KeYTestGen is an automated test case generation system for the JavaCard programming language, which almost (almost!) means that it supports the nice and juicy bits of the core Java 1.5.
KTG works by using the symbolic execution engine of the KeY system (www.key-project.org) in order to understand what paths may be taken through a programs execution tree at runtime. Based on this information, it isolates a set of leaves on the tree which are then used as the basis for test case generation. The system deduces what conditions must be binding on the pre-state of the program in order for each leave to be reached, and generates a test case for each one of them, satisfying this constraint.
KTG is meant to be flexible and support a wide array of target frameworks for test case generation. Currently, basic support for JUnit4 is is the main concern, but this will grow over time.
You can see a Prezi which provides an overview here: http://prezi.com/byvnxmmikjyj/keytestgen2/
I have very little spare time to develop KTG in, but I would very much love to see this project grow to its full potential. If you are willing to join in, I would be more than happy to hear from you!