Question

how to run the async task at specific time? (I want to run it every 2 mins)

I tried using post delayed but it’s not working?

    tvData.postDelayed(new Runnable(){

    @Override
    public void run() {
        readWebpage();

    }}, 100);

In the above code readwebpage is function which calls the async task for me..

Right now below is the method which I am using

   public void onCreate(Bundle savedInstanceState) {

         readwebapage();

   }

   public void readWebpage() {
    DownloadWebPageTask task = new DownloadWebPageTask();
    task.execute("http://www.google.com");

   }

   private class DownloadWebPageTask extends AsyncTask<String, Void, String> {
    @Override
    protected String doInBackground(String... urls) {
        String response1 = "";
        response1=read(); 
                   //read is my another function which does the real work    
        response1=read(); 
        super.onPostExecute(response1);
        return response1;
    }


      protected void onPostExecute(String result) {


         try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            TextView tvData = (TextView) findViewById(R.id.TextView01);
            tvData.setText(result);

        DownloadWebPageTask task = new DownloadWebPageTask();
        task.execute(new String[] { "http://www.google.com" });

    }

    }

This is what I my code is and it works perfectly fine but the big problem I drains my battery?

Answer 1

You can use handler if you want to initiate something every X seconds. Handler is good because you don’t need extra thread to keep tracking when firing the event. Here is a short snippet:

private final static int INTERVAL = 1000 * 60 * 2; //2 minutes
Handler mHandler = new Handler();

Runnable mHandlerTask = new Runnable()
{
     @Override 
     public void run() {
          doSomething();
          mHandler.postDelayed(mHandlerTask, INTERVAL);
     }
};

void startRepeatingTask()
{
    mHandlerTask.run(); 
}

void stopRepeatingTask()
{
    mHandler.removeCallbacks(mHandlerTask);
}

Note that doSomething should not take long (something like update position of audio playback in UI). If it can potentially take some time (like downloading or uploading to the web), then you should use ScheduledExecutorService‘s scheduleWithFixedDelay function instead.