Why are some KeyEvent keycodes throwing “IllegalArgumentException: Invalid key code”?

Question

I\'m trying to automate some processes using Robot and it seems certain keycodes (only symbols that require you to hold shift when typing it normally) in

Answer 1

I don't know Robot, but isn't that because it needs to be two keys pressed to an exclamation mark to be inserted.

There are no exclamation mark key on the keyboards.