Java + arduino

I am having some trouble with something that should be easy to do. I want my Java application to talk to my arduino. Problem is that it isn't as simple as I thought (I had previously done it with applesctipt and it took a few lines of code).

Everything that I find seems to want some localy installed drivers/libraries or something. What I want is something hat can be packaged into my application and doesn't require anything to be installed manualy. Of course my app must work on windows/mac/linux(this one is optional). Any ideas on how I could do this?

I have been trying the example that is on the playground (with RXTX) and got it working. Well sort of. When I select the port where arduino is connected I get the gnu.io.PortInUseException: Unknown Application. And I can't figure out who is using the serial port. I closed the arduino IDE but it doesn't help. I also tryed plugging in the arduino in another USB port. But I still get the PortInUseException.

Have you looked at 'Processing' the Java Computer half of the Arduino pair?

It builds cross-platform executables.

Can you explain that a little?

I managed to get the rxtx working but I still don't like it because it isn't realy multiplatform. Well it is if you install the rxtx library but that isn't optimal solution.