Android Timer within a service

Question

I am having problems running a timer in a service I have created. The task that the timer calls simply isn't called. I know that the service starts as I have put toasts within it and they are called, but not when they are within the timer. Help appreciated.

service class:

public class LocalService extends Service
{
    private static Timer timer = new Timer(); 
    private Context ctx;

    public IBinder onBind(Intent arg0) 
    {
          return null;
    }

    public void onCreate() 
    {
          super.onCreate();
          ctx = this; 
          startService();
    }

    private void startService()
    {           
        timer.scheduleAtFixedRate(new mainTask(), 0, 5000);
    }

    private class mainTask extends TimerTask
    { 
        public void run() 
        {
            Toast.makeText(ctx, "test", Toast.LENGTH_SHORT).show();
        }
    }    

    public void onDestroy() 
    {
          super.onDestroy();
          Toast.makeText(this, "Service Stopped ...", Toast.LENGTH_SHORT).show();
    }    
}

Main class:

public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    startService(new Intent(RingerSchedule.this, LocalService.class));      
}

score 53 · Accepted Answer · answered Sep 29 '10 at 07:55

Android does not allow UI events like Toasts from outside the main thread. The run is getting called, but the Toast is being ignored.

To create the Toast on the UI thread, you can use a Handler and an empty Message like so:

public class LocalService extends Service
{
    private static Timer timer = new Timer(); 
    private Context ctx;

    public IBinder onBind(Intent arg0) 
    {
          return null;
    }

    public void onCreate() 
    {
          super.onCreate();
          ctx = this; 
          startService();
    }

    private void startService()
    {           
        timer.scheduleAtFixedRate(new mainTask(), 0, 5000);
    }

    private class mainTask extends TimerTask
    { 
        public void run() 
        {
            toastHandler.sendEmptyMessage(0);
        }
    }    

    public void onDestroy() 
    {
          super.onDestroy();
          Toast.makeText(this, "Service Stopped ...", Toast.LENGTH_SHORT).show();
    }

    private final Handler toastHandler = new Handler()
    {
        @Override
        public void handleMessage(Message msg)
        {
            Toast.makeText(getApplicationContext(), "test", Toast.LENGTH_SHORT).show();
        }
    };    
}

Don't you need to have a static `Handler` with a `WeakReference` to prevent from leaks? — Apostrofix, Mar 08 '16 at 07:52
This is great thanks. How may I pass into the service an int variable instead of the 5000 for the millis? I want to be able to dynamically/programattically adjust the timer interval. — Frank Zappa, Aug 28 '17 at 14:29
@Frank Zappa just use `Long.parseLong(variable)` instead of `5000` — Prateek Chaubey, Oct 15 '21 at 11:15

score 2 · Answer 2 · answered Aug 06 '17 at 06:12

2

Thanks, I also needed to cancel the timer ..

public void onDestroy() {
        timer.cancel();
        Toast.makeText(this, "ServiceTalkGeology stopped.", 
        Toast.LENGTH_SHORT).show();
        super.onDestroy();
}

answered Aug 06 '17 at 06:12

Tybion

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Android Timer within a service

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