How to receive location updates in background? (API 26)

Question

I need to get continuous location updates from the application for my application. To do so, I followed the Android Developer Guide to get location updates. Because location updates can't be received in background in API 26, I added a foreground service (Background location limits). However, I still only receive updates when an other activity which requests location updates is in the foreground.

Location Service:

public class LocationUpdateService extends Service {

private static final String TAG = LocationUpdateService.class.getSimpleName();

private static final String NOTIFICATION_CHANNEL_ID = "TrackNotification";
private static final int FOREGROUND_SERVICE_ID = 1;
private static final int NOTIFICATION_ID = 1;
public static final String STATUS_INTENT = "status";
private static final int CONFIG_CACHE_EXPIRY = 600;

private NotificationManager mNotificationManager;
private NotificationCompat.Builder mNotificationBuilder;

private DatabaseReference mDatabaseReference;

private FusedLocationProviderClient mFusedLocationProviderClient;
private LocationRequest mLocationRequest;

private FirebaseRemoteConfig mFirebaseRemoteConfig;

private String uid;

@Override
public void onCreate() {
    super.onCreate();

    uid = FirebaseAuth.getInstance().getUid();
    if(uid == null)
        stopSelf();

    mFirebaseRemoteConfig = FirebaseRemoteConfig.getInstance();
    FirebaseRemoteConfigSettings configSettings = new FirebaseRemoteConfigSettings.Builder().build();
    mFirebaseRemoteConfig.setConfigSettings(configSettings);
    mFirebaseRemoteConfig.setDefaults(R.xml.remode_config_defaults);
    fetchRemoteConfig();

    mFusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this);
    mDatabaseReference = FirebaseDatabase.getInstance().getReference();

    mLocationRequest = new LocationRequest()
            .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
            .setFastestInterval(mFirebaseRemoteConfig.getLong("LOCATION_REQUEST_INTERVAL"))
            .setFastestInterval(mFirebaseRemoteConfig.getLong("LOCATION_REQUEST_INTERVAL_FASTEST"));

    bindNotification();
    setStatusMessage(R.string.connecting);


    startLocationTracking();
}

private LocationCallback mLocationCallback = new LocationCallback() {
    @Override
    public void onLocationResult(LocationResult locationResult) {
        Log.d(TAG,"Got location update!");
        if(locationResult == null)
            return;
        for(Location location : locationResult.getLocations()) {

            CustomLocation customLocation = LocationAdapter.toDatabaseLocation(location);
            mDatabaseReference.child("locations").child(uid).setValue(customLocation);
        }

    }

    @Override
    public void onLocationAvailability(LocationAvailability locationAvailability) {
        locationAvailability.isLocationAvailable();
        // TODO handle no location here
        super.onLocationAvailability(locationAvailability);
    }
};

@SuppressWarnings({"MissingPermission"})
private void startLocationTracking() {
    mFusedLocationProviderClient.requestLocationUpdates(mLocationRequest,mLocationCallback, Looper.myLooper());
}


private void fetchRemoteConfig() {
    mFirebaseRemoteConfig.fetch(CONFIG_CACHE_EXPIRY)
            .addOnCompleteListener(new OnCompleteListener<Void>() {
        @Override
        public void onComplete(@NonNull Task<Void> task) {
            Log.i(TAG,"Remote config fetched");
            mFirebaseRemoteConfig.activateFetched();
        }
    });
}

@Override
public void onDestroy() {
    setStatusMessage(R.string.not_tracking);
    mNotificationManager.cancel(NOTIFICATION_ID);
    mFusedLocationProviderClient.removeLocationUpdates(mLocationCallback);
    super.onDestroy();
}

@Nullable
@Override
public IBinder onBind(Intent intent) { return null; }

private void bindNotification() {
    mNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
    PendingIntent resultPendingIntent = PendingIntent.getActivity(this,0,
            new Intent(this, MainActivity.class),PendingIntent.FLAG_UPDATE_CURRENT);

    mNotificationBuilder = new NotificationCompat.Builder(this,NOTIFICATION_CHANNEL_ID)
            .setCategory(NotificationCompat.CATEGORY_STATUS)
            .setShowWhen(false)
            .setSmallIcon(R.drawable.ic_car)
    //        .setColor(getColor(R.color.colorPrimary))
            .setContentTitle(getString(R.string.app_name))
            .setOngoing(true)
            .setContentIntent(resultPendingIntent);
    startForeground(FOREGROUND_SERVICE_ID, mNotificationBuilder.build());
}

/**
 *
 * @param message Status message to display
 */
private void setStatusMessage(String message) {
    mNotificationBuilder.setContentText(message);
    mNotificationManager.notify(NOTIFICATION_ID, mNotificationBuilder.build());

    Intent intent = new Intent(STATUS_INTENT);
    intent.putExtra(getString(R.string.status),message);
    LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
}

private void setStatusMessage(int resID) {
    setStatusMessage(getString(resID));
}
}

And I gets started with

startService(new Intent(this,LocationUpdateService.class));

Android Manifest:

<service android:name=".LocationUpdateService" />

EDIT1: I now tested it on older API versions (22) and the problem is still the same: As long as some app with location requests is in the foreground it works, otherwise not. Maybe it's a problem with the FusedLocationProviderClient but I don't know what. I only found code examples with the old FusedLocationProvider API which is now deprecated.

Answer 1

Have you tried debugging to make sure your service is being hit?

This might sound silly, but have you checked if your service is registered in your manifest? I know I've definitely run into that issue.

<service android:name=".LocationService"
        android:label="Location Service"
        android:exported="true"
        android:enabled="true"
        android:process=":location_background_service"/>

For getting the location, when I set mine up, I created a class that implemented android.location.LocationListener.

private class LocationListener implements android.location.LocationListener {
    Location mLastLocation;

    public LocationListener(String provider) {
        Log.e(TAG, "LocationListener " + provider);
        mLastLocation = new Location(provider);
    }

    @Override
    public void onLocationChanged(Location location) {
        Log.e(TAG, "onLocationChanged: " + location);
        mLastLocation.set(location);
    }

    @Override
    public void onProviderDisabled(String provider) {
        Log.e(TAG, "onProviderDisabled: " + provider);
    }

    @Override
    public void onProviderEnabled(String provider) {
        Log.e(TAG, "onProviderEnabled: " + provider);
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        Log.e(TAG, "onStatusChanged: " + provider);
    }
}

You can create multiple instances for different providers. In my case, I ended up using 2.

LocationListener[] mLocationListeners = new LocationListener[]{
        new LocationListener(LocationManager.GPS_PROVIDER),
        new LocationListener(LocationManager.NETWORK_PROVIDER)
};

Then I initialized a LocationManager that can set a polling rate for each a LocationListener.

private void initializeLocationManager() {
    Log.e(TAG, "initializeLocationManager");
    if (mLocationManager == null) {
        mLocationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
    }
}

Then in your Service onCreate function, initialize your LocationManager, and use one of the listeners as your main source and the other as a fallback.

try {
        mLocationManager.requestLocationUpdates(
                LocationManager.NETWORK_PROVIDER,
                5 * 60 * 1000, //5 Minutes
                1F /*METERS*/,
                mLocationListeners[0]
        );
    } catch (java.lang.SecurityException ex) {
        Log.e(TAG, "failed to request location update. Insufficient permissions. ", ex);
        try {
            mLocationManager.requestLocationUpdates(
                    LocationManager.NETWORK_PROVIDER,
                    5 * 60 * 1000, //5 Minutes
                    1F /*METERS*/,
                    mLocationListeners[1]
            );
        } catch (java.lang.SecurityException e) {
            Log.e(TAG, "failed to request location update. Insufficient permissions. ", e);
        } catch (IllegalArgumentException e) {
            Log.e(TAG, "Network provider does not exist.", e);
        }
    } catch (IllegalArgumentException ex) {
        Log.e(TAG, "Network provider does not exist.", ex);
    }
}

(Sorry if this code is gross, it's a quick and dirty example.)