If the class loader of one class is the parent of the class loader of
the other path, I think you should be okay.  If not, you'll need to have
at least one interface that is loaded by a mutual parent in order for
the two classes to communicate without using reflection.

So, why exactly are you having this problem? Its not a common problem,
so I take it you have an unusual set up. It might help us to help you if
you tell us what your set up is and why.  We might be able to tell you
how to "fix" you setup or tell you a different approach to what you're
trying to do.

HTH,
Daniel.