How to trap incoming EJB method calls

[Mac]

We´re building a framework for our home apps. Among some other
services we've planned to build this services:
- Declarative EJB exception handling
- Automatic statistic reports (of EJB execution times and errors)
- Automatic auditory (to know a user have been doing)

All this is solved in the Web container. We use struts so we have a
central point to trap calls to "servlets" and do our custom exception
handling (send events to managers, log to JMS...)

We can not rely exclusively on the Web tier to do all this stuff
because we also have Fat (or Thick) clients attached directly to the
EJB tier.

But... How do we trap incoming EJB calls in a transparent way to
apps??