我怎么能在计时器中做到这一点我的程序会每秒做一些事情？

Question

在MainActivity.java的顶部，我添加了：

private Handler customHandler = new Handler();
long timeSwapBuff = 0L;

然后在onCreate里面我做了：

@Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        startTime = SystemClock.uptimeMillis();
customHandler.postDelayed(updateTimerThread,0);

        timerValue = (TextView) findViewById(R.id.timerValue);

        startButton = (Button) findViewById(R.id.startButton);

        startButton.setOnClickListener(new View.OnClickListener() {

            public void onClick(View view) {
                startTime = SystemClock.uptimeMillis();
                customHandler.postDelayed(updateTimerThread, 0);

            }
        });

        pauseButton = (Button) findViewById(R.id.pauseButton);
        pauseButton.setOnClickListener(new View.OnClickListener() {

            public void onClick(View view) {
                customHandler.removeCallbacks(updateTimerThread);

            }
        });

然后在updateTimerThread：

private Runnable updateTimerThread = new Runnable() {

        public void run() {

            long updatedTime = 0L;
            long timeInMilliseconds = 0L;
            timeInMilliseconds = SystemClock.uptimeMillis() - startTime;//System.currentTimeMillis() - startTime;
            updatedTime = timeSwapBuff + timeInMilliseconds;

            int secs = (int) (updatedTime / 1000);
            int mins = secs / 60;
            secs = secs % 60;
            int milliseconds = (int) (updatedTime % 1000);
            timerValue.setText("" + mins + ":"
                    + String.format("%02d", secs) + ":"
                    + String.format("%03d", milliseconds));
            customHandler.postDelayed(this, 0);
        }

    };

现在每次从开始运行我的程序时，计时器将从00:00:00开始

现在我想以某种方式添加每一秒做某事的东西。 不要重置计时器不暂停或停止它让它继续运行，但每一秒我想在我的程序中做其他事情。

问题是如何检查每一秒做某事？