Event Java


            import java.awt.KeyEventDispatcher;
import java.awt.KeyboardFocusManager;
import java.awt.event.KeyEvent;
public class Main {
  public static void main(String[] argv) throws Exception {
    KeyboardFocusManager.getCurrentKeyboardFocusManager().addKeyEventDispatcher(
        new KeyEventDispatcher() {
          public boolean dispatchKeyEvent(KeyEvent e) {
            if (e.getID() == KeyEvent.KEY_TYPED) {
              e.setKeyChar('a');
            }
            boolean discardEvent = false;
            return discardEvent;
          }
        });
  }
}