Exit Focused JFrame by Pressing Esc Key

ExitJFrameGUI.java

        getRootPane().getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(
          KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0), "Cancel");
          getRootPane().getActionMap().put("Cancel", new AbstractAction()
          { 
              public void actionPerformed(ActionEvent e)
              {
                  System.exit(0);
              }
       });