Came across another technique in animation, see this site
This guy uses java.awt.image.MemoryImageSource and lets you see his source code and how he did it.
I looked at some java games online and found a pool one which uses the above method at:
This is one smooth game...I looked under covers at his class file and it is chock full of math with the most bodacious doubles imaginable.
Hope that points you in a good direction...