How to force an IntentService to stop immediately with a cancel button from an Activity?

Question

I have an IntentService that is started from an Activity and I would like to be able to stop the service immediately from the activity with a \"cancel\" button in the activi

Answer 1

Stopping a thread or a process immediately is often a dirty thing. However, it should be fine if your service is stateless.

Declare the service as a separate process in the manifest:

<service
     android:process=":service"
     ...

And when you want to stop its execution, just kill that process:

ActivityManager am = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
List<RunningAppProcessInfo> runningAppProcesses = am.getRunningAppProcesses();

Iterator<RunningAppProcessInfo> iter = runningAppProcesses.iterator();

while(iter.hasNext()){
    RunningAppProcessInfo next = iter.next();

    String pricessName = getPackageName() + ":service";

    if(next.processName.equals(pricessName)){
        Process.killProcess(next.pid);
        break;
    }
}

Answer 2

If using an IntentService, then I think you are stuck doing something like you describe, where the onHandleIntent() code has to poll for its "stop" signal.

If your background task is potentially long-running, and if you need to be able to stop it, I think you are better off using a plain Service instead. At a high level, write your Service to:

• Expose a "start" Intent to start an AsyncTask to perform your background work, saving off a reference to that newly-created AsyncTask.
• Expose a "cancel" Intent to invoke AsyncTask.cancel(true), or have onDestroy() invoke AsyncTask.cancel(true).
• The Activity can then either send the "cancel" Intent or just call stopService().

In exchange for the ability to cancel the background work, the Service takes on the following responsibilities:

• The AsyncTask doInBackground() will have to gracefully handle InterruptedException and/or periodically check for Thread.interrupted(), and return "early".
• The Service will have to ensure that stopSelf() is called (maybe in AsyncTask onPostExecute/onCancelled).

Answer 3

context.stopService(GPSService);

Answer 4

@Override
protected void onHandleIntent(Intent intent) {
    String action = intent.getAction();
    if (action.equals(Action_CANCEL)) {
        stopSelf();
    } else if (action.equals(Action_START)) {
        //handle
    }
}

Hope it works.

Answer 5

As @budius already mentioned in his comment, you should set a boolean on the Service when you click that button:

// your Activity.java
public boolean onClick() {
   //...
   mService.performTasks = false;
   mService.stopSelf();
}

And in your Intent handling, before you do the important task of committing/sending the intent information, just use that boolean:

// your Service.java
public boolean performTasks = true;

protected void onHandleIntent(Intent intent) {
   Bundle intentInfo = intent.getBundle();
   if (this.performTasks) {
      // Then handle the intent...
   }
}

Otherwise, the Service will do it's task of processing that Intent. That's how it was meant to be used, because I can't quite see how you could solve it otherwise if you look at the core code.

Answer 6

In case of IntentService it does not stop or takes any other request through some intent action until its onHandleIntent method completes the previous request.

If we try to start IntentService again with some other action, onHandleIntent will be called only when previous intent / task is finished.

Also stopService(intent); or stopSelf(); does not work until the onHandleIntent() method finishes its task.

So I think here better solution is to use normal Service here.

I hope it will help!