How can I preset a JFrame?

Question

Hi, using an external library which creates a JFrame window, there is a way to preset its l&f before showing it?

also something like accessing its own thread could be a solution (via reflection I mean)?

Another question, time ago I watched some JFrame having custom aplha borders (some shape applied), could you tell me if it was a supported/standard JFrame feature?

Answer 1

How to Set the Look and Feel