I've used ZenTest and autotest to work on Ruby projects before, and I used to using them for test-driven development a la this configuration. I have a project that I'm currently working on in Java, and I was wondering if there is something similar in the Java world to achieve the same effect.
Might I also suggest Infinitest, it is under active development and works with other languages besides Java. I believe it works fine with Scala, but I haven't had much luck using it with Groovy.
It is free for personal use and is being developed by Improving.