Develop Reference

why mobile phone gps provide sometime same coordinates on different location

Background: I am now working on an Android app to track vehicles where I required to get device location on every 10 second as on management decision. We are already developed this app which provides us updated location on time as our expected time interval.
Problem: When Vehicles are driving on the roads, the app gives us correct coordinates as our expected time interval, but sometime 5-20 minutes it provide same coordinates yet the vehicle is in a different location.
Code Review: 1) We use a method named getLocation() inside LocationClass that provide us latitude longitude of a device current location.
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 5;
private static final long MIN_TIME_BW_UPDATES = 1000*20;
public Location getLocation(Context context) {
Location location=null;
try {
locationManager = (LocationManager) context
.getSystemService(Context.LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider is enabled
} else {
this.canGetLocation = true;
if (ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
Toast.makeText(context,"Please! Provide Location Access Permission.....", Toast.LENGTH_LONG).show();
return TODO;
}
// if GPS Enabled get lat/long using GPS Services
if(isGPSEnabled) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
location.setProvider("GPS");
}
}
}
if (isNetworkEnabled && location==null) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
location.setProvider("AGPS");
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
2) We repeat this method using a timer on a service named GPSTracker at fixed time interval.
public class GPSTracker extends Service implements LocationListener {
private Timer mTimer = null;
private Handler mHandler = new Handler();
Location location;
#Override
public void onCreate() {
super.onCreate();
if (mTimer != null) {
mTimer.cancel();
} else {
// recreate new
mTimer = new Timer();
}
// schedule task
mTimer.scheduleAtFixedRate(new TimeDisplayTimerTask(), 10 * 1000, 10 * 1000);
}
class TimeDisplayTimerTask extends TimerTask {
#Override
public void run() {
// run on another thread
mHandler.post(new Runnable() {
#Override
public void run() {
location=new Location("");
LocationCls cls = new LocationCls();
location = cls.getLocation(getBaseContext());
}
});
}
}
}
I am trying to solve this issue a 2 long day but not found any coding problem or solution yet. Any Solution or Suggestion is highly appreciate.
Thanks in advance....

Trouble finding current Location Android [duplicate]

How do I get the current Latitude and Longitude of the mobile device in android using location tools?

Use the LocationManager.
LocationManager lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
Location location = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
double longitude = location.getLongitude();
double latitude = location.getLatitude();
The call to getLastKnownLocation() doesn't block - which means it will return null if no position is currently available - so you probably want to have a look at passing a LocationListener to the requestLocationUpdates() method instead, which will give you asynchronous updates of your location.
private final LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
longitude = location.getLongitude();
latitude = location.getLatitude();
}
}
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 2000, 10, locationListener);
You'll need to give your application the ACCESS_FINE_LOCATION permission if you want to use GPS.
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
You may also want to add the ACCESS_COARSE_LOCATION permission for when GPS isn't available and select your location provider with the getBestProvider() method.

Here is the class LocationFinder to find the GPS location. This class will call MyLocation, which will do the business.
LocationFinder
public class LocationFinder extends Activity {
int increment = 4;
MyLocation myLocation = new MyLocation();
// private ProgressDialog dialog;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.intermediat);
myLocation.getLocation(getApplicationContext(), locationResult);
boolean r = myLocation.getLocation(getApplicationContext(),
locationResult);
startActivity(new Intent(LocationFinder.this,
// Nearbyhotelfinder.class));
GPSMyListView.class));
finish();
}
public LocationResult locationResult = new LocationResult() {
#Override
public void gotLocation(Location location) {
// TODO Auto-generated method stub
double Longitude = location.getLongitude();
double Latitude = location.getLatitude();
Toast.makeText(getApplicationContext(), "Got Location",
Toast.LENGTH_LONG).show();
try {
SharedPreferences locationpref = getApplication()
.getSharedPreferences("location", MODE_WORLD_READABLE);
SharedPreferences.Editor prefsEditor = locationpref.edit();
prefsEditor.putString("Longitude", Longitude + "");
prefsEditor.putString("Latitude", Latitude + "");
prefsEditor.commit();
System.out.println("SHARE PREFERENCE ME PUT KAR DIYA.");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
};
// handler for the background updating
}
MyLocation
public class MyLocation {
Timer timer1;
LocationManager lm;
LocationResult locationResult;
boolean gps_enabled=false;
boolean network_enabled=false;
public boolean getLocation(Context context, LocationResult result)
{
//I use LocationResult callback class to pass location value from MyLocation to user code.
locationResult=result;
if(lm==null)
lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
//exceptions will be thrown if provider is not permitted.
try{gps_enabled=lm.isProviderEnabled(LocationManager.GPS_PROVIDER);}catch(Exception ex){}
try{network_enabled=lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);}catch(Exception ex){}
//Toast.makeText(context, gps_enabled+" "+network_enabled, Toast.LENGTH_LONG).show();
//don't start listeners if no provider is enabled
if(!gps_enabled && !network_enabled)
return false;
if(gps_enabled)
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps);
if(network_enabled)
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork);
timer1=new Timer();
timer1.schedule(new GetLastLocation(), 10000);
// Toast.makeText(context, " Yaha Tak AAya", Toast.LENGTH_LONG).show();
return true;
}
LocationListener locationListenerGps = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerNetwork);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
LocationListener locationListenerNetwork = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerGps);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
class GetLastLocation extends TimerTask {
#Override
public void run() {
//Context context = getClass().getgetApplicationContext();
Location net_loc=null, gps_loc=null;
if(gps_enabled)
gps_loc=lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(network_enabled)
net_loc=lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
//if there are both values use the latest one
if(gps_loc!=null && net_loc!=null){
if(gps_loc.getTime()>net_loc.getTime())
locationResult.gotLocation(gps_loc);
else
locationResult.gotLocation(net_loc);
return;
}
if(gps_loc!=null){
locationResult.gotLocation(gps_loc);
return;
}
if(net_loc!=null){
locationResult.gotLocation(net_loc);
return;
}
locationResult.gotLocation(null);
}
}
public static abstract class LocationResult{
public abstract void gotLocation(Location location);
}
}

With google things changes very often: non of the previous answers worked for me.
based on this google training here is how you do it using
fused location provider
this requires Set Up Google Play Services
Activity class
public class GPSTrackerActivity extends AppCompatActivity implements
GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener {
private GoogleApiClient mGoogleApiClient;
Location mLastLocation;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (mGoogleApiClient == null) {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
}
}
protected void onStart() {
mGoogleApiClient.connect();
super.onStart();
}
protected void onStop() {
mGoogleApiClient.disconnect();
super.onStop();
}
#Override
public void onConnected(Bundle bundle) {
try {
mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
mGoogleApiClient);
if (mLastLocation != null) {
Intent intent = new Intent();
intent.putExtra("Longitude", mLastLocation.getLongitude());
intent.putExtra("Latitude", mLastLocation.getLatitude());
setResult(1,intent);
finish();
}
} catch (SecurityException e) {
}
}
#Override
public void onConnectionSuspended(int i) {
}
#Override
public void onConnectionFailed(ConnectionResult connectionResult) {
}
}
usage
in you activity
Intent intent = new Intent(context, GPSTrackerActivity.class);
startActivityForResult(intent,1);
And this method
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(requestCode == 1){
Bundle extras = data.getExtras();
Double longitude = extras.getDouble("Longitude");
Double latitude = extras.getDouble("Latitude");
}
}

you can got Current latlng using this
`
public class MainActivity extends ActionBarActivity {
private LocationManager locationManager;
private String provider;
private MyLocationListener mylistener;
private Criteria criteria;
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
#SuppressLint("NewApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
// Define the criteria how to select the location provider
criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_COARSE); //default
// user defines the criteria
criteria.setCostAllowed(false);
// get the best provider depending on the criteria
provider = locationManager.getBestProvider(criteria, false);
// the last known location of this provider
Location location = locationManager.getLastKnownLocation(provider);
mylistener = new MyLocationListener();
if (location != null) {
mylistener.onLocationChanged(location);
} else {
// leads to the settings because there is no last known location
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(intent);
}
// location updates: at least 1 meter and 200millsecs change
locationManager.requestLocationUpdates(provider, 200, 1, mylistener);
String a=""+location.getLatitude();
Toast.makeText(getApplicationContext(), a, 222).show();
}
private class MyLocationListener implements LocationListener {
#Override
public void onLocationChanged(Location location) {
// Initialize the location fields
Toast.makeText(MainActivity.this, ""+location.getLatitude()+location.getLongitude(),
Toast.LENGTH_SHORT).show()
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
Toast.makeText(MainActivity.this, provider + "'s status changed to "+status +"!",
Toast.LENGTH_SHORT).show();
}
#Override
public void onProviderEnabled(String provider) {
Toast.makeText(MainActivity.this, "Provider " + provider + " enabled!",
Toast.LENGTH_SHORT).show();
}
#Override
public void onProviderDisabled(String provider) {
Toast.makeText(MainActivity.this, "Provider " + provider + " disabled!",
Toast.LENGTH_SHORT).show();
}
}
`

Above solutions is also correct, but some time if location is null then it crash the app or not working properly. The best way to get Latitude and Longitude of android is:
Geocoder geocoder;
String bestProvider;
List<Address> user = null;
double lat;
double lng;
LocationManager lm = (LocationManager) activity.getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
bestProvider = lm.getBestProvider(criteria, false);
Location location = lm.getLastKnownLocation(bestProvider);
if (location == null){
Toast.makeText(activity,"Location Not found",Toast.LENGTH_LONG).show();
}else{
geocoder = new Geocoder(activity);
try {
user = geocoder.getFromLocation(location.getLatitude(), location.getLongitude(), 1);
lat=(double)user.get(0).getLatitude();
lng=(double)user.get(0).getLongitude();
System.out.println(" DDD lat: " +lat+", longitude: "+lng);
}catch (Exception e) {
e.printStackTrace();
}
}

Best way is
Add permission manifest file
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
Then you can get GPS location or if GPS location is not available then this function return NETWORK location
public static Location getLocationWithCheckNetworkAndGPS(Context mContext) {
LocationManager lm = (LocationManager)
mContext.getSystemService(Context.LOCATION_SERVICE);
assert lm != null;
isGpsEnabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
isNetworkLocationEnabled = lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
Location networkLoacation = null, gpsLocation = null, finalLoc = null;
if (isGpsEnabled)
if (ActivityCompat.checkSelfPermission(mContext, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(mContext, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return null;
}gpsLocation = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (isNetworkLocationEnabled)
networkLoacation = lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (gpsLocation != null && networkLoacation != null) {
//smaller the number more accurate result will
if (gpsLocation.getAccuracy() > networkLoacation.getAccuracy())
return finalLoc = networkLoacation;
else
return finalLoc = gpsLocation;
} else {
if (gpsLocation != null) {
return finalLoc = gpsLocation;
} else if (networkLoacation != null) {
return finalLoc = networkLoacation;
}
}
return finalLoc;
}

You can use FusedLocationProvider
For using Fused Location Provider in your project you will have to add the google play services location dependency in our app level build.gradle file
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
...
...
...
implementation 'com.google.android.gms:play-services-location:17.0.0'
}
Permissions in Manifest
Apps that use location services must request location permissions. Android offers two location permissions: ACCESS_COARSE_LOCATION and ACCESS_FINE_LOCATION.
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
As you may know that from Android 6.0 (Marshmallow) you must request permissions for important access in the runtime. Cause it’s a security issue where while installing an application, user may not clearly understand about an important permission of their device.
ActivityCompat.requestPermissions(
this,
arrayOf(Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION),
PERMISSION_ID
)
Then you can use the FusedLocationProvider Client to get the updated location in your desired place.
mFusedLocationClient.lastLocation.addOnCompleteListener(this) { task ->
var location: Location? = task.result
if (location == null) {
requestNewLocationData()
} else {
findViewById<TextView>(R.id.latTextView).text = location.latitude.toString()
findViewById<TextView>(R.id.lonTextView).text = location.longitude.toString()
}
}
You can also check certain configuration like if the device has location settings on or not. You can also check the article on Detect Current Latitude & Longitude using Kotlin in Android for more functionality.
If there is no cache location then it will catch the current location using:
private fun requestNewLocationData() {
var mLocationRequest = LocationRequest()
mLocationRequest.priority = LocationRequest.PRIORITY_HIGH_ACCURACY
mLocationRequest.interval = 0
mLocationRequest.fastestInterval = 0
mLocationRequest.numUpdates = 1
mFusedLocationClient = LocationServices.getFusedLocationProviderClient(this)
mFusedLocationClient!!.requestLocationUpdates(
mLocationRequest, mLocationCallback,
Looper.myLooper()
)
}

Plug and play location-manager that can be used both in XML-based projects and Jetpack Compose projects (personally using it in JetpackCompose)
class LocationManager(context: Context): LocationCallback() {
val context = context
var publicCompletion: ((Double, Double) -> Unit)? = null
var fusedLocationProviderClient = FusedLocationProviderClient(
context
)
fun requestLocationPermission() {
val activity = context as Activity?
ActivityCompat.requestPermissions(
activity!!,
arrayOf(
Manifest.permission.ACCESS_FINE_LOCATION
),
101
)
}
fun checkIfLocationPermissionIsGranted(): Boolean {
return (ActivityCompat.checkSelfPermission(
context,
Manifest.permission.ACCESS_FINE_LOCATION
) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(
context,
Manifest.permission.ACCESS_COARSE_LOCATION
) != PackageManager.PERMISSION_GRANTED
)
}
fun getLatitudeLongitude(completion: (Double, Double) -> Unit) {
publicCompletion = { latitude, longitude ->
completion(latitude, longitude)
}
if (ActivityCompat.checkSelfPermission(
context,
Manifest.permission.ACCESS_FINE_LOCATION
) == PackageManager.PERMISSION_GRANTED
) {
val activity = context as Activity?
fusedLocationProviderClient.lastLocation.addOnCompleteListener(activity!!) { task ->
var location: Location? = task.result
if (location != null) {
publicCompletion?.let { it(location!!.latitude, location!!.longitude) }
} else {
requestLocationUpdates()
}
}
}
}
fun requestLocationUpdates() {
var request = LocationRequest()
request.priority = com.google.android.gms.location.LocationRequest.PRIORITY_HIGH_ACCURACY
request.fastestInterval = 0
request.numUpdates = 1
if (ActivityCompat.checkSelfPermission(
context,
Manifest.permission.ACCESS_FINE_LOCATION
) == PackageManager.PERMISSION_GRANTED
) {
fusedLocationProviderClient.requestLocationUpdates(
request, this, Looper.myLooper()
)
}
}
override fun onLocationResult(p0: LocationResult?) {
super.onLocationResult(p0)
publicCompletion?.let { it(p0!!.lastLocation!!.latitude, p0!!.lastLocation!!.longitude) }
}
override fun onLocationAvailability(p0: LocationAvailability?) {
super.onLocationAvailability(p0)
}
}

Just follow Google recommendation and prepared codes in kotlin: (Supports also Android 11 and 12):
https://github.com/googlecodelabs/while-in-use-location
and its step by step explanation:
https://codelabs.developers.google.com/codelabs/while-in-use-location

Get Location Android

I have a service that get the location of my phone. When i turn the GPS off and turn it on again, i can't get the location anymore.
Some times it return null the latitude and longitude but GPS is on...
I have a checkbox when i check it, it begin to send to my server the latitude and longitude of my device.
Here is the code. Can someone help me to optimize my code please?
SERVICE
public class LocalizationService extends Service implements Runnable {
private static final int tempo = (30 * 1000); // 1800
private LocationManager locationManager = null;
private Thread t;
#Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
#Override
public void onCreate() {
super.onCreate();
}
#Override
public void onStart(Intent intent, int startId) {
}
#Override
public void onDestroy() {
super.onDestroy();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
if (t == null || !t.isAlive()) {
t = new Thread(this, "ServicoId: " + startId);
t.start();
}
return Service.START_STICKY;
}
#Override
public void run() {
// TODO Auto-generated method stub
while (true) {
try {
sendLocation();
Thread.sleep(tempo);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public void sendLocation() {
LatLng latlong = getLocation();
PolifreteApplication manager = (PolifreteApplication) getApplicationContext();
Veiculo veiculo = manager.getTransportador().getVeiculo();
int user = manager.getTransportador().getCodigo();
if (latlong == null) {
} else {
veiculo.setLatitude(latlong.latitude + "");
veiculo.setLongitude(latlong.longitude + "");
VeiculoDAL.SendLocationVeiculo(veiculo, user);
}
}
public LatLng getLocation() {
// Get the location manager
LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
String bestProvider = locationManager.getBestProvider(criteria, false);
Location location = locationManager.getLastKnownLocation(bestProvider);
Double lat, lon;
try {
lat = location.getLatitude();
lon = location.getLongitude();
return new LatLng(lat, lon);
} catch (NullPointerException e) {
e.printStackTrace();
return null;
}
}
}
ACTIVITY METHOD
public void onCheckboxClicked(View view) {
if (WebService.conexaoOk()) {
CheckBox cblocalizacao = (CheckBox) findViewById(R.id.checkboxlocalizacao);
boolean checked = ((CheckBox) view).isChecked();
locationManager = (LocationManager) this
.getSystemService(Context.LOCATION_SERVICE);
boolean isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
switch (view.getId()) {
case R.id.checkboxlocalizacao:
if (checked && !isGPSEnabled) {
cblocalizacao.setChecked(false);
showSettingsAlert();
} else if (checked && isGPSEnabled) {
Intent i = new Intent(this, LocalizationService.class);
this.startService(i);
} else {
cblocalizacao.setChecked(false);
}
}
}
}

If you want to get location from Gps, see this link, http://www.androidhive.info/2012/07/android-Gps-location-manager-tutorial/, getting location from Gps is not instantaneous, you need to implement location listener and wait the call back from the Gps provider:
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
or you can use network provider
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Just visit the link, and you will find the best strategy to get the most accurate possible location..

This video from Udacity gives idea about using the location services in GoogleApiClient.
Since your LocationListener tries to get location using only Network not GPS, with this code snippet: locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER)
probably you are getting latitude and longitude values but with a delay. I had the same problem then I begin to use new/latest Location service API and use:
GoogleApiClient.
First you need to implement
GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener,
LocationListener
from you activity that want to fetch the location data.
Define
private GoogleApiClient mGoogleApiClient;
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(LocationServices.API)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build();
If you haven't add
<uses-permission `android:name="android.permission.ACCESS_FINE_LOCATION"/>`
to the manifest file, add that.
For further documentation : https://developers.google.com/android/reference/com/google/android/gms/common/api/GoogleApiClient
More comprehensive answer about GoogleClientApi:
https://stackoverflow.com/a/33599343/2644905

getlastknownlocation always return null after I re-install the apk file via eclipse

Recently, I created a simple application to get the GPS location and display it on an Android phone.
In the beginning I was able to get the location after a few tries. But, after I reinstalled the APK file, the getLastKnownLocation() always returns a null value.
The development environment:
API 10 Gingerbread 2.3.6
GPS provider is used
Below is the code I applied to my Android project:
public class MyActivity extends MapActivity {
protected void onCreate(Bundle savedInstanceState) {
mapView = (MapView) findViewById(R.id.myTripMap);
mapController = mapView.getController();
mapView.setSatellite(false);
mapView.setStreetView(true);
mapView.displayZoomControls(false);
mapView.setBuiltInZoomControls(true);//
mapView.setClickable(true);
mapController.setZoom(14);
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setAltitudeRequired(false);
criteria.setBearingRequired(false);
criteria.setCostAllowed(true);
criteria.setPowerRequirement(Criteria.POWER_LOW);
provider = locationManager.getBestProvider(criteria, true);
location = locationManager.getLastKnownLocation(provider);
updateMyCurrentLoc(location);
locationManager.requestLocationUpdates(provider, 2, 1, locationListener);
}
private final LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
updateMyCurrentLoc(location);
}
public void onProviderDisabled(String provider) {
updateMyCurrentLoc(null);
}
public void onProviderEnabled(String provider) {
}
public void onStatusChanged(String provider, int status,
Bundle extras) {
}
};
private void updateMyCurrentLoc(Location location) {
if (location != null) {
// other codes to get the address and display
Toast.makeText(getBaseContext(), "provider used : " + provider).show(); //testing purpose
} else {
str = "No location found";
Toast.makeText(getBaseContext(), str, Toast.LENGTH_SHORT).show();
}
}
}
Can anyone suggest a possible solution to solve the null value returned by getLastKnownLocation()?

Try Following Code
LocationManager locationManager = (LocationManager) getActivity()
.getSystemService(Context.LOCATION_SERVICE);
String locationProvider = LocationManager.NETWORK_PROVIDER;
Location lastlocation = locationManager.getLastKnownLocation(locationProvider);
String CurLat = String.valueOf(lastlocation.getLatitude());
String Curlongi= String.valueOf(lastlocation.getLongitude());

This solution is my little improvement for code by Ravi Tamada.
public Location getLocation() {
int MIN_TIME_BW_UPDATES = 10000;
int MIN_DISTANCE_CHANGE_FOR_UPDATES = 10000;
try {
locationManager = (LocationManager) getApplicationContext()
.getSystemService(LOCATION_SERVICE);
boolean isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
boolean isPassiveEnabled = locationManager
.isProviderEnabled(LocationManager.PASSIVE_PROVIDER);
boolean isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (isGPSEnabled || isNetworkEnabled || isPassiveEnabled) {
this.canGetLocation = true;
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled && location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
}
}
if (isPassiveEnabled && location == null) {
locationManager.requestLocationUpdates(
LocationManager.PASSIVE_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.PASSIVE_PROVIDER);
}
}
if (isNetworkEnabled && location == null) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
}
}
}else{
return null;
}
} catch (Exception e) {
e.printStackTrace();
}

You just need to add one more line into the code
if (locationManager != null) {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
} else {
Toast.makeText(
mContext,
"Location Null", Toast.LENGTH_SHORT).show();
}
}

I got the same issue after re-install via eclipse.
I solved going to Android settings / Security / app permissions and confirm location permissions to the application.

Send GPS data while App is running background in Android

I developed app that getting GPS data and send to Server. So i want to get GPS data while my app is running background in Android device. I have search in many websites, but i could not answer.
I use 2 class. One of them is Main class and another is GPSTracker class. Now i give some part code of 2 class.
Main Class
public class Request extends Activity {
public static Float longitude;
public static Float latitude;
public static int ID;
public static String URL="http://xxx.xxx";
GPSTracker gps;
#SuppressLint("NewApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_request);
final Button button_send_info = (Button)findViewById(R.id.button_send_info);
final TextView show_infos = (TextView) findViewById (R.id.textView1);
gps = new GPSTracker(Request.this);
if(gps.canGetLocation()){
latitude = (float) gps.getLatitude();
longitude = (float) gps.getLongitude();
// \n is for new line
Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
}else{
// can't get location
// GPS or Network is not enabled
// Ask user to enable GPS/network in settings
gps.showSettingsAlert();
}
if( Build.VERSION.SDK_INT >= 8){
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}
button_send_info.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("latitude", latitude.toString()));
postParameters.add(new BasicNameValuePair("longitude", longitude.toString()));
String response = null;
try
{
response = CustomHttpClient.executeHttpPost(URL, postParameters);
String res=response.toString();
show_infos.setText(res);
}
catch (Exception e)
{
//hata alanı
}
}
});
GPSTracker Class;
public class GPSTracker extends Service implements LocationListener {
protected LocationManager locationManager;
public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}
public Location getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider is enabled
} else {
this.canGetLocation = true;
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
How can i do it?

There is a component called Service in android. It provides background activity. You can perform background process in it. Service has no GUI. You can write a GPS fetching code there.
Have a look at simple tutorial of Service components from Vogella.