Is there any tool or framework able to make it easier to test distributed software written in Java? My system under test is a peer-to-peer software, and I'd like to perform testing using something like PNUnit, but with Java instead of .Net.

The system under test is a framework I'm developing to build P2P applications. It uses JXTA as a lower subsystem, trying to hide some complexities of it. It's currently an academic project, so I'm pursuing simplicity at this moment.

In my test, I want to demonstrate that a peer (running in its own process, possibly with multiple threads) can discover another one (running in another process or even another machine) and that they can exchange a few messages. I'm not using mocks nor stubs because I need to see both sides working simultaneously. I realize that some kind of coordination mechanism is needed, and PNUnit seems to be able to do that.

I've bumped into some initiatives like Pisces, which "aims to provide a distributed testing environment that extends JUnit, giving the developer/tester an ability to run remote JUnits and create complex test suites that are composed of several remote JUnit tests running in parallel or serially", but this project and a few others I have found seem to be long dead.