I ported Iain Lobb's Gamepad ActionScript library to a Processing library [0], which is still available from the Library Manager in Processing as far as I know.

It abstracts away keyboard handling behind a Gamepad class. Please feel free to use it in a template!

[0] https://github.com/heuermh/gamepad-processing

Excellent for use as a teaching tool that will get some audiences excited about programming.