Maybe it would be easier to have your jedit module interact with a screen session, ie..you change buffers in jedit, and it automatically sends an appropriate command to a named screen sesssion, changing its directory as needed.
It is a thought. I've got a plugin that will do something (anything -- I could make it play a game of Go if you like...) on a buffer change. The thing is I still want to be able to access the current buffer from within basically any xterm, or possibly even a normal console, not just one specific xterm or screen session. I think I'll stick with my original plan. Got about three minutes work left for that.
Gotta love these small projects! :-D No more of this 8 months on the same project crap!!! (Anybody laying odds yet on how soon it will be before I start hacking Ensmer again?)