How to ensure that an AlarmManager fires even if the android app is closed?

Question

I have an app that should update/get data from a server every six hours. To do so I made an AlarmManager the following way:

public class Repository {

public static AlarmManager alarmManager;

public static void initAlarmManager(Context context){

    //start the update alarm manager
    Intent resultIntent = new Intent(context,AlarmReceiver.class);
    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, resultIntent, PendingIntent.FLAG_UPDATE_CURRENT);

    alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
    alarmManager.setInexactRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, 0,  60 * 60 * 1000, pendingIntent);
}

My AlarmReceiver now has to look for updates and if there is new data of a specific condition it has to notify the user via a notification. This is a part of my AlarmReceiver:

public class AlarmReceiver extends BroadcastReceiver {

@Override
public void onReceive(Context context, Intent intent) {

    if(Repository.ddfDb == null){
        Repository.initDdfDb(context);
    }

    if(Repository.alarmManager == null){
        Repository.initAlarmManager(context);
    }

    for(Episode episode : Repository.ddfDb.getListOfNextEpisodes()){
        Notification.showNotification(context,episode);
    }
}

}

Since my AlarmManager should run all the time I let him start also when boot is completed. To do so I added the following to my manifest file:

<receiver android:name=".AlarmReceiver">
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED"/>
        </intent-filter>
    </receiver>

I run the function initAlarmManager() in my onCreate() of the mainActivity. So if the app is started, the AlarmManager starts too and everything works fine. Even if I close my app via the home button or change to another app via the "change between recent apps" button, my AlarmManager still fires and I get the notifications although my app is in the background.

I also run the function initAlarmManager() in my AlarmReceiver. So if I reboot my phone, the receiver gets called, sees that my AlarmManager is null and inits it afterwards. So everything works fine here too.

But here is my problem: If I press the "change between recent apps" button and close my app with a swipe my AlarmManager stops and I won't get any further notifications. This is weird, since after a reboot my app also doesn't appear in the recent apps menu but there it works.

I googled a lot and some people say it is impossible, since if the user really wants to close the app, he has to be able to do so. I understand this, since it provides security against virus apps. But also I see apps like WhattsApp being able to always notify the user.

So is there really no way to accomplish my always running AlarmManager or if there is a way, how do I implement this?

Thank you in advance!

for debugging reasons or does that already ensure that my AlarmManager run always? — selmaohneh, Jan 23 '16 at 09:41
Try using Services it will run even after app is closed. but it may drain battery. — Muthu, Jan 23 '16 at 09:44
what about using android:process=":remote" in my manifest? could this solve my problem? — selmaohneh, Jan 23 '16 at 10:19

score 1 · Accepted Answer · answered Jan 26 '16 at 08:38

I solved this issue the following way:

I moved all operations I did in the BroadcastReceiver to an IntentService. All the BroadcastReceiver now does is starting this IntentService.

When the app is now closed by swiping it away from the recent apps menu, my notifications still pop up.

Thanks to Muthu for giving me the right hint!

How to ensure that an AlarmManager fires even if the android app is closed?

1 Answers1