( enhancementContext.isCompositeClass( managedCtClass ) ) {
+			log.infof( "Enhancing [%s] as Composite", managedCtClass.getName() );
+
+			builder = builder.implement( ManagedComposite.class );
+			builder = addInterceptorHandling( builder, managedCtClass );
+
+			if ( enhancementContext.doDirtyCheckingInline( managedCtClass ) ) {
+				builder = builder.implement( CompositeTracker.class )
+						.defineField(
+								EnhancerConstants.TRACKER_COMPOSITE_FIELD_NAME,
+								CompositeOwnerTracker.class,
+								FieldManifestation.TRANSIENT,
+								Visibility.PRIVATE
+						)
+						.annotateField( AnnotationDescription.Builder.ofType( Transient.class ).build() )
+						.defineMethod(
+								EnhancerConstants.TRACKER_COMPOSITE_SET_OWNER,
+								void.class,
+								Visibility.PUBLIC
+						)
+						.withParameters( String.class, CompositeOwner.class )
+						.intercept( Advice.to( CodeTemplates.SetOwner.class ).wrap( StubMethod.INSTANCE ) )
+						.defineMethod(
+								EnhancerConstants.TRACKER_COMPOSITE_CLEAR_OWNER,
+								void.class,
+								Visibility.PUBLIC
+						)
+						.withParameters( String.class )
+						.intercept( Advice.to( CodeTemplates.ClearOwner.class ).wrap( StubMethod.INSTANCE ) );
+			}
+
+			return transformer.applyTo( builder, false );
+		}
+		else if ( enhancementContext.isMappedSuperclassClass( managedCtClass ) ) {
+			log.infof( "Enhancing [%s] as MappedSuperclass", managedCtClass.getName() );
+			return transformer.applyTo( builder, true );
+		}
+		else if ( enhancementContext.doExtendedEnhancement( managedCtClass ) ) {
+			log.infof( "Extended enhancement of [%s]", managedCtClass.getName() );
+			return transformer.applyExtended( builder );
+		}
+		else {
+			log.debugf( "Skipping enhancement of [%s]: not entity or composite", managedCtClass.getName() );
+			return null;
+		}
+	}
+
+	private boolean alreadyEnhanced(TypeDescription managedCtClass) {
+		if ( !managedCtClass.isAssignableTo( Managed.class ) ) {
+			return false;
+		}
+		// HHH-10977 - When a mapped superclass gets enhanced before a subclassing entity, the entity does not get enhanced, but it implements the Managed interface
+		return enhancementContext.isEntityClass( managedCtClass ) && managedCtClass.isAssignableTo( ManagedEntity.class )
+				|| enhancementContext.isCompositeClass( managedCtClass ) && managedCtClass.isAssignableTo( ManagedComposite.class )
+				|| enhancementContext.isMappedSuperclassClass( managedCtClass ) && managedCtClass.isAssignableTo( ManagedMappedSuperclass.class );
+	}
+
+	private DynamicType.Builder<?> addInterceptorHandling(DynamicType.Builder<?> builder, TypeDescription managedCtClass) {
+		// interceptor handling is only needed if class has lazy-loadable attributes
+		if ( enhancementContext.hasLazyLoadableAttributes( managedCtClass ) ) {
+			log.debugf( "Weaving in PersistentAttributeInterceptable implementation on [%s]", managedCtClass.getName() );
+
+			builder = builder.implement( PersistentAttributeInterceptable.class );
+
+			builder = addFieldWithGetterAndSetter(
+					builder,
+					PersistentAttributeInterceptor.class,
+					EnhancerConstants.INTERCEPTOR_FIELD_NAME,
+					EnhancerConstants.INTERCEPTOR_GETTER_NAME,
+					EnhancerConstants.INTERCEPTOR_SETTER_NAME
+			);
+		}
+
+		return builder;
+	}
+
+	private static DynamicType.Builder<?> addFieldWithGetterAndSetter(
+			DynamicType.Builder<?> builder,
+			Class<?> type,
+			String fieldName,
+			String getterName,
+			String setterName) {
+		return builder.defineField( fieldName, type, Visibility.PRIVATE, FieldManifestation.TRANSIENT )
+				.annotateField( AnnotationDescription.Builder.ofType( Transient.class ).build() )
+				.defineMethod( getterName, type, Visibility.PUBLIC )
+				.intercept( FieldAccessor.ofField( fieldName ) )
+				.defineMethod( setterName, void.class, Visibility.PUBLIC )
+				.withParameters( type )
+				.intercept( FieldAccessor.ofField( fieldName ) );
+	}
+
+	private List<FieldDescription> collectCollectionFields(TypeDescription managedCtClass) {
+		List<FieldDescription> collectionList = new ArrayList<>();
+
+		for ( FieldDescription ctField : managedCtClass.getDeclaredFields() ) {
+			// skip static fields and skip fields added by enhancement
+			if ( Modifier.isStatic( ctField.getModifiers() ) || ctField.getName().startsWith( "$$_hibernate_" ) ) {
+				continue;
+			}
+			if ( enhancementContext.isPersistentField( ctField ) ) {
+				if ( ctField.getType().asErasure().isAssignableTo( Collection.class ) || ctField.getType().asErasure().isAssignableTo( Map.class ) ) {
+					collectionList.add( ctField );
+				}
+			}
+		}
+
+		// HHH-10646 Add fields inherited from @MappedSuperclass
+		// HHH-10981 There is no need to do it for @MappedSuperclass
+		if ( !enhancementContext.isMappedSuperclassClass( managedCtClass ) ) {
+			collectionList.addAll( collectInheritCollectionFields( managedCtClass ) );
+		}
+
+		return collectionList;
+	}
+
+	private Collection<FieldDescription> collectInheritCollectionFields(TypeDefinition managedCtClass) {
+		TypeDefinition managedCtSuperclass = managedCtClass.getSuperClass();
+		if ( managedCtSuperclass == null || managedCtSuperclass.represents( Object.class ) ) {
+			return Collections.emptyList();
+		}
+
+		if ( !enhancementContext.isMappedSuperclassClass( managedCtSuperclass.asErasure() ) ) {
+			return collectInheritCollectionFields( managedCtSuperclass.asErasure() );
+		}
+		List<FieldDescription> collectionList = new ArrayList<FieldDescription>();
+
+		for ( FieldDescription ctField : managedCtSuperclass.getDeclaredFields() ) {
+			if ( !Modifier.isStatic( ctField.getModifiers() ) && enhancementContext.isPersistentField( ctField ) ) {
+				if ( ctField.getType().asErasure().isAssignableTo( Collection.class ) || ctField.getType().asErasure().isAssignableTo( Map.class ) ) {
+					collectionList.add( ctField );
+				}
+			}
+		}
+		collectionList.addAll( collectInheritCollectionFields( managedCtSuperclass ) );
+		return collectionList;
+	}
+
+	static String capitalize(String value) {
+		return Character.toUpperCase( value.charAt( 0 ) ) + value.substring( 1 );
+	}
+
+	static boolean isAnnotationPresent(FieldDescription fieldDescription, Class<? extends Annotation> type) {
+		return getAnnotation( fieldDescription, type ) != null;
+	}
+
+	static <T extends Annotation> AnnotationDescription.Loadable<T> getAnnotation(FieldDescription fieldDescription, Class<T> type) {
+		AnnotationDescription.Loadable<Access> access = fieldDescription.getDeclaringType().asErasure().getDeclaredAnnotations().ofType( Access.class );
+		if ( access != null && access.loadSilent().value() == AccessType.PROPERTY ) {
+			MethodDescription getter = getterOf( fieldDescription );
+			if ( getter == null ) {
+				return fieldDescription.getDeclaredAnnotations().ofType( type );
+			}
+			else {
+				return getter.getDeclaredAnnotations().ofType( type );
+			}
+		}
+		else if ( access != null && access.loadSilent().value() == AccessType.FIELD ) {
+			return fieldDescription.getDeclaredAnnotations().ofType( type );
+		}
+		else {
+			MethodDescription getter = getterOf( fieldDescription );
+			if ( getter != null ) {
+				AnnotationDescription.Loadable<T> annotationDescription = getter.getDeclaredAnnotations().ofType( type );
+				if ( annotationDescription != null ) {
+					return annotationDescription;
+				}
+			}
+			return fieldDescription.getDeclaredAnnotations().ofType( type );
+		}
+	}
+
+	static MethodDescription getterOf(FieldDescription persistentField) {
+		MethodList<?> methodList = MethodGraph.Compiler.DEFAULT.compile( persistentField.getDeclaringType().asErasure() )
+				.listNodes()
+				.asMethodList()
+				.filter( isGetter(persistentField.getName() ) );
+		if ( methodList.size() == 1 ) {
+			return methodList.getOnly();
+		}
+		else {
+			return null;
+		}
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/bytebuddy/FieldAccessEnhancer.java

@@ -0,0 +1,131 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.bytebuddy;
+
+import javax.persistence.Id;
+
+import org.hibernate.bytecode.enhance.spi.EnhancementException;
+import org.hibernate.bytecode.enhance.spi.EnhancerConstants;
+import org.hibernate.internal.CoreLogging;
+import org.hibernate.internal.CoreMessageLogger;
+
+import net.bytebuddy.ClassFileVersion;
+import net.bytebuddy.asm.AsmVisitorWrapper;
+import net.bytebuddy.description.field.FieldDescription;
+import net.bytebuddy.description.field.FieldList;
+import net.bytebuddy.description.method.MethodDescription;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.implementation.Implementation;
+import net.bytebuddy.jar.asm.MethodVisitor;
+import net.bytebuddy.jar.asm.Opcodes;
+import net.bytebuddy.jar.asm.Type;
+import net.bytebuddy.pool.TypePool;
+
+import static net.bytebuddy.matcher.ElementMatchers.hasDescriptor;
+import static net.bytebuddy.matcher.ElementMatchers.named;
+
+class FieldAccessEnhancer implements AsmVisitorWrapper.ForDeclaredMethods.MethodVisitorWrapper {
+
+	private static final CoreMessageLogger log = CoreLogging.messageLogger( FieldAccessEnhancer.class );
+
+	private final TypeDescription managedCtClass;
+
+	private final ByteBuddyEnhancementContext enhancementContext;
+
+	private final TypePool classPool;
+
+	FieldAccessEnhancer(TypeDescription managedCtClass, ByteBuddyEnhancementContext enhancementContext, TypePool classPool) {
+		this.managedCtClass = managedCtClass;
+		this.enhancementContext = enhancementContext;
+		this.classPool = classPool;
+	}
+
+	@Override
+	public MethodVisitor wrap(
+			TypeDescription instrumentedType,
+			MethodDescription.InDefinedShape instrumentedMethod,
+			MethodVisitor methodVisitor,
+			Implementation.Context implementationContext,
+			TypePool typePool,
+			int writerFlags,
+			int readerFlags) {
+		return new MethodVisitor( Opcodes.ASM5, methodVisitor ) {
+			@Override
+			public void visitFieldInsn(int opcode, String owner, String name, String desc) {
+				if ( opcode != Opcodes.GETFIELD && opcode != Opcodes.PUTFIELD ) {
+					super.visitFieldInsn( opcode, owner, name, desc );
+					return;
+				}
+
+				FieldDescription field = findField( owner, name, desc );
+
+				if ( ( enhancementContext.isEntityClass( field.getDeclaringType().asErasure() )
+						|| enhancementContext.isCompositeClass( field.getDeclaringType().asErasure() ) )
+						&& !field.getType().asErasure().equals( managedCtClass )
+						&& enhancementContext.isPersistentField( field )
+						&& !EnhancerImpl.isAnnotationPresent( field, Id.class )
+						&& !field.getName().equals( "this$0" ) ) {
+
+					log.debugf(
+							"Extended enhancement: Transforming access to field [%s.%s] from method [%s#%s]",
+							field.getType().asErasure(),
+							field.getName(),
+							field.getName(),
+							name
+					);
+
+					switch ( opcode ) {
+						case Opcodes.GETFIELD:
+							methodVisitor.visitMethodInsn(
+									Opcodes.INVOKEVIRTUAL,
+									owner,
+									EnhancerConstants.PERSISTENT_FIELD_READER_PREFIX + name,
+									Type.getMethodDescriptor( Type.getType( desc ) ),
+									false
+							);
+							return;
+						case Opcodes.PUTFIELD:
+							methodVisitor.visitMethodInsn(
+									Opcodes.INVOKEVIRTUAL,
+									owner,
+									EnhancerConstants.PERSISTENT_FIELD_WRITER_PREFIX + name,
+									Type.getMethodDescriptor( Type.getType( void.class ), Type.getType( desc ) ),
+									false
+							);
+							return;
+						default:
+							throw new EnhancementException( "Unexpected opcode: " + opcode );
+					}
+				}
+				else {
+					super.visitFieldInsn( opcode, owner, name, desc );
+				}
+			}
+		};
+	}
+
+	private FieldDescription findField(String owner, String name, String desc) {
+		TypePool.Resolution resolution = classPool.describe( owner.replace( '/', '.' ) );
+		if ( !resolution.isResolved() ) {
+			final String msg = String.format(
+					"Unable to perform extended enhancement - Unable to locate [%s]",
+					owner.replace( '/', '.' )
+			);
+			throw new EnhancementException( msg );
+		}
+		FieldList<?> fields = resolution.resolve().getDeclaredFields().filter( named( name ).and( hasDescriptor( desc ) ) );
+		if ( fields.size() != 1 ) {
+			final String msg = String.format(
+					"Unable to perform extended enhancement - No unique field [%s] defined by [%s]",
+					name,
+					owner.replace( '/', '.' )
+			);
+			throw new EnhancementException( msg );
+		}
+		return fields.getOnly();
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/bytebuddy/FieldReaderAppender.java

@@ -0,0 +1,166 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.bytebuddy;
+
+import org.hibernate.bytecode.enhance.spi.EnhancerConstants;
+import org.hibernate.engine.spi.PersistentAttributeInterceptor;
+
+import net.bytebuddy.ClassFileVersion;
+import net.bytebuddy.description.field.FieldDescription;
+import net.bytebuddy.description.method.MethodDescription;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.implementation.Implementation;
+import net.bytebuddy.implementation.bytecode.ByteCodeAppender;
+import net.bytebuddy.jar.asm.Label;
+import net.bytebuddy.jar.asm.MethodVisitor;
+import net.bytebuddy.jar.asm.Opcodes;
+import net.bytebuddy.jar.asm.Type;
+
+abstract class FieldReaderAppender implements ByteCodeAppender {
+
+	protected final TypeDescription managedCtClass;
+
+	protected final FieldDescription persistentField;
+
+	private FieldReaderAppender(TypeDescription managedCtClass, FieldDescription.InDefinedShape persistentField) {
+		this.managedCtClass = managedCtClass;
+		this.persistentField = persistentField;
+	}
+
+	static ByteCodeAppender of(TypeDescription managedCtClass, FieldDescription persistentField) {
+		if ( !persistentField.isVisibleTo( managedCtClass ) ) {
+			return new MethodDispatching( managedCtClass, persistentField.asDefined() );
+		}
+		else {
+			return new FieldWriting( managedCtClass, persistentField.asDefined() );
+		}
+	}
+
+	@Override
+	public Size apply(
+			MethodVisitor methodVisitor,
+			Implementation.Context implementationContext,
+			MethodDescription instrumentedMethod) {
+		TypeDescription dispatcherType = persistentField.getType().isPrimitive()
+				? persistentField.getType().asErasure()
+				: TypeDescription.OBJECT;
+		// if ( this.$$_hibernate_getInterceptor() != null )
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		methodVisitor.visitMethodInsn(
+				Opcodes.INVOKEVIRTUAL,
+				managedCtClass.getInternalName(),
+				EnhancerConstants.INTERCEPTOR_GETTER_NAME,
+				Type.getMethodDescriptor( Type.getType( PersistentAttributeInterceptor.class ) ),
+				false
+		);
+		Label skip = new Label();
+		methodVisitor.visitJumpInsn( Opcodes.IFNULL, skip );
+		// this (for field write)
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		// this.$$_hibernate_getInterceptor();
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		methodVisitor.visitMethodInsn(
+				Opcodes.INVOKEVIRTUAL,
+				managedCtClass.getInternalName(),
+				EnhancerConstants.INTERCEPTOR_GETTER_NAME,
+				Type.getMethodDescriptor( Type.getType( PersistentAttributeInterceptor.class ) ),
+				false
+		);
+		// .readXXX( self, fieldName, field );
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		methodVisitor.visitLdcInsn( persistentField.getName() );
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		fieldRead( methodVisitor );
+		methodVisitor.visitMethodInsn(
+				Opcodes.INVOKEINTERFACE,
+				Type.getInternalName( PersistentAttributeInterceptor.class ),
+				"read" + EnhancerImpl.capitalize( dispatcherType.getSimpleName() ),
+				Type.getMethodDescriptor(
+						Type.getType( dispatcherType.getDescriptor() ),
+						Type.getType( Object.class ),
+						Type.getType( String.class ),
+						Type.getType( dispatcherType.getDescriptor() )
+				),
+				true
+		);
+		// field = (cast) XXX
+		if ( !dispatcherType.isPrimitive() ) {
+			methodVisitor.visitTypeInsn( Opcodes.CHECKCAST, persistentField.getType().asErasure().getInternalName() );
+		}
+		fieldWrite( methodVisitor );
+		// end if
+		methodVisitor.visitLabel( skip );
+		if ( implementationContext.getClassFileVersion().isAtLeast( ClassFileVersion.JAVA_V6 ) ) {
+			methodVisitor.visitFrame( Opcodes.F_SAME, 0, null, 0, null );
+		}
+		// return field
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		fieldRead( methodVisitor );
+		methodVisitor.visitInsn( Type.getType( persistentField.getType().asErasure().getDescriptor() ).getOpcode( Opcodes.IRETURN ) );
+		return new Size( 4 + persistentField.getType().getStackSize().getSize(), instrumentedMethod.getStackSize() );
+	}
+
+	protected abstract void fieldRead(MethodVisitor methodVisitor);
+
+	protected abstract void fieldWrite(MethodVisitor methodVisitor);
+
+	private static class FieldWriting extends FieldReaderAppender {
+
+		private FieldWriting(TypeDescription managedCtClass, FieldDescription.InDefinedShape fieldDescription) {
+			super( managedCtClass, fieldDescription );
+		}
+
+		@Override
+		protected void fieldRead(MethodVisitor methodVisitor) {
+			methodVisitor.visitFieldInsn(
+					Opcodes.GETFIELD,
+					persistentField.getDeclaringType().asErasure().getInternalName(),
+					persistentField.getInternalName(),
+					persistentField.getDescriptor()
+			);
+		}
+
+		@Override
+		protected void fieldWrite(MethodVisitor methodVisitor) {
+			methodVisitor.visitFieldInsn(
+					Opcodes.PUTFIELD,
+					persistentField.getDeclaringType().asErasure().getInternalName(),
+					persistentField.getInternalName(),
+					persistentField.getDescriptor()
+			);
+		}
+	}
+
+	private static class MethodDispatching extends FieldReaderAppender {
+
+		private MethodDispatching(TypeDescription managedCtClass, FieldDescription.InDefinedShape fieldDescription) {
+			super( managedCtClass, fieldDescription );
+		}
+
+		@Override
+		protected void fieldRead(MethodVisitor methodVisitor) {
+			methodVisitor.visitMethodInsn(
+					Opcodes.INVOKESPECIAL,
+					managedCtClass.getSuperClass().asErasure().getInternalName(),
+					EnhancerConstants.PERSISTENT_FIELD_READER_PREFIX + persistentField.getName(),
+					Type.getMethodDescriptor( Type.getType( persistentField.getType().asErasure().getDescriptor() ) ),
+					false
+			);
+		}
+
+		@Override
+		protected void fieldWrite(MethodVisitor methodVisitor) {
+			methodVisitor.visitMethodInsn(
+					Opcodes.INVOKESPECIAL,
+					managedCtClass.getSuperClass().asErasure().getInternalName(),
+					EnhancerConstants.PERSISTENT_FIELD_WRITER_PREFIX + persistentField.getName(),
+					Type.getMethodDescriptor( Type.getType( void.class ), Type.getType( persistentField.getType().asErasure().getDescriptor() ) ),
+					false
+			);
+		}
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/bytebuddy/FieldWriterAppender.java

@@ -0,0 +1,176 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.bytebuddy;
+
+import org.hibernate.bytecode.enhance.spi.EnhancerConstants;
+import org.hibernate.engine.spi.PersistentAttributeInterceptor;
+
+import net.bytebuddy.ClassFileVersion;
+import net.bytebuddy.description.field.FieldDescription;
+import net.bytebuddy.description.method.MethodDescription;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.implementation.Implementation;
+import net.bytebuddy.implementation.bytecode.ByteCodeAppender;
+import net.bytebuddy.jar.asm.Label;
+import net.bytebuddy.jar.asm.MethodVisitor;
+import net.bytebuddy.jar.asm.Opcodes;
+import net.bytebuddy.jar.asm.Type;
+
+abstract class FieldWriterAppender implements ByteCodeAppender {
+
+	protected final TypeDescription managedCtClass;
+
+	protected final FieldDescription.InDefinedShape persistentField;
+
+	private FieldWriterAppender(TypeDescription managedCtClass, FieldDescription.InDefinedShape persistentField) {
+		this.managedCtClass = managedCtClass;
+		this.persistentField = persistentField;
+	}
+
+	static ByteCodeAppender of(TypeDescription managedCtClass, FieldDescription persistentField) {
+		if ( !persistentField.isVisibleTo( managedCtClass ) ) {
+			return new MethodDispatching( managedCtClass, persistentField.asDefined() );
+		}
+		else {
+			return new FieldWriting( managedCtClass, persistentField.asDefined() );
+		}
+	}
+
+	@Override
+	public Size apply(
+			MethodVisitor methodVisitor,
+			Implementation.Context implementationContext,
+			MethodDescription instrumentedMethod) {
+		TypeDescription dispatcherType = persistentField.getType().isPrimitive()
+				? persistentField.getType().asErasure()
+				: TypeDescription.OBJECT;
+		// if ( this.$$_hibernate_getInterceptor() != null )
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		methodVisitor.visitMethodInsn(
+				Opcodes.INVOKEVIRTUAL,
+				managedCtClass.getInternalName(),
+				EnhancerConstants.INTERCEPTOR_GETTER_NAME,
+				Type.getMethodDescriptor( Type.getType( PersistentAttributeInterceptor.class ) ),
+				false
+		);
+		Label noInterceptor = new Label();
+		methodVisitor.visitJumpInsn( Opcodes.IFNULL, noInterceptor );
+		// this (for field write)
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		// this.$$_hibernate_getInterceptor();
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		methodVisitor.visitMethodInsn(
+				Opcodes.INVOKEVIRTUAL,
+				managedCtClass.getInternalName(),
+				EnhancerConstants.INTERCEPTOR_GETTER_NAME,
+				Type.getMethodDescriptor( Type.getType( PersistentAttributeInterceptor.class ) ),
+				false
+		);
+		// .writeXXX( self, fieldName, field, arg1 );
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		methodVisitor.visitLdcInsn( persistentField.getName() );
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		fieldRead( methodVisitor );
+		methodVisitor.visitVarInsn( Type.getType( dispatcherType.getDescriptor() ).getOpcode( Opcodes.ILOAD ), 1 );
+		methodVisitor.visitMethodInsn(
+				Opcodes.INVOKEINTERFACE,
+				Type.getInternalName( PersistentAttributeInterceptor.class ),
+				"write" + EnhancerImpl.capitalize( dispatcherType.getSimpleName() ),
+				Type.getMethodDescriptor(
+						Type.getType( dispatcherType.getDescriptor() ),
+						Type.getType( Object.class ),
+						Type.getType( String.class ),
+						Type.getType( dispatcherType.getDescriptor() ),
+						Type.getType( dispatcherType.getDescriptor() )
+				),
+				true
+		);
+		// arg1 = (cast) XXX
+		if ( !dispatcherType.isPrimitive() ) {
+			methodVisitor.visitTypeInsn( Opcodes.CHECKCAST, persistentField.getType().asErasure().getInternalName() );
+		}
+		fieldWrite( methodVisitor );
+		// return
+		methodVisitor.visitInsn( Opcodes.RETURN );
+		// else
+		methodVisitor.visitLabel( noInterceptor );
+		if ( implementationContext.getClassFileVersion().isAtLeast( ClassFileVersion.JAVA_V6 ) ) {
+			methodVisitor.visitFrame( Opcodes.F_SAME, 0, null, 0, null );
+		}
+		// this (for field write)
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		// arg1 = (cast) XXX
+		methodVisitor.visitVarInsn( Type.getType( dispatcherType.getDescriptor() ).getOpcode( Opcodes.ILOAD ), 1 );
+		if ( !dispatcherType.isPrimitive() ) {
+			methodVisitor.visitTypeInsn( Opcodes.CHECKCAST, persistentField.getType().asErasure().getInternalName() );
+		}
+		fieldWrite( methodVisitor );
+		// return
+		methodVisitor.visitInsn( Opcodes.RETURN );
+		return new Size( 4 + 2 * persistentField.getType().getStackSize().getSize(), instrumentedMethod.getStackSize() );
+	}
+
+	protected abstract void fieldRead(MethodVisitor methodVisitor);
+
+	protected abstract void fieldWrite(MethodVisitor methodVisitor);
+
+	private static class FieldWriting extends FieldWriterAppender {
+
+		private FieldWriting(TypeDescription managedCtClass, FieldDescription.InDefinedShape fieldDescription) {
+			super( managedCtClass, fieldDescription );
+		}
+
+		@Override
+		protected void fieldRead(MethodVisitor methodVisitor) {
+			methodVisitor.visitFieldInsn(
+					Opcodes.GETFIELD,
+					persistentField.getDeclaringType().asErasure().getInternalName(),
+					persistentField.getInternalName(),
+					persistentField.getDescriptor()
+			);
+		}
+
+		@Override
+		protected void fieldWrite(MethodVisitor methodVisitor) {
+			methodVisitor.visitFieldInsn(
+					Opcodes.PUTFIELD,
+					persistentField.getDeclaringType().asErasure().getInternalName(),
+					persistentField.getInternalName(),
+					persistentField.getDescriptor()
+			);
+		}
+	}
+
+	private static class MethodDispatching extends FieldWriterAppender {
+
+		private MethodDispatching(TypeDescription managedCtClass, FieldDescription.InDefinedShape fieldDescription) {
+			super( managedCtClass, fieldDescription );
+		}
+
+		@Override
+		protected void fieldRead(MethodVisitor methodVisitor) {
+			methodVisitor.visitMethodInsn(
+					Opcodes.INVOKESPECIAL,
+					managedCtClass.getSuperClass().asErasure().getInternalName(),
+					EnhancerConstants.PERSISTENT_FIELD_READER_PREFIX + persistentField.getName(),
+					Type.getMethodDescriptor( Type.getType( persistentField.getType().asErasure().getDescriptor() ) ),
+					false
+			);
+		}
+
+		@Override
+		protected void fieldWrite(MethodVisitor methodVisitor) {
+			methodVisitor.visitMethodInsn(
+					Opcodes.INVOKESPECIAL,
+					managedCtClass.getSuperClass().asErasure().getInternalName(),
+					EnhancerConstants.PERSISTENT_FIELD_WRITER_PREFIX + persistentField.getName(),
+					Type.getMethodDescriptor( Type.getType( void.class ), Type.getType( persistentField.getType().asErasure().getDescriptor() ) ),
+					false
+			);
+		}
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/bytebuddy/InlineDirtyCheckingHandler.java

@@ -0,0 +1,154 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.bytebuddy;
+
+import java.util.Collection;
+import javax.persistence.Embedded;
+import javax.persistence.EmbeddedId;
+import javax.persistence.Id;
+
+import org.hibernate.bytecode.enhance.spi.EnhancerConstants;
+import org.hibernate.internal.util.compare.EqualsHelper;
+
+import net.bytebuddy.ClassFileVersion;
+import net.bytebuddy.asm.Advice;
+import net.bytebuddy.description.field.FieldDescription;
+import net.bytebuddy.description.method.MethodDescription;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.dynamic.scaffold.InstrumentedType;
+import net.bytebuddy.implementation.Implementation;
+import net.bytebuddy.implementation.bytecode.ByteCodeAppender;
+import net.bytebuddy.jar.asm.Label;
+import net.bytebuddy.jar.asm.MethodVisitor;
+import net.bytebuddy.jar.asm.Opcodes;
+import net.bytebuddy.jar.asm.Type;
+
+class InlineDirtyCheckingHandler implements Implementation, ByteCodeAppender {
+
+	private final Implementation delegate;
+
+	private final TypeDescription managedCtClass;
+
+	private final FieldDescription.InDefinedShape persistentField;
+
+	private InlineDirtyCheckingHandler(Implementation delegate, TypeDescription managedCtClass, FieldDescription.InDefinedShape persistentField) {
+		this.delegate = delegate;
+		this.managedCtClass = managedCtClass;
+		this.persistentField = persistentField;
+	}
+
+	static Implementation wrap(
+			TypeDescription managedCtClass,
+			ByteBuddyEnhancementContext enhancementContext,
+			FieldDescription persistentField,
+			Implementation implementation) {
+		if ( enhancementContext.doDirtyCheckingInline( managedCtClass ) ) {
+
+			if ( enhancementContext.isCompositeClass( managedCtClass ) ) {
+				implementation = Advice.to( CodeTemplates.CompositeDirtyCheckingHandler.class ).wrap( implementation );
+			}
+			else if ( !EnhancerImpl.isAnnotationPresent( persistentField, Id.class )
+					&& !EnhancerImpl.isAnnotationPresent( persistentField, EmbeddedId.class )
+					&& !( persistentField.getType().asErasure().isAssignableTo( Collection.class )
+					&& enhancementContext.isMappedCollection( persistentField ) ) ) {
+				implementation = new InlineDirtyCheckingHandler( implementation, managedCtClass, persistentField.asDefined() );
+			}
+
+			if ( enhancementContext.isCompositeClass( persistentField.getType().asErasure() )
+					&& EnhancerImpl.isAnnotationPresent( persistentField, Embedded.class ) ) {
+
+				implementation = Advice.withCustomMapping()
+						.bind( CodeTemplates.FieldValue.class, persistentField )
+						.bind( CodeTemplates.FieldName.class, persistentField.getName() )
+						.to( CodeTemplates.CompositeFieldDirtyCheckingHandler.class )
+						.wrap( implementation );
+			}
+		}
+		return implementation;
+	}
+
+	@Override
+	public ByteCodeAppender appender(Target implementationTarget) {
+		return new ByteCodeAppender.Compound( this, delegate.appender( implementationTarget ) );
+	}
+
+	@Override
+	public InstrumentedType prepare(InstrumentedType instrumentedType) {
+		return delegate.prepare( instrumentedType );
+	}
+
+	@Override
+	public Size apply(
+			MethodVisitor methodVisitor,
+			Context implementationContext,
+			MethodDescription instrumentedMethod) {
+		// if (arg != field) {
+		methodVisitor.visitVarInsn( Type.getType( persistentField.getType().asErasure().getDescriptor() ).getOpcode( Opcodes.ILOAD ), 1 );
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		if ( persistentField.getDeclaringType().asErasure().equals( managedCtClass ) ) {
+			methodVisitor.visitFieldInsn(
+					Opcodes.GETFIELD,
+					persistentField.getDeclaringType().asErasure().getInternalName(),
+					persistentField.getName(),
+					persistentField.getDescriptor()
+			);
+		}
+		else {
+			methodVisitor.visitMethodInsn(
+					Opcodes.INVOKEVIRTUAL,
+					persistentField.getDeclaringType().asErasure().getInternalName(),
+					EnhancerConstants.PERSISTENT_FIELD_READER_PREFIX + persistentField.getName(),
+					Type.getMethodDescriptor( Type.getType( persistentField.getDescriptor() ) ),
+					false
+			);
+		}
+		int branchCode;
+		if ( persistentField.getType().isPrimitive() ) {
+			if ( persistentField.getType().represents( long.class ) ) {
+				methodVisitor.visitInsn( Opcodes.LCMP );
+			}
+			else if ( persistentField.getType().represents( float.class ) ) {
+				methodVisitor.visitInsn( Opcodes.FCMPL );
+			}
+			else if ( persistentField.getType().represents( double.class ) ) {
+				methodVisitor.visitInsn( Opcodes.DCMPL );
+			}
+			else {
+				methodVisitor.visitInsn( Opcodes.ISUB );
+			}
+			branchCode = Opcodes.IFEQ;
+		}
+		else {
+			methodVisitor.visitMethodInsn(
+					Opcodes.INVOKESTATIC,
+					Type.getInternalName( EqualsHelper.class ),
+					"areEqual",
+					Type.getMethodDescriptor( Type.getType( boolean.class ), Type.getType( Object.class ), Type.getType( Object.class ) ),
+					false
+			);
+			branchCode = Opcodes.IFNE;
+		}
+		Label skip = new Label();
+		methodVisitor.visitJumpInsn( branchCode, skip );
+		// this.$$_hibernate_trackChange(fieldName)
+		methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+		methodVisitor.visitLdcInsn( persistentField.getName() );
+		methodVisitor.visitMethodInsn(
+				Opcodes.INVOKEVIRTUAL,
+				managedCtClass.getInternalName(),
+				EnhancerConstants.TRACKER_CHANGER_NAME,
+				Type.getMethodDescriptor( Type.getType( void.class ), Type.getType( String.class ) ),
+				false
+		);
+		// }
+		methodVisitor.visitLabel( skip );
+		if ( implementationContext.getClassFileVersion().isAtLeast( ClassFileVersion.JAVA_V6 ) ) {
+			methodVisitor.visitFrame( Opcodes.F_SAME, 0, null, 0, null );
+		}
+		return new Size( 1 + 2 * persistentField.getType().asErasure().getStackSize().getSize(), instrumentedMethod.getStackSize() );
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/bytebuddy/PersistentAttributeTransformer.java

@@ -0,0 +1,314 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.bytebuddy;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import javax.persistence.Embedded;
+
+import org.hibernate.bytecode.enhance.spi.EnhancerConstants;
+import org.hibernate.engine.spi.CompositeOwner;
+import org.hibernate.internal.CoreLogging;
+import org.hibernate.internal.CoreMessageLogger;
+
+import net.bytebuddy.ClassFileVersion;
+import net.bytebuddy.asm.Advice;
+import net.bytebuddy.asm.AsmVisitorWrapper;
+import net.bytebuddy.description.field.FieldDescription;
+import net.bytebuddy.description.method.MethodDescription;
+import net.bytebuddy.description.modifier.Visibility;
+import net.bytebuddy.description.type.TypeDefinition;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.dynamic.DynamicType;
+import net.bytebuddy.implementation.FieldAccessor;
+import net.bytebuddy.implementation.Implementation;
+import net.bytebuddy.implementation.StubMethod;
+import net.bytebuddy.implementation.bytecode.ByteCodeAppender;
+import net.bytebuddy.jar.asm.MethodVisitor;
+import net.bytebuddy.jar.asm.Opcodes;
+import net.bytebuddy.jar.asm.Type;
+import net.bytebuddy.pool.TypePool;
+
+import static net.bytebuddy.matcher.ElementMatchers.nameStartsWith;
+import static net.bytebuddy.matcher.ElementMatchers.not;
+
+class PersistentAttributeTransformer implements AsmVisitorWrapper.ForDeclaredMethods.MethodVisitorWrapper {
+
+	private static final CoreMessageLogger log = CoreLogging.messageLogger( PersistentAttributeTransformer.class );
+
+	private final TypeDescription managedCtClass;
+
+	private final ByteBuddyEnhancementContext enhancementContext;
+
+	private final TypePool classPool;
+
+	private final FieldDescription[] enhancedFields;
+
+	private PersistentAttributeTransformer(
+			TypeDescription managedCtClass,
+			ByteBuddyEnhancementContext enhancementContext,
+			TypePool classPool,
+			FieldDescription[] enhancedFields) {
+		this.managedCtClass = managedCtClass;
+		this.enhancementContext = enhancementContext;
+		this.classPool = classPool;
+		this.enhancedFields = enhancedFields;
+	}
+
+	public static PersistentAttributeTransformer collectPersistentFields(
+			TypeDescription managedCtClass,
+			ByteBuddyEnhancementContext enhancementContext,
+			TypePool classPool) {
+		List<FieldDescription> persistentFieldList = new ArrayList<FieldDescription>();
+		for ( FieldDescription ctField : managedCtClass.getDeclaredFields() ) {
+			// skip static fields and skip fields added by enhancement and  outer reference in inner classes
+			if ( ctField.getName().startsWith( "$$_hibernate_" ) || "this$0".equals( ctField.getName() ) ) {
+				continue;
+			}
+			if ( !ctField.isStatic() && enhancementContext.isPersistentField( ctField ) ) {
+				persistentFieldList.add( ctField );
+			}
+		}
+		// HHH-10646 Add fields inherited from @MappedSuperclass
+		// HHH-10981 There is no need to do it for @MappedSuperclass
+		if ( !enhancementContext.isMappedSuperclassClass( managedCtClass ) ) {
+			persistentFieldList.addAll( collectInheritPersistentFields( managedCtClass, enhancementContext ) );
+		}
+
+		FieldDescription[] orderedFields = enhancementContext.order( persistentFieldList.toArray( new FieldDescription[0] ) );
+		log.debugf( "Persistent fields for entity %s: %s", managedCtClass.getName(), Arrays.toString( orderedFields ) );
+		return new PersistentAttributeTransformer( managedCtClass, enhancementContext, classPool, orderedFields );
+	}
+
+	private static Collection<FieldDescription> collectInheritPersistentFields(
+			TypeDefinition managedCtClass,
+			ByteBuddyEnhancementContext enhancementContext) {
+		if ( managedCtClass == null || managedCtClass.represents( Object.class ) ) {
+			return Collections.emptyList();
+		}
+		TypeDefinition managedCtSuperclass = managedCtClass.getSuperClass();
+
+		if ( !enhancementContext.isMappedSuperclassClass( managedCtSuperclass.asErasure() ) ) {
+			return collectInheritPersistentFields( managedCtSuperclass, enhancementContext );
+		}
+		log.debugf( "Found @MappedSuperclass %s to collectPersistenceFields", managedCtSuperclass );
+		List<FieldDescription> persistentFieldList = new ArrayList<FieldDescription>();
+
+		for ( FieldDescription ctField : managedCtSuperclass.getDeclaredFields() ) {
+			if ( ctField.getName().startsWith( "$$_hibernate_" ) || "this$0".equals( ctField.getName() ) ) {
+				continue;
+			}
+			if ( !ctField.isStatic() && enhancementContext.isPersistentField( ctField ) ) {
+				persistentFieldList.add( ctField );
+			}
+		}
+		persistentFieldList.addAll( collectInheritPersistentFields( managedCtSuperclass, enhancementContext ) );
+		return persistentFieldList;
+	}
+
+	@Override
+	public MethodVisitor wrap(
+			TypeDescription instrumentedType,
+			MethodDescription.InDefinedShape instrumentedMethod,
+			MethodVisitor methodVisitor,
+			Implementation.Context implementationContext,
+			TypePool typePool,
+			int writerFlags,
+			int readerFlags) {
+		return new MethodVisitor( Opcodes.ASM5, methodVisitor ) {
+			@Override
+			public void visitFieldInsn(int opcode, String owner, String name, String desc) {
+				if ( isEnhanced( owner, name, desc ) ) {
+					switch ( opcode ) {
+						case Opcodes.GETFIELD:
+							methodVisitor.visitMethodInsn(
+									Opcodes.INVOKEVIRTUAL,
+									owner,
+									EnhancerConstants.PERSISTENT_FIELD_READER_PREFIX + name,
+									"()" + desc,
+									false
+							);
+							return;
+						case Opcodes.PUTFIELD:
+							methodVisitor.visitMethodInsn(
+									Opcodes.INVOKEVIRTUAL,
+									owner,
+									EnhancerConstants.PERSISTENT_FIELD_WRITER_PREFIX + name,
+									"(" + desc + ")V",
+									false
+							);
+							return;
+					}
+				}
+				super.visitFieldInsn( opcode, owner, name, desc );
+			}
+		};
+	}
+
+	private boolean isEnhanced(String owner, String name, String desc) {
+		for ( FieldDescription enhancedField : enhancedFields ) {
+			if ( enhancedField.getName().equals( name )
+					&& enhancedField.getDescriptor().equals( desc )
+					&& enhancedField.getDeclaringType().asErasure().getInternalName().equals( owner ) ) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	DynamicType.Builder<?> applyTo(DynamicType.Builder<?> builder, boolean accessor) {
+		boolean compositeOwner = false;
+
+		builder = builder.visit( new AsmVisitorWrapper.ForDeclaredMethods().method( not( nameStartsWith( "$$_hibernate_" ) ), this ) );
+		for ( FieldDescription enhancedField : enhancedFields ) {
+			builder = builder
+					.defineMethod(
+							EnhancerConstants.PERSISTENT_FIELD_READER_PREFIX + enhancedField.getName(),
+							enhancedField.getType().asErasure(),
+							Visibility.PUBLIC
+					)
+					.intercept(
+							accessor
+									? FieldAccessor.ofField( enhancedField.getName() ).in( enhancedField.getDeclaringType().asErasure() )
+									: fieldReader( enhancedField )
+					)
+					.defineMethod(
+							EnhancerConstants.PERSISTENT_FIELD_WRITER_PREFIX + enhancedField.getName(),
+							TypeDescription.VOID,
+							Visibility.PUBLIC
+					)
+					.withParameters( enhancedField.getType().asErasure() )
+					.intercept( accessor
+										? FieldAccessor.ofField( enhancedField.getName() ).in( enhancedField.getDeclaringType().asErasure() )
+										: fieldWriter( enhancedField ) );
+
+			if ( !compositeOwner
+					&& !accessor
+					&& EnhancerImpl.isAnnotationPresent( enhancedField, Embedded.class )
+					&& enhancementContext.isCompositeClass( enhancedField.getType().asErasure() )
+					&& enhancementContext.doDirtyCheckingInline( managedCtClass ) ) {
+				compositeOwner = true;
+			}
+		}
+
+		if ( compositeOwner ) {
+			builder = builder.implement( CompositeOwner.class );
+
+			if ( enhancementContext.isCompositeClass( managedCtClass ) ) {
+				builder = builder.defineMethod( EnhancerConstants.TRACKER_CHANGER_NAME, void.class, Visibility.PUBLIC )
+						.withParameters( String.class )
+						.intercept( Advice.to( CodeTemplates.CompositeOwnerDirtyCheckingHandler.class ).wrap( StubMethod.INSTANCE ) );
+			}
+		}
+
+		if ( enhancementContext.doExtendedEnhancement( managedCtClass ) ) {
+			builder = applyExtended( builder );
+		}
+
+		return builder;
+	}
+
+	private Implementation fieldReader(FieldDescription enhancedField) {
+		if ( !enhancementContext.hasLazyLoadableAttributes( managedCtClass ) || !enhancementContext.isLazyLoadable( enhancedField ) ) {
+			if ( enhancedField.getDeclaringType().asErasure().equals( managedCtClass ) ) {
+				return FieldAccessor.ofField( enhancedField.getName() ).in( enhancedField.getDeclaringType().asErasure() );
+			}
+			else {
+				return new Implementation.Simple( new FieldMethodReader( managedCtClass, enhancedField ) );
+			}
+		}
+		else {
+			return new Implementation.Simple( FieldReaderAppender.of( managedCtClass, enhancedField ) );
+		}
+	}
+
+	private Implementation fieldWriter(FieldDescription enhancedField) {
+		Implementation implementation;
+		if ( !enhancementContext.hasLazyLoadableAttributes( managedCtClass ) || !enhancementContext.isLazyLoadable( enhancedField ) ) {
+			if ( enhancedField.getDeclaringType().asErasure().equals( managedCtClass ) ) {
+				implementation = FieldAccessor.ofField( enhancedField.getName() ).in( enhancedField.getDeclaringType().asErasure() );
+			}
+			else {
+				implementation = new Implementation.Simple( new FieldMethodWriter( managedCtClass, enhancedField ) );
+			}
+		}
+		else {
+			implementation = new Implementation.Simple( FieldWriterAppender.of( managedCtClass, enhancedField ) );
+		}
+		implementation = InlineDirtyCheckingHandler.wrap( managedCtClass, enhancementContext, enhancedField, implementation );
+		return BiDirectionalAssociationHandler.wrap( managedCtClass, enhancementContext, enhancedField, implementation );
+	}
+
+	DynamicType.Builder<?> applyExtended(DynamicType.Builder<?> builder) {
+		AsmVisitorWrapper.ForDeclaredMethods.MethodVisitorWrapper enhancer = new FieldAccessEnhancer( managedCtClass, enhancementContext, classPool );
+		return builder.visit( new AsmVisitorWrapper.ForDeclaredMethods().method( not( nameStartsWith( "$$_hibernate_" ) ), enhancer ) );
+	}
+
+	private static class FieldMethodReader implements ByteCodeAppender {
+
+		private final TypeDescription managedCtClass;
+
+		private final FieldDescription persistentField;
+
+		private FieldMethodReader(TypeDescription managedCtClass, FieldDescription persistentField) {
+			this.managedCtClass = managedCtClass;
+			this.persistentField = persistentField;
+		}
+
+		@Override
+		public Size apply(
+				MethodVisitor methodVisitor,
+				Implementation.Context implementationContext,
+				MethodDescription instrumentedMethod
+		) {
+			methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+			methodVisitor.visitMethodInsn(
+					Opcodes.INVOKESPECIAL,
+					managedCtClass.getSuperClass().asErasure().getInternalName(),
+					EnhancerConstants.PERSISTENT_FIELD_READER_PREFIX + persistentField.getName(),
+					Type.getMethodDescriptor( Type.getType( persistentField.getType().asErasure().getDescriptor() ) ),
+					false
+			);
+			methodVisitor.visitInsn( Type.getType( persistentField.getType().asErasure().getDescriptor() ).getOpcode( Opcodes.IRETURN ) );
+			return new Size( persistentField.getType().getStackSize().getSize(), instrumentedMethod.getStackSize() );
+		}
+	}
+
+	private static class FieldMethodWriter implements ByteCodeAppender {
+
+		private final TypeDescription managedCtClass;
+
+		private final FieldDescription persistentField;
+
+		private FieldMethodWriter(TypeDescription managedCtClass, FieldDescription persistentField) {
+			this.managedCtClass = managedCtClass;
+			this.persistentField = persistentField;
+		}
+
+		@Override
+		public Size apply(
+				MethodVisitor methodVisitor,
+				Implementation.Context implementationContext,
+				MethodDescription instrumentedMethod
+		) {
+			methodVisitor.visitVarInsn( Opcodes.ALOAD, 0 );
+			methodVisitor.visitVarInsn( Type.getType( persistentField.getType().asErasure().getDescriptor() ).getOpcode( Opcodes.ILOAD ), 1 );
+			methodVisitor.visitMethodInsn(
+					Opcodes.INVOKESPECIAL,
+					managedCtClass.getSuperClass().asErasure().getInternalName(),
+					EnhancerConstants.PERSISTENT_FIELD_WRITER_PREFIX + persistentField.getName(),
+					Type.getMethodDescriptor( Type.getType( void.class ), Type.getType( persistentField.getType().asErasure().getDescriptor() ) ),
+					false
+			);
+			methodVisitor.visitInsn( Opcodes.RETURN );
+			return new Size( 1 + persistentField.getType().getStackSize().getSize(), instrumentedMethod.getStackSize() );
+		}
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/bytebuddy/UnloadedFieldDescription.java

@@ -0,0 +1,27 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.bytebuddy;
+
+import java.lang.annotation.Annotation;
+
+import org.hibernate.bytecode.enhance.spi.UnloadedField;
+
+import net.bytebuddy.description.field.FieldDescription;
+
+class UnloadedFieldDescription implements UnloadedField {
+
+	final FieldDescription fieldDescription;
+
+	UnloadedFieldDescription(FieldDescription fieldDescription) {
+		this.fieldDescription = fieldDescription;
+	}
+
+	@Override
+	public boolean hasAnnotation(Class<? extends Annotation> annotationType) {
+		return fieldDescription.getDeclaredAnnotations().isAnnotationPresent( annotationType );
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/bytebuddy/UnloadedTypeDescription.java

@@ -0,0 +1,33 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.bytebuddy;
+
+import java.lang.annotation.Annotation;
+
+import org.hibernate.bytecode.enhance.spi.UnloadedClass;
+import org.hibernate.bytecode.enhance.spi.UnloadedField;
+
+import net.bytebuddy.description.type.TypeDescription;
+
+class UnloadedTypeDescription implements UnloadedClass {
+
+	private final TypeDescription typeDescription;
+
+	UnloadedTypeDescription(TypeDescription typeDescription) {
+		this.typeDescription = typeDescription;
+	}
+
+	@Override
+	public boolean hasAnnotation(Class<? extends Annotation> annotationType) {
+		return typeDescription.getDeclaredAnnotations().isAnnotationPresent( annotationType );
+	}
+
+	@Override
+	public String getName() {
+		return typeDescription.getName();
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/bytebuddy/package-info.java

@@ -0,0 +1,11 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+
+/**
+ * package containing bytecode enhancement code (internals)
+ */
+package org.hibernate.bytecode.enhance.internal.bytebuddy;

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/javassist/AttributeTypeDescriptor.java

@@ -4,7 +4,7 @@
  * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
  * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
  */
-package org.hibernate.bytecode.enhance.internal;
+package org.hibernate.bytecode.enhance.internal.javassist;
 
 import java.util.Collection;
 import java.util.Locale;
@@ -37,7 +37,7 @@ public abstract class AttributeTypeDescriptor {
 
 	public abstract String buildWriteInterceptionBodyFragment(String fieldName);
 
-	public String buildInLineDirtyCheckingBodyFragment(EnhancementContext context, CtField currentValue) {
+	public String buildInLineDirtyCheckingBodyFragment(JavassistEnhancementContext context, CtField currentValue) {
 		StringBuilder builder = new StringBuilder();
 		try {
 			// should ignore primary keys

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/javassist/CompositeEnhancer.java

@@ -4,10 +4,11 @@
  * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
  * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
  */
-package org.hibernate.bytecode.enhance.internal;
+package org.hibernate.bytecode.enhance.internal.javassist;
 
 import javassist.CannotCompileException;
 import javassist.CtClass;
+
 import org.hibernate.bytecode.enhance.internal.tracker.CompositeOwnerTracker;
 import org.hibernate.bytecode.enhance.spi.EnhancementContext;
 import org.hibernate.bytecode.enhance.spi.EnhancerConstants;
@@ -22,7 +23,7 @@ import org.hibernate.engine.spi.ManagedComposite;
  */
 public class CompositeEnhancer extends PersistentAttributesEnhancer {
 
-	public CompositeEnhancer(EnhancementContext context) {
+	public CompositeEnhancer(JavassistEnhancementContext context) {
 		super( context );
 	}
 
@@ -57,10 +58,10 @@ public class CompositeEnhancer extends PersistentAttributesEnhancer {
 							"  if (%2$s == null) { %2$s = new %4$s(); }%n" +
 							"  %2$s.add(name, tracker);%n" +
 							"}",
-					EnhancerConstants.TRACKER_COMPOSITE_SET_OWNER,
-					EnhancerConstants.TRACKER_COMPOSITE_FIELD_NAME,
-					CompositeOwner.class.getName(),
-					CompositeOwnerTracker.class.getName() );
+								EnhancerConstants.TRACKER_COMPOSITE_SET_OWNER,
+								EnhancerConstants.TRACKER_COMPOSITE_FIELD_NAME,
+								CompositeOwner.class.getName(),
+								CompositeOwnerTracker.class.getName() );
 
 			MethodWriter.write( managedCtClass, "" +
 							"public void %1$s(String name) {%n" +

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/javassist/EnhancerImpl.java

@@ -0,0 +1,224 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.javassist;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.DataOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+import javassist.CannotCompileException;
+import javassist.ClassPool;
+import javassist.CtClass;
+import javassist.LoaderClassPath;
+
+import org.hibernate.HibernateException;
+import org.hibernate.bytecode.enhance.spi.EnhancementContext;
+import org.hibernate.bytecode.enhance.spi.EnhancementException;
+import org.hibernate.bytecode.enhance.spi.Enhancer;
+import org.hibernate.bytecode.enhance.spi.EnhancerConstants;
+import org.hibernate.engine.spi.Managed;
+import org.hibernate.engine.spi.ManagedComposite;
+import org.hibernate.engine.spi.ManagedEntity;
+import org.hibernate.engine.spi.ManagedMappedSuperclass;
+import org.hibernate.engine.spi.PersistentAttributeInterceptable;
+import org.hibernate.engine.spi.PersistentAttributeInterceptor;
+import org.hibernate.internal.CoreLogging;
+import org.hibernate.internal.CoreMessageLogger;
+
+public class EnhancerImpl implements Enhancer {
+
+	private static final CoreMessageLogger log = CoreLogging.messageLogger( Enhancer.class );
+
+	protected final JavassistEnhancementContext enhancementContext;
+	private final ClassPool classPool;
+
+	/**
+	 * Constructs the Enhancer, using the given context.
+	 *
+	 * @param enhancementContext Describes the context in which enhancement will occur so as to give access
+	 * to contextual/environmental information.
+	 */
+	public EnhancerImpl(EnhancementContext enhancementContext) {
+		this.enhancementContext = new JavassistEnhancementContext( enhancementContext );
+		this.classPool = buildClassPool( this.enhancementContext );
+	}
+
+	EnhancerImpl(JavassistEnhancementContext enhancementContext) {
+		this.enhancementContext = enhancementContext;
+		this.classPool = buildClassPool( enhancementContext );
+	}
+
+	/**
+	 * Performs the enhancement.
+	 *
+	 * @param className The name of the class whose bytecode is being enhanced.
+	 * @param originalBytes The class's original (pre-enhancement) byte code
+	 *
+	 * @return The enhanced bytecode. Could be the same as the original bytecode if the original was
+	 * already enhanced or we could not enhance it for some reason.
+	 *
+	 * @throws EnhancementException Indicates a problem performing the enhancement
+	 */
+	@Override
+	public synchronized byte[] enhance(String className, byte[] originalBytes) throws EnhancementException {
+		try {
+			final CtClass managedCtClass = classPool.makeClassIfNew( new ByteArrayInputStream( originalBytes ) );
+			if ( enhance( managedCtClass ) ) {
+				return getByteCode( managedCtClass );
+			}
+			else {
+				return null;
+			}
+		}
+		catch (IOException e) {
+			log.unableToBuildEnhancementMetamodel( className );
+			return null;
+		}
+	}
+
+	@Override
+	public byte[] enhance(File javaClassFile) throws EnhancementException, IOException {
+		final CtClass ctClass = classPool.makeClass( new FileInputStream( javaClassFile ) );
+		try {
+			return enhance( ctClass.getName(), ctClass.toBytecode() );
+		}
+		catch (CannotCompileException e) {
+			log.warn( "Unable to enhance class file [" + javaClassFile.getAbsolutePath() + "]", e );
+			return null;
+		}
+	}
+
+	private ClassPool buildClassPool(final JavassistEnhancementContext enhancementContext) {
+		final ClassPool classPool = new ClassPool( false ) {
+			@Override
+			public ClassLoader getClassLoader() {
+				return enhancementContext.getLoadingClassLoader();
+			}
+		};
+
+		final ClassLoader loadingClassLoader = enhancementContext.getLoadingClassLoader();
+		if ( loadingClassLoader != null ) {
+			classPool.appendClassPath( new LoaderClassPath( loadingClassLoader ) );
+		}
+		return classPool;
+	}
+
+	protected CtClass loadCtClassFromClass(Class<?> aClass) {
+		String resourceName = aClass.getName().replace( '.', '/' ) + ".class";
+		InputStream resourceAsStream = aClass.getClassLoader().getResourceAsStream( resourceName );
+		try {
+			return classPool.makeClass( resourceAsStream );
+		}
+		catch (IOException e) {
+			throw new EnhancementException( "Could not prepare Javassist ClassPool", e );
+		}
+		finally {
+			try {
+				resourceAsStream.close();
+			}
+			catch (IOException ioe) {
+				log.debugf( "An error occurs closing InputStream for class [%s]", aClass.getName() );
+			}
+		}
+	}
+
+	private boolean enhance(CtClass managedCtClass) {
+		// can't effectively enhance interfaces
+		if ( managedCtClass.isInterface() ) {
+			log.debugf( "Skipping enhancement of [%s]: it's an interface!", managedCtClass.getName() );
+			return false;
+		}
+		// skip already enhanced classes
+		if ( alreadyEnhanced( managedCtClass ) ) {
+			log.debugf( "Skipping enhancement of [%s]: already enhanced", managedCtClass.getName() );
+			return false;
+		}
+
+		if ( enhancementContext.isEntityClass( managedCtClass ) ) {
+			log.infof( "Enhancing [%s] as Entity", managedCtClass.getName() );
+			new EntityEnhancer( enhancementContext ).enhance( managedCtClass );
+			return true;
+		}
+		else if ( enhancementContext.isCompositeClass( managedCtClass ) ) {
+			log.infof( "Enhancing [%s] as Composite", managedCtClass.getName() );
+			new CompositeEnhancer( enhancementContext ).enhance( managedCtClass );
+			return true;
+		}
+		else if ( enhancementContext.isMappedSuperclassClass( managedCtClass ) ) {
+			log.infof( "Enhancing [%s] as MappedSuperclass", managedCtClass.getName() );
+			new MappedSuperclassEnhancer( enhancementContext ).enhance( managedCtClass );
+			return true;
+		}
+		else if ( enhancementContext.doExtendedEnhancement( managedCtClass ) ) {
+			log.infof( "Extended enhancement of [%s]", managedCtClass.getName() );
+			new PersistentAttributesEnhancer( enhancementContext ).extendedEnhancement( managedCtClass );
+			return true;
+		}
+		else {
+			log.debugf( "Skipping enhancement of [%s]: not entity or composite", managedCtClass.getName() );
+			return false;
+		}
+	}
+
+	private boolean alreadyEnhanced(CtClass managedCtClass) {
+		if ( !PersistentAttributesHelper.isAssignable( managedCtClass, Managed.class.getName() ) ) {
+			return false;
+		}
+		// HHH-10977 - When a mapped superclass gets enhanced before a subclassing entity, the entity does not get enhanced, but it implements the Managed interface
+		return enhancementContext.isEntityClass( managedCtClass ) && PersistentAttributesHelper.isAssignable( managedCtClass, ManagedEntity.class.getName() )
+				|| enhancementContext.isCompositeClass( managedCtClass ) && PersistentAttributesHelper.isAssignable(
+				managedCtClass,
+				ManagedComposite.class.getName()
+		)
+				|| enhancementContext.isMappedSuperclassClass( managedCtClass ) && PersistentAttributesHelper.isAssignable(
+				managedCtClass,
+				ManagedMappedSuperclass.class.getName()
+		);
+	}
+
+	private byte[] getByteCode(CtClass managedCtClass) {
+		final ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
+		final DataOutputStream out = new DataOutputStream( byteStream );
+		try {
+			managedCtClass.toBytecode( out );
+			return byteStream.toByteArray();
+		}
+		catch (Exception e) {
+			log.unableToTransformClass( e.getMessage() );
+			throw new HibernateException( "Unable to transform class: " + e.getMessage() );
+		}
+		finally {
+			try {
+				out.close();
+			}
+			catch (IOException ignored) {
+			}
+		}
+	}
+
+	protected void addInterceptorHandling(CtClass managedCtClass) {
+		// interceptor handling is only needed if class has lazy-loadable attributes
+		if ( !enhancementContext.hasLazyLoadableAttributes( managedCtClass ) ) {
+			return;
+		}
+		log.debugf( "Weaving in PersistentAttributeInterceptable implementation on [%s]", managedCtClass.getName() );
+
+		managedCtClass.addInterface( loadCtClassFromClass( PersistentAttributeInterceptable.class ) );
+
+		FieldWriter.addFieldWithGetterAndSetter(
+				managedCtClass,
+				loadCtClassFromClass( PersistentAttributeInterceptor.class ),
+				EnhancerConstants.INTERCEPTOR_FIELD_NAME,
+				EnhancerConstants.INTERCEPTOR_GETTER_NAME,
+				EnhancerConstants.INTERCEPTOR_SETTER_NAME
+		);
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/javassist/EntityEnhancer.java

@@ -4,12 +4,11 @@
  * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
  * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
  */
-package org.hibernate.bytecode.enhance.internal;
+package org.hibernate.bytecode.enhance.internal.javassist;
 
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -20,6 +19,7 @@ import javassist.CtField;
 import javassist.Modifier;
 
 import javassist.NotFoundException;
+
 import org.hibernate.bytecode.enhance.internal.tracker.DirtyTracker;
 import org.hibernate.bytecode.enhance.internal.tracker.SimpleCollectionTracker;
 import org.hibernate.bytecode.enhance.internal.tracker.SimpleFieldTracker;
@@ -40,7 +40,7 @@ import org.hibernate.engine.spi.SelfDirtinessTracker;
  */
 public class EntityEnhancer extends PersistentAttributesEnhancer {
 
-	public EntityEnhancer(EnhancementContext context) {
+	public EntityEnhancer(JavassistEnhancementContext context) {
 		super( context );
 	}
 

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/javassist/FieldWriter.java

@@ -4,7 +4,7 @@
  * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
  * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
  */
-package org.hibernate.bytecode.enhance.internal;
+package org.hibernate.bytecode.enhance.internal.javassist;
 
 import javax.persistence.Transient;
 

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/javassist/JavassistEnhancementContext.java

@@ -0,0 +1,79 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.javassist;
+
+import javassist.CtClass;
+import javassist.CtField;
+
+import org.hibernate.bytecode.enhance.spi.EnhancementContext;
+import org.hibernate.bytecode.enhance.spi.UnloadedField;
+
+public class JavassistEnhancementContext {
+
+	private final EnhancementContext enhancementContext;
+
+	public JavassistEnhancementContext(EnhancementContext enhancementContext) {
+		this.enhancementContext = enhancementContext;
+	}
+
+	public ClassLoader getLoadingClassLoader() {
+		return enhancementContext.getLoadingClassLoader();
+	}
+
+	public boolean isEntityClass(CtClass classDescriptor) {
+		return enhancementContext.isEntityClass( new UnloadedCtClass( classDescriptor ) );
+	}
+
+	public boolean isCompositeClass(CtClass classDescriptor) {
+		return enhancementContext.isCompositeClass( new UnloadedCtClass( classDescriptor ) );
+	}
+
+	public boolean isMappedSuperclassClass(CtClass classDescriptor) {
+		return enhancementContext.isMappedSuperclassClass( new UnloadedCtClass( classDescriptor ) );
+	}
+
+	public boolean doBiDirectionalAssociationManagement(CtField field) {
+		return enhancementContext.doBiDirectionalAssociationManagement( new UnloadedCtField( field ) );
+	}
+
+	public boolean doDirtyCheckingInline(CtClass classDescriptor) {
+		return enhancementContext.doDirtyCheckingInline( new UnloadedCtClass( classDescriptor ) );
+	}
+
+	public boolean doExtendedEnhancement(CtClass classDescriptor) {
+		return enhancementContext.doExtendedEnhancement( new UnloadedCtClass( classDescriptor ) );
+	}
+
+	public boolean hasLazyLoadableAttributes(CtClass classDescriptor) {
+		return enhancementContext.hasLazyLoadableAttributes( new UnloadedCtClass( classDescriptor ) );
+	}
+
+	public boolean isPersistentField(CtField ctField) {
+		return enhancementContext.isPersistentField( new UnloadedCtField( ctField ) );
+	}
+
+	public CtField[] order(CtField[] persistentFields) {
+		UnloadedField[] unloadedFields = new UnloadedField[persistentFields.length];
+		for ( int i = 0; i < unloadedFields.length; i++ ) {
+			unloadedFields[i] = new UnloadedCtField( persistentFields[i] );
+		}
+		UnloadedField[] ordered = enhancementContext.order( unloadedFields );
+		CtField[] orderedFields = new CtField[persistentFields.length];
+		for ( int i = 0; i < orderedFields.length; i++ ) {
+			orderedFields[i] = ( (UnloadedCtField) ordered[i] ).ctField;
+		}
+		return orderedFields;
+	}
+
+	public boolean isLazyLoadable(CtField field) {
+		return enhancementContext.isLazyLoadable( new UnloadedCtField( field ) );
+	}
+
+	public boolean isMappedCollection(CtField field) {
+		return enhancementContext.isMappedCollection( new UnloadedCtField( field ) );
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/javassist/MappedSuperclassEnhancer.java

@@ -4,11 +4,12 @@
  * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
  * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
  */
-package org.hibernate.bytecode.enhance.internal;
+package org.hibernate.bytecode.enhance.internal.javassist;
 
 import javassist.CtClass;
 import javassist.CtField;
 import javassist.CtMethod;
+
 import org.hibernate.bytecode.enhance.spi.EnhancementContext;
 import org.hibernate.bytecode.enhance.spi.EnhancerConstants;
 import org.hibernate.engine.spi.ManagedMappedSuperclass;
@@ -20,7 +21,7 @@ import org.hibernate.engine.spi.ManagedMappedSuperclass;
  */
 public class MappedSuperclassEnhancer extends PersistentAttributesEnhancer {
 
-	public MappedSuperclassEnhancer(EnhancementContext context) {
+	public MappedSuperclassEnhancer(JavassistEnhancementContext context) {
 		super( context );
 	}
 

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/javassist/MethodWriter.java

@@ -4,7 +4,7 @@
  * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
  * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
  */
-package org.hibernate.bytecode.enhance.internal;
+package org.hibernate.bytecode.enhance.internal.javassist;
 
 import javassist.CannotCompileException;
 import javassist.CtClass;

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/javassist/PersistentAttributesEnhancer.java

@@ -4,14 +4,13 @@
  * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
  * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
  */
-package org.hibernate.bytecode.enhance.internal;
+package org.hibernate.bytecode.enhance.internal.javassist;
 
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.IdentityHashMap;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import javax.persistence.Embedded;
@@ -36,9 +35,7 @@ import javassist.bytecode.Opcode;
 import javassist.bytecode.stackmap.MapMaker;
 
 import org.hibernate.Hibernate;
-import org.hibernate.bytecode.enhance.spi.EnhancementContext;
 import org.hibernate.bytecode.enhance.spi.EnhancementException;
-import org.hibernate.bytecode.enhance.spi.Enhancer;
 import org.hibernate.bytecode.enhance.spi.EnhancerConstants;
 import org.hibernate.engine.spi.CompositeOwner;
 import org.hibernate.engine.spi.CompositeTracker;
@@ -50,11 +47,11 @@ import org.hibernate.internal.CoreMessageLogger;
  *
  * @author <a href="mailto:lbarreiro@redhat.com">Luis Barreiro</a>
  */
-public class PersistentAttributesEnhancer extends Enhancer {
+public class PersistentAttributesEnhancer extends EnhancerImpl {
 
 	private static final CoreMessageLogger log = CoreLogging.messageLogger( PersistentAttributesEnhancer.class );
 
-	public PersistentAttributesEnhancer(EnhancementContext context) {
+	public PersistentAttributesEnhancer(JavassistEnhancementContext context) {
 		super( context );
 	}
 
@@ -97,7 +94,7 @@ public class PersistentAttributesEnhancer extends Enhancer {
 		}
 
 		CtField[] orderedFields = enhancementContext.order( persistentFieldList.toArray( new CtField[0] ) );
-		log.debugf( "Persistent fields for entity %s: %s", managedCtClass.getName(), Arrays.toString( orderedFields ));
+		log.debugf( "Persistent fields for entity %s: %s", managedCtClass.getName(), Arrays.toString( orderedFields ) );
 		return orderedFields;
 	}
 
@@ -131,7 +128,7 @@ public class PersistentAttributesEnhancer extends Enhancer {
 		}
 	}
 
-	private PersistentAttributeAccessMethods enhancePersistentAttribute( CtClass managedCtClass, CtField persistentField) {
+	private PersistentAttributeAccessMethods enhancePersistentAttribute(CtClass managedCtClass, CtField persistentField) {
 		try {
 			AttributeTypeDescriptor typeDescriptor = AttributeTypeDescriptor.resolve( managedCtClass, persistentField );
 			return new PersistentAttributeAccessMethods(
@@ -165,13 +162,13 @@ public class PersistentAttributesEnhancer extends Enhancer {
 			String declaredReadFragment = "this." + fieldName + "";
 			String superReadFragment = "super." + readerName + "()";
 
-			if (!declared) {
+			if ( !declared ) {
 				// create a temporary getter on the supper entity to be able to compile our code
 				try {
 					persistentField.getDeclaringClass().getDeclaredMethod( readerName );
 					persistentField.getDeclaringClass().getDeclaredMethod( writerName );
 				}
-				catch (NotFoundException nfe){
+				catch ( NotFoundException nfe ) {
 					tmpSuperReader = MethodWriter.addGetter( persistentField.getDeclaringClass(), persistentField.getName(), readerName );
 					tmpSuperWriter = MethodWriter.addSetter( persistentField.getDeclaringClass(), persistentField.getName(), writerName );
 				}
@@ -179,8 +176,7 @@ public class PersistentAttributesEnhancer extends Enhancer {
 
 			// read attempts only have to deal lazy-loading support, not dirty checking;
 			// so if the field is not enabled as lazy-loadable return a plain simple getter as the reader
-			if ( !enhancementContext.hasLazyLoadableAttributes( managedCtClass )
-					|| !enhancementContext.isLazyLoadable( persistentField ) ) {
+			if ( !enhancementContext.hasLazyLoadableAttributes( managedCtClass ) || !enhancementContext.isLazyLoadable( persistentField ) ) {
 				reader = MethodWriter.write(
 						managedCtClass, "public %s %s() {  return %s;%n}",
 						persistentField.getType().getName(),
@@ -237,15 +233,15 @@ public class PersistentAttributesEnhancer extends Enhancer {
 		try {
 			boolean declared = persistentField.getDeclaringClass().equals( managedCtClass );
 			String declaredWriteFragment = "this." + fieldName + "=" + fieldName + ";";
-			String superWriteFragment =	"super." + writerName + "(" + fieldName + ");";
+			String superWriteFragment = "super." + writerName + "(" + fieldName + ");";
 
-			if (!declared) {
+			if ( !declared ) {
 				// create a temporary setter on the supper entity to be able to compile our code
 				try {
 					persistentField.getDeclaringClass().getDeclaredMethod( readerName );
 					persistentField.getDeclaringClass().getDeclaredMethod( writerName );
 				}
-				catch (NotFoundException nfe){
+				catch ( NotFoundException nfe ) {
 					tmpSuperReader = MethodWriter.addGetter( persistentField.getDeclaringClass(), persistentField.getName(), readerName );
 					tmpSuperWriter = MethodWriter.addSetter( persistentField.getDeclaringClass(), persistentField.getName(), writerName );
 				}
@@ -352,7 +348,7 @@ public class PersistentAttributesEnhancer extends Enhancer {
 			getter = targetEntity.getDeclaredMethod( mappedByGetterName );
 			setter = targetEntity.getDeclaredMethod( mappedByGetterName );
 		}
-		catch (NotFoundException nfe){
+		catch ( NotFoundException nfe ) {
 			getter = MethodWriter.addGetter( targetEntity, mappedBy, mappedByGetterName );
 			setter = MethodWriter.addSetter( targetEntity, mappedBy, mappedBySetterName );
 			tmpTargetMethods = true;
@@ -397,19 +393,19 @@ public class PersistentAttributesEnhancer extends Enhancer {
 		}
 		if ( PersistentAttributesHelper.hasAnnotation( persistentField, OneToMany.class ) ) {
 			boolean isMap = PersistentAttributesHelper.isAssignable( persistentField.getType(), Map.class.getName() );
-			String toArrayMethod = isMap ? "values().toArray()" : "toArray()" ;
+			String toArrayMethod = isMap ? "values().toArray()" : "toArray()";
 
 			// only remove elements not in the new collection or else we would loose those elements
 			// don't use iterator to avoid ConcurrentModException
 			fieldWriter.insertBefore(
 					String.format(
 							"  if (this.%3$s != null && %1$s) {%n" +
-							"    Object[] array = this.%3$s.%2$s;%n" +
-							"    for (int i = 0; i < array.length; i++) {%n" +
-							"      %4$s target = (%4$s) array[i];%n" +
-							"      if ($1 == null || !$1.contains(target)) { target.%5$s(null); }%n" +
-							"    }%n" +
-							"  }%n",
+									"    Object[] array = this.%3$s.%2$s;%n" +
+									"    for (int i = 0; i < array.length; i++) {%n" +
+									"      %4$s target = (%4$s) array[i];%n" +
+									"      if ($1 == null || !$1.contains(target)) { target.%5$s(null); }%n" +
+									"    }%n" +
+									"  }%n",
 							currentAssociationLoaded,
 							toArrayMethod,
 							persistentField.getName(),
@@ -420,12 +416,12 @@ public class PersistentAttributesEnhancer extends Enhancer {
 			fieldWriter.insertAfter(
 					String.format(
 							"  if ($1 != null && %1$s) {%n" +
-							"    Object[] array = $1.%2$s;%n" +
-							"    for (int i = 0; i < array.length; i++) {%n" +
-							"      %4$s target = (%4$s) array[i];%n" +
-							"      if (%3$s && target.%5$s() != this) { target.%6$s(this); }%n" +
-							"    }%n" +
-							"  }%n",
+									"    Object[] array = $1.%2$s;%n" +
+									"    for (int i = 0; i < array.length; i++) {%n" +
+									"      %4$s target = (%4$s) array[i];%n" +
+									"      if (%3$s && target.%5$s() != this) { target.%6$s(this); }%n" +
+									"    }%n" +
+									"  }%n",
 							newAssociationLoaded,
 							toArrayMethod,
 							targetElementLoaded,
@@ -448,9 +444,9 @@ public class PersistentAttributesEnhancer extends Enhancer {
 			fieldWriter.insertAfter(
 					String.format(
 							"  if ($1 != null && %s) {%n" +
-							"    java.util.Collection c = $1.%s();%n" +
-							"    if (c != null && !c.contains(this)) { c.add(this); }%n" +
-							"  }%n",
+									"    java.util.Collection c = $1.%s();%n" +
+									"    if (c != null && !c.contains(this)) { c.add(this); }%n" +
+									"  }%n",
 							newAssociationLoaded,
 							mappedByGetterName
 					)
@@ -458,7 +454,7 @@ public class PersistentAttributesEnhancer extends Enhancer {
 		}
 		if ( PersistentAttributesHelper.hasAnnotation( persistentField, ManyToMany.class ) ) {
 			if ( PersistentAttributesHelper.isAssignable( persistentField.getType(), Map.class.getName() ) ||
-					PersistentAttributesHelper.isAssignable( targetEntity.getField( mappedBy ).getType() , Map.class.getName() ) ) {
+					PersistentAttributesHelper.isAssignable( targetEntity.getField( mappedBy ).getType(), Map.class.getName() ) ) {
 				log.infof(
 						"Bi-directional association for field [%s#%s] not managed: @ManyToMany in java.util.Map attribute not supported ",
 						managedCtClass.getName(),
@@ -469,12 +465,12 @@ public class PersistentAttributesEnhancer extends Enhancer {
 			fieldWriter.insertBefore(
 					String.format(
 							"  if (this.%2$s != null && %1$s) {%n" +
-							"    Object[] array = this.%2$s.toArray();%n" +
-							"    for (int i = 0; i < array.length; i++) {%n" +
-							"      %3$s target = (%3$s) array[i];%n" +
-							"      if ($1 == null || !$1.contains(target)) { target.%4$s().remove(this); }%n" +
-							"    }%n" +
-							"  }%n",
+									"    Object[] array = this.%2$s.toArray();%n" +
+									"    for (int i = 0; i < array.length; i++) {%n" +
+									"      %3$s target = (%3$s) array[i];%n" +
+									"      if ($1 == null || !$1.contains(target)) { target.%4$s().remove(this); }%n" +
+									"    }%n" +
+									"  }%n",
 							currentAssociationLoaded,
 							persistentField.getName(),
 							targetEntity.getName(),
@@ -484,15 +480,15 @@ public class PersistentAttributesEnhancer extends Enhancer {
 			fieldWriter.insertAfter(
 					String.format(
 							"  if ($1 != null && %s) {%n" +
-							"    Object[] array = $1.toArray();%n" +
-							"    for (int i = 0; i < array.length; i++) {%n" +
-							"      %s target = (%s) array[i];%n" +
-							"	   if (%s) {%n" +
-							"        java.util.Collection c = target.%s();%n" +
-							"        if (c != this && c != null) { c.add(this); }%n" +
-							"      }%n" +
-							"    }%n" +
-							"  }%n",
+									"    Object[] array = $1.toArray();%n" +
+									"    for (int i = 0; i < array.length; i++) {%n" +
+									"      %s target = (%s) array[i];%n" +
+									"	   if (%s) {%n" +
+									"        java.util.Collection c = target.%s();%n" +
+									"        if (c != this && c != null) { c.add(this); }%n" +
+									"      }%n" +
+									"    }%n" +
+									"  }%n",
 							newAssociationLoaded,
 							targetEntity.getName(),
 							targetEntity.getName(),
@@ -523,7 +519,7 @@ public class PersistentAttributesEnhancer extends Enhancer {
 		// cleanup previous owner
 		fieldWriter.insertBefore(
 				String.format(
-								"if (%1$s != null) { ((%2$s) %1$s).%3$s(\"%1$s\"); }%n",
+						"if (%1$s != null) { ((%2$s) %1$s).%3$s(\"%1$s\"); }%n",
 						persistentField.getName(),
 						CompositeTracker.class.getName(),
 						EnhancerConstants.TRACKER_COMPOSITE_CLEAR_OWNER
@@ -533,7 +529,7 @@ public class PersistentAttributesEnhancer extends Enhancer {
 		// trigger track changes
 		fieldWriter.insertAfter(
 				String.format(
-								"if (%1$s != null) { ((%2$s) %1$s).%4$s(\"%1$s\", (%3$s) this); }%n" +
+						"if (%1$s != null) { ((%2$s) %1$s).%4$s(\"%1$s\", (%3$s) this); }%n" +
 								"%5$s(\"%1$s\");",
 						persistentField.getName(),
 						CompositeTracker.class.getName(),
@@ -691,11 +687,13 @@ public class PersistentAttributesEnhancer extends Enhancer {
 						continue;
 					}
 
-					log.debugf( "Extended enhancement: Transforming access to field [%s.%s] from method [%s#%s]",
-								fieldClassName,
-								fieldName,
-								aCtClass.getName(),
-								methodName );
+					log.debugf(
+							"Extended enhancement: Transforming access to field [%s.%s] from method [%s#%s]",
+							fieldClassName,
+							fieldName,
+							aCtClass.getName(),
+							methodName
+					);
 
 					if ( op == Opcode.GETFIELD ) {
 						int fieldReaderMethodIndex = constPool.addMethodrefInfo(

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/javassist/PersistentAttributesHelper.java

@@ -4,7 +4,7 @@
  * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
  * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
  */
-package org.hibernate.bytecode.enhance.internal;
+package org.hibernate.bytecode.enhance.internal.javassist;
 
 import java.beans.Introspector;
 import java.lang.annotation.Annotation;
@@ -207,7 +207,7 @@ public class PersistentAttributesHelper {
 				PersistentAttributesHelper.hasAnnotation( persistentField, ManyToMany.class );
 	}
 
-	public static String getMappedBy(CtField persistentField, CtClass targetEntity, EnhancementContext context) throws NotFoundException {
+	public static String getMappedBy(CtField persistentField, CtClass targetEntity, JavassistEnhancementContext context) throws NotFoundException {
 		final String local = getMappedByFromAnnotation( persistentField );
 		return local.isEmpty() ? getMappedByFromTargetEntity( persistentField, targetEntity, context ) : local;
 	}
@@ -233,7 +233,7 @@ public class PersistentAttributesHelper {
 	private static String getMappedByFromTargetEntity(
 			CtField persistentField,
 			CtClass targetEntity,
-			EnhancementContext context) throws NotFoundException {
+			JavassistEnhancementContext context) throws NotFoundException {
 		// get mappedBy value by searching in the fields of the target entity class
 		for ( CtField f : targetEntity.getDeclaredFields() ) {
 			if ( context.isPersistentField( f )

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/javassist/UnloadedCtClass.java

@@ -0,0 +1,32 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.javassist;
+
+import java.lang.annotation.Annotation;
+
+import javassist.CtClass;
+
+import org.hibernate.bytecode.enhance.spi.UnloadedClass;
+
+public class UnloadedCtClass implements UnloadedClass {
+
+	private final CtClass ctClass;
+
+	public UnloadedCtClass(CtClass ctClass) {
+		this.ctClass = ctClass;
+	}
+
+	@Override
+	public boolean hasAnnotation(Class<? extends Annotation> annotationType) {
+		return ctClass.hasAnnotation( annotationType );
+	}
+
+	@Override
+	public String getName() {
+		return ctClass.getName();
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/javassist/UnloadedCtField.java

@@ -0,0 +1,27 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.internal.javassist;
+
+import java.lang.annotation.Annotation;
+
+import javassist.CtField;
+
+import org.hibernate.bytecode.enhance.spi.UnloadedField;
+
+public class UnloadedCtField implements UnloadedField {
+
+	final CtField ctField;
+
+	public UnloadedCtField(CtField ctField) {
+		this.ctField = ctField;
+	}
+
+	@Override
+	public boolean hasAnnotation(Class<? extends Annotation> annotationType) {
+		return ctField.hasAnnotation( annotationType );
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/javassist/package-info.java

@@ -0,0 +1,11 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+
+/**
+ * package containing bytecode enhancement code (internals)
+ */
+package org.hibernate.bytecode.enhance.internal.javassist;

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/package-info.java

@@ -6,6 +6,6 @@
  */
 
 /**
- * package containing bytecode enhancement code (internals)
+ * package containing bytecode enhancement (internals)
  */
 package org.hibernate.bytecode.enhance.internal;

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/spi/DefaultEnhancementContext.java

@@ -14,9 +14,6 @@ import javax.persistence.MappedSuperclass;
 import javax.persistence.OneToMany;
 import javax.persistence.Transient;
 
-import javassist.CtClass;
-import javassist.CtField;
-
 /**
  * default implementation of EnhancementContext. May be sub-classed as needed.
  *
@@ -27,6 +24,7 @@ public class DefaultEnhancementContext implements EnhancementContext {
 	/**
 	 * @return the classloader for this class
 	 */
+	@Override
 	public ClassLoader getLoadingClassLoader() {
 		return getClass().getClassLoader();
 	}
@@ -34,77 +32,88 @@ public class DefaultEnhancementContext implements EnhancementContext {
 	/**
 	 * look for @Entity annotation
 	 */
-	public boolean isEntityClass(CtClass classDescriptor) {
+	@Override
+	public boolean isEntityClass(UnloadedClass classDescriptor) {
 		return classDescriptor.hasAnnotation( Entity.class );
 	}
 
 	/**
 	 * look for @Embeddable annotation
 	 */
-	public boolean isCompositeClass(CtClass classDescriptor) {
+	@Override
+	public boolean isCompositeClass(UnloadedClass classDescriptor) {
 		return classDescriptor.hasAnnotation( Embeddable.class );
 	}
 
 	/**
 	 * look for @MappedSuperclass annotation
 	 */
-	public boolean isMappedSuperclassClass(CtClass classDescriptor) {
+	@Override
+	public boolean isMappedSuperclassClass(UnloadedClass classDescriptor) {
 		return classDescriptor.hasAnnotation( MappedSuperclass.class );
 	}
 
 	/**
 	 * @return true
 	 */
-	public boolean doBiDirectionalAssociationManagement(CtField field) {
+	@Override
+	public boolean doBiDirectionalAssociationManagement(UnloadedField field) {
 		return true;
 	}
 
 	/**
 	 * @return true
 	 */
-	public boolean doDirtyCheckingInline(CtClass classDescriptor) {
+	@Override
+	public boolean doDirtyCheckingInline(UnloadedClass classDescriptor) {
 		return true;
 	}
 
 	/**
 	 * @return false
 	 */
-	public boolean doExtendedEnhancement(CtClass classDescriptor) {
+	@Override
+	public boolean doExtendedEnhancement(UnloadedClass classDescriptor) {
 		return false;
 	}
 
 	/**
 	 * @return true
 	 */
-	public boolean hasLazyLoadableAttributes(CtClass classDescriptor) {
+	@Override
+	public boolean hasLazyLoadableAttributes(UnloadedClass classDescriptor) {
 		return true;
 	}
 
 	/**
 	 * @return true
 	 */
-	public boolean isLazyLoadable(CtField field) {
+	@Override
+	public boolean isLazyLoadable(UnloadedField field) {
 		return true;
 	}
 
 	/**
 	 * look for @Transient annotation
 	 */
-	public boolean isPersistentField(CtField ctField) {
+	@Override
+	public boolean isPersistentField(UnloadedField ctField) {
 		return ! ctField.hasAnnotation( Transient.class );
 	}
 
 	/**
 	 * look for @OneToMany, @ManyToMany and @ElementCollection annotations
 	 */
-	public boolean isMappedCollection(CtField field) {
+	@Override
+	public boolean isMappedCollection(UnloadedField field) {
 		return field.hasAnnotation( OneToMany.class ) || field.hasAnnotation( ManyToMany.class )  || field.hasAnnotation( ElementCollection.class );
 	}
 
 	/**
 	 * keep the same order.
 	 */
-	public CtField[] order(CtField[] persistentFields) {
+	@Override
+	public UnloadedField[] order(UnloadedField[] persistentFields) {
 		return persistentFields;
 	}
 }

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/spi/EnhancementContext.java

@@ -6,9 +6,6 @@
  */
 package org.hibernate.bytecode.enhance.spi;
 
-import javassist.CtClass;
-import javassist.CtField;
-
 /**
  * The context for performing an enhancement.  Enhancement can happen in any number of ways:<ul>
  * <li>Build time, via Ant</li>
@@ -22,7 +19,6 @@ import javassist.CtField;
  * the enhancement is being performed.
  *
  * @author Steve Ebersole
- * @todo Not sure its a great idea to expose Javassist classes this way.  maybe wrap them in our own contracts?
  */
 public interface EnhancementContext {
 	/**
@@ -41,7 +37,7 @@ public interface EnhancementContext {
 	 *
 	 * @return {@code true} if the class is an entity; {@code false} otherwise.
 	 */
-	public boolean isEntityClass(CtClass classDescriptor);
+	public boolean isEntityClass(UnloadedClass classDescriptor);
 
 	/**
 	 * Does the given class name represent an embeddable/component class?
@@ -50,7 +46,7 @@ public interface EnhancementContext {
 	 *
 	 * @return {@code true} if the class is an embeddable/component; {@code false} otherwise.
 	 */
-	public boolean isCompositeClass(CtClass classDescriptor);
+	public boolean isCompositeClass(UnloadedClass classDescriptor);
 
 	/**
 	 * Does the given class name represent an MappedSuperclass class?
@@ -59,7 +55,7 @@ public interface EnhancementContext {
 	 *
 	 * @return {@code true} if the class is an mapped super class; {@code false} otherwise.
 	 */
-	public boolean isMappedSuperclassClass(CtClass classDescriptor);
+	public boolean isMappedSuperclassClass(UnloadedClass classDescriptor);
 
 	/**
 	 * Should we manage association of bi-directional persistent attributes for this field?
@@ -70,7 +66,7 @@ public interface EnhancementContext {
 	 * 			the association is managed, i.e. the associations are automatically set; {@code false} indicates that
 	 * 			the management is handled by the user.
 	 */
-	public boolean doBiDirectionalAssociationManagement(CtField field);
+	public boolean doBiDirectionalAssociationManagement(UnloadedField field);
 
 	/**
 	 * Should we in-line dirty checking for persistent attributes for this class?
@@ -80,7 +76,7 @@ public interface EnhancementContext {
 	 * @return {@code true} indicates that dirty checking should be in-lined within the entity; {@code false}
 	 *         indicates it should not.  In-lined is more easily serializable and probably more performant.
 	 */
-	public boolean doDirtyCheckingInline(CtClass classDescriptor);
+	public boolean doDirtyCheckingInline(UnloadedClass classDescriptor);
 
 	/**
 	 * Should we enhance field access to entities from this class?
@@ -90,7 +86,7 @@ public interface EnhancementContext {
 	 * @return {@code true} indicates that any direct access to fields of entities should be routed to the enhanced
 	 *         getter / setter  method.
 	 */
-	public boolean doExtendedEnhancement(CtClass classDescriptor);
+	public boolean doExtendedEnhancement(UnloadedClass classDescriptor);
 
 	/**
 	 * Does the given class define any lazy loadable attributes?
@@ -99,7 +95,7 @@ public interface EnhancementContext {
 	 *
 	 * @return true/false
 	 */
-	public boolean hasLazyLoadableAttributes(CtClass classDescriptor);
+	public boolean hasLazyLoadableAttributes(UnloadedClass classDescriptor);
 
 	// todo : may be better to invert these 2 such that the context is asked for an ordered list of persistent fields for an entity/composite
 
@@ -113,7 +109,7 @@ public interface EnhancementContext {
 	 *
 	 * @return {@code true} if the field is ; {@code false} otherwise.
 	 */
-	public boolean isPersistentField(CtField ctField);
+	public boolean isPersistentField(UnloadedField ctField);
 
 	/**
 	 * For fields which are persistent (according to {@link #isPersistentField}), determine the corresponding ordering
@@ -123,7 +119,7 @@ public interface EnhancementContext {
 	 *
 	 * @return The ordered references.
 	 */
-	public CtField[] order(CtField[] persistentFields);
+	public UnloadedField[] order(UnloadedField[] persistentFields);
 
 	/**
 	 * Determine if a field is lazy loadable.
@@ -132,12 +128,12 @@ public interface EnhancementContext {
 	 *
 	 * @return {@code true} if the field is lazy loadable; {@code false} otherwise.
 	 */
-	public boolean isLazyLoadable(CtField field);
+	public boolean isLazyLoadable(UnloadedField field);
 
 	/**
 	 * @param field the field to check
 	 *
 	 * @return {@code true} if the field is mapped
 	 */
-	public boolean isMappedCollection(CtField field);
+	public boolean isMappedCollection(UnloadedField field);
 }

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/spi/EnhancementContextWrapper.java

@@ -0,0 +1,78 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.spi;
+
+public class EnhancementContextWrapper implements EnhancementContext {
+
+	private final ClassLoader loadingClassloader;
+	private final EnhancementContext wrappedContext;
+
+	public EnhancementContextWrapper(EnhancementContext wrappedContext, ClassLoader loadingClassloader) {
+		this.wrappedContext = wrappedContext;
+		this.loadingClassloader = loadingClassloader;
+	}
+
+	@Override
+	public ClassLoader getLoadingClassLoader() {
+		return loadingClassloader;
+	}
+
+	@Override
+	public boolean isEntityClass(UnloadedClass classDescriptor) {
+		return wrappedContext.isEntityClass( classDescriptor );
+	}
+
+	@Override
+	public boolean isCompositeClass(UnloadedClass classDescriptor) {
+		return wrappedContext.isCompositeClass( classDescriptor );
+	}
+
+	@Override
+	public boolean isMappedSuperclassClass(UnloadedClass classDescriptor) {
+		return wrappedContext.isMappedSuperclassClass( classDescriptor );
+	}
+
+	@Override
+	public boolean doBiDirectionalAssociationManagement(UnloadedField field) {
+		return wrappedContext.doBiDirectionalAssociationManagement( field );
+	}
+
+	@Override
+	public boolean doDirtyCheckingInline(UnloadedClass classDescriptor) {
+		return wrappedContext.doDirtyCheckingInline( classDescriptor );
+	}
+
+	@Override
+	public boolean doExtendedEnhancement(UnloadedClass classDescriptor) {
+		return wrappedContext.doExtendedEnhancement( classDescriptor );
+	}
+
+	@Override
+	public boolean hasLazyLoadableAttributes(UnloadedClass classDescriptor) {
+		return wrappedContext.hasLazyLoadableAttributes( classDescriptor );
+	}
+
+	@Override
+	public boolean isPersistentField(UnloadedField ctField) {
+		return wrappedContext.isPersistentField( ctField );
+	}
+
+	@Override
+	public UnloadedField[] order(UnloadedField[] persistentFields) {
+		return wrappedContext.order( persistentFields );
+	}
+
+	@Override
+	public boolean isLazyLoadable(UnloadedField field) {
+		return wrappedContext.isLazyLoadable( field );
+	}
+
+	@Override
+	public boolean isMappedCollection(UnloadedField field) {
+		return wrappedContext.isMappedCollection( field );
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/spi/EnhancementException.java

@@ -14,6 +14,11 @@ import org.hibernate.HibernateException;
  * @author Steve Ebersole
  */
 public class EnhancementException extends HibernateException {
+
+	public EnhancementException(String message) {
+		super( message );
+	}
+
 	/**
 	 * Constructs an EnhancementException
 	 *

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/spi/Enhancer.java

@@ -6,31 +6,8 @@
  */
 package org.hibernate.bytecode.enhance.spi;
 
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.DataOutputStream;
+import java.io.File;
 import java.io.IOException;
-import java.io.InputStream;
-
-import javassist.ClassPool;
-import javassist.CtClass;
-import javassist.LoaderClassPath;
-
-import org.hibernate.HibernateException;
-import org.hibernate.bytecode.enhance.internal.CompositeEnhancer;
-import org.hibernate.bytecode.enhance.internal.EntityEnhancer;
-import org.hibernate.bytecode.enhance.internal.FieldWriter;
-import org.hibernate.bytecode.enhance.internal.MappedSuperclassEnhancer;
-import org.hibernate.bytecode.enhance.internal.PersistentAttributesEnhancer;
-import org.hibernate.bytecode.enhance.internal.PersistentAttributesHelper;
-import org.hibernate.engine.spi.Managed;
-import org.hibernate.engine.spi.ManagedComposite;
-import org.hibernate.engine.spi.ManagedEntity;
-import org.hibernate.engine.spi.ManagedMappedSuperclass;
-import org.hibernate.engine.spi.PersistentAttributeInterceptable;
-import org.hibernate.engine.spi.PersistentAttributeInterceptor;
-import org.hibernate.internal.CoreLogging;
-import org.hibernate.internal.CoreMessageLogger;
 
 /**
  * Class responsible for performing enhancement.
@@ -39,22 +16,7 @@ import org.hibernate.internal.CoreMessageLogger;
  * @author Jason Greene
  * @author Luis Barreiro
  */
-public class Enhancer {
-	private static final CoreMessageLogger log = CoreLogging.messageLogger( Enhancer.class );
-
-	protected final EnhancementContext enhancementContext;
-	private final ClassPool classPool;
-
-	/**
-	 * Constructs the Enhancer, using the given context.
-	 *
-	 * @param enhancementContext Describes the context in which enhancement will occur so as to give access
-	 * to contextual/environmental information.
-	 */
-	public Enhancer(EnhancementContext enhancementContext) {
-		this.enhancementContext = enhancementContext;
-		this.classPool = buildClassPool( enhancementContext );
-	}
+public interface Enhancer {
 
 	/**
 	 * Performs the enhancement.
@@ -62,140 +24,11 @@ public class Enhancer {
 	 * @param className The name of the class whose bytecode is being enhanced.
 	 * @param originalBytes The class's original (pre-enhancement) byte code
 	 *
-	 * @return The enhanced bytecode. Could be the same as the original bytecode if the original was
-	 *         already enhanced or we could not enhance it for some reason.
+	 * @return The enhanced bytecode. If the original bytes are not enhanced, null is returned.
 	 *
 	 * @throws EnhancementException Indicates a problem performing the enhancement
 	 */
-	public synchronized byte[] enhance(String className, byte[] originalBytes) throws EnhancementException {
-		try {
-			final CtClass managedCtClass = classPool.makeClassIfNew( new ByteArrayInputStream( originalBytes ) );
-			enhance( managedCtClass );
-			return getByteCode( managedCtClass );
-		}
-		catch (IOException e) {
-			log.unableToBuildEnhancementMetamodel( className );
-			return originalBytes;
-		}
-	}
+	byte[] enhance(String className, byte[] originalBytes) throws EnhancementException;
 
-	private ClassPool buildClassPool(final EnhancementContext enhancementContext) {
-		final ClassPool classPool = new ClassPool( false ) {
-			@Override
-			public ClassLoader getClassLoader() {
-				return enhancementContext.getLoadingClassLoader();
-			}
-		};
-
-		final ClassLoader loadingClassLoader = enhancementContext.getLoadingClassLoader();
-		if ( loadingClassLoader != null ) {
-			classPool.appendClassPath( new LoaderClassPath( loadingClassLoader ) );
-		}
-		return classPool;
-	}
-
-	protected CtClass loadCtClassFromClass(Class<?> aClass) {
-		String resourceName = aClass.getName().replace( '.', '/' ) + ".class";
-		InputStream resourceAsStream = aClass.getClassLoader().getResourceAsStream( resourceName );
-		try {
-			return classPool.makeClass( resourceAsStream );
-		}
-		catch (IOException e) {
-			throw new EnhancementException( "Could not prepare Javassist ClassPool", e );
-		}
-		finally {
-			try {
-				resourceAsStream.close();
-			}
-			catch (IOException ioe) {
-				log.debugf( "An error occurs closing InputStream for class [%s]", aClass.getName() );
-			}
-		}
-	}
-
-	private void enhance(CtClass managedCtClass) {
-		// can't effectively enhance interfaces
-		if ( managedCtClass.isInterface() ) {
-			log.debugf( "Skipping enhancement of [%s]: it's an interface!", managedCtClass.getName() );
-			return;
-		}
-		// skip already enhanced classes
-		if ( alreadyEnhanced( managedCtClass ) ) {
-			log.debugf( "Skipping enhancement of [%s]: already enhanced", managedCtClass.getName() );
-			return;
-		}
-
-		if ( enhancementContext.isEntityClass( managedCtClass ) ) {
-			log.infof( "Enhancing [%s] as Entity", managedCtClass.getName() );
-			new EntityEnhancer( enhancementContext ).enhance( managedCtClass );
-		}
-		else if ( enhancementContext.isCompositeClass( managedCtClass ) ) {
-			log.infof( "Enhancing [%s] as Composite", managedCtClass.getName() );
-			new CompositeEnhancer( enhancementContext ).enhance( managedCtClass );
-		}
-		else if ( enhancementContext.isMappedSuperclassClass( managedCtClass ) ) {
-			log.infof( "Enhancing [%s] as MappedSuperclass", managedCtClass.getName() );
-			new MappedSuperclassEnhancer( enhancementContext ).enhance( managedCtClass );
-		}
-		else if ( enhancementContext.doExtendedEnhancement( managedCtClass ) ) {
-			log.infof( "Extended enhancement of [%s]", managedCtClass.getName() );
-			new PersistentAttributesEnhancer( enhancementContext ).extendedEnhancement( managedCtClass );
-		}
-		else {
-			log.debugf( "Skipping enhancement of [%s]: not entity or composite", managedCtClass.getName() );
-		}
-	}
-
-	private boolean alreadyEnhanced(CtClass managedCtClass) {
-		if ( !PersistentAttributesHelper.isAssignable( managedCtClass, Managed.class.getName() ) ) {
-			return false;
-		}
-		// HHH-10977 - When a mapped superclass gets enhanced before a subclassing entity, the entity does not get enhanced, but it implements the Managed interface
-		return enhancementContext.isEntityClass( managedCtClass ) && PersistentAttributesHelper.isAssignable( managedCtClass, ManagedEntity.class.getName() )
-				|| enhancementContext.isCompositeClass( managedCtClass ) && PersistentAttributesHelper.isAssignable( managedCtClass, ManagedComposite.class.getName() )
-				|| enhancementContext.isMappedSuperclassClass( managedCtClass ) && PersistentAttributesHelper.isAssignable( managedCtClass, ManagedMappedSuperclass.class.getName() );
-	}
-
-	private byte[] getByteCode(CtClass managedCtClass) {
-		final ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
-		final DataOutputStream out = new DataOutputStream( byteStream );
-		try {
-			managedCtClass.toBytecode( out );
-			return byteStream.toByteArray();
-		}
-		catch (Exception e) {
-			log.unableToTransformClass( e.getMessage() );
-			throw new HibernateException( "Unable to transform class: " + e.getMessage() );
-		}
-		finally {
-			try {
-				out.close();
-			}
-			catch (IOException ignored) {
-			}
-		}
-	}
-
-	protected void addInterceptorHandling(CtClass managedCtClass) {
-		// interceptor handling is only needed if class has lazy-loadable attributes
-		if ( !enhancementContext.hasLazyLoadableAttributes( managedCtClass ) ) {
-			return;
-		}
-		log.debugf( "Weaving in PersistentAttributeInterceptable implementation on [%s]", managedCtClass.getName() );
-
-		managedCtClass.addInterface( loadCtClassFromClass( PersistentAttributeInterceptable.class ) );
-
-		FieldWriter.addFieldWithGetterAndSetter( managedCtClass, loadCtClassFromClass( PersistentAttributeInterceptor.class ),
-				EnhancerConstants.INTERCEPTOR_FIELD_NAME,
-				EnhancerConstants.INTERCEPTOR_GETTER_NAME,
-				EnhancerConstants.INTERCEPTOR_SETTER_NAME );
-	}
-
-	/**
-	 * @deprecated Should use enhance(String, byte[]) and a proper EnhancementContext
-	 */
-	@Deprecated
-	public byte[] enhanceComposite(String className, byte[] originalBytes) throws EnhancementException {
-		return enhance( className, originalBytes );
-	}
+	byte[] enhance(File javaClassFile) throws EnhancementException, IOException;
 }

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/spi/UnloadedClass.java

@@ -0,0 +1,16 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.spi;
+
+import java.lang.annotation.Annotation;
+
+public interface UnloadedClass {
+
+	boolean hasAnnotation(Class<? extends Annotation> annotationType);
+
+	String getName();
+}

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/spi/UnloadedField.java

@@ -0,0 +1,14 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.spi;
+
+import java.lang.annotation.Annotation;
+
+public interface UnloadedField {
+
+	boolean hasAnnotation(Class<? extends Annotation> annotationType);
+}

hibernate-core/src/main/java/org/hibernate/bytecode/internal/bytebuddy/BasicProxyFactoryImpl.java

@@ -0,0 +1,89 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.internal.bytebuddy;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+import org.hibernate.AssertionFailure;
+import org.hibernate.HibernateException;
+import org.hibernate.bytecode.spi.BasicProxyFactory;
+import org.hibernate.proxy.ProxyConfiguration;
+
+import net.bytebuddy.ByteBuddy;
+import net.bytebuddy.description.modifier.Visibility;
+import net.bytebuddy.dynamic.scaffold.TypeValidation;
+import net.bytebuddy.implementation.FieldAccessor;
+import net.bytebuddy.implementation.MethodDelegation;
+import net.bytebuddy.implementation.auxiliary.AuxiliaryType;
+import net.bytebuddy.implementation.bytecode.assign.Assigner;
+import net.bytebuddy.matcher.ElementMatchers;
+
+public class BasicProxyFactoryImpl implements BasicProxyFactory {
+
+	private static final ConcurrentMap<Set<Class>, Class> CACHE = new ConcurrentHashMap<Set<Class>, Class>();
+
+	private static final Class[] NO_INTERFACES = new Class[0];
+
+	private final Class proxyClass;
+
+	public BasicProxyFactoryImpl(Class superClass, Class[] interfaces) {
+		if ( superClass == null && ( interfaces == null || interfaces.length < 1 ) ) {
+			throw new AssertionFailure( "attempting to build proxy without any superclass or interfaces" );
+		}
+
+		Set<Class> key = new HashSet<Class>();
+		if ( superClass != null ) {
+			key.add( superClass );
+		}
+		if ( interfaces != null && interfaces.length > 0 ) {
+			key.addAll( Arrays.asList( interfaces ) );
+		}
+
+		Class proxyClass = CACHE.get( key );
+
+		if ( proxyClass == null ) {
+			proxyClass = new ByteBuddy()
+					.with( TypeValidation.DISABLED )
+					.with( new AuxiliaryType.NamingStrategy.SuffixingRandom( "HibernateBasicProxy" ) )
+					.subclass( superClass == null ? Object.class : superClass )
+					.implement( interfaces == null ? NO_INTERFACES : interfaces )
+					.defineField( ProxyConfiguration.INTERCEPTOR_FIELD_NAME, ProxyConfiguration.Interceptor.class, Visibility.PRIVATE )
+					.method( ElementMatchers.isVirtual().and( ElementMatchers.not( ElementMatchers.isFinalizer() ) ) )
+					.intercept( MethodDelegation.toField( ProxyConfiguration.INTERCEPTOR_FIELD_NAME ) )
+					.implement( ProxyConfiguration.class )
+					.intercept( FieldAccessor.ofField( ProxyConfiguration.INTERCEPTOR_FIELD_NAME ).withAssigner( Assigner.DEFAULT, Assigner.Typing.DYNAMIC ) )
+					.make()
+					.load( BasicProxyFactory.class.getClassLoader() )
+					.getLoaded();
+			Class previousProxy = CACHE.putIfAbsent( key, proxyClass );
+			if ( previousProxy != null ) {
+				proxyClass = previousProxy;
+			}
+		}
+
+		this.proxyClass = proxyClass;
+	}
+
+	public Object getProxy() {
+		try {
+			final ProxyConfiguration proxy = (ProxyConfiguration) proxyClass.newInstance();
+			proxy.$$_hibernate_set_interceptor( new PassThroughInterceptor( proxy, proxyClass.getName() ) );
+			return proxy;
+		}
+		catch (Throwable t) {
+			throw new HibernateException( "Unable to instantiate proxy instance" );
+		}
+	}
+
+	public boolean isInstance(Object object) {
+		return proxyClass.isInstance( object );
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/internal/bytebuddy/BulkAccessorException.java

@@ -0,0 +1,34 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.internal.bytebuddy;
+
+import org.hibernate.HibernateException;
+
+public class BulkAccessorException extends HibernateException {
+	private final int index;
+
+	public BulkAccessorException(String message) {
+		this( message, -1 );
+	}
+
+	public BulkAccessorException(String message, int index) {
+		this( message, index, null );
+	}
+
+	public BulkAccessorException(String message, Exception cause) {
+		this( message, -1, cause );
+	}
+
+	public BulkAccessorException(String message, int index, Exception cause) {
+		super( message + " : @" + index, cause );
+		this.index = index;
+	}
+
+	public int getIndex() {
+		return this.index;
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/internal/bytebuddy/BytecodeProviderImpl.java

@@ -0,0 +1,285 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.internal.bytebuddy;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+import org.hibernate.HibernateException;
+import org.hibernate.bytecode.enhance.internal.bytebuddy.EnhancerImpl;
+import org.hibernate.bytecode.enhance.spi.EnhancementContext;
+import org.hibernate.bytecode.enhance.spi.Enhancer;
+import org.hibernate.bytecode.spi.BytecodeProvider;
+import org.hibernate.bytecode.spi.ProxyFactoryFactory;
+import org.hibernate.bytecode.spi.ReflectionOptimizer;
+
+import net.bytebuddy.ByteBuddy;
+import net.bytebuddy.NamingStrategy;
+import net.bytebuddy.description.method.MethodDescription;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.dynamic.scaffold.TypeValidation;
+import net.bytebuddy.implementation.Implementation;
+import net.bytebuddy.implementation.MethodCall;
+import net.bytebuddy.implementation.bytecode.ByteCodeAppender;
+import net.bytebuddy.implementation.bytecode.assign.Assigner;
+import net.bytebuddy.implementation.bytecode.assign.primitive.PrimitiveBoxingDelegate;
+import net.bytebuddy.implementation.bytecode.assign.primitive.PrimitiveUnboxingDelegate;
+import net.bytebuddy.implementation.bytecode.assign.reference.ReferenceTypeAwareAssigner;
+import net.bytebuddy.jar.asm.MethodVisitor;
+import net.bytebuddy.jar.asm.Opcodes;
+import net.bytebuddy.jar.asm.Type;
+import net.bytebuddy.matcher.ElementMatchers;
+
+public class BytecodeProviderImpl implements BytecodeProvider {
+
+	private final ConcurrentMap<Class, Class> FAST_CLASSES = new ConcurrentHashMap<Class, Class>();
+	private final ConcurrentMap<Class, Class> BULK_ACCESSORS = new ConcurrentHashMap<Class, Class>();
+
+	@Override
+	public ProxyFactoryFactory getProxyFactoryFactory() {
+		return new ProxyFactoryFactoryImpl();
+	}
+
+	@Override
+	public ReflectionOptimizer getReflectionOptimizer(
+			final Class clazz,
+			final String[] getterNames,
+			final String[] setterNames,
+			final Class[] types) {
+		final Method[] getters = new Method[getterNames.length];
+		final Method[] setters = new Method[setterNames.length];
+		findAccessors( clazz, getterNames, setterNames, types, getters, setters );
+		final Constructor<?> constructor = findConstructor( clazz );
+
+		Class fastClass = FAST_CLASSES.get( clazz );
+
+		if ( fastClass == null ) {
+			fastClass = new ByteBuddy()
+					.with( TypeValidation.DISABLED )
+					.with( new NamingStrategy.SuffixingRandom( "HibernateInstantiator" ) )
+					.subclass( ReflectionOptimizer.InstantiationOptimizer.class )
+					.method( ElementMatchers.named( "newInstance" ) )
+					.intercept( MethodCall.construct( constructor ) )
+					.make()
+					.load( clazz.getClassLoader() )
+					.getLoaded();
+		}
+
+		Class previousFastClass = FAST_CLASSES.putIfAbsent( clazz, fastClass );
+		if ( previousFastClass != null ) {
+			fastClass = previousFastClass;
+		}
+
+		Class bulkAccessor = BULK_ACCESSORS.get( clazz );
+
+		if ( bulkAccessor == null ) {
+			bulkAccessor = new ByteBuddy()
+					.with( TypeValidation.DISABLED )
+					.with( new NamingStrategy.SuffixingRandom( "HibernateAccessOptimizer" ) )
+					.subclass( ReflectionOptimizer.AccessOptimizer.class )
+					.method( ElementMatchers.named( "getPropertyValues" ) )
+					.intercept( new Implementation.Simple( new GetPropertyValues( clazz, getters ) ) )
+					.method( ElementMatchers.named( "setPropertyValues" ) )
+					.intercept( new Implementation.Simple( new SetPropertyValues( clazz, setters ) ) )
+					.method( ElementMatchers.named( "getPropertyNames" ) )
+					.intercept( MethodCall.call( new CloningPropertyCall( getterNames ) ) )
+					.make()
+					.load( clazz.getClassLoader() )
+					.getLoaded();
+		}
+
+
+		Class previousBulkAccessor = BULK_ACCESSORS.putIfAbsent( clazz, fastClass );
+		if ( previousBulkAccessor != null ) {
+			bulkAccessor = previousBulkAccessor;
+		}
+
+		try {
+			return new ReflectionOptimizerImpl(
+					(ReflectionOptimizer.InstantiationOptimizer) fastClass.newInstance(),
+					(ReflectionOptimizer.AccessOptimizer) bulkAccessor.newInstance()
+			);
+		}
+		catch (Exception exception) {
+			throw new HibernateException( exception );
+		}
+	}
+
+	private static class GetPropertyValues implements ByteCodeAppender {
+
+		private final Class clazz;
+
+		private final Method[] getters;
+
+		public GetPropertyValues(Class clazz, Method[] getters) {
+			this.clazz = clazz;
+			this.getters = getters;
+		}
+
+		@Override
+		public Size apply(
+				MethodVisitor methodVisitor,
+				Implementation.Context implementationContext,
+				MethodDescription instrumentedMethod) {
+			methodVisitor.visitLdcInsn( getters.length );
+			methodVisitor.visitTypeInsn( Opcodes.ANEWARRAY, Type.getInternalName( Object.class ) );
+			int index = 0;
+			for ( Method getter : getters ) {
+				methodVisitor.visitInsn( Opcodes.DUP );
+				methodVisitor.visitLdcInsn( index++ );
+				methodVisitor.visitVarInsn( Opcodes.ALOAD, 1 );
+				methodVisitor.visitTypeInsn( Opcodes.CHECKCAST, Type.getInternalName( clazz ) );
+				methodVisitor.visitMethodInsn(
+						Opcodes.INVOKEVIRTUAL,
+						Type.getInternalName( clazz ),
+						getter.getName(),
+						Type.getMethodDescriptor( getter ),
+						false
+				);
+				if ( getter.getReturnType().isPrimitive() ) {
+					PrimitiveBoxingDelegate.forPrimitive( new TypeDescription.ForLoadedType( getter.getReturnType() ) )
+							.assignBoxedTo(
+									TypeDescription.Generic.OBJECT,
+									ReferenceTypeAwareAssigner.INSTANCE,
+									Assigner.Typing.STATIC
+							)
+							.apply( methodVisitor, implementationContext );
+				}
+				methodVisitor.visitInsn( Opcodes.AASTORE );
+			}
+			methodVisitor.visitInsn( Opcodes.ARETURN );
+			return new Size( 6, instrumentedMethod.getStackSize() );
+		}
+	}
+
+	private static class SetPropertyValues implements ByteCodeAppender {
+
+		private final Class clazz;
+
+		private final Method[] setters;
+
+		public SetPropertyValues(Class clazz, Method[] setters) {
+			this.clazz = clazz;
+			this.setters = setters;
+		}
+
+		@Override
+		public Size apply(
+				MethodVisitor methodVisitor,
+				Implementation.Context implementationContext,
+				MethodDescription instrumentedMethod) {
+			int index = 0;
+			for ( Method setter : setters ) {
+				methodVisitor.visitVarInsn( Opcodes.ALOAD, 1 );
+				methodVisitor.visitTypeInsn( Opcodes.CHECKCAST, Type.getInternalName( clazz ) );
+				methodVisitor.visitVarInsn( Opcodes.ALOAD, 2 );
+				methodVisitor.visitLdcInsn( index++ );
+				methodVisitor.visitInsn( Opcodes.AALOAD );
+				if ( setter.getParameterTypes()[0].isPrimitive() ) {
+					PrimitiveUnboxingDelegate.forReferenceType( TypeDescription.Generic.OBJECT )
+							.assignUnboxedTo(
+									new TypeDescription.Generic.OfNonGenericType.ForLoadedType( setter.getParameterTypes()[0] ),
+									ReferenceTypeAwareAssigner.INSTANCE,
+									Assigner.Typing.DYNAMIC
+							)
+							.apply( methodVisitor, implementationContext );
+				}
+				else {
+					methodVisitor.visitTypeInsn( Opcodes.CHECKCAST, Type.getInternalName( setter.getParameterTypes()[0] ) );
+				}
+				methodVisitor.visitMethodInsn(
+						Opcodes.INVOKEVIRTUAL,
+						Type.getInternalName( clazz ),
+						setter.getName(),
+						Type.getMethodDescriptor( setter ),
+						false
+				);
+			}
+			methodVisitor.visitInsn( Opcodes.RETURN );
+			return new Size( 4, instrumentedMethod.getStackSize() );
+		}
+	}
+
+	private static void findAccessors(
+			Class clazz,
+			String[] getterNames,
+			String[] setterNames,
+			Class[] types,
+			Method[] getters,
+			Method[] setters) {
+		final int length = types.length;
+		if ( setterNames.length != length || getterNames.length != length ) {
+			throw new BulkAccessorException( "bad number of accessors" );
+		}
+
+		final Class[] getParam = new Class[0];
+		final Class[] setParam = new Class[1];
+		for ( int i = 0; i < length; i++ ) {
+			if ( getterNames[i] != null ) {
+				final Method getter = findAccessor( clazz, getterNames[i], getParam, i );
+				if ( getter.getReturnType() != types[i] ) {
+					throw new BulkAccessorException( "wrong return type: " + getterNames[i], i );
+				}
+
+				getters[i] = getter;
+			}
+
+			if ( setterNames[i] != null ) {
+				setParam[0] = types[i];
+				setters[i] = findAccessor( clazz, setterNames[i], setParam, i );
+			}
+		}
+	}
+
+	@SuppressWarnings("unchecked")
+	private static Method findAccessor(Class clazz, String name, Class[] params, int index)
+			throws BulkAccessorException {
+		try {
+			final Method method = clazz.getDeclaredMethod( name, params );
+			if ( Modifier.isPrivate( method.getModifiers() ) ) {
+				throw new BulkAccessorException( "private property", index );
+			}
+
+			return method;
+		}
+		catch (NoSuchMethodException e) {
+			throw new BulkAccessorException( "cannot find an accessor", index );
+		}
+	}
+
+	private static Constructor<?> findConstructor(Class clazz) {
+		try {
+			return clazz.getDeclaredConstructor();
+		}
+		catch (NoSuchMethodException e) {
+			throw new HibernateException( e );
+		}
+	}
+
+	public static class CloningPropertyCall implements Callable<String[]> {
+
+		private final String[] propertyNames;
+
+		private CloningPropertyCall(String[] propertyNames) {
+			this.propertyNames = propertyNames;
+		}
+
+		@Override
+		public String[] call() {
+			return propertyNames.clone();
+		}
+	}
+
+	@Override
+	public Enhancer getEnhancer(EnhancementContext enhancementContext) {
+		return new EnhancerImpl( enhancementContext );
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/internal/bytebuddy/PassThroughInterceptor.java

@@ -0,0 +1,67 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.internal.bytebuddy;
+
+import java.lang.reflect.Method;
+import java.util.HashMap;
+
+import org.hibernate.proxy.ProxyConfiguration;
+
+import net.bytebuddy.implementation.bind.annotation.AllArguments;
+import net.bytebuddy.implementation.bind.annotation.Origin;
+import net.bytebuddy.implementation.bind.annotation.RuntimeType;
+import net.bytebuddy.implementation.bind.annotation.This;
+
+public class PassThroughInterceptor implements ProxyConfiguration.Interceptor {
+
+	private HashMap data = new HashMap();
+	private final Object proxiedObject;
+	private final String proxiedClassName;
+
+	public PassThroughInterceptor(Object proxiedObject, String proxiedClassName) {
+		this.proxiedObject = proxiedObject;
+		this.proxiedClassName = proxiedClassName;
+	}
+
+	@SuppressWarnings("unchecked")
+	@Override
+	public Object intercept(Object instance, Method method, Object[] arguments) throws Exception {
+		final String name = method.getName();
+		if ( "toString".equals( name ) ) {
+			return proxiedClassName + "@" + System.identityHashCode( instance );
+		}
+		else if ( "equals".equals( name ) ) {
+			return proxiedObject == instance;
+		}
+		else if ( "hashCode".equals( name ) ) {
+			return System.identityHashCode( instance );
+		}
+
+		final boolean hasGetterSignature = method.getParameterCount() == 0
+				&& method.getReturnType() != null;
+		final boolean hasSetterSignature = method.getParameterCount() == 1
+				&& ( method.getReturnType() == null || method.getReturnType() == void.class );
+
+		if ( name.startsWith( "get" ) && hasGetterSignature ) {
+			final String propName = name.substring( 3 );
+			return data.get( propName );
+		}
+		else if ( name.startsWith( "is" ) && hasGetterSignature ) {
+			final String propName = name.substring( 2 );
+			return data.get( propName );
+		}
+		else if ( name.startsWith( "set" ) && hasSetterSignature ) {
+			final String propName = name.substring( 3 );
+			data.put( propName, arguments[0] );
+			return null;
+		}
+		else {
+			// todo : what else to do here?
+			return null;
+		}
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/internal/bytebuddy/ProxyFactoryFactoryImpl.java

@@ -0,0 +1,26 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.internal.bytebuddy;
+
+import org.hibernate.bytecode.spi.BasicProxyFactory;
+import org.hibernate.bytecode.spi.ProxyFactoryFactory;
+import org.hibernate.engine.spi.SessionFactoryImplementor;
+import org.hibernate.proxy.ProxyFactory;
+import org.hibernate.proxy.pojo.bytebuddy.ByteBuddyProxyFactory;
+
+public class ProxyFactoryFactoryImpl implements ProxyFactoryFactory {
+
+	@Override
+	public ProxyFactory buildProxyFactory(SessionFactoryImplementor sessionFactory) {
+		return new ByteBuddyProxyFactory();
+	}
+
+	@Override
+	public BasicProxyFactory buildBasicProxyFactory(Class superClass, Class[] interfaces) {
+		return new BasicProxyFactoryImpl( superClass, interfaces );
+	}
+}

hibernate-core/src/main/java/org/hibernate/bytecode/internal/bytebuddy/ReflectionOptimizerImpl.java

@@ -0,0 +1,34 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.internal.bytebuddy;
+
+import java.io.Serializable;
+
+import org.hibernate.bytecode.spi.ReflectionOptimizer;
+
+public class ReflectionOptimizerImpl implements ReflectionOptimizer, Serializable {
+	private final InstantiationOptimizer instantiationOptimizer;
+	private final AccessOptimizer accessOptimizer;
+
+	public ReflectionOptimizerImpl(
+			InstantiationOptimizer instantiationOptimizer,
+			AccessOptimizer accessOptimizer) {
+		this.instantiationOptimizer = instantiationOptimizer;
+		this.accessOptimizer = accessOptimizer;
+	}
+
+	@Override
+	public InstantiationOptimizer getInstantiationOptimizer() {
+		return instantiationOptimizer;
+	}
+
+	@Override
+	public AccessOptimizer getAccessOptimizer() {
+		return accessOptimizer;
+	}
+
+}

hibernate-core/src/main/java/org/hibernate/bytecode/internal/bytebuddy/package-info.java

@@ -0,0 +1,11 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+
+/**
+ * Byte Buddy support internals
+ */
+package org.hibernate.bytecode.internal.bytebuddy;

hibernate-core/src/main/java/org/hibernate/bytecode/internal/javassist/BytecodeProviderImpl.java

@@ -8,6 +8,9 @@ package org.hibernate.bytecode.internal.javassist;
 
 import java.lang.reflect.Modifier;
 
+import org.hibernate.bytecode.enhance.internal.javassist.EnhancerImpl;
+import org.hibernate.bytecode.enhance.spi.EnhancementContext;
+import org.hibernate.bytecode.enhance.spi.Enhancer;
 import org.hibernate.bytecode.spi.BytecodeProvider;
 import org.hibernate.bytecode.spi.ProxyFactoryFactory;
 import org.hibernate.bytecode.spi.ReflectionOptimizer;
@@ -92,4 +95,8 @@ public class BytecodeProviderImpl implements BytecodeProvider {
 		return null;
 	}
 
+	@Override
+	public Enhancer getEnhancer(EnhancementContext enhancementContext) {
+		return new EnhancerImpl( enhancementContext );
+	}
 }

hibernate-core/src/main/java/org/hibernate/bytecode/spi/BytecodeProvider.java

@@ -6,6 +6,9 @@
  */
 package org.hibernate.bytecode.spi;
 
+import org.hibernate.bytecode.enhance.spi.EnhancementContext;
+import org.hibernate.bytecode.enhance.spi.Enhancer;
+
 /**
  * Contract for providers of bytecode services to Hibernate.
  * <p/>
@@ -36,4 +39,13 @@ public interface BytecodeProvider {
 	 * @return The reflection optimization delegate.
 	 */
 	ReflectionOptimizer getReflectionOptimizer(Class clazz, String[] getterNames, String[] setterNames, Class[] types);
+
+	/**
+	 * Returns a byte code enhancer that implements the enhancements described in the supplied enhancement context.
+	 *
+	 * @param enhancementContext The enhancement context that describes the enhancements to apply.
+	 *
+	 * @return An enhancer to perform byte code manipulations.
+	 */
+	Enhancer getEnhancer(EnhancementContext enhancementContext);
 }

hibernate-core/src/main/java/org/hibernate/bytecode/spi/InstrumentedClassLoader.java

@@ -48,7 +48,7 @@ public class InstrumentedClassLoader extends ClassLoader {
 		try {
 			final byte[] originalBytecode = ByteCodeHelper.readByteCode( is );
 			final byte[] transformedBytecode = classTransformer.transform( getParent(), name, null, null, originalBytecode );
-			if ( originalBytecode == transformedBytecode ) {
+			if ( transformedBytecode == null ) {
 				// no transformations took place, so handle it as we would a
 				// non-instrumented class
 				return getParent().loadClass( name );
@@ -57,7 +57,7 @@ public class InstrumentedClassLoader extends ClassLoader {
 				return defineClass( name, transformedBytecode, 0, transformedBytecode.length );
 			}
 		}
-		catch( Throwable t ) {
+		catch ( Throwable t ) {
 			throw new ClassNotFoundException( name + " not found", t );
 		}
 	}

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

@@ -314,17 +314,20 @@ public final class Environment implements AvailableSettings {
 	}
 
 	public static BytecodeProvider buildBytecodeProvider(Properties properties) {
-		String provider = ConfigurationHelper.getString( BYTECODE_PROVIDER, properties, "javassist" );
+		String provider = ConfigurationHelper.getString( BYTECODE_PROVIDER, properties, "bytebuddy" );
 		LOG.bytecodeProvider( provider );
 		return buildBytecodeProvider( provider );
 	}
 
 	private static BytecodeProvider buildBytecodeProvider(String providerName) {
+		if ( "bytebuddy".equals( providerName ) ) {
+			return new org.hibernate.bytecode.internal.bytebuddy.BytecodeProviderImpl();
+		}
 		if ( "javassist".equals( providerName ) ) {
 			return new org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl();
 		}
 
 		LOG.unknownBytecodeProvider( providerName );
-		return new org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl();
+		return new org.hibernate.bytecode.internal.bytebuddy.BytecodeProviderImpl();
 	}
 }

hibernate-core/src/main/java/org/hibernate/engine/spi/ExtendedSelfDirtinessTracker.java

@@ -0,0 +1,28 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.engine.spi;
+
+import org.hibernate.bytecode.enhance.internal.tracker.DirtyTracker;
+import org.hibernate.bytecode.enhance.spi.interceptor.LazyAttributeLoadingInterceptor;
+import org.hibernate.engine.spi.SelfDirtinessTracker;
+
+/**
+ * A self dirtiness tracker that declares additional methods that are intended for internal communication. This
+ * interface can be implemented optionally instead of the plain {@link SelfDirtinessTracker}.
+ */
+public interface ExtendedSelfDirtinessTracker extends SelfDirtinessTracker {
+
+	String REMOVE_DIRTY_FIELDS_NAME = "$$_hibernate_removeDirtyFields";
+
+	void $$_hibernate_getCollectionFieldDirtyNames(DirtyTracker dirtyTracker);
+
+	boolean $$_hibernate_areCollectionFieldsDirty();
+
+	void $$_hibernate_clearDirtyCollectionNames();
+
+	void $$_hibernate_removeDirtyFields(LazyAttributeLoadingInterceptor lazyInterceptor);
+}

hibernate-core/src/main/java/org/hibernate/internal/CoreMessageLogger.java

@@ -467,8 +467,8 @@ public interface CoreMessageLogger extends BasicLogger {
 			String old,
 			String name);
 
-	@Message(value = "Javassist Enhancement failed: %s", id = 142)
-	String javassistEnhancementFailed(String entityName);
+	@Message(value = "Bytecode enhancement failed: %s", id = 142)
+	String bytecodeEnhancementFailed(String entityName);
 
 	@LogMessage(level = WARN)
 	@Message(value = "%s = false breaks the EJB3 specification", id = 144)
@@ -1327,7 +1327,7 @@ public interface CoreMessageLogger extends BasicLogger {
 	void unexpectedRowCounts();
 
 	@LogMessage(level = WARN)
-	@Message(value = "unrecognized bytecode provider [%s], using javassist by default", id = 382)
+	@Message(value = "unrecognized bytecode provider [%s], using 'bytebuddy' by default", id = 382)
 	void unknownBytecodeProvider(String providerName);
 
 	@LogMessage(level = WARN)

hibernate-core/src/main/java/org/hibernate/jpa/boot/internal/EntityManagerFactoryBuilderImpl.java

@@ -51,6 +51,8 @@ import org.hibernate.boot.spi.MetadataImplementor;
 import org.hibernate.boot.spi.SessionFactoryBuilderImplementor;
 import org.hibernate.bytecode.enhance.spi.DefaultEnhancementContext;
 import org.hibernate.bytecode.enhance.spi.EnhancementContext;
+import org.hibernate.bytecode.enhance.spi.UnloadedClass;
+import org.hibernate.bytecode.enhance.spi.UnloadedField;
 import org.hibernate.cfg.AttributeConverterDefinition;
 import org.hibernate.cfg.Environment;
 import org.hibernate.cfg.beanvalidation.BeanValidationIntegrator;
@@ -276,39 +278,39 @@ public class EntityManagerFactoryBuilderImpl implements EntityManagerFactoryBuil
 		return new DefaultEnhancementContext() {
 
 			@Override
-			public boolean isEntityClass(CtClass classDescriptor) {
+			public boolean isEntityClass(UnloadedClass classDescriptor) {
 				return managedResources.getAnnotatedClassNames().contains( classDescriptor.getName() )
 						&& super.isEntityClass( classDescriptor );
 			}
 
 			@Override
-			public boolean isCompositeClass(CtClass classDescriptor) {
+			public boolean isCompositeClass(UnloadedClass classDescriptor) {
 				return managedResources.getAnnotatedClassNames().contains( classDescriptor.getName() )
 						&& super.isCompositeClass( classDescriptor );
 			}
 
 			@Override
-			public boolean doBiDirectionalAssociationManagement(CtField field) {
+			public boolean doBiDirectionalAssociationManagement(UnloadedField field) {
 				return associationManagementEnabled;
 			}
 
 			@Override
-			public boolean doDirtyCheckingInline(CtClass classDescriptor) {
+			public boolean doDirtyCheckingInline(UnloadedClass classDescriptor) {
 				return dirtyTrackingEnabled;
 			}
 
 			@Override
-			public boolean hasLazyLoadableAttributes(CtClass classDescriptor) {
+			public boolean hasLazyLoadableAttributes(UnloadedClass classDescriptor) {
 				return lazyInitializationEnabled;
 			}
 
 			@Override
-			public boolean isLazyLoadable(CtField field) {
+			public boolean isLazyLoadable(UnloadedField field) {
 				return lazyInitializationEnabled;
 			}
 
 			@Override
-			public boolean doExtendedEnhancement(CtClass classDescriptor) {
+			public boolean doExtendedEnhancement(UnloadedClass classDescriptor) {
 				// doesn't make any sense to have extended enhancement enabled at runtime. we only enhance entities anyway.
 				return false;
 			}

hibernate-core/src/main/java/org/hibernate/jpa/internal/enhance/EnhancingClassTransformerImpl.java

@@ -9,12 +9,11 @@ package org.hibernate.jpa.internal.enhance;
 import java.lang.instrument.IllegalClassFormatException;
 import java.security.ProtectionDomain;
 
-import javassist.CtClass;
-import javassist.CtField;
-
 import org.hibernate.bytecode.enhance.spi.EnhancementContext;
+import org.hibernate.bytecode.enhance.spi.EnhancementContextWrapper;
 import org.hibernate.bytecode.enhance.spi.Enhancer;
 import org.hibernate.bytecode.spi.ClassTransformer;
+import org.hibernate.cfg.Environment;
 
 /**
  * @author Steve Ebersole
@@ -41,7 +40,7 @@ public class EnhancingClassTransformerImpl implements ClassTransformer {
 		// It also assumed that all calls come from the same class loader, which is fair, but this makes it more robust.
 
 		try {
-			Enhancer enhancer = new Enhancer( new EnhancementContextWrapper( enhancementContext, loader ) );
+			Enhancer enhancer = Environment.getBytecodeProvider().getEnhancer( new EnhancementContextWrapper( enhancementContext, loader ) );
 			return enhancer.enhance( className, classfileBuffer );
 		}
 		catch (final Exception e) {
@@ -54,76 +53,4 @@ public class EnhancingClassTransformerImpl implements ClassTransformer {
 		}
 	}
 
-	// Wrapper for a EnhancementContext that allows to set the right classloader.
-	private class EnhancementContextWrapper implements EnhancementContext {
-
-		private final ClassLoader loadingClassloader;
-		private final EnhancementContext wrappedContext;
-
-		private EnhancementContextWrapper(EnhancementContext wrappedContext, ClassLoader loadingClassloader) {
-			this.wrappedContext = wrappedContext;
-			this.loadingClassloader = loadingClassloader;
-		}
-
-		@Override
-		public ClassLoader getLoadingClassLoader() {
-			return loadingClassloader;
-		}
-
-		@Override
-		public boolean isEntityClass(CtClass classDescriptor) {
-			return wrappedContext.isEntityClass( classDescriptor );
-		}
-
-		@Override
-		public boolean isCompositeClass(CtClass classDescriptor) {
-			return wrappedContext.isCompositeClass( classDescriptor );
-		}
-
-		@Override
-		public boolean isMappedSuperclassClass(CtClass classDescriptor) {
-			return wrappedContext.isMappedSuperclassClass( classDescriptor );
-		}
-
-		@Override
-		public boolean doBiDirectionalAssociationManagement(CtField field) {
-			return wrappedContext.doBiDirectionalAssociationManagement( field );
-		}
-
-		@Override
-		public boolean doDirtyCheckingInline(CtClass classDescriptor) {
-			return wrappedContext.doDirtyCheckingInline( classDescriptor );
-		}
-
-		@Override
-		public boolean doExtendedEnhancement(CtClass classDescriptor) {
-			return wrappedContext.doExtendedEnhancement( classDescriptor );
-		}
-
-		@Override
-		public boolean hasLazyLoadableAttributes(CtClass classDescriptor) {
-			return wrappedContext.hasLazyLoadableAttributes( classDescriptor );
-		}
-
-		@Override
-		public boolean isPersistentField(CtField ctField) {
-			return wrappedContext.isPersistentField( ctField );
-		}
-
-		@Override
-		public CtField[] order(CtField[] persistentFields) {
-			return wrappedContext.order( persistentFields );
-		}
-
-		@Override
-		public boolean isLazyLoadable(CtField field) {
-			return wrappedContext.isLazyLoadable( field );
-		}
-
-		@Override
-		public boolean isMappedCollection(CtField field) {
-			return wrappedContext.isMappedCollection( field );
-		}
-	}
-
 }

hibernate-core/src/main/java/org/hibernate/proxy/ProxyConfiguration.java

@@ -0,0 +1,99 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.proxy;
+
+import java.lang.reflect.Method;
+
+import net.bytebuddy.implementation.bind.annotation.AllArguments;
+import net.bytebuddy.implementation.bind.annotation.FieldValue;
+import net.bytebuddy.implementation.bind.annotation.Origin;
+import net.bytebuddy.implementation.bind.annotation.RuntimeType;
+import net.bytebuddy.implementation.bind.annotation.StubValue;
+import net.bytebuddy.implementation.bind.annotation.This;
+
+/**
+ * A proxy configuration allows the definition of an interceptor object that decides on the behavior of a proxy.
+ * This interface is meant for internal use but is in a public package in order to provide code generation.
+ * <p>
+ * While this interface depends on Byte Buddy types, this is only true for annotation types which are silently
+ * suppressed by the runtime if they are not available on a class loader. This allows using this interceptor
+ * and configuration with for example OSGi without any export of Byte Buddy when using Hibernate.
+ */
+public interface ProxyConfiguration {
+
+	/**
+	 * The canonical field name for an interceptor object stored in a proxied object.
+	 */
+	String INTERCEPTOR_FIELD_NAME = "$$_hibernate_interceptor";
+
+	/**
+	 * Defines an interceptor object that specifies the behavior of the proxy object.
+	 *
+	 * @param interceptor The interceptor object.
+	 */
+	void $$_hibernate_set_interceptor(Interceptor interceptor);
+
+	/**
+	 * An interceptor object that is responsible for invoking a proxy's method.
+	 */
+	interface Interceptor {
+
+		/**
+		 * Intercepts a method call to a proxy.
+		 *
+		 * @param instance The proxied instance.
+		 * @param method The invoked method.
+		 * @param arguments The intercepted method arguments.
+		 *
+		 * @return The method's return value.
+		 *
+		 * @throws Throwable If the intercepted method raises an exception.
+		 */
+		@RuntimeType
+		Object intercept(@This Object instance, @Origin Method method, @AllArguments Object[] arguments) throws Throwable;
+	}
+
+	/**
+	 * An static interceptor that guards against method calls before the interceptor is set.
+	 */
+	class InterceptorDispatcher {
+
+		/**
+		 * Intercepts a method call to a proxy.
+		 *
+		 * @param instance The proxied instance.
+		 * @param method The invoked method.
+		 * @param arguments The method arguments.
+		 * @param stubValue The intercepted method's default value.
+		 * @param interceptor The proxy object's interceptor instance.
+		 *
+		 * @return The intercepted method's return value.
+		 *
+		 * @throws Throwable If the intercepted method raises an exception.
+		 */
+		@RuntimeType
+		public static Object intercept(
+				@This final Object instance,
+				@Origin final Method method,
+				@AllArguments final Object[] arguments,
+				@StubValue final Object stubValue,
+				@FieldValue(INTERCEPTOR_FIELD_NAME) Interceptor interceptor
+		) throws Throwable {
+			if ( interceptor == null ) {
+				if ( method.getName().equals( "getHibernateLazyInitializer" ) ) {
+					return instance;
+				}
+				else {
+					return stubValue;
+				}
+			}
+			else {
+				return interceptor.intercept( instance, method, arguments );
+			}
+		}
+	}
+}

hibernate-core/src/main/java/org/hibernate/proxy/pojo/bytebuddy/ByteBuddyInterceptor.java

@@ -0,0 +1,108 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.proxy.pojo.bytebuddy;
+
+import java.io.Serializable;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
+import org.hibernate.internal.CoreMessageLogger;
+import org.hibernate.internal.util.ReflectHelper;
+import org.hibernate.proxy.ProxyConfiguration;
+import org.hibernate.proxy.pojo.BasicLazyInitializer;
+import org.hibernate.type.CompositeType;
+
+import net.bytebuddy.implementation.bind.annotation.AllArguments;
+import net.bytebuddy.implementation.bind.annotation.FieldValue;
+import net.bytebuddy.implementation.bind.annotation.Origin;
+import net.bytebuddy.implementation.bind.annotation.RuntimeType;
+import net.bytebuddy.implementation.bind.annotation.StubValue;
+import net.bytebuddy.implementation.bind.annotation.This;
+
+import static org.hibernate.internal.CoreLogging.messageLogger;
+
+public class ByteBuddyInterceptor extends BasicLazyInitializer implements ProxyConfiguration.Interceptor {
+	private static final CoreMessageLogger LOG = messageLogger( ByteBuddyInterceptor.class );
+
+	private final Class[] interfaces;
+
+	public ByteBuddyInterceptor(
+			String entityName,
+			Class persistentClass,
+			Class[] interfaces,
+			Serializable id,
+			Method getIdentifierMethod,
+			Method setIdentifierMethod,
+			CompositeType componentIdType,
+			SharedSessionContractImplementor session,
+			boolean overridesEquals) {
+		super( entityName, persistentClass, id, getIdentifierMethod, setIdentifierMethod, componentIdType, session, overridesEquals );
+		this.interfaces = interfaces;
+	}
+
+	@Override
+	public Object intercept(Object proxy, Method thisMethod, Object[] args) throws Throwable {
+		Object result;
+		try {
+			result = this.invoke( thisMethod, args, proxy );
+		}
+		catch (Throwable t) {
+			throw new Exception( t.getCause() );
+		}
+		if ( result == INVOKE_IMPLEMENTATION ) {
+			Object target = getImplementation();
+			final Object returnValue;
+			try {
+				if ( ReflectHelper.isPublic( persistentClass, thisMethod ) ) {
+					if ( !thisMethod.getDeclaringClass().isInstance( target ) ) {
+						throw new ClassCastException(
+								target.getClass().getName()
+										+ " incompatible with "
+										+ thisMethod.getDeclaringClass().getName()
+						);
+					}
+					returnValue = thisMethod.invoke( target, args );
+				}
+				else {
+					thisMethod.setAccessible( true );
+					returnValue = thisMethod.invoke( target, args );
+				}
+
+				if ( returnValue == target ) {
+					if ( returnValue.getClass().isInstance( proxy ) ) {
+						return proxy;
+					}
+					else {
+						LOG.narrowingProxy( returnValue.getClass() );
+					}
+				}
+				return returnValue;
+			}
+			catch (InvocationTargetException ite) {
+				throw ite.getTargetException();
+			}
+		}
+		else {
+			return result;
+		}
+	}
+
+	@Override
+	protected Object serializableProxy() {
+		return new SerializableProxy(
+				getEntityName(),
+				persistentClass,
+				interfaces,
+				getIdentifier(),
+				( isReadOnlySettingAvailable() ? Boolean.valueOf( isReadOnly() ) : isReadOnlyBeforeAttachedToSession() ),
+				getIdentifierMethod,
+				setIdentifierMethod,
+				componentIdType
+		);
+	}
+}

hibernate-core/src/main/java/org/hibernate/proxy/pojo/bytebuddy/ByteBuddyProxyFactory.java

@@ -0,0 +1,229 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.proxy.pojo.bytebuddy;
+
+import java.io.Serializable;
+import java.lang.reflect.Method;
+import java.lang.reflect.Type;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Locale;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+import org.hibernate.HibernateException;
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
+import org.hibernate.internal.CoreMessageLogger;
+import org.hibernate.internal.util.ReflectHelper;
+import org.hibernate.internal.util.collections.ArrayHelper;
+import org.hibernate.proxy.HibernateProxy;
+import org.hibernate.proxy.ProxyFactory;
+import org.hibernate.proxy.ProxyConfiguration;
+import org.hibernate.type.CompositeType;
+
+import net.bytebuddy.ByteBuddy;
+import net.bytebuddy.NamingStrategy;
+import net.bytebuddy.description.modifier.Visibility;
+import net.bytebuddy.dynamic.scaffold.TypeValidation;
+import net.bytebuddy.dynamic.scaffold.subclass.ConstructorStrategy;
+import net.bytebuddy.implementation.FieldAccessor;
+import net.bytebuddy.implementation.FixedValue;
+import net.bytebuddy.implementation.MethodDelegation;
+import net.bytebuddy.implementation.SuperMethodCall;
+import net.bytebuddy.implementation.bytecode.assign.Assigner;
+import net.bytebuddy.matcher.ElementMatchers;
+
+import static net.bytebuddy.matcher.ElementMatchers.named;
+import static org.hibernate.internal.CoreLogging.messageLogger;
+
+public class ByteBuddyProxyFactory implements ProxyFactory, Serializable {
+	private static final CoreMessageLogger LOG = messageLogger( ByteBuddyProxyFactory.class );
+
+	private static final ConcurrentMap<Set<Class>, Class> CACHE = new ConcurrentHashMap<Set<Class>, Class>();
+
+	private Class persistentClass;
+	private String entityName;
+	private Class[] interfaces;
+	private Method getIdentifierMethod;
+	private Method setIdentifierMethod;
+	private CompositeType componentIdType;
+	private boolean overridesEquals;
+
+	private Class proxyClass;
+
+	@Override
+	public void postInstantiate(
+			String entityName,
+			Class persistentClass,
+			Set<Class> interfaces,
+			Method getIdentifierMethod,
+			Method setIdentifierMethod,
+			CompositeType componentIdType) throws HibernateException {
+		this.entityName = entityName;
+		this.persistentClass = persistentClass;
+		this.interfaces = toArray( interfaces );
+		this.getIdentifierMethod = getIdentifierMethod;
+		this.setIdentifierMethod = setIdentifierMethod;
+		this.componentIdType = componentIdType;
+		this.overridesEquals = ReflectHelper.overridesEquals( persistentClass );
+
+		this.proxyClass = buildProxy( persistentClass, this.interfaces );
+	}
+
+	private Class[] toArray(Set<Class> interfaces) {
+		if ( interfaces == null ) {
+			return ArrayHelper.EMPTY_CLASS_ARRAY;
+		}
+
+		return interfaces.toArray( new Class[interfaces.size()] );
+	}
+
+	public static Class buildProxy(
+			final Class persistentClass,
+			final Class[] interfaces) {
+		Set<Class> key = new HashSet<Class>();
+		if ( interfaces.length == 1 ) {
+			key.add( persistentClass );
+		}
+		key.addAll( Arrays.asList( interfaces ) );
+
+		Class<?> proxy = CACHE.get( key );
+		if ( proxy != null ) {
+			return proxy;
+		}
+
+		proxy = new ByteBuddy()
+				.with( TypeValidation.DISABLED )
+				.with( new NamingStrategy.SuffixingRandom( "HibernateProxy" ) )
+				.subclass( interfaces.length == 1 ? persistentClass : Object.class, ConstructorStrategy.Default.IMITATE_SUPER_CLASS_OPENING )
+				.implement( (Type[]) interfaces )
+				.method( ElementMatchers.isVirtual().and( ElementMatchers.not( ElementMatchers.isFinalizer() ) ) )
+				.intercept( MethodDelegation.to( ProxyConfiguration.InterceptorDispatcher.class ) )
+				.method( ElementMatchers.nameStartsWith( "$$_hibernate_" ).and( ElementMatchers.isVirtual() ) )
+				.intercept( SuperMethodCall.INSTANCE )
+				.defineField( ProxyConfiguration.INTERCEPTOR_FIELD_NAME, ProxyConfiguration.Interceptor.class, Visibility.PRIVATE )
+				.implement( ProxyConfiguration.class )
+				.intercept( FieldAccessor.ofField( ProxyConfiguration.INTERCEPTOR_FIELD_NAME ).withAssigner( Assigner.DEFAULT, Assigner.Typing.DYNAMIC ) )
+				.make()
+				.load( persistentClass.getClassLoader() )
+				.getLoaded();
+
+		Class previousProxy = CACHE.putIfAbsent( key, proxy );
+		if ( previousProxy != null ) {
+			proxy = previousProxy;
+		}
+		return proxy;
+	}
+
+	@Override
+	public HibernateProxy getProxy(
+			Serializable id,
+			SharedSessionContractImplementor session) throws HibernateException {
+		final ByteBuddyInterceptor interceptor = new ByteBuddyInterceptor(
+				entityName,
+				persistentClass,
+				interfaces,
+				id,
+				getIdentifierMethod,
+				setIdentifierMethod,
+				componentIdType,
+				session,
+				overridesEquals
+		);
+
+		try {
+			final HibernateProxy proxy = (HibernateProxy) proxyClass.newInstance();
+			( (ProxyConfiguration) proxy ).$$_hibernate_set_interceptor( interceptor );
+
+			return proxy;
+		}
+		catch (Throwable t) {
+			LOG.error( LOG.bytecodeEnhancementFailed( entityName ), t );
+			throw new HibernateException( LOG.bytecodeEnhancementFailed( entityName ), t );
+		}
+	}
+
+	public static HibernateProxy deserializeProxy(SerializableProxy serializableProxy) {
+		final ByteBuddyInterceptor interceptor = new ByteBuddyInterceptor(
+				serializableProxy.getEntityName(),
+				serializableProxy.getPersistentClass(),
+				serializableProxy.getInterfaces(),
+				serializableProxy.getId(),
+				resolveIdGetterMethod( serializableProxy ),
+				resolveIdSetterMethod( serializableProxy ),
+				serializableProxy.getComponentIdType(),
+				null,
+				ReflectHelper.overridesEquals( serializableProxy.getPersistentClass() )
+		);
+
+		// note: interface is assumed to already contain HibernateProxy.class
+		try {
+			final Class proxyClass = buildProxy(
+					serializableProxy.getPersistentClass(),
+					serializableProxy.getInterfaces()
+			);
+			final HibernateProxy proxy = (HibernateProxy) proxyClass.newInstance();
+			( (ProxyConfiguration) proxy ).$$_hibernate_set_interceptor( interceptor );
+			return proxy;
+		}
+		catch (Throwable t) {
+			final String message = LOG.bytecodeEnhancementFailed( serializableProxy.getEntityName() );
+			LOG.error( message, t );
+			throw new HibernateException( message, t );
+		}
+	}
+
+	@SuppressWarnings("unchecked")
+	private static Method resolveIdGetterMethod(SerializableProxy serializableProxy) {
+		if ( serializableProxy.getIdentifierGetterMethodName() == null ) {
+			return null;
+		}
+
+		try {
+			return serializableProxy.getIdentifierGetterMethodClass().getDeclaredMethod( serializableProxy.getIdentifierGetterMethodName() );
+		}
+		catch (NoSuchMethodException e) {
+			throw new HibernateException(
+					String.format(
+							Locale.ENGLISH,
+							"Unable to deserialize proxy [%s, %s]; could not locate id getter method [%s] on entity class [%s]",
+							serializableProxy.getEntityName(),
+							serializableProxy.getId(),
+							serializableProxy.getIdentifierGetterMethodName(),
+							serializableProxy.getIdentifierGetterMethodClass()
+					)
+			);
+		}
+	}
+
+	@SuppressWarnings("unchecked")
+	private static Method resolveIdSetterMethod(SerializableProxy serializableProxy) {
+		if ( serializableProxy.getIdentifierSetterMethodName() == null ) {
+			return null;
+		}
+
+		try {
+			return serializableProxy.getIdentifierSetterMethodClass().getDeclaredMethod(
+					serializableProxy.getIdentifierSetterMethodName(),
+					serializableProxy.getIdentifierSetterMethodParams()
+			);
+		}
+		catch (NoSuchMethodException e) {
+			throw new HibernateException(
+					String.format(
+							Locale.ENGLISH,
+							"Unable to deserialize proxy [%s, %s]; could not locate id setter method [%s] on entity class [%s]",
+							serializableProxy.getEntityName(),
+							serializableProxy.getId(),
+							serializableProxy.getIdentifierSetterMethodName(),
+							serializableProxy.getIdentifierSetterMethodClass()
+					)
+			);
+		}
+	}
+}

hibernate-core/src/main/java/org/hibernate/proxy/pojo/bytebuddy/SerializableProxy.java

@@ -0,0 +1,111 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.proxy.pojo.bytebuddy;
+
+import java.io.Serializable;
+import java.lang.reflect.Method;
+
+import org.hibernate.proxy.AbstractSerializableProxy;
+import org.hibernate.proxy.HibernateProxy;
+import org.hibernate.type.CompositeType;
+
+public final class SerializableProxy extends AbstractSerializableProxy {
+	private final Class persistentClass;
+	private final Class[] interfaces;
+
+	private final String identifierGetterMethodName;
+	private final Class identifierGetterMethodClass;
+
+	private final String identifierSetterMethodName;
+	private final Class identifierSetterMethodClass;
+	private final Class[] identifierSetterMethodParams;
+
+	private final CompositeType componentIdType;
+
+	public SerializableProxy(
+			String entityName,
+			Class persistentClass,
+			Class[] interfaces,
+			Serializable id,
+			Boolean readOnly,
+			Method getIdentifierMethod,
+			Method setIdentifierMethod,
+			CompositeType componentIdType) {
+		super( entityName, id, readOnly );
+		this.persistentClass = persistentClass;
+		this.interfaces = interfaces;
+		if ( getIdentifierMethod != null ) {
+			identifierGetterMethodName = getIdentifierMethod.getName();
+			identifierGetterMethodClass = getIdentifierMethod.getDeclaringClass();
+		}
+		else {
+			identifierGetterMethodName = null;
+			identifierGetterMethodClass = null;
+		}
+
+		if ( setIdentifierMethod != null ) {
+			identifierSetterMethodName = setIdentifierMethod.getName();
+			identifierSetterMethodClass = setIdentifierMethod.getDeclaringClass();
+			identifierSetterMethodParams = setIdentifierMethod.getParameterTypes();
+		}
+		else {
+			identifierSetterMethodName = null;
+			identifierSetterMethodClass = null;
+			identifierSetterMethodParams = null;
+		}
+
+		this.componentIdType = componentIdType;
+	}
+
+	@Override
+	protected String getEntityName() {
+		return super.getEntityName();
+	}
+
+	@Override
+	protected Serializable getId() {
+		return super.getId();
+	}
+
+	protected Class getPersistentClass() {
+		return persistentClass;
+	}
+
+	protected Class[] getInterfaces() {
+		return interfaces;
+	}
+
+	protected String getIdentifierGetterMethodName() {
+		return identifierGetterMethodName;
+	}
+
+	protected Class getIdentifierGetterMethodClass() {
+		return identifierGetterMethodClass;
+	}
+
+	protected String getIdentifierSetterMethodName() {
+		return identifierSetterMethodName;
+	}
+
+	protected Class getIdentifierSetterMethodClass() {
+		return identifierSetterMethodClass;
+	}
+
+	protected Class[] getIdentifierSetterMethodParams() {
+		return identifierSetterMethodParams;
+	}
+
+	protected CompositeType getComponentIdType() {
+		return componentIdType;
+	}
+
+	private Object readResolve() {
+		HibernateProxy proxy = ByteBuddyProxyFactory.deserializeProxy( this );
+		setReadOnlyBeforeAttachedToSession( (ByteBuddyInterceptor) proxy.getHibernateLazyInitializer() );
+		return proxy;
+	}
+}

hibernate-core/src/main/java/org/hibernate/proxy/pojo/javassist/JavassistProxyFactory.java

@@ -126,8 +126,8 @@ public class JavassistProxyFactory implements ProxyFactory, Serializable {
 			return proxy;
 		}
 		catch (Throwable t) {
-			LOG.error( LOG.javassistEnhancementFailed( entityName ), t );
-			throw new HibernateException( LOG.javassistEnhancementFailed( entityName ), t );
+			LOG.error( LOG.bytecodeEnhancementFailed( entityName ), t );
+			throw new HibernateException( LOG.bytecodeEnhancementFailed( entityName ), t );
 		}
 	}
 
@@ -158,7 +158,7 @@ public class JavassistProxyFactory implements ProxyFactory, Serializable {
 			return proxy;
 		}
 		catch ( Throwable t ) {
-			final String message = LOG.javassistEnhancementFailed( serializableProxy.getEntityName() );
+			final String message = LOG.bytecodeEnhancementFailed( serializableProxy.getEntityName() );
 			LOG.error( message, t );
 			throw new HibernateException( message, t );
 		}

hibernate-core/src/main/java/org/hibernate/tool/enhance/EnhancementTask.java

@@ -14,11 +14,9 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 
-import javassist.ClassPool;
-import javassist.CtClass;
-
 import org.hibernate.bytecode.enhance.spi.DefaultEnhancementContext;
 import org.hibernate.bytecode.enhance.spi.Enhancer;
+import org.hibernate.cfg.Environment;
 
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.DirectoryScanner;
@@ -39,9 +37,7 @@ import org.apache.tools.ant.types.FileSet;
 public class EnhancementTask extends Task {
 	private List<FileSet> filesets = new ArrayList<FileSet>();
 
-	// Enhancer also builds CtClass instances.  Might make sense to share these (ClassPool).
-	private final ClassPool classPool = new ClassPool( false );
-	private final Enhancer enhancer = new Enhancer( new DefaultEnhancementContext() );
+	private final Enhancer enhancer = Environment.getBytecodeProvider().getEnhancer( new DefaultEnhancementContext() );
 
 	public void addFileset(FileSet set) {
 		this.filesets.add( set );
@@ -72,8 +68,7 @@ public class EnhancementTask extends Task {
 
 	private void processClassFile(File javaClassFile) {
 		try {
-			final CtClass ctClass = classPool.makeClass( new FileInputStream( javaClassFile ) );
-			byte[] result = enhancer.enhance( ctClass.getName(), ctClass.toBytecode() );
+			byte[] result = enhancer.enhance( javaClassFile );
 			if ( result != null ) {
 				writeEnhancedClass( javaClassFile, result );
 			}

hibernate-core/src/test/java/org/hibernate/jpa/test/enhancement/InstrumentedClassLoader.java

@@ -11,10 +11,9 @@ import java.io.InputStream;
 import java.lang.instrument.IllegalClassFormatException;
 import java.util.List;
 
-import javassist.CtClass;
-
 import org.hibernate.bytecode.enhance.spi.DefaultEnhancementContext;
 import org.hibernate.bytecode.enhance.spi.EnhancementContext;
+import org.hibernate.bytecode.enhance.spi.UnloadedClass;
 import org.hibernate.jpa.internal.enhance.EnhancingClassTransformerImpl;
 
 /**
@@ -31,29 +30,36 @@ public class InstrumentedClassLoader extends ClassLoader {
 	@Override
 	public Class<?> loadClass(String name) throws ClassNotFoundException {
 		// Do not instrument the following packages
-		if (name != null
-				&& (name.startsWith("java.lang.") || 
-					name.startsWith("java.util.")))
-			return getParent().loadClass(name);
+		if ( name != null
+				&& ( name.startsWith( "java.lang." ) ||
+				name.startsWith( "java.util." ) ) ) {
+			return getParent().loadClass( name );
+		}
 		Class c = findLoadedClass( name );
-		if ( c != null ) return c;
+		if ( c != null ) {
+			return c;
+		}
+
+		byte[] transformed = loadClassBytes( name );
 
-		byte[] transformed = loadClassBytes(name);
-		
 		return defineClass( name, transformed, 0, transformed.length );
 	}
-	
+
 	/**
 	 * Specialized {@link ClassLoader#loadClass(String)} that returns the class
 	 * as a byte array.
-	 * 
+	 *
 	 * @param name
+	 *
 	 * @return
+	 *
 	 * @throws ClassNotFoundException
 	 */
 	public byte[] loadClassBytes(String name) throws ClassNotFoundException {
 		InputStream is = this.getResourceAsStream( name.replace( ".", "/" ) + ".class" );
-		if ( is == null ) throw new ClassNotFoundException( name );
+		if ( is == null ) {
+			throw new ClassNotFoundException( name );
+		}
 		byte[] buffer = new byte[409600];
 		byte[] originalClass = new byte[0];
 		int r = 0;
@@ -64,13 +70,13 @@ public class InstrumentedClassLoader extends ClassLoader {
 			throw new ClassNotFoundException( name + " not found", e );
 		}
 		while ( r >= buffer.length ) {
-			byte[] temp = new byte[ originalClass.length + buffer.length ];
+			byte[] temp = new byte[originalClass.length + buffer.length];
 			System.arraycopy( originalClass, 0, temp, 0, originalClass.length );
 			System.arraycopy( buffer, 0, temp, originalClass.length, buffer.length );
 			originalClass = temp;
 		}
 		if ( r != -1 ) {
-			byte[] temp = new byte[ originalClass.length + r ];
+			byte[] temp = new byte[originalClass.length + r];
 			System.arraycopy( originalClass, 0, temp, 0, originalClass.length );
 			System.arraycopy( buffer, 0, temp, originalClass.length, r );
 			originalClass = temp;
@@ -84,13 +90,20 @@ public class InstrumentedClassLoader extends ClassLoader {
 
 		EnhancingClassTransformerImpl t = new EnhancingClassTransformerImpl( getEnhancementContext( getParent(), entities ) );
 		try {
-			return t.transform(
+			byte[] transformed = t.transform(
 					getParent(),
 					name,
 					null,
 					null,
 					originalClass
 			);
+
+			if ( transformed == null ) {
+				return originalClass;
+			}
+			else {
+				return transformed;
+			}
 		}
 		catch (IllegalClassFormatException e) {
 			throw new ClassNotFoundException( name + " not found", e );
@@ -110,12 +123,12 @@ public class InstrumentedClassLoader extends ClassLoader {
 			}
 
 			@Override
-			public boolean isEntityClass(CtClass classDescriptor) {
+			public boolean isEntityClass(UnloadedClass classDescriptor) {
 				return entities.contains( classDescriptor.getName() ) && super.isEntityClass( classDescriptor );
 			}
 
 			@Override
-			public boolean isCompositeClass(CtClass classDescriptor) {
+			public boolean isCompositeClass(UnloadedClass classDescriptor) {
 				return entities.contains( classDescriptor.getName() ) && super.isCompositeClass( classDescriptor );
 			}
 		};

hibernate-core/src/test/java/org/hibernate/jpa/test/enhancement/InterceptFieldClassFileTransformerTest.java

@@ -6,24 +6,14 @@
  */
 package org.hibernate.jpa.test.enhancement;
 
-import java.io.ByteArrayInputStream;
-import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 
-import javassist.ClassPool;
-import javassist.CtClass;
-import javassist.CtMethod;
-import javassist.bytecode.AttributeInfo;
-import javassist.bytecode.StackMapTable;
-
 import org.hibernate.engine.spi.Managed;
 import org.hibernate.engine.spi.ManagedComposite;
 import org.hibernate.engine.spi.ManagedEntity;
 import org.hibernate.jpa.test.enhancement.cases.domain.Simple;
 
-import org.hibernate.testing.TestForIssue;
-import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -36,10 +26,10 @@ import static org.junit.Assert.assertTrue;
  * @author Dustin Schultz
  */
 public class InterceptFieldClassFileTransformerTest {
-	
+
 	private List<String> entities = new ArrayList<String>();
 	private InstrumentedClassLoader loader = null;
-	
+
 	@Before
 	public void setup() {
 		entities.add( Simple.class.getName() );
@@ -48,13 +38,13 @@ public class InterceptFieldClassFileTransformerTest {
 		cl.setEntities( entities );
 		this.loader = cl;
 	}
-	
+
 	/**
 	 * Tests that class file enhancement works.
-	 * 
+	 *
 	 * @throws Exception in case the test fails.
 	 */
-    @Test
+	@Test
 	public void testEnhancement() throws Exception {
 		// sanity check that the class is unmodified and does not contain getFieldHandler()
 		assertFalse( implementsManaged( Simple.class ) );
@@ -75,35 +65,4 @@ public class InterceptFieldClassFileTransformerTest {
 		}
 		return false;
 	}
-
-	/**
-	 * Tests that methods that were enhanced by javassist have
-	 * StackMapTables for java verification. Without these,
-	 * java.lang.VerifyError's occur in JDK7.
-	 * 
-	 * @throws ClassNotFoundException
-	 * @throws InstantiationException
-	 * @throws IllegalAccessException
-	 * @throws IOException
-	 */
-	@Test
-	@TestForIssue(jiraKey = "HHH-7747")
-	public void testStackMapTableEnhancment() throws ClassNotFoundException,
-			InstantiationException, IllegalAccessException, IOException {
-		byte[] classBytes = loader.loadClassBytes(entities.get(0));
-		ClassPool classPool = new ClassPool();
-		CtClass ctClass = classPool.makeClass(new ByteArrayInputStream(
-				classBytes));
-		for (CtMethod ctMethod : ctClass.getMethods()) {
-			//Only check methods that were added by javassist
-			if (ctMethod.getName().startsWith("$javassist_")) {
-				AttributeInfo attributeInfo = ctMethod
-						.getMethodInfo().getCodeAttribute()
-						.getAttribute(StackMapTable.tag);
-				Assert.assertNotNull(attributeInfo);
-				StackMapTable smt = (StackMapTable)attributeInfo;
-				Assert.assertNotNull(smt.get());
-			}
-		}
-	}
 }

hibernate-core/src/test/java/org/hibernate/test/annotations/inheritance/singletable/DuplicatedDiscriminatorValueTest.java

@@ -75,18 +75,18 @@ public class DuplicatedDiscriminatorValueTest extends BaseUnitTestCase {
 
 	@Entity
 	@DiscriminatorValue(DISCRIMINATOR_VALUE) // Duplicated discriminator value in single hierarchy.
-	private static class Building1 extends Building {
+	public static class Building1 extends Building {
 	}
 
 	@Entity
 	@DiscriminatorValue(DISCRIMINATOR_VALUE) // Duplicated discriminator value in single hierarchy.
-	private static class Building2 extends Building {
+	public static class Building2 extends Building {
 	}
 
 	@Entity
 	@DiscriminatorColumn(name = "entity_type")
 	@DiscriminatorValue("F")
-	private static class Furniture {
+	public static class Furniture {
 		@Id
 		@GeneratedValue
 		private Integer id;
@@ -94,6 +94,6 @@ public class DuplicatedDiscriminatorValueTest extends BaseUnitTestCase {
 
 	@Entity
 	@DiscriminatorValue(DISCRIMINATOR_VALUE) // Duplicated discriminator value in different hierarchy.
-	private static class Chair extends Furniture {
+	public static class Chair extends Furniture {
 	}
 }

hibernate-core/src/test/java/org/hibernate/test/bytecode/InvocationTargetExceptionTest.java

@@ -4,40 +4,20 @@
  * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
  * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
  */
-package org.hibernate.test.bytecode.javassist;
+package org.hibernate.test.bytecode;
 
 import java.text.ParseException;
 
 import org.hibernate.Hibernate;
 import org.hibernate.Session;
-import org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl;
-import org.hibernate.cfg.Environment;
 
-import org.hibernate.testing.Skip;
 import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
-import org.hibernate.test.bytecode.Bean;
 import org.junit.Test;
 
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.fail;
 
-/**
- * Test that the Javassist-based lazy initializer properly handles InvocationTargetExceptions
- *
- * @author Steve Ebersole
- */
-@Skip(
-		condition = InvocationTargetExceptionTest.LocalSkipMatcher.class,
-		message = "environment not configured for javassist bytecode provider"
-)
 public class InvocationTargetExceptionTest extends BaseCoreFunctionalTestCase {
-	public static class LocalSkipMatcher implements Skip.Matcher {
-		@Override
-		public boolean isMatch() {
-			return ! BytecodeProviderImpl.class.isInstance( Environment.getBytecodeProvider() );
-		}
-	}
-
 	@Override
 	public String[] getMappings() {
 		return new String[] { "bytecode/Bean.hbm.xml" };

hibernate-core/src/test/java/org/hibernate/test/bytecode/ReflectionOptimizerTest.java

@@ -4,15 +4,15 @@
  * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
  * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
  */
-package org.hibernate.test.bytecode.javassist;
+package org.hibernate.test.bytecode;
 
 import org.junit.Test;
 
 import org.hibernate.bytecode.internal.javassist.BulkAccessor;
-import org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl;
+import org.hibernate.bytecode.spi.BytecodeProvider;
 import org.hibernate.bytecode.spi.ReflectionOptimizer;
-import org.hibernate.test.bytecode.Bean;
-import org.hibernate.test.bytecode.BeanReflectionHelper;
+import org.hibernate.cfg.Environment;
+
 import org.hibernate.testing.junit4.BaseUnitTestCase;
 
 import static org.junit.Assert.assertEquals;
@@ -34,7 +34,7 @@ public class ReflectionOptimizerTest extends BaseUnitTestCase {
 
 	@Test
 	public void testReflectionOptimization() {
-		BytecodeProviderImpl provider = new BytecodeProviderImpl();
+		BytecodeProvider provider = Environment.getBytecodeProvider();
 		ReflectionOptimizer optimizer = provider.getReflectionOptimizer(
 				Bean.class,
 		        BeanReflectionHelper.getGetterNames(),

hibernate-core/src/test/java/org/hibernate/test/bytecode/enhancement/EnhancerTest.java

@@ -6,7 +6,7 @@
  */
 package org.hibernate.test.bytecode.enhancement;
 
-import javassist.CtClass;
+import org.hibernate.bytecode.enhance.spi.UnloadedClass;
 
 import org.hibernate.test.bytecode.enhancement.association.InheritedAttributeAssociationTestTask;
 import org.hibernate.test.bytecode.enhancement.lazy.group.LazyGroupUpdateTestTask;
@@ -50,6 +50,7 @@ import org.hibernate.test.bytecode.enhancement.merge.CompositeMergeTestTask;
 import org.hibernate.test.bytecode.enhancement.ondemandload.LazyCollectionWithClearedSessionTestTask;
 import org.hibernate.test.bytecode.enhancement.ondemandload.LazyCollectionWithClosedSessionTestTask;
 import org.hibernate.test.bytecode.enhancement.ondemandload.LazyEntityLoadingWithClosedSessionTestTask;
+import org.hibernate.test.bytecode.enhancement.otherentityentrycontext.OtherEntityEntryContextTestTask;
 import org.hibernate.test.bytecode.enhancement.pk.EmbeddedPKTestTask;
 import org.junit.Test;
 
@@ -112,7 +113,7 @@ public class EnhancerTest extends BaseUnitTestCase {
 	public void testLazyProxyOnEnhancedEntity() {
 		EnhancerTestUtils.runEnhancerTestTask( LazyProxyOnEnhancedEntityTestTask.class, new EnhancerTestContext() {
 			@Override
-			public boolean hasLazyLoadableAttributes(CtClass classDescriptor) {
+			public boolean hasLazyLoadableAttributes(UnloadedClass classDescriptor) {
 				return false;
 			}
 		} );
@@ -176,7 +177,7 @@ public class EnhancerTest extends BaseUnitTestCase {
 		EnhancerTestUtils.runEnhancerTestTask( MappedSuperclassTestTask.class );
 		EnhancerTestUtils.runEnhancerTestTask( MappedSuperclassTestTask.class, new EnhancerTestContext() {
 			@Override
-			public boolean hasLazyLoadableAttributes(CtClass classDescriptor) {
+			public boolean hasLazyLoadableAttributes(UnloadedClass classDescriptor) {
 				// HHH-10981 - Without lazy loading, the generation of getters and setters has a different code path
 				return false;
 			}

hibernate-core/src/test/java/org/hibernate/test/classloader/ProxyInterfaceClassLoaderTest.java

@@ -56,7 +56,7 @@ public class ProxyInterfaceClassLoaderTest extends BaseCoreFunctionalTestCase {
 		s.close();
 	}
 
-	interface IPerson {
+	public interface IPerson {
 
 		int getId();
 

hibernate-entitymanager/hibernate-entitymanager.gradle

@@ -5,6 +5,7 @@ dependencies {
 	compile( libraries.commons_annotations )
 	compile( libraries.jpa )
 	compile( libraries.javassist )
+	compile( libraries.byteBuddy )
 	compile( libraries.jta )
 }
 

hibernate-envers/hibernate-envers.gradle

@@ -16,6 +16,7 @@ dependencies {
     testCompile( project( ':hibernate-testing' ) )
     testCompile( project( path: ':hibernate-core', configuration: 'tests' ) )
     testRuntime( libraries.javassist )
+    testRuntime( libraries.byteBuddy )
 
     // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     // Java 9 ftw!

hibernate-envers/src/main/java/org/hibernate/envers/internal/tools/EntityTools.java

@@ -6,7 +6,6 @@
  */
 package org.hibernate.envers.internal.tools;
 
-import javassist.util.proxy.ProxyFactory;
 import org.hibernate.Session;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.SessionImplementor;
@@ -76,7 +75,7 @@ public abstract class EntityTools {
 		if ( clazz == null ) {
 			return null;
 		}
-		else if ( ProxyFactory.isProxyClass( clazz ) ) {
+		else if ( HibernateProxy.class.isAssignableFrom( clazz ) ) {
 			// Get the source class of Javassist proxy instance.
 			return (Class<T>) clazz.getSuperclass();
 		}

hibernate-orm-modules/hibernate-orm-modules.gradle

@@ -37,7 +37,8 @@ ext {
             minorSlot: minorSlot,
             version: rootProject.hibernateTargetVersion,
             wildflyVersion: wildflyVersion,
-            javassistVersion: javassistVersion
+            javassistVersion: javassistVersion,
+            byteBuddyVersion: byteBuddyVersion
     ];
 }
 
@@ -54,12 +55,14 @@ configurations {
     wildflyDist
 
     javassist
+    byteBuddy
 }
 
 dependencies {
     jipijapa "org.wildfly:jipijapa-hibernate5:${wildflyVersion}"
     wildflyDist "org.wildfly:wildfly-dist:${wildflyVersion}@zip"
     javassist libraries.javassist
+    byteBuddy libraries.byteBuddy
 
     testCompile project( ":hibernate-core" )
     testCompile project( ":hibernate-envers" )
@@ -121,6 +124,8 @@ task createModulesZip(type: Zip, dependsOn: [copyAndExpandModuleXml]) {
 
         // also need Javassist's jar
         from configurations.javassist
+        // also need Byte Buddy's jar
+        from configurations.byteBuddy
     }
 
     into( 'org/hibernate/infinispan/' + slot ) {

hibernate-orm-modules/src/main/modules/org/hibernate/core/module.xml

@@ -10,6 +10,7 @@
         <resource-root path="hibernate-core-${version}.jar"/>
         <resource-root path="hibernate-envers-${version}.jar"/>
         <resource-root path="javassist-${javassistVersion}.jar"/>
+        <resource-root path="byte-buddy-${byteBuddyVersion}.jar"/>
     </resources>
 
     <dependencies>

hibernate-spatial/hibernate-spatial.gradle

@@ -47,6 +47,7 @@ dependencies {
 
     testRuntime('jaxen:jaxen:1.1')
     testRuntime(libraries.javassist)
+    testRuntime(libraries.byteBuddy)
 
 
     // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

hibernate-testing/src/main/java/org/hibernate/testing/bytecode/enhancement/EnhancerTestContext.java

@@ -10,6 +10,8 @@ import javassist.CtClass;
 import javassist.CtField;
 
 import org.hibernate.bytecode.enhance.spi.DefaultEnhancementContext;
+import org.hibernate.bytecode.enhance.spi.UnloadedClass;
+import org.hibernate.bytecode.enhance.spi.UnloadedField;
 
 /**
  * Enhancement context used in tests
@@ -19,27 +21,27 @@ import org.hibernate.bytecode.enhance.spi.DefaultEnhancementContext;
 public class EnhancerTestContext extends DefaultEnhancementContext {
 
 	@Override
-	public boolean doBiDirectionalAssociationManagement(CtField field) {
+	public boolean doBiDirectionalAssociationManagement(UnloadedField field) {
 		return true;
 	}
 
 	@Override
-	public boolean doDirtyCheckingInline(CtClass classDescriptor) {
+	public boolean doDirtyCheckingInline(UnloadedClass classDescriptor) {
 		return true;
 	}
 
 	@Override
-	public boolean doExtendedEnhancement(CtClass classDescriptor) {
+	public boolean doExtendedEnhancement(UnloadedClass classDescriptor) {
 		return true;
 	}
 
 	@Override
-	public boolean hasLazyLoadableAttributes(CtClass classDescriptor) {
+	public boolean hasLazyLoadableAttributes(UnloadedClass classDescriptor) {
 		return true;
 	}
 
 	@Override
-	public boolean isLazyLoadable(CtField field) {
+	public boolean isLazyLoadable(UnloadedField field) {
 		return true;
 	}
 

hibernate-testing/src/main/java/org/hibernate/testing/bytecode/enhancement/EnhancerTestUtils.java

@@ -23,6 +23,7 @@ import org.hibernate.HibernateException;
 import org.hibernate.LockMode;
 import org.hibernate.bytecode.enhance.spi.EnhancementContext;
 import org.hibernate.bytecode.enhance.spi.Enhancer;
+import org.hibernate.cfg.Environment;
 import org.hibernate.engine.internal.MutableEntityEntryFactory;
 import org.hibernate.engine.spi.EntityEntry;
 import org.hibernate.engine.spi.SelfDirtinessTracker;
@@ -57,8 +58,8 @@ public abstract class EnhancerTestUtils extends BaseUnitTestCase {
 		CtClass entityCtClass = generateCtClassForAnEntity( classToEnhance );
 
 		byte[] original = entityCtClass.toBytecode();
-		byte[] enhanced = new Enhancer( new EnhancerTestContext() ).enhance( entityCtClass.getName(), original );
-		assertFalse( "entity was not enhanced", Arrays.equals( original, enhanced ) );
+		byte[] enhanced = Environment.getBytecodeProvider().getEnhancer( new EnhancerTestContext() ).enhance( entityCtClass.getName(), original );
+		assertFalse( "entity was not enhanced", enhanced == null );
 		log.infof( "enhanced entity [%s]", entityCtClass.getName() );
 
 		ClassPool cp = new ClassPool( false );
@@ -127,7 +128,7 @@ public abstract class EnhancerTestUtils extends BaseUnitTestCase {
 	private static ClassLoader getEnhancerClassLoader(EnhancementContext context, String packageName) {
 		return new ClassLoader() {
 
-			private Enhancer enhancer = new Enhancer( context );
+			private Enhancer enhancer = Environment.getBytecodeProvider().getEnhancer( context );
 
 			@SuppressWarnings("ResultOfMethodCallIgnored")
 			@Override
@@ -151,12 +152,17 @@ public abstract class EnhancerTestUtils extends BaseUnitTestCase {
 
 					byte[] enhanced = enhancer.enhance( name, original );
 
-					File f = new File( workingDir + File.separator + name.replace( ".", File.separator ) + ".class" );
-					f.getParentFile().mkdirs();
-					f.createNewFile();
-					FileOutputStream out = new FileOutputStream( f );
-					out.write( enhanced );
-					out.close();
+					if ( enhanced != null ) {
+						File f = new File( workingDir + File.separator + name.replace( ".", File.separator ) + ".class" );
+						f.getParentFile().mkdirs();
+						f.createNewFile();
+						FileOutputStream out = new FileOutputStream( f );
+						out.write( enhanced );
+						out.close();
+					}
+					else {
+						enhanced = original;
+					}
 
 					return defineClass( name, enhanced, 0, enhanced.length );
 				}

libraries.gradle

@@ -19,6 +19,7 @@ ext {
     cdiVersion = '1.1'
 
     javassistVersion = '3.20.0-GA'
+    byteBuddyVersion = '1.5.4'
 
     // Wildfly version targeted by module ZIP; Arquillian/Shrinkwrap versions used for CDI testing and testing the module ZIP
     wildflyVersion = '10.0.0.Final'
@@ -48,6 +49,9 @@ ext {
             // Javassist
             javassist:      "org.javassist:javassist:${javassistVersion}",
 
+            // Byte Buddy
+            byteBuddy:      "net.bytebuddy:byte-buddy:${byteBuddyVersion}",
+
             // javax
             jpa:            'org.hibernate.javax.persistence:hibernate-jpa-2.1-api:1.0.0.Final',
             // There is a bug in the OSGi information in the JBoss one.  See https://issues.jboss.org/browse/JBEE-160

tooling/hibernate-enhance-maven-plugin/hibernate-enhance-maven-plugin.gradle

@@ -29,6 +29,7 @@ dependencies {
     compile( project(':hibernate-core') ) { transitive = false }
     compile( libraries.jpa ) { transitive = false }
     compile( libraries.javassist ) { transitive = false }
+    compile( libraries.byteBuddy ) { transitive = false }
     compile 'org.codehaus.plexus:plexus-utils:3.0.1'
     runtime( libraries.maven_core )
     runtime( libraries.maven_artifact )
@@ -37,6 +38,7 @@ dependencies {
     runtime( project(':hibernate-core') )
     runtime( libraries.jpa )
     runtime( libraries.javassist )
+    runtime( libraries.byteBuddy )
     runtime 'org.codehaus.plexus:plexus-utils:3.0.1'
 }
 
@@ -56,6 +58,7 @@ task processPluginXml(type: Copy) {
             + generateMavenDependency(libraries.jta)\
             + generateMavenDependency(libraries.commons_annotations)\
             + generateMavenDependency(libraries.javassist)\
+            + generateMavenDependency(libraries.byteBuddy)\
             + generateMavenDependency(libraries.logging)\
             + generateMavenDependency("org.hibernate:hibernate-core:" + project.version)])
 }

tooling/hibernate-enhance-maven-plugin/src/main/java/org/hibernate/orm/tooling/maven/MavenEnhancePlugin.java

@@ -8,11 +8,9 @@ package org.hibernate.orm.tooling.maven;
 
 import java.io.File;
 import java.io.FileFilter;
-import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
-import java.io.InputStream;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLClassLoader;
@@ -21,10 +19,6 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Set;
 
-import javassist.ClassPool;
-import javassist.CtClass;
-import javassist.CtField;
-
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
@@ -39,6 +33,9 @@ import org.apache.maven.project.MavenProject;
 import org.hibernate.bytecode.enhance.spi.DefaultEnhancementContext;
 import org.hibernate.bytecode.enhance.spi.EnhancementContext;
 import org.hibernate.bytecode.enhance.spi.Enhancer;
+import org.hibernate.bytecode.enhance.spi.UnloadedClass;
+import org.hibernate.bytecode.enhance.spi.UnloadedField;
+import org.hibernate.cfg.Environment;
 
 /**
  * This plugin will enhance Entity objects.
@@ -105,27 +102,27 @@ public class MavenEnhancePlugin extends AbstractMojo {
 			}
 
 			@Override
-			public boolean doBiDirectionalAssociationManagement(CtField field) {
+			public boolean doBiDirectionalAssociationManagement(UnloadedField field) {
 				return enableAssociationManagement;
 			}
 
 			@Override
-			public boolean doDirtyCheckingInline(CtClass classDescriptor) {
+			public boolean doDirtyCheckingInline(UnloadedClass classDescriptor) {
 				return enableDirtyTracking;
 			}
 
 			@Override
-			public boolean hasLazyLoadableAttributes(CtClass classDescriptor) {
+			public boolean hasLazyLoadableAttributes(UnloadedClass classDescriptor) {
 				return enableLazyInitialization;
 			}
 
 			@Override
-			public boolean isLazyLoadable(CtField field) {
+			public boolean isLazyLoadable(UnloadedField field) {
 				return enableLazyInitialization;
 			}
 
 			@Override
-			public boolean doExtendedEnhancement(CtClass classDescriptor) {
+			public boolean doExtendedEnhancement(UnloadedClass classDescriptor) {
 				return enableExtendedEnhancement;
 			}
 		};
@@ -134,28 +131,19 @@ public class MavenEnhancePlugin extends AbstractMojo {
 			getLog().warn( "Extended enhancement is enabled. Classes other than entities may be modified. You should consider access the entities using getter/setter methods and disable this property. Use at your own risk." );
 		}
 
-		final Enhancer enhancer = new Enhancer( enhancementContext );
-		final ClassPool classPool = new ClassPool( false );
+		final Enhancer enhancer = Environment.getBytecodeProvider().getEnhancer( enhancementContext );
 
 		for ( File file : sourceSet ) {
-			final CtClass ctClass = toCtClass( file, classPool );
-			if ( ctClass == null ) {
+
+			final byte[] enhancedBytecode = doEnhancement( file, enhancer );
+
+			if ( enhancedBytecode == null ) {
 				continue;
 			}
 
-			if ( !enableLazyInitialization ) {
-				if ( !enhancementContext.isEntityClass( ctClass )
-						&& !enhancementContext.isCompositeClass( ctClass )
-						&& !enhancementContext.isMappedSuperclassClass( ctClass ) ) {
-					getLog().info( "Skipping class file [" + file.getAbsolutePath() + "], not an entity nor embeddable" );
-					continue;
-				}
-			}
+			writeOutEnhancedClass( enhancedBytecode, file );
 
-			final byte[] enhancedBytecode = doEnhancement( ctClass, enhancer );
-			writeOutEnhancedClass( enhancedBytecode, ctClass, file );
-
-			getLog().info( "Successfully enhanced class [" + ctClass.getName() + "]" );
+			getLog().info( "Successfully enhanced class [" + file + "]" );
 		}
 	}
 
@@ -204,47 +192,12 @@ public class MavenEnhancePlugin extends AbstractMojo {
 		return new URLClassLoader( urls.toArray( new URL[urls.size()] ), Enhancer.class.getClassLoader() );
 	}
 
-	private CtClass toCtClass(File file, ClassPool classPool) throws MojoExecutionException {
+	private byte[] doEnhancement(File javaClassFile, Enhancer enhancer) throws MojoExecutionException {
 		try {
-			final InputStream is = new FileInputStream( file.getAbsolutePath() );
-
-			try {
-				return classPool.makeClass( is );
-			}
-			catch (IOException e) {
-				String msg = "Javassist unable to load class in preparation for enhancing: " + file.getAbsolutePath();
-				if ( failOnError ) {
-					throw new MojoExecutionException( msg, e );
-				}
-				getLog().warn( msg );
-				return null;
-			}
-			finally {
-				try {
-					is.close();
-				}
-				catch (IOException e) {
-					getLog().info( "Was unable to close InputStream : " + file.getAbsolutePath(), e );
-				}
-			}
-		}
-		catch (FileNotFoundException e) {
-			// should never happen, but...
-			String msg = "Unable to locate class file for InputStream: " + file.getAbsolutePath();
-			if ( failOnError ) {
-				throw new MojoExecutionException( msg, e );
-			}
-			getLog().warn( msg );
-			return null;
-		}
-	}
-
-	private byte[] doEnhancement(CtClass ctClass, Enhancer enhancer) throws MojoExecutionException {
-		try {
-			return enhancer.enhance( ctClass.getName(), ctClass.toBytecode() );
+			return enhancer.enhance(javaClassFile);
 		}
 		catch (Exception e) {
-			String msg = "Unable to enhance class: " + ctClass.getName();
+			String msg = "Unable to enhance class: " + javaClassFile.getName();
 			if ( failOnError ) {
 				throw new MojoExecutionException( msg, e );
 			}
@@ -283,22 +236,19 @@ public class MavenEnhancePlugin extends AbstractMojo {
 		Collections.addAll( this.sourceSet, files );
 	}
 
-	private void writeOutEnhancedClass(byte[] enhancedBytecode, CtClass ctClass, File file) throws MojoExecutionException{
-		if ( enhancedBytecode == null ) {
-			return;
-		}
+	private void writeOutEnhancedClass(byte[] enhancedBytecode, File file) throws MojoExecutionException {
 		try {
 			if ( file.delete() ) {
 				if ( !file.createNewFile() ) {
-					getLog().error( "Unable to recreate class file [" + ctClass.getName() + "]" );
+					getLog().error( "Unable to recreate class file [" + file.getName() + "]" );
 				}
 			}
 			else {
-				getLog().error( "Unable to delete class file [" + ctClass.getName() + "]" );
+				getLog().error( "Unable to delete class file [" + file.getName() + "]" );
 			}
 		}
 		catch (IOException e) {
-			getLog().warn( "Problem preparing class file for writing out enhancements [" + ctClass.getName() + "]" );
+			getLog().warn( "Problem preparing class file for writing out enhancements [" + file.getName() + "]" );
 		}
 
 		try {
@@ -308,7 +258,7 @@ public class MavenEnhancePlugin extends AbstractMojo {
 				outputStream.flush();
 			}
 			catch (IOException e) {
-				String msg = String.format( "Error writing to enhanced class [%s] to file [%s]", ctClass.getName(), file.getAbsolutePath() );
+				String msg = String.format( "Error writing to enhanced class [%s] to file [%s]", file.getName(), file.getAbsolutePath() );
 				if ( failOnError ) {
 					throw new MojoExecutionException( msg, e );
 				}
@@ -317,7 +267,6 @@ public class MavenEnhancePlugin extends AbstractMojo {
 			finally {
 				try {
 					outputStream.close();
-					ctClass.detach();
 				}
 				catch (IOException ignore) {
 				}

tooling/hibernate-gradle-plugin/hibernate-gradle-plugin.gradle

@@ -14,6 +14,7 @@ dependencies {
 	compile( project( ':hibernate-core' ) )
 	compile( libraries.jpa )
 	compile( libraries.javassist )
+	compile( libraries.byteBuddy )
 	compile gradleApi()
 	compile localGroovy()
 }

tooling/hibernate-gradle-plugin/src/main/groovy/org/hibernate/orm/tooling/gradle/HibernatePlugin.java

@@ -7,21 +7,15 @@
 package org.hibernate.orm.tooling.gradle;
 
 import java.io.File;
-import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
-import java.io.InputStream;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.ArrayList;
 import java.util.List;
 
-import javassist.ClassPool;
-import javassist.CtClass;
-import javassist.CtField;
-
 import org.gradle.api.Action;
 import org.gradle.api.GradleException;
 import org.gradle.api.Plugin;
@@ -36,6 +30,9 @@ import org.gradle.api.tasks.SourceSet;
 import org.hibernate.bytecode.enhance.spi.DefaultEnhancementContext;
 import org.hibernate.bytecode.enhance.spi.EnhancementContext;
 import org.hibernate.bytecode.enhance.spi.Enhancer;
+import org.hibernate.bytecode.enhance.spi.UnloadedClass;
+import org.hibernate.bytecode.enhance.spi.UnloadedField;
+import org.hibernate.cfg.Environment;
 
 /**
  * The Hibernate Gradle plugin.  Adds Hibernate build-time capabilities into your Gradle-based build.
@@ -92,37 +89,36 @@ public class HibernatePlugin implements Plugin<Project> {
 								}
 
 								@Override
-								public boolean doBiDirectionalAssociationManagement(CtField field) {
+								public boolean doBiDirectionalAssociationManagement(UnloadedField field) {
 									return hibernateExtension.enhance.getEnableAssociationManagement();
 								}
 
 								@Override
-								public boolean doDirtyCheckingInline(CtClass classDescriptor) {
+								public boolean doDirtyCheckingInline(UnloadedClass classDescriptor) {
 									return hibernateExtension.enhance.getEnableDirtyTracking();
 								}
 
 								@Override
-								public boolean hasLazyLoadableAttributes(CtClass classDescriptor) {
+								public boolean hasLazyLoadableAttributes(UnloadedClass classDescriptor) {
 									return hibernateExtension.enhance.getEnableLazyInitialization();
 								}
 
 								@Override
-								public boolean isLazyLoadable(CtField field) {
+								public boolean isLazyLoadable(UnloadedField field) {
 									return hibernateExtension.enhance.getEnableLazyInitialization();
 								}
 
 								@Override
-								public boolean doExtendedEnhancement(CtClass classDescriptor) {
+								public boolean doExtendedEnhancement(UnloadedClass classDescriptor) {
 									return hibernateExtension.enhance.getEnableExtendedEnhancement();
 								}
 							};
 
 							if ( hibernateExtension.enhance.getEnableExtendedEnhancement() ) {
-								logger.warn( "Extended enhancement is enabled. Classes other than entities may be modified. You should consider access the entities using getter/setter methods and disable this property. Use at your own risk." );
+								logger.warn("Extended enhancement is enabled. Classes other than entities may be modified. You should consider access the entities using getter/setter methods and disable this property. Use at your own risk." );
 							}
 
-							final Enhancer enhancer = new Enhancer( enhancementContext );
-							final ClassPool classPool = new ClassPool( false );
+							final Enhancer enhancer = Environment.getBytecodeProvider().getEnhancer( enhancementContext );
 
 							final FileTree fileTree = project.fileTree( sourceSet.getOutput().getClassesDir() );
 							for ( File file : fileTree ) {
@@ -130,19 +126,14 @@ public class HibernatePlugin implements Plugin<Project> {
 									continue;
 								}
 
-								final CtClass ctClass = toCtClass( file, classPool );
-
-								if ( !enhancementContext.isEntityClass( ctClass )
-										&& !enhancementContext.isCompositeClass( ctClass )
-										&& !enhancementContext.isMappedSuperclassClass( ctClass ) ) {
-									logger.info( "Skipping class [" + file.getAbsolutePath() + "], not an entity nor embeddable" );
-									continue;
+								final byte[] enhancedBytecode = doEnhancement( file, enhancer );
+								if ( enhancedBytecode != null ) {
+									writeOutEnhancedClass( enhancedBytecode, file );
+									logger.info( "Successfully enhanced class [" + file + "]" );
+								}
+								else {
+									logger.info( "Skipping class [" + file.getAbsolutePath() + "], not an entity nor embeddable" );
 								}
-
-								final byte[] enhancedBytecode = doEnhancement( ctClass, enhancer );
-								writeOutEnhancedClass( enhancedBytecode, ctClass, file );
-
-								logger.info( "Successfully enhanced class [" + ctClass.getName() + "]" );
 							}
 						}
 					}
@@ -164,53 +155,28 @@ public class HibernatePlugin implements Plugin<Project> {
 		return new URLClassLoader( urls.toArray( new URL[urls.size()] ), Enhancer.class.getClassLoader() );
 	}
 
-	private CtClass toCtClass(File file, ClassPool classPool) {
+	private byte[] doEnhancement(File javaClassFile, Enhancer enhancer) {
 		try {
-			final InputStream is = new FileInputStream( file.getAbsolutePath() );
-
-			try {
-				return classPool.makeClass( is );
-			}
-			catch (IOException e) {
-				throw new GradleException( "Javassist unable to load class in preparation for enhancing : " + file.getAbsolutePath(), e );
-			}
-			finally {
-				try {
-					is.close();
-				}
-				catch (IOException e) {
-					logger.info( "Was unable to close InputStream : " + file.getAbsolutePath(), e );
-				}
-			}
-		}
-		catch (FileNotFoundException e) {
-			// should never happen, but...
-			throw new GradleException( "Unable to locate class file for InputStream: " + file.getAbsolutePath(), e );
-		}
-	}
-
-	private byte[] doEnhancement(CtClass ctClass, Enhancer enhancer) {
-		try {
-			return enhancer.enhance( ctClass.getName(), ctClass.toBytecode() );
+			return enhancer.enhance( javaClassFile );
 		}
 		catch (Exception e) {
-			throw new GradleException( "Unable to enhance class : " + ctClass.getName(), e );
+			throw new GradleException( "Unable to enhance class : " + javaClassFile, e );
 		}
 	}
 
-	private void writeOutEnhancedClass(byte[] enhancedBytecode, CtClass ctClass, File file) {
+	private void writeOutEnhancedClass(byte[] enhancedBytecode, File file) {
 		try {
 			if ( file.delete() ) {
 				if ( !file.createNewFile() ) {
-					logger.error( "Unable to recreate class file [" + ctClass.getName() + "]" );
+					logger.error( "Unable to recreate class file [" + file.getName() + "]" );
 				}
 			}
 			else {
-				logger.error( "Unable to delete class file [" + ctClass.getName() + "]" );
+				logger.error( "Unable to delete class file [" + file.getName() + "]" );
 			}
 		}
 		catch (IOException e) {
-			logger.warn( "Problem preparing class file for writing out enhancements [" + ctClass.getName() + "]" );
+			logger.warn( "Problem preparing class file for writing out enhancements [" + file.getName() + "]" );
 		}
 
 		try {
@@ -220,12 +186,11 @@ public class HibernatePlugin implements Plugin<Project> {
 				outputStream.flush();
 			}
 			catch (IOException e) {
-				throw new GradleException( "Error writing to enhanced class [" + ctClass.getName() + "] to file [" + file.getAbsolutePath() + "]", e );
+				throw new GradleException( "Error writing to enhanced class [" + file.getName() + "] to file [" + file.getAbsolutePath() + "]", e );
 			}
 			finally {
 				try {
 					outputStream.close();
-					ctClass.detach();
 				}
 				catch (IOException ignore) {
 				}