Javassist classes can be shared with multiple threads?

Question

Can I share Javassist classes in multiple threads to gets a better performance in a web app? I think that I can create a cache with ConcurrentMap for proxyClass to avoid creation in each page request.

My code is:

ProxyFactory factory = new ProxyFactory();
factory.setFilter(IGNORE_BRIDGE_AND_OBJECT_METHODS);
factory.setInterfaces(new Class[] { type });

Class<?> proxyClass = factory.createClass(); // can I cache here after class creation?

Object proxyInstance = ...; // objenesis creates new instance here
setHandler(proxyInstance, myCustomHandlerHere);

UPDATE: I see the Javassist code, and Javassist also provides a cache.

Answer 1

Sure you can. Javassist compiled classes are first class classes (even if only for a short time) so it's a good idea to cache the created classes once they've been created to save yourself the overhead of recompiling them over-and-over. Plus you don't have to invent improbable names for your classes since you will only recompile the same virtual code once.