Handler handler = new Handler() {
    public void handleMessage(Message msg) {
      //do something
    };
  };
handler.sendEmptyMessageDelayed(0, 100 * 1000);

private static class MyHandler extends Handler {
    WeakReference<MainActivity> mWeakReferenceActivity;
    public MyHandler(MainActivity activity) {
      mWeakReferenceActivity = new WeakReference<MainActivity>(activity);
    }

    @Override
    public void handleMessage(Message msg) {
      super.handleMessage(msg);
      if (null != mWeakReferenceActivity) {
        MainActivity _activity = mWeakReferenceActivity.get();
        //_activity.dosomething();
      }
    }
  }