Play Location Services getLastLocation returns null

Question

I am trying to listen to location changes but sometimes onLocationChanged callback is never called and getLastLocation returns null, w

Answer 1

I have developed my application based on below code you can use if you want My application name is "https://play.google.com/store/apps/details?id=com.deep.profilemaper" .

Here is my code : BackgroundLocationService.java

public class BackgroundLocationService extends Service implements
    GooglePlayServicesClient.ConnectionCallbacks,GooglePlayServicesClient.OnConnectionFailedListener,LocationListener  {

    IBinder mBinder = new LocalBinder();

    private LocationClient mLocationClient;
    private LocationRequest mLocationRequest;
   // Flag that indicates if a request is underway.
   private boolean mInProgress;

   private Boolean servicesAvailable = false;

public class LocalBinder extends Binder {
    public BackgroundLocationService getServerInstance() {
        return BackgroundLocationService.this;
    }
}

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


    mInProgress = false;
    // Create the LocationRequest object
    mLocationRequest = LocationRequest.create();
    // Use high accuracy
    mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
    // Set the update interval to 5 seconds
    mLocationRequest.setInterval(Constants.UPDATE_INTERVAL);
    // Set the fastest update interval to 1 second
    mLocationRequest.setFastestInterval(Constants.FASTEST_INTERVAL);

    servicesAvailable = servicesConnected();

    /*
     * Create a new location client, using the enclosing class to
     * handle callbacks.
     */
    mLocationClient = new LocationClient(this, this, this);


}

private boolean servicesConnected() {

    // Check that Google Play services is available
    int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);

    // If Google Play services is available
    if (ConnectionResult.SUCCESS == resultCode) {

        return true;
    } else {

        return false;
    }
}

public int onStartCommand (Intent intent, int flags, int startId)
{
    super.onStartCommand(intent, flags, startId);

    if(!servicesAvailable || mLocationClient.isConnected() || mInProgress)
        return START_STICKY;

    setUpLocationClientIfNeeded();
    if(!mLocationClient.isConnected() || !mLocationClient.isConnecting() && !mInProgress)
    {
        appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Started", Constants.LOG_FILE);
        mInProgress = true;
        mLocationClient.connect();
    }

    return START_STICKY;
}

/*
 * Create a new location client, using the enclosing class to
 * handle callbacks.
 */
private void setUpLocationClientIfNeeded()
{
    if(mLocationClient == null) 
        mLocationClient = new LocationClient(this, this, this);
}

// Define the callback method that receives location updates
@Override
public void onLocationChanged(Location location) {
    // Report to the UI that the location was updated
    String msg = Double.toString(location.getLatitude()) + "," +
            Double.toString(location.getLongitude());
    Log.d("debug", msg);
    // Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
    appendLog(msg, Constants.LOCATION_FILE);
}

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

public String getTime() {
    SimpleDateFormat mDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    return mDateFormat.format(new Date());
}

public void appendLog(String text, String filename)
{       
   File logFile = new File(filename);
   if (!logFile.exists())
   {
      try
      {
         logFile.createNewFile();
      } 
      catch (IOException e)
      {
         // TODO Auto-generated catch block
         e.printStackTrace();
      }
   }
   try
   {
      //BufferedWriter for performance, true to set append to file flag
      BufferedWriter buf = new BufferedWriter(new FileWriter(logFile, true)); 
      buf.append(text);
      buf.newLine();
      buf.close();
   }
   catch (IOException e)
   {
      // TODO Auto-generated catch block
      e.printStackTrace();
   }
}

@Override
public void onDestroy(){
    // Turn off the request flag
    mInProgress = false;
    if(servicesAvailable && mLocationClient != null) {
        mLocationClient.removeLocationUpdates(this);
        // Destroy the current location client
        mLocationClient = null;
    }
    // Display the connection status
    // Toast.makeText(this, DateFormat.getDateTimeInstance().format(new Date()) + ": Disconnected. Please re-connect.", Toast.LENGTH_SHORT).show();
    appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Stopped", Constants.LOG_FILE);
    super.onDestroy();  
}

/*
 * Called by Location Services when the request to connect the
 * client finishes successfully. At this point, you can
 * request the current location or start periodic updates
 */
@Override
public void onConnected(Bundle bundle) {

    // Request location updates using static settings
    mLocationClient.requestLocationUpdates(mLocationRequest, this);
    appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Connected", Constants.LOG_FILE);

}

/*
 * Called by Location Services if the connection to the
 * location client drops because of an error.
 */
@Override
public void onDisconnected() {
    // Turn off the request flag
    mInProgress = false;
    // Destroy the current location client
    mLocationClient = null;
    // Display the connection status
    // Toast.makeText(this, DateFormat.getDateTimeInstance().format(new Date()) + ": Disconnected. Please re-connect.", Toast.LENGTH_SHORT).show();
    appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Disconnected", Constants.LOG_FILE);
}

/*
 * Called by Location Services if the attempt to
 * Location Services fails.
 */
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
    mInProgress = false;

    /*
     * Google Play services can resolve some errors it detects.
     * If the error has a resolution, try sending an Intent to
     * start a Google Play services activity that can resolve
     * error.
     */
    if (connectionResult.hasResolution()) {

    // If no resolution is available, display an error dialog
    } else {

      }
    }

}

***Constants.java***

public final class Constants {

// Milliseconds per second
private static final int MILLISECONDS_PER_SECOND = 1000;
// Update frequency in seconds
private static final int UPDATE_INTERVAL_IN_SECONDS = 30;
// Update frequency in milliseconds
public static final long UPDATE_INTERVAL = MILLISECONDS_PER_SECOND * UPDATE_INTERVAL_IN_SECONDS;
// The fastest update frequency, in seconds
private static final int FASTEST_INTERVAL_IN_SECONDS = 30;
// A fast frequency ceiling in milliseconds
public static final long FASTEST_INTERVAL = MILLISECONDS_PER_SECOND * FASTEST_INTERVAL_IN_SECONDS;
// Stores the lat / long pairs in a text file
public static final String LOCATION_FILE = "sdcard/location.txt";
// Stores the connect / disconnect data in a text file
public static final String LOG_FILE = "sdcard/log.txt";


/**
 * Suppress default constructor for noninstantiability
 */
private Constants() {
    throw new AssertionError();
    }
}

This code contains some variables like current Date and Time and constants like LOG_File that is only for logging purpose . so, i have excluded that code . This code is perfectly tested and working . Give it a try.

Thanks.