/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008-2013, Red Hat Inc. 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 Inc.
*
* 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.internal.javassist;
import java.lang.reflect.Method;
import java.util.HashMap;
import javassist.util.proxy.MethodFilter;
import javassist.util.proxy.MethodHandler;
import javassist.util.proxy.Proxy;
import org.hibernate.AssertionFailure;
import org.hibernate.HibernateException;
import org.hibernate.bytecode.spi.BasicProxyFactory;
import org.hibernate.bytecode.spi.ProxyFactoryFactory;
import org.hibernate.proxy.ProxyFactory;
import org.hibernate.proxy.pojo.javassist.JavassistProxyFactory;
/**
* A factory for Javassist-based {@link ProxyFactory} instances.
*
* @author Steve Ebersole
*/
public class ProxyFactoryFactoryImpl implements ProxyFactoryFactory {
/**
* Builds a Javassist-based proxy factory.
*
* @return a new Javassist-based proxy factory.
*/
public ProxyFactory buildProxyFactory() {
return new JavassistProxyFactory();
}
/**
* Constructs a BasicProxyFactoryImpl
*
* @param superClass The abstract super class (or null if none).
* @param interfaces Interfaces to be proxied (or null if none).
*
* @return The constructed BasicProxyFactoryImpl
*/
public BasicProxyFactory buildBasicProxyFactory(Class superClass, Class[] interfaces) {
return new BasicProxyFactoryImpl( superClass, interfaces );
}
private static class BasicProxyFactoryImpl implements BasicProxyFactory {
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" );
}
final javassist.util.proxy.ProxyFactory factory = new javassist.util.proxy.ProxyFactory();
factory.setFilter( FINALIZE_FILTER );
if ( superClass != null ) {
factory.setSuperclass( superClass );
}
if ( interfaces != null && interfaces.length > 0 ) {
factory.setInterfaces( interfaces );
}
proxyClass = factory.createClass();
}
public Object getProxy() {
try {
final Proxy proxy = (Proxy) proxyClass.newInstance();
proxy.setHandler( new PassThroughHandler( proxy, proxyClass.getName() ) );
return proxy;
}
catch ( Throwable t ) {
throw new HibernateException( "Unable to instantiated proxy instance" );
}
}
public boolean isInstance(Object object) {
return proxyClass.isInstance( object );
}
}
private static final MethodFilter FINALIZE_FILTER = new MethodFilter() {
public boolean isHandled(Method m) {
// skip finalize methods
return !( m.getParameterTypes().length == 0 && m.getName().equals( "finalize" ) );
}
};
private static class PassThroughHandler implements MethodHandler {
private HashMap data = new HashMap();
private final Object proxiedObject;
private final String proxiedClassName;
public PassThroughHandler(Object proxiedObject, String proxiedClassName) {
this.proxiedObject = proxiedObject;
this.proxiedClassName = proxiedClassName;
}
@SuppressWarnings("unchecked")
public Object invoke(
Object object,
Method method,
Method method1,
Object[] args) throws Exception {
final String name = method.getName();
if ( "toString".equals( name ) ) {
return proxiedClassName + "@" + System.identityHashCode( object );
}
else if ( "equals".equals( name ) ) {
return proxiedObject == object;
}
else if ( "hashCode".equals( name ) ) {
return System.identityHashCode( object );
}
final boolean hasGetterSignature = method.getParameterTypes().length == 0
&& method.getReturnType() != null;
final boolean hasSetterSignature = method.getParameterTypes().length == 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, args[0] );
return null;
}
else {
// todo : what else to do here?
return null;
}
}
}
}