Why is run() getting called just once?

Question

Consider this class, AnimationThread:

class AnimationThread implements Runnable {
    public void pause() {
        doAnimation = false;
    }

    public void doStart(){
        doAnimation = true;
    }

    @Override
    public void run() {
        // TODO Auto-generated method stub
        if (doAnimation) {
            //my code
        }

        try {
            Thread.sleep(500);
        } 
        catch (InterruptedException e) {

        }
    }
}

Now I am starting this thread in onCreate of an activity (just showing rough code):

AnimationThread animRunnable = new AnimationThread();
animationThread = new Thread(animRunnable);
animationThread.start();

But run() is getting called just once (I traced a log to confirm that). I just want to know that when I started the thread why run() is not getting called repeatedly with 500 sleep. It is just called once.

Answer 1

That is how it is supposed to be.

A Thread runs by executing its run method (just once). After that it is considered done/dead/finished/completed.

If you want to loop, you have to do it yourself (inside of the run method), or use some ExecutorService to call the Runnable repeatedly.

Answer 2

Of course the run() method will be executed once. If you want to repeat the statements inside the run method then you have to use loop. Take a look at TimerTask - will runs a task at a specified time or repeatedly.

EDIT:

1. Android - Controlling a task with Timer and TimerTask?
2. Timer task schedule