Java2d, Java3d or Opengl best performance

I am planning to write a game in java that must be multi-platform and must have a very good performance. I am making a kind of rts. This rts will only be 2d. I am planning to get as many moving little objects(pics) within a second as i can. What is the best method in doing so. Performance wise and implementing wise. I never worked with Java2d or Java3d and Opengl only with c++. So what is the best choice you reckon?

Also every performance/programming tip is welcom :-)

[486 byte] By [LA Onda] at [2007-9-27 16:59:43]