Maybe this book can help you out. It includes a 2d/3d game library java2d etc. Just got my copy, looks good  
It uses software rendering, but also mentions lwjgl , gl4java.

"Developing Games in Java - David Brackeen"

In the NeHe opengl tutorial 9 about moving bitmaps across the screen, the first paragraph says:

"You'll learn the following: Moving bitmaps around the screen in 3D, removing the black pixels around the bitmap (using blending)".

The bitmap they use is a white star with a black background and its blended with the screen back ground to remove the black in the animation.  Haven't found out how to do it in java

Hello, does java 2d have a method to enable image blending to take out the black background as does opengl?