Hi,

It is a known problem that 4.0.4 and EJB-3 leaks Hibernate lazy proxy classes generated by Javassist. The cache introduced in Javassist-3.4 (4.0.4 ships with Javassist-3.2) should solve the problem, but unfortunately doesn't. Probably because Hibernate uses a different MethodHandler for each new proxy and so you get a cache miss.

However it is possible to use Javassist-3.4 and supply a custom ClassLoaderProvider instance. It is important that this provide creates a new CL instance that just delegates. So the CL can be collected (and so can the proxy). Here is how to do that. The code can be put into a service mbean:

 ProxyFactory.useCache = false;
 ProxyFactory.classLoaderProvider = new ClassLoaderProvider() {
 public ClassLoader get(ProxyFactory pf) {
 ClassLoader parent = getClassLoader(pf);
 ClassLoader cl = new ClassLoader(parent) {
 @Override
 public Class loadClass(final String className) throws ClassNotFoundException {
 try {
 return super.loadClass(className);
 } catch (ClassNotFoundException e) {
 // only allow loading of ProxyObject from this loader
 if (className.equals(ProxyObject.class.getName())) {
 return ProxyObject.class.getClassLoader().loadClass(className);
 }
 // was some other classname, throw the CNFE
 throw e;
 }
 }
 };
 return cl;
 }

 private ClassLoader getClassLoader(ProxyFactory pf) {
 Class superClass = pf.getSuperclass();
 Class[] interfaces = pf.getInterfaces();
 ClassLoader loader = null;
 if (superClass != null && !superClass.getName().equals("java.lang.Object"))
 loader = superClass.getClassLoader();
 else if (interfaces != null && interfaces.length > 0)
 loader = interfaces[0].getClassLoader();

 if (loader == null) {
 loader = getClass().getClassLoader();
 // In case javassist is in the endorsed dir
 if (loader == null) {
 loader = Thread.currentThread().getContextClassLoader();
 if (loader == null)
 loader = ClassLoader.getSystemClassLoader();
 }
 }

 return loader;
 }

 };