Android implements 30 minutes of countdown function

public class MainActivity extends AppCompatActivity {

  private int minute = 30;//This is a minute  private int second = 0;//This is the number of seconds after the minute.  Here is a case of 30 minutes, so minute is 30 and second is 0  private TextView timeView;
  private Timer timer;
  private TimerTask timerTask;
  //This is a message received and processed  private Handler handler = new Handler() {
    public void handleMessage(Message msg) {
      if (minute == 0) {
        if (second == 0) {
          ("Time out !");
          if (timer != null) {
            ();
            timer = null;
          }
          if (timerTask != null) {
            timerTask = null;
          }
        } else {
          second--;
          if (second >= 10) {
            ("0" + minute + ":" + second);
          } else {
            ("0" + minute + ":0" + second);
          }
        }
      } else {
        if (second == 0) {
          second = 59;
          minute--;
          if (minute >= 10) {
            (minute + ":" + second);
          } else {
            ("0" + minute + ":" + second);
          }
        } else {
          second--;
          if (second >= 10) {
            if (minute >= 10) {
              (minute + ":" + second);
            } else {
              ("0" + minute + ":" + second);
            }
          } else {
            if (minute >= 10) {
              (minute + ":0" + second);
            } else {
              ("0" + minute + ":0" + second);
            }
          }
        }
      }
    }

  };


  @Override
  protected void onCreate(Bundle savedInstanceState) {
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    (savedInstanceState);
    setContentView(.activity_main);
    timeView = (TextView) findViewById();

    (minute + ":" + second);

    timerTask = new TimerTask() {

      @Override
      public void run() {
        Message msg = new Message();
         = 0;
        (msg);
      }
    };

    timer = new Timer();
    (timerTask, 0, 1000);

  }

  @Override
  protected void onDestroy() {
    if (timer != null) {
      ();
      timer = null;
    }
    if (timerTask != null) {
      timerTask = null;
    }
    minute = -1;
    second = -1;
    ();
  }

  @Override
  protected void onStart() {
    ();
  }

  @Override
  protected void onStop() {
    ();
  }

  @Override
  protected void onResume() {
    ();
  }

  @Override
  protected void onRestart() {
    ();
  }

  @Override
  protected void onPause() {
    ();
  }
}