Jetpackager is a project mainly written in Java, it's free.
Java wrapper for Excelsior's command line tools for Jet Compiler and JetPackII
A Java wrapper for Excelsior JET Java compiler and bundler for Java6.
This is Java wrapper for the JET compiler & JetPackII.
This wrapper was developer for JET 6 and 6.5, but has been seen working with JET7 (so give it a try!).
Visit Excelsior JET homepage at [http://www.excelsior-usa.com/jet.html]