JAVA程序全局键盘监听事件

// 注册应用程序全局键盘事件, 所有的键盘事件都会被此事件监听器处理.
Toolkit tk = Toolkit.getDefaultToolkit();
tk.addAWTEventListener(new MyAWTEventListener(), AWTEvent.KEY_EVENT_MASK);
class MyAWTEventListener implements AWTEventListener {
    private boolean controlPressed = false;
    private boolean cPressed       = false;
    @Override
    public void eventDispatched(AWTEvent event) {
        if (event.getClass() == KeyEvent.class) {
            // 被处理的事件是键盘事件.
            KeyEvent keyEvent = (KeyEvent) event;
            if (keyEvent.getID() == KeyEvent.KEY_PRESSED) {
                keyPressed(keyEvent);
            } else if (keyEvent.getID() == KeyEvent.KEY_RELEASED) {
                keyReleased(keyEvent);
            }
        }
    }
    private void keyPressed(KeyEvent event) {
        if (event.getKeyCode() == KeyEvent.VK_CONTROL) {
            controlPressed = true;
        } else if (event.getKeyCode() == KeyEvent.VK_C) {
            cPressed = true;
        }
        if (controlPressed && cPressed) {
         &nbs