I don't think you can have 2 copies of log4j running at the same time in jboss, certainly not in the same LoaderRepository (essentially "classloader").
Can't you do what you want by setting up the log4j.xml file appropriately?
Ta for the reply.
In order to convince management to switch from WebLogic to JBoss I am making sure the application runs in both before the decision is influenced, erm I mean made.
This seemed the best solution I could think of to allow App Server independent logging - AFAIK WebLogic doesn't use Log4j and has it's own logging API.