"adrian(a)jboss.org" wrote : | You should use an agent. | | The Transformer is only there for backwards compatibility with AOP from before the agent api was available. | The problem with agents is that they scan every class, regardless of where it came from, which usually has a performance impact (although, in fairness we can probably optimize this away to an instanceof) . We also do not install one by default, and have different ones depending on the JVM (although JRockit support is going away). Since we control classloading, it seems like adding a transformer to specific domains is a better approach. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4222644#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...