How to run a task every second for 10 seconds.

Question

I have the following code which runs a task every second, but I also want the task to stop after 10 seconds. Can this logic be implemented with a handler in which I'm using? I've tried implementing a counter with a while loop but couldn't get it to work

mHandler = new Handler();
mUpdateUI = new Runnable() {
    public void run() {
        mVistaInspectionDate = HousingFragment.getVistaInspectionDate();
        mVistaInspectionDateTextView.setText(mVistaInspectionDate);     

        if (mVistaInspectionDate != null) {
            mHandler.removeCallbacks(mUpdateUI);
        }
            mHandler.postDelayed(mUpdateUI, 1000); // 1 second
    }
};  

mHandler.post(mUpdateUI);

See http://stackoverflow.com/questions/4544197/how-do-i-schedule-a-task-to-run-at-periodic-intervals — iflorit, May 22 '14 at 06:17

score 0 · Answer 1 · answered May 22 '14 at 06:00

Use a While loop with a boolean variable and set this variable to true, then you could count how many times your task has run and stop the task for 1 sec after each run but it could happen that the delay for 1 sec is not one sec because of thread sheduling.

So you could use the time to count and stop the while loop. Save your curennt time and every 1 second will your task executed. After 10 times your Thread terminate, either throu terminating the thread in the while loop or to set the boolean variable to false.

score 0 · Answer 2 · answered May 22 '14 at 07:32

0

Try using Timer class, or Quartz scheduler if you can have external dependencies, rather than coding the scheduling and threading logic in your own application.

answered May 22 '14 at 07:32

Amir Moghimi

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score 0 · Accepted Answer · answered May 22 '14 at 07:54

In order to use a counter, you can wrap it in a function like this:

private void postDelayedWrapped(final int counter, int delay) {
    if (counter <= 0) return;
    mUpdateUI = new Runnable() {
        public void run() {
            mVistaInspectionDate = HousingFragment.getVistaInspectionDate();
            mVistaInspectionDateTextView.setText(mVistaInspectionDate);

            if (mVistaInspectionDate != null) {
                mHandler.removeCallbacks(mUpdateUI); //necessary?
            }
            postDelayedWrapped(counter - 1, 1000);
        }
    };

    mHandler.postDelayed(mUpdateUI, delay);
}

And you start it like this:

mHandler = new Handler();
postDelayedWrapped(10,0);

score 0 · Answer 4 · answered May 22 '14 at 09:01

How about subclassing the Handler class and use an instance of this class keeping track of how many times postDelayed() was called?

   public class MyHandler extends Handler {
        private int maxTimes;
        private int currentTimes; 
        private Runnable runner;
        public Handler(int maxTimes) {
              this.maxTimes = maxTimes;
        }

        @Override
        public void post(Runnable runner) {
              this.runner = runner;
        }

        @Override
        public void postDelayed(Runnable runner,long ms) {
               if (currentTimes == maxTimes) {
                    this.removeCallbacks(runner);
               } else {
                    super.postDelayed(runner,ms);
                    currentTimes++;
               }
        } 


   }

   mHandler = new MyHandler(10);//using subclass instance
   //from here on is the same as the original code.
   mUpdateUI = new Runnable() {
   public void run() {
      mVistaInspectionDate = HousingFragment.getVistaInspectionDate();
      mVistaInspectionDateTextView.setText(mVistaInspectionDate);     

      if (mVistaInspectionDate != null) {
          mHandler.removeCallbacks(mUpdateUI);
      }
         mHandler.postDelayed(mUpdateUI, 1000); // 1 second
    }
  };  

  mHandler.post(mUpdateUI);

How to run a task every second for 10 seconds.

4 Answers4