2. iv read something about an ogl profiler.... where what how?
or is a normal profiler good enough to detect ogl bottleholes?
A normal Java profiler should be able to give you an idea of where time is being spent in the OpenGL portions of your application. The built-in -Xprof profiler in HotSpot used to be a good low-cost way of profiling your app, but it got much more expensive in 1.5. Nowadays I would probably recommend one of the commercial profilers or JFluid.
3. what does resize()? (the one from the glenvent listener)
i read it sets the viewport.....
also i need to set the viewport by myself on some places (drawing into textures)... but i need to reset it afterwarts to its original size... is there a better way then use getHight/With from the glcanvas to do this?
Before your resize() callback is called, JOGL makes a call to glViewport(0, 0, width, height) where width and height are the parameters supplied by the AWT (and which are equivalent to the component's width and height). Based on this information you can reset the viewport or do any other operations you need to.