Debugging IntentService that syncs ParseObjects

Question

I have an android project that uses parse.com for its backend. To cut the number of api calls, I had been pinning "not so important" data to the local data store and trying to sync it once every user session. I am using a IntentService for this. I am calling the IntentService as shown below. But I don't see any Log messages or debugging breakpoints getting called when the IntentService gets called.

Question 1: How do I debug any Intent service?

Question 2: I want to execute the service once per user session(everytime the user opens and closes the app). I don't want to add the code to the onPause method of the activity because my app has multiple activities and so the onPause gets called multiple times in a session. Therefore I am calling the service from onBackPressed of the activity which is the last screen before the user can quit the app. Is this fool proof?

Intent Calling code :

@Override
public void onBackPressed() {
    if(exitCount == 1)
    {
        exitCount=0;

        Intent i= new Intent(this, SyncChoiceService.class);
        this.startService(i);
        super.onBackPressed();
    }
    else
    {
        Toast.makeText(getApplicationContext(), "Press Back again to quit.", Toast.LENGTH_SHORT).show();
        exitCount++;
    }

    return;
}

IntentService Code

    public class SyncChoiceService extends IntentService {

    /**
     * Creates an IntentService.  Invoked by your subclass's constructor.
     *
     * @param name Used to name the worker thread, important only for debugging.
     */
    public SyncChoiceService(String name) {
        super("SyncChoiceService");
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        //android.os.Debug.waitForDebugger();
// Adding this waitForDebugger doesn't make a difference
        ParseQuery query = new ParseQuery("PostChoice");
        query.fromPin();
        query.findInBackground(new FindCallback<ParseObject>() {
            @Override
            public void done(final List<ParseObject> list, ParseException e) {
                    if(list!=null)
                    {
                        if(!list.isEmpty())
                        {
                            ParseObject.saveAllInBackground(list, new SaveCallback() {
                                @Override
                                public void done(ParseException e) {
                                    ParseObject.unpinAllInBackground(list, new DeleteCallback() {
                                        @Override
                                        public void done(ParseException e) {
                                            Log.i("Unpinned ","everything");
                                        }
                                    });
                                }
                            });
                        }
                    }
            }
        });

    }
}

Answer 1

Question 1: How do I debug any Intent service? As mentioned in the comments you should be able to set a break point and attach the debugger to the service.

Question 2: I want to execute the service ...? This will depend on your requirement and how you want to define a session.

If a session is defined as when the user logs in/logs out then you can simply put the code simple start your in your login / log out logic

It gets a little more complicated if you define a session as when your app is in the fore ground/until it goes to the background/killed. I will try to provide as much info/cases as possible:

Starting the application is the easier part so, you can simply start your service in onCreate of your launcher activity or even onCreate of Application if you sub class it

Closing the app depends on what you define as closing. If you require the user to explicitly back out of the app then you do not need to take care of the case below:

User can simply put the app in the background by pressing the home button in which case onBackPressed will not be called and its possible that the system cleans up your app in the background so you'll never get a chance to start your service. In this case system will call onSaveInstanceState and give you a chance to start your service. (If you do not care a bout this case then you should be fine). One edge case here is that onSavedInstance state is also called on screen rotation so you'll need some logic to distinguish between when the app is going to the background vs. screen rotation

One thing on the side: onHandleIntent is called on the background thread so you can just use the synchronous versions of find save and unpin this will help you avoid all the nesting.

Hopefully this helps.