CountDownTimer，0，0

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Log.e("yw","kaishi"+System.currentTimeMillis());
        CountDownTimer timer = new CountDownTimer(, ) {//输入0,0则直接进入onFinish()
            @Override
            public void onTick(long millisUntilFinished) {
                Log.e("yw","zhongjian"+System.currentTimeMillis());
            }
            @Override
            public void onFinish() {
                Log.e("yw","over"+System.currentTimeMillis());
            }
        };
        timer.start();
    }