One clever way to deal with java permissions is to have a snippet of LostusScript (which isn't subject to java security policy) that finds and edits the java policy file. You generally have to restart the client for it to take effect, but it's an option.
As for multiple windows, I know there's a way that you can put a reference to your original JFrame somewhere global, which then allows you to check whether it exists already before creating a new one. If it's there, you can just order it to go to the front of the screen.
One clever way to deal with java permissions is to have a snippet of LostusScript (which isn't subject to java security policy) that finds and edits the java policy file. You generally have to restart the client for it to take effect, but it's an option.
As for multiple windows, I know there's a way that you can put a reference to your original JFrame somewhere global, which then allows you to check whether it exists already before creating a new one. If it's there, you can just order it to go to the front of the screen.