My PIC compiler of choice is BoostC, here is the license page for it:
http://www.sourceboost.com/Products/...mitations.html
Java isn't going to be an ideal language for PICs, due to very limited system resources. I doubt that there is a Java interpreter that will run on a PIC12/PIC16 as a result. A quick check on embedded Java found Jcontrol, requiring a minimum of 60KB just for the interpreter, and several others that were even more resource hungry.