/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*
*/
package org.hibernate.bytecode.cglib;
import org.hibernate.bytecode.ProxyFactoryFactory;
import org.hibernate.bytecode.BasicProxyFactory;
import org.hibernate.proxy.ProxyFactory;
import org.hibernate.proxy.pojo.cglib.CGLIBProxyFactory;
import org.hibernate.AssertionFailure;
import org.hibernate.HibernateException;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.CallbackFilter;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import net.sf.cglib.proxy.NoOp;
import net.sf.cglib.proxy.Callback;
import net.sf.cglib.proxy.Factory;
import java.lang.reflect.Method;
import java.util.HashMap;
/**
* A factory for CGLIB-based {@link ProxyFactory} instances.
*
* @author Steve Ebersole
*/
public class ProxyFactoryFactoryImpl implements ProxyFactoryFactory {
/**
* Builds a CGLIB-based proxy factory.
*
* @return a new CGLIB-based proxy factory.
*/
public ProxyFactory buildProxyFactory() {
return new CGLIBProxyFactory();
}
public BasicProxyFactory buildBasicProxyFactory(Class superClass, Class[] interfaces) {
return new BasicProxyFactoryImpl( superClass, interfaces );
}
public static class BasicProxyFactoryImpl implements BasicProxyFactory {
private final Class proxyClass;
private final Factory factory;
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" );
}
Enhancer en = new Enhancer();
en.setUseCache( false );
en.setInterceptDuringConstruction( false );
en.setUseFactory( true );
en.setCallbackTypes( CALLBACK_TYPES );
en.setCallbackFilter( FINALIZE_FILTER );
if ( superClass != null ) {
en.setSuperclass( superClass );
}
if ( interfaces != null && interfaces.length > 0 ) {
en.setInterfaces( interfaces );
}
proxyClass = en.createClass();
try {
factory = ( Factory ) proxyClass.newInstance();
}
catch ( Throwable t ) {
throw new HibernateException( "Unable to build CGLIB Factory instance" );
}
}
public Object getProxy() {
try {
return factory.newInstance(
new Callback[] { new PassThroughInterceptor( proxyClass.getName() ), NoOp.INSTANCE }
);
}
catch ( Throwable t ) {
throw new HibernateException( "Unable to instantiate proxy instance" );
}
}
}
private static final CallbackFilter FINALIZE_FILTER = new CallbackFilter() {
public int accept(Method method) {
if ( method.getParameterTypes().length == 0 && method.getName().equals("finalize") ){
return 1;
}
else {
return 0;
}
}
};
private static final Class[] CALLBACK_TYPES = new Class[] { MethodInterceptor.class, NoOp.class };
private static class PassThroughInterceptor implements MethodInterceptor {
private HashMap data = new HashMap();
private final String proxiedClassName;
public PassThroughInterceptor(String proxiedClassName) {
this.proxiedClassName = proxiedClassName;
}
public Object intercept(
Object obj,
Method method,
Object[] args,
MethodProxy proxy) throws Throwable {
String name = method.getName();
if ( "toString".equals( name ) ) {
return proxiedClassName + "@" + System.identityHashCode( obj );
}
else if ( "equals".equals( name ) ) {
return args[0] instanceof Factory && ( ( Factory ) args[0] ).getCallback( 0 ) == this
? Boolean.TRUE
: Boolean.FALSE;
}
else if ( "hashCode".equals( name ) ) {
return new Integer( System.identityHashCode( obj ) );
}
boolean hasGetterSignature = method.getParameterTypes().length == 0 && method.getReturnType() != null;
boolean hasSetterSignature = method.getParameterTypes().length == 1 && ( method.getReturnType() == null || method.getReturnType() == void.class );
if ( name.startsWith( "get" ) && hasGetterSignature ) {
String propName = name.substring( 3 );
return data.get( propName );
}
else if ( name.startsWith( "is" ) && hasGetterSignature ) {
String propName = name.substring( 2 );
return data.get( propName );
}
else if ( name.startsWith( "set" ) && hasSetterSignature) {
String propName = name.substring( 3 );
data.put( propName, args[0] );
return null;
}
else {
// todo : what else to do here?
return null;
}
}
}
}