Android 监听返回等按键事件

@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
    switch (keyCode) {
        case KeyEvent.KEYCODE_BACK:
            //执行的代码
            break;
    }
    return super.onKeyUp(keyCode, event);
}
@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
    switch (keyCode) {
        case KeyEvent.KEYCODE_BACK:
            long secondTime = System.currentTimeMillis();
            if (secondTime - firstTime > 1000) {
                //执行的代码
                return true;
            } else {
                //执行的代码
            }
            break;
    }
    return super.onKeyUp(keyCode, event);
}