How to use a Shader in Java3D?

Hi,
I’m trying to put a shader made in Cg in a Java3D animation.
But I really don’t know how to do it!

I was trying to create a moon sphere and than use a shader to chance the appearance of this moon.
After crating the moon, it’s texture etc, how can I put a shader on this animation?
Does any one know how to do it??