ode4j works nicely
This is currently the best way to use ODE in Java.
fully functional port of ode to pure java. usable for realtime physics simulations.
This works great! I had a little trouble getting it to compile and run in Eclipse, but it was well worth my time. There are about 30 working demos which compile from source code, some of which are amazing. I would recommend this to anybody interested in doing 3D Java coding which requires physics.