FusedLocationApi.getLastLocation always null

I'd like to simply retrieve device location in my Android project and in order to do so I use the play-services approach:

    protected synchronized void buildGoogleApiClient() {

    mGoogleApiClient = new GoogleApiClient.Builder( MainSearchActivity.this )
        .addConnectionCallbacks(new GoogleApiClient.ConnectionCallbacks() {
            @Override
            public void onConnected( Bundle bundle ){
                Location location = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
                if( location == null ){
                    LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, new LocationListener() {
                        @Override
                        public void onLocationChanged(Location location) {
                            lastLocation = location;
                        }
                    });
                }
            }
            @Override
            public void onConnectionSuspended( int i ){

            }

        })
        .addOnConnectionFailedListener(new GoogleApiClient.OnConnectionFailedListener() {
            @Override
            public void onConnectionFailed( ConnectionResult connectionResult ){
                if( connectionResult.hasResolution() ){
                    try {
                        // Start an Activity that tries to resolve the error
                        connectionResult.startResolutionForResult(MainSearchActivity.this, CONNECTION_FAILURE_RESOLUTION_REQUEST);
                    }catch( IntentSender.SendIntentException e ){
                        e.printStackTrace();
                    }
                }else{
                    Utils.logger("Location services connection failed with code " + connectionResult.getErrorCode(), Utils.LOG_DEBUG );
                }
            }
        })
        .addApi(LocationServices.API)
        .build();

    mGoogleApiClient.connect();
}

public Location retrieveLastLocation(){
    Location loc = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
    if( loc == null)
    {

    }
    return loc; //TODO: What if loc is null?
}

but the loc variable is ALWAYS null. It's as such on different phones, every single time. Also lastLocation, that I try to assign in the onLocationChanged, never changes. Always null.

These are the permission I set for the app

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="com.vogella.android.locationapi.maps.permission.MAPS_RECEIVE" />
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />

I just don't get it: Why can't the LocationServices retrieve a position? I have all geolocation settings enabled on all three the devices I tested on.

Solution 1:

The fused Location Provider will only maintain background location if at least one client is connected to it. Now just turning on the location service will not guarantee to store the last known location.

Once the first client connects, it will immediately try to get a location. If your activity is the first client to connect and getLastLocation() is invoked right away in onConnected(), that might not be enough time for the first location to arrive..

I suggest you to launch the Maps app first, so that there is at least some confirmed location, and then test your app.

Solution 2:

As in this post said, The fused Location Provider will only maintain background location if at least one client is connected to it.

But we can skip the process of launching the Google Maps app to get last location by following way.

What we need to do is

1. We have to request location update from FusedLocationProviderClient
2. Then we can get the last location from FusedLocationProviderClient, it wouldn't be null.

Request Location

LocationRequest mLocationRequest = LocationRequest.create();
mLocationRequest.setInterval(60000);
mLocationRequest.setFastestInterval(5000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
LocationCallback mLocationCallback = new LocationCallback() {
    @Override
    public void onLocationResult(LocationResult locationResult) {
        if (locationResult == null) {
            return;
        }
        for (Location location : locationResult.getLocations()) {
            if (location != null) {
                //TODO: UI updates.
            }
        }
    }
};
LocationServices.getFusedLocationProviderClient(context).requestLocationUpdates(mLocationRequest, mLocationCallback, null);

Get last location

LocationServices.getFusedLocationProviderClient(context).getLastLocation().addOnSuccessListener(new OnSuccessListener<Location>() {
        @Override
        public void onSuccess(Location location) {
            //TODO: UI updates.
        }
    });

For best result requestLocationUpdates in onStart() of the Activity, and then you can get last location.

Solution 3:

I think there is a small miss which is not visible to me in the code shown.

The mGoogleApiClient is built but seems not connected.You can verify this by calling mGoogleApiClient.isConnected().

You can just override the onStart method and call connect there. Or you can override onResume() in case you want to access the location whenever ur activity is visible.

  @Override
protected void onStart() {
    super.onStart();
    if (mGoogleApiClient != null) {
        mGoogleApiClient.connect();
    }
}

Solution 4:

First, create a LocationRequest object:

 // Create the LocationRequest object
 mLocationRequest = LocationRequest.create()
    .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
    .setInterval(10 * 1000)        // 10 seconds, in milliseconds
    .setFastestInterval(1 * 1000); // 1 second, in milliseconds

Then, make sure the user has granted permission to use location. If so, get the location from requestLocationUpdates as follows:

void getLocation() {
    Location location = null;
    if (ContextCompat.checkSelfPermission(activity, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, 1);

        /*TODO!! INSERT CODE TO PROMPT USER TO GIVE PERMISSION*/

    } else {
        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
    }

    mLastLocation = location;
    LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient,this);
}

Be sure to remove the updates if you only need one location without constant monitoring. This way, you will never get a null Location.

For more information, go to http://blog.teamtreehouse.com/beginners-guide-location-android.