java.util.Scanner

The PlayerKeyEvent and the java.util.Scanner are doing completely different things so they are not really comparable to use one in place of the other.

The PlayerKeyEvent is called when a player presses a button on their keyboard and does something using that key.

The java.util.Scanner requires a full text input, it reads that input and then does something with it i.e. like you do with the PlayerCommandEvent, getting the command as a whole and splitting it to identify what the player wants to do. The Scanner would do more or less what the String.split() method does in this case but in a more complex manner.

But generally speaking you can use every Java method you want since the game is not limiting your coding to API methods only

btw to use the PlayerKeyEvent you need:

1) use player.registerKeys(blablabla)

2) use player.setListenForKeyInput(true);