Add KeyListener On Swing JPanel

Use code like this

JFrame frame = new JFrame();
JPanel pnl = new JPanel();
pnl.addKeyListener(keyListener);
pnl.setFocusable(true);
frame.add(pnl);
frame.pack();
pnl.drawing.requestFocus();

How to minimize and restore Java Swing JFrame

1. Minimize -> use this method frame.setState ( Frame.ICONIFIED );
2. Restore -> use this method frame.setState ( Frame.NORMAL );

frame is instance of JFrame