How to force Java to reload class upon instantiation?

Question

Background:
I have a MainTest class that has many buttons, each of which instantiate a class that I am coding/testing. I want the code/test cycle for these classes to be

Answer 1

I found an article on exactly this problem.
http://www.zeroturnaround.com/blog/reloading-objects-classes-classloaders/

BUT, maerics answer looks good too. will try it later.