Foreground service not receiving location updates in Android 7.0+ when screen is off

问题

I am trying to create an Android application that continuously logs device location data in realtime while the device screen is off. My code works correctly with Android 6.0 and earlier but it seems that Android 7.0+ breaks my app.

I have implemented an Android foreground service that uses a wakelock and subscribes to the Google FusedLocation API. Once the screen is turned off the onLocationChanged callback is never triggered.

Has anyone seen a solution to this problem? I have tried disabling Battery Optimization through the Android Device Settings for my app as well as for the Google Services Framework and the Fused Location.

public class ForegroundLocationService extends Service implements
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener,
        LocationListener {

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

    // the notification id for the foreground notification
    public static final int GPS_NOTIFICATION = 1;

    // the interval in seconds that gps updates are requested
    private static final int UPDATE_INTERVAL_IN_SECONDS = 15;

    // is this service currently running in the foreground?
    private boolean isForeground = false;

    // the google api client
    private GoogleApiClient googleApiClient;

    // the wakelock used to keep the app alive while the screen is off
    private PowerManager.WakeLock wakeLock;

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

        // create google api client
        googleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();

        // get a wakelock from the power manager
        final PowerManager powerManager = (PowerManager) getSystemService(Context.POWER_SERVICE);
        wakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {

        if (!isForeground) {

            Log.v(TAG, "Starting the " + this.getClass().getSimpleName());

            startForeground(ForegroundLocationService.GPS_NOTIFICATION,
                    notifyUserThatLocationServiceStarted());
            isForeground = true;

            // connect to google api client
            googleApiClient.connect();

            // acquire wakelock
            wakeLock.acquire();
        }

        return START_REDELIVER_INTENT;
    }

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

    @Override
    public void onDestroy() {

        Log.v(TAG, "Stopping the " + this.getClass().getSimpleName());

        stopForeground(true);
        isForeground = false;

        // disconnect from google api client
        googleApiClient.disconnect();

        // release wakelock if it is held
        if (null != wakeLock && wakeLock.isHeld()) {
            wakeLock.release();
        }

        super.onDestroy();
    }

    private LocationRequest getLocationRequest() {

        LocationRequest locationRequest = LocationRequest.create();

        // we always want the highest accuracy
        locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

        // we want to make sure that we get an updated location at the specified interval
        locationRequest.setInterval(TimeUnit.SECONDS.toMillis(0));

        // this sets the fastest interval that the app can receive updates from other apps accessing
        // the location service. for example, if Google Maps is running in the background
        // we can update our location from what it sees every five seconds
        locationRequest.setFastestInterval(TimeUnit.SECONDS.toMillis(0));
        locationRequest.setMaxWaitTime(TimeUnit.SECONDS.toMillis(UPDATE_INTERVAL_IN_SECONDS));

        return locationRequest;
    }

    private Notification notifyUserThatLocationServiceStarted() {

        // pop up a notification that the location service is running
        Intent notificationIntent = new Intent(this, NotificationActivity.class);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0,
                notificationIntent, PendingIntent.FLAG_CANCEL_CURRENT);

        final Notification.Builder builder = new Notification.Builder(this)
                .setSmallIcon(R.drawable.ic_launcher_foreground)
                .setContentTitle(getString(R.string.foreground_location_service))
                .setContentText(getString(R.string.service_is_running))
                .setContentIntent(pendingIntent)
                .setWhen(System.currentTimeMillis());

        final Notification notification;
        if (Build.VERSION.SDK_INT < 16) {
            notification = builder.getNotification();
        } else {
            notification = builder.build();
        }

        return notification;
    }

    @Override
    public void onConnected(@Nullable Bundle bundle) {

        try {

            // request location updates from the fused location provider
            LocationServices.FusedLocationApi.requestLocationUpdates(
                    googleApiClient, getLocationRequest(), this);

        } catch (SecurityException securityException) {
            Log.e(TAG, "Exception while requesting location updates", securityException);
        }
    }

    @Override
    public void onConnectionSuspended(int i) {
        Log.i(TAG, "Google API Client suspended.");
    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
        Log.e(TAG, "Failed to connect to Google API Client.");
    }

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

I have included a complete working sample of the code that I am using to test here: https://github.com/joshuajwitter/ForegroundLocationService

FitBit seems to have the same issue, here is the discussion

Here are the resources that I have already looked at:

Code Samples for Android O

Keep app running in background on Android all the time

Android, get the location when the screen is off

Background Location Limits

Inconsistent location updates in foreground service when in deep sleep (doze)

Foreground service not receiving location updates in Doze mode in Android O

EDIT 2018.01.30: I have also tried running the ForegroundLocationService in its own process:

<service
    android:name="foregroundlocation.stackoverflowexample.com.foregroundlocation.ForegroundLocationService"
    android:enabled="true"
    android:stopWithTask="false"
    android:process=":ForegroundLocationService"
    android:exported="false" >
</service>

as well as updating my code to use the FusedLocationProviderClient, still no luck.

回答1:

I had the same issue and I have found a working solution. In order to listen to location updates, you should NOT call this method:

public Task<Void> requestLocationUpdates (LocationRequest request, 
LocationCallback callback, Looper looper)

You should use a pending intent instead of a callback, i.e. you should call the method:

public Task<Void> requestLocationUpdates (LocationRequest request, 
PendingIntent callbackIntent)

Checkout the link to read more: https://developers.google.com/android/reference/com/google/android/gms/location/FusedLocationProviderClient.html#requestLocationUpdates(com.google.android.gms.location.LocationRequest, android.app.PendingIntent)

回答2:

I had been experiencing this issue on emulated devices running 7.0 and 8.0 and consistently the location callback was not being triggered when the screen was off (cmd+P). I was finally able to get my hands on a real 7.0 device (Galaxy S7) and I was not able to replicate the issue. Sorry if I wasted anyone's time, apparently it is an emulator issue.

回答3:

LocationServices.FusedLocationApi is deprecated.

I just refactored my App as follows. Hope it helps:

This is what I am calling in the onCreate-Method of my Service:

public void start(Context ctx) {
        FusedLocationProviderClient client = LocationServices
                .getFusedLocationProviderClient(ctx);
        //Define quality of service:
        LocationRequest request = LocationRequest.create();
        request.setInterval(1000); //Every second
        request.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        if (locCallback != null) {
            client.removeLocationUpdates(locCallback);
        }
        locCallback = createNewLocationCallback();
        client.requestLocationUpdates(request, locCallback, null);
}

And this is the method for creating the Callback:

private LocationCallback createNewLocationCallback() {
    LocationCallback locationCallback = new LocationCallback() {
        @Override
        public void onLocationResult(LocationResult result) {
            Location loc = result.getLastLocation();
            // Do something with the location (may be null!)
        }
    };
    return locationCallback;
}

Guess, I also found that somewhere as example, but did not keep the reference.

I do not have Oreo on my own. But some testers confirmed, that it works.

To keep the service in foreground, I am just calling "startForeground" afterwards in the onCreate method of my service.