Want to control jdb inside java program with stdout but won't work

[Ron]

I'm developing a lightweight frontend for java and I'd like to add
debugging capabilities to it. I figured I could just launch jdb in my
program and use write(byte[] b) to stdout to control it. But, it
doesn't work. In fact, stdin gives me this much:

Set uncaught java.lang.Throwable
Set deferred uncaught java.lang.Throwable
Initializing jdb ...VM Started: No frames on the current call stack

And that's it. No "main[1]". Using println("cont") does nothing. Can
anyone shed some light on the situation?

Thanks,
Ron