Background service with location listener in android

I am creating a background service that will run in its own process. It should allow me to listen if the device location has changed. I should be able to change criteria like the distance moved before notifying the UI.

How can I do the same? I have a little knowledge of service and LocationListener implementations. Any tutorials around the net would be appreciated.

I got one back-link from stack overflow, but I didn't understand much of it.

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最佳答案

First you need to create a Service. In that Service, create a class extending LocationListener. For this, use the following code snippet of Service: 

public class LocationService extends Service {
public static final String BROADCAST_ACTION = "Hello World";
private static final int TWO_MINUTES = 1000 * 60 * 2;
public LocationManager locationManager;
public MyLocationListener listener;
public Location previousBestLocation = null;


Intent intent;
int counter = 0;


@Override
public void onCreate() {
super.onCreate();
intent = new Intent(BROADCAST_ACTION);
}


@Override
public void onStart(Intent intent, int startId) {
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
listener = new MyLocationListener();
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 4000, 0, (LocationListener) listener);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 4000, 0, listener);
}


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


protected boolean isBetterLocation(Location location, Location currentBestLocation) {
if (currentBestLocation == null) {
// A new location is always better than no location
return true;
}


// Check whether the new location fix is newer or older
long timeDelta = location.getTime() - currentBestLocation.getTime();
boolean isSignificantlyNewer = timeDelta > TWO_MINUTES;
boolean isSignificantlyOlder = timeDelta < -TWO_MINUTES;
boolean isNewer = timeDelta > 0;


// If it's been more than two minutes since the current location, use the new location
// because the user has likely moved
if (isSignificantlyNewer) {
return true;
// If the new location is more than two minutes older, it must be worse
} else if (isSignificantlyOlder) {
return false;
}


// Check whether the new location fix is more or less accurate
int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation.getAccuracy());
boolean isLessAccurate = accuracyDelta > 0;
boolean isMoreAccurate = accuracyDelta < 0;
boolean isSignificantlyLessAccurate = accuracyDelta > 200;


// Check if the old and new location are from the same provider
boolean isFromSameProvider = isSameProvider(location.getProvider(),
currentBestLocation.getProvider());


// Determine location quality using a combination of timeliness and accuracy
if (isMoreAccurate) {
return true;
} else if (isNewer && !isLessAccurate) {
return true;
} else if (isNewer && !isSignificantlyLessAccurate && isFromSameProvider) {
return true;
}
return false;
}






/** Checks whether two providers are the same */
private boolean isSameProvider(String provider1, String provider2) {
if (provider1 == null) {
return provider2 == null;
}
return provider1.equals(provider2);
}






@Override
public void onDestroy() {
// handler.removeCallbacks(sendUpdatesToUI);
super.onDestroy();
Log.v("STOP_SERVICE", "DONE");
locationManager.removeUpdates(listener);
}


public static Thread performOnBackgroundThread(final Runnable runnable) {
final Thread t = new Thread() {
@Override
public void run() {
try {
runnable.run();
} finally {


}
}
};
t.start();
return t;
}
public class MyLocationListener implements LocationListener
{


public void onLocationChanged(final Location loc)
{
Log.i("*****", "Location changed");
if(isBetterLocation(loc, previousBestLocation)) {
loc.getLatitude();
loc.getLongitude();
intent.putExtra("Latitude", loc.getLatitude());
intent.putExtra("Longitude", loc.getLongitude());
intent.putExtra("Provider", loc.getProvider());
sendBroadcast(intent);


}
}


@Override
public void onStatusChanged(String provider, int status, Bundle extras) {


}


public void onProviderDisabled(String provider)
{
Toast.makeText( getApplicationContext(), "Gps Disabled", Toast.LENGTH_SHORT ).show();
}




public void onProviderEnabled(String provider)
{
Toast.makeText( getApplicationContext(), "Gps Enabled", Toast.LENGTH_SHORT).show();
}
}

Add this Service any where in your project, the way you want! :)

小开

I know I am posting this answer little late, but I felt it is worth using Google's fuse location provider service to get the current location.

Main features of this api are :

1.Simple APIs: Lets you choose your accuracy level as well as power consumption.

2.Immediately available: Gives your apps immediate access to the best, most recent location.

3.Power-efficiency: It chooses the most efficient way to get the location with less power consumptions

4.Versatility: Meets a wide range of needs, from foreground uses that need highly accurate location to background uses that need periodic location updates with negligible power impact.

It is flexible in while updating in location also. If you want current location only when your app starts then you can use getLastLocation(GoogleApiClient) method.

If you want to update your location continuously then you can use requestLocationUpdates(GoogleApiClient,LocationRequest, LocationListener)

You can find a very nice blog about fuse location here and google doc for fuse location also can be found here.

Update

According to developer docs starting from Android O they have added new limits on background location.

If your app is running in the background, the location system service computes a new location for your app only a few times each hour. This is the case even when your app is requesting more frequent location updates. However if your app is running in the foreground, there is no change in location sampling rates compared to Android 7.1.1 (API level 25).

小开

Very easy no need create class extends LocationListener 1- Variable 

private LocationManager mLocationManager;
private LocationListener mLocationListener;
private static double currentLat =0;
private static double currentLon =0;

2- onStartService()

@Override public void onStartService() {
addListenerLocation();
}

3- Method addListenerLocation()

 private void addListenerLocation() {
mLocationManager = (LocationManager)
getSystemService(Context.LOCATION_SERVICE);
mLocationListener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
currentLat = location.getLatitude();
currentLon = location.getLongitude();


Toast.makeText(getBaseContext(),currentLat+"-"+currentLon, Toast.LENGTH_SHORT).show();


}


@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}


@Override
public void onProviderEnabled(String provider) {
Location lastKnownLocation = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if(lastKnownLocation!=null){
currentLat = lastKnownLocation.getLatitude();
currentLon = lastKnownLocation.getLongitude();
}


}


@Override
public void onProviderDisabled(String provider) {
}
};
mLocationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, 500, 10, mLocationListener);
}

4- onDestroy()

@Override
public void onDestroy() {
super.onDestroy();
mLocationManager.removeUpdates(mLocationListener);
}
小开

Background location service. It will be restarted even after killing the app.

MainActivity.java

public class MainActivity extends AppCompatActivity {
AlarmManager alarmManager;
Button stop;
PendingIntent pendingIntent;


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);


if (alarmManager == null) {
alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(this, AlarmReceive.class);
pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), 30000,
pendingIntent);
}
}
}

BookingTrackingService.java

public class BookingTrackingService extends Service implements LocationListener {


private static final String TAG = "BookingTrackingService";
private Context context;
boolean isGPSEnable = false;
boolean isNetworkEnable = false;
double latitude, longitude;
LocationManager locationManager;
Location location;
private Handler mHandler = new Handler();
private Timer mTimer = null;
long notify_interval = 30000;


public double track_lat = 0.0;
public double track_lng = 0.0;
public static String str_receiver = "servicetutorial.service.receiver";
Intent intent;


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


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


mTimer = new Timer();
mTimer.schedule(new TimerTaskToGetLocation(), 5, notify_interval);
intent = new Intent(str_receiver);
}


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


this.context = this;




return START_NOT_STICKY;
}


@Override
public void onDestroy() {
super.onDestroy();
Log.e(TAG, "onDestroy <<");
if (mTimer != null) {
mTimer.cancel();
}
}


private void trackLocation() {
Log.e(TAG, "trackLocation");
String TAG_TRACK_LOCATION = "trackLocation";
Map<String, String> params = new HashMap<>();
params.put("latitude", "" + track_lat);
params.put("longitude", "" + track_lng);


Log.e(TAG, "param_track_location >> " + params.toString());


stopSelf();
mTimer.cancel();


}


@Override
public void onLocationChanged(Location location) {


}


@Override
public void onStatusChanged(String provider, int status, Bundle extras) {


}


@Override
public void onProviderEnabled(String provider) {


}


@Override
public void onProviderDisabled(String provider) {


}


/******************************/


private void fn_getlocation() {
locationManager = (LocationManager) getApplicationContext().getSystemService(LOCATION_SERVICE);
isGPSEnable = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
isNetworkEnable = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);


if (!isGPSEnable && !isNetworkEnable) {
Log.e(TAG, "CAN'T GET LOCATION");
stopSelf();
} else {
if (isNetworkEnable) {
location = null;
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 1000, 0, this);
if (locationManager != null) {
location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {


Log.e(TAG, "isNetworkEnable latitude" + location.getLatitude() + "\nlongitude" + location.getLongitude() + "");
latitude = location.getLatitude();
longitude = location.getLongitude();
track_lat = latitude;
track_lng = longitude;
//                        fn_update(location);
}
}
}


if (isGPSEnable) {
location = null;
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 0, this);
if (locationManager != null) {
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
Log.e(TAG, "isGPSEnable latitude" + location.getLatitude() + "\nlongitude" + location.getLongitude() + "");
latitude = location.getLatitude();
longitude = location.getLongitude();
track_lat = latitude;
track_lng = longitude;
//                        fn_update(location);
}
}
}


Log.e(TAG, "START SERVICE");
trackLocation();


}
}


private class TimerTaskToGetLocation extends TimerTask {
@Override
public void run() {


mHandler.post(new Runnable() {
@Override
public void run() {
fn_getlocation();
}
});


}
}


//    private void fn_update(Location location) {
//
//        intent.putExtra("latutide", location.getLatitude() + "");
//        intent.putExtra("longitude", location.getLongitude() + "");
//        sendBroadcast(intent);
//    }
}

AlarmReceive.java (BroadcastReceiver)

public class AlarmReceive extends BroadcastReceiver {


@Override
public void onReceive(Context context, Intent intent) {
Log.e("Service_call_"  , "You are in AlarmReceive class.");
Intent background = new Intent(context, BookingTrackingService.class);
//        Intent background = new Intent(context, GoogleService.class);
Log.e("AlarmReceive ","testing called broadcast called");
context.startService(background);
}
}

AndroidManifest.xml

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />


<service
android:name=".ServiceAndBroadcast.BookingTrackingService"
android:enabled="true" />


<receiver
android:name=".ServiceAndBroadcast.AlarmReceive"
android:exported="false">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>

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