[jboss-jira] [JBoss JIRA] Commented: (JBSER-117) Problem with JBoss serializing of dynamic proxies

Problem with JBoss serializing of dynamic proxies ------------------------------------------------- Key: JBSER-117 URL: https://jira.jboss.org/jira/browse/JBSER-117 Project: JBoss Serialization Issue Type: Bug Affects Versions: 1.0.3 GA, 1.1.0 Beta Reporter: Maksym Ivanchenko Assignee: Clebert Suconic When we try to serialize a proxy that contains some child entity which points to proxy itself the following exception occurs: org.jboss.serial.exception.SerializationException: Object reference 1 was not found Simple test case for problem reproducing: import java.io.Serializable; import java.lang.reflect.InvocationHandler; import java.lang.reflect.Method; import java.lang.reflect.Proxy; import org.jboss.serial.io.JBossObjectOutputStream; import org.junit.Test; public class StandaloneProxySerializationTest { @Test public void testSerialization() throws Exception { ISampleEntity entity = new SampleEntityImpl(); Class<?>[] interfaces = new Class<?>[] {ISampleEntity.class}; SampleEntityInvocationHandler handler = new SampleEntityInvocationHandler(entity); ISampleEntity proxy = (ISampleEntity) Proxy.newProxyInstance(Thread.currentThread() .getContextClassLoader(), interfaces, handler); ISampleEntity childEntity = new SampleEntityImpl(); proxy.setChild(childEntity); childEntity.setParent(proxy); JBossObjectOutputStream jbossSerializer = new JBossObjectOutputStream(null); jbossSerializer.smartClone(proxy); } private static interface ISampleEntity { public ISampleEntity getParent(); public void setParent(ISampleEntity parent); public ISampleEntity getChild(); public void setChild(ISampleEntity child); } private static class SampleEntityImpl implements ISampleEntity, Serializable { private static final long serialVersionUID = 1L; private ISampleEntity parent; private ISampleEntity child; @Override public ISampleEntity getParent() { return parent; } @Override public void setParent(ISampleEntity parent) { this.parent = parent; } @Override public ISampleEntity getChild() { return child; } @Override public void setChild(ISampleEntity child) { this.child = child; } } private static class SampleEntityInvocationHandler implements InvocationHandler, Serializable { private static final long serialVersionUID = 1L; private ISampleEntity entity; public SampleEntityInvocationHandler(ISampleEntity entity) { this.entity = entity; } @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { return method.invoke(entity, args); } } } Upon ivestigating this issue we found that the problem is in ProxyPersister.readData() method. It reads the handler, the proxy class, constructs a proxy and only then puts it to cache. But if a proxy data contains proxy itself then it tries to find it by reference (which is not in cache yet, because the handler is still being read). So it throws "Object reference not found" exception. We worked around this problem by introducing an InvocationHandler wrapper in ProxyPersister: Patched ProxyPersister.java: /* * JBoss, Home of Professional Open Source * Copyright 2005, JBoss Inc., and individual contributors as indicated * by the @authors tag. See the copyright.txt in the distribution for a * full listing of individual contributors. * * This is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * This software 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 software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */ package org.jboss.serial.persister; import java.io.IOException; import java.io.ObjectInput; import java.io.ObjectOutput; import java.lang.reflect.Constructor; import java.lang.reflect.InvocationHandler; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.lang.reflect.Proxy; import org.jboss.serial.classmetamodel.ClassMetaData; import org.jboss.serial.classmetamodel.StreamingClass; import org.jboss.serial.exception.SerializationException; import org.jboss.serial.objectmetamodel.ObjectSubstitutionInterface; import org.jboss.serial.objectmetamodel.ObjectsCache; /** * $Id: ProxyPersister.java,v 1.11 2006/04/24 23:49:40 csuconic Exp $ * * @author <a href="mailto:clebert.suconic@jboss.com">Clebert Suconic</a> */ public class ProxyPersister implements Persister { private byte id; public byte getId() { return id; } public void setId(byte id) { this.id = id; } public void writeData(ClassMetaData metaData, ObjectOutput output, Object obj, ObjectSubstitutionInterface substitution) throws IOException{ Object handler = Proxy.getInvocationHandler(obj); output.writeObject(obj.getClass()); output.writeObject(handler); } static class InvocationHandlerWrapper implements InvocationHandler { private InvocationHandler wrappedHandler; public void setWrappedHandler(InvocationHandler wrappedHandler) { this.wrappedHandler = wrappedHandler; } public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { return wrappedHandler.invoke(proxy, method, args); } } public Object readData (ClassLoader loader, StreamingClass streaming, ClassMetaData metaData, int referenceId, ObjectsCache cache, ObjectInput input, ObjectSubstitutionInterface substitution) throws IOException{ try { Class proxy = (Class)input.readObject(); Constructor constructor = proxy.getConstructor(new Class[] { InvocationHandler.class }); InvocationHandlerWrapper wrapper = new InvocationHandlerWrapper(); Object obj = constructor.newInstance(new Object[]{wrapper}); cache.putObjectInCacheRead(referenceId,obj); Object handler = input.readObject(); wrapper.setWrappedHandler((InvocationHandler) handler); return obj; } catch (ClassNotFoundException e) { throw new SerializationException(e); } catch (NoSuchMethodException e) { throw new SerializationException(e); } catch (IllegalAccessException e) { throw new SerializationException(e); } catch (InstantiationException e) { throw new SerializationException(e); } catch (InvocationTargetException e) { throw new SerializationException(e); } } public boolean canPersist(Object obj) { // not implemented return false; } }