Not receiving Location Updates in Android - java

I have two classes "GPSTracker" and "Live".
The GPSTracker has the GPS related functions i.e. to get the latitude and the longitude, while the Live class calls it to get the current Latitude and the Longitude and then calculate the distance travelled.
My problem is that I am not getting any changes in the location, the location remains at whatever it is at the start! No locationUpdates!
GPSTracker.java:
public class GPSTracker extends Service implements LocationListener
{
private final Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES =5; // 5 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 5; // 5 seconds
// Declaring a Location Manager
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;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS()
{
if(locationManager != null)
{
locationManager.removeUpdates(GPSTracker.this);
}
}
/**
* Function to get latitude
* */
public double getLatitude()
{
if(location != null)
{
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude()
{
if(location != null)
{
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
* #return boolean
* */
public boolean canGetLocation()
{
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert()
{
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is not enabled");
// Setting Dialog Message
alertDialog.setMessage("Enable location services to determine your location.");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which)
{
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which)
{
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
#Override
public void onLocationChanged(Location location)
{
}
#Override
public void onProviderDisabled(String provider)
{
}
#Override
public void onProviderEnabled(String provider)
{
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras)
{
}
#Override
public IBinder onBind(Intent arg0)
{
return null;
}
}
Live.java:
public class Live extends Activity implements LocationListener
{
GPSTracker gps;
Location newLocation = new Location(LocationManager.GPS_PROVIDER);
Location oldLocation = new Location(LocationManager.GPS_PROVIDER);
float distanceTravelled=0;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_live);
startactivity();
}
public void startactivity()
{
gps = new GPSTracker(Live.this);
if(gps.canGetLocation())
{
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
Toast.makeText(getApplicationContext(), "Your Location is: \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
newLocation.setLatitude(latitude);
newLocation.setLongitude(longitude);
}
else
{
gps.showSettingsAlert();
}
}
public void resumeactivity()
{
gps = new GPSTracker(Live.this);
if(gps.canGetLocation())
{
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
//Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
newLocation.setLatitude(latitude);
newLocation.setLongitude(longitude);
}
else
{
}
}
public void onResume()
{
super.onResume();
resumeactivity();
}
#Override
public void onLocationChanged(Location location)
{
oldLocation.set(newLocation);
newLocation.set(location);
//resumeactivity();
distanceTravelled+=newLocation.distanceTo(oldLocation);
String stringDistance= Float.toString(distanceTravelled);
TextView distance = (TextView) findViewById(R.id.textDistance);
distance.setText(stringDistance);
}
#Override
public void onProviderDisabled(String arg0)
{
GPSTracker gps = new GPSTracker(Live.this);
gps.showSettingsAlert();
}
#Override
public void onProviderEnabled(String arg0)
{
}
#Override
public void onStatusChanged(String arg0, int arg1, Bundle arg2)
{
}

I was facing same problem with my app, so what I did is reboot phone and Start the app under clear sky. It will might help you.

You can find a working example here. It is not calculating the distance, but this should be easy to add.

Related

how to set a priority high accuracy location for the following code

someone already did this code in the project. But how to set a priority high accuracy in the location manager. They use location manager to get the current location.
So any one can help out. This not working if any possibilities to change the logic .
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
public boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 1;
// 10 meters to 1 meters change by me ..
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1;
// 1 minute
// Declaring a Location Manager
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;
// First get location from Network Provider
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;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
//#RequiresApi(api = Build.VERSION_CODES.M)
public void stopUsingGPS(){
if (locationManager != null) {
if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
|| checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
locationManager.removeUpdates(GPSTracker.this);
}
}
}
public double getLatitude()
{
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude()
{
if(location != null)
{
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to get latitude
* */
/**
* Function to check GPS/wifi enabled
* #return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
#Override
public void onLocationChanged(Location location){
}
#Override
public void onProviderDisabled(String provider){
}
#Override
public void onProviderEnabled(String provider){
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras){
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
}
You shoul add criteria:
LocationManager locationManager = (LocationManager) this
.getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE); // Choose your accuracy requirement.
locationManager.getBestProvider(criteria, true)

Getting permission on runtime in android

I'm new to android, don't know what I'm doing wrong
this class get longitude and latitude and sent to another class
the code is throwing an error onrequstpermission please tell me what to do how to do:
error on public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute
// Declaring a Location Manager
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;
// First get location from Network Provider
if (isNetworkEnabled) {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
switch (requestCode) {
case Manifest.permission.ACCESS_COARSE_LOCATION:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// All good!
} else {
Toast.makeText(this, "Need your location!", Toast.LENGTH_SHORT).show();
}
break;
}
}
}
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;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(GPSTracker.this);
}
}
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
* #return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
#Override
public void onLocationChanged(Location location) {
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
onRequestPermissionsResult is a method which should be outside the current method
public Location getLocation(){
//...code
if (ActivityCompat.checkSelfPermissio... ) {
// ERROR : cannot have function declaration inside another function
public void onRequestPermissionsResult(...) {
switch (requestCode) {//..code}
}
}
Note: you cannot have this in a Service class , you need some Activity to ask permission
ActivityCompat.OnRequestPermissionsResultCallback is implemented by FragmentActivity which is a parent of AppCompatActivity so it's not implemented by Service so you need to implement the runtime-permission code is some FragmentActivity | AppCompatActivity or you can check and show a notification (in case of no permission or probably a dialog) and redirect user to Activity to proceed with permission code.
Reference:
Implement runtime permission

Toast message shows 0 for both latitude and longitude

I am trying to build an app from here, where the user clicks on a button and get the current latitude and longitude but the problem is that I am getting 0.0 for both latitude and longitude. I have one activity and one service in my application. The code for activity and service is given below :
GpsActivity.java
public class GpsActivity extends AppCompatActivity {
Button show;
private static final int REQUEST_CODE_PERMISSION = 2;
String mPermission = Manifest.permission.ACCESS_FINE_LOCATION;
GPSTracker gps;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_gps);
try {
if (ActivityCompat.checkSelfPermission(this, mPermission)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{mPermission},
REQUEST_CODE_PERMISSION);
// If any permission above not allowed by user, this condition will
// execute every time, else your else part will work
}
} catch (Exception e) {
e.printStackTrace();
}
show=(Button)findViewById(R.id.showLocation);
show.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
gps=new GPSTracker(GpsActivity.this);
// check if GPS enabled
if(gps.canGetLocation()){
double latitude = gps.getLatitude();
double longitude = 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();
}
}
});
}
}
GPSTracker.java
public class GPSTracker extends Service implements LocationListener {
private Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute
protected LocationManager locationManager;
public GPSTracker() {
//mContext = null;
}
public GPSTracker(Context mContext) {
this.mContext = mContext;
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;
// First get location from Network Provider
if (isNetworkEnabled) {
if (ActivityCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return location;
}
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;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(GPSTracker.this);
}
}
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
* #return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
#Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
return null;
}
#Override
public void onLocationChanged(Location location) {
}
#Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
#Override
public void onProviderEnabled(String s) {
}
#Override
public void onProviderDisabled(String s) {
}
}
I have mentioned all the permissions required for the location updates in the manifest file. The only problem here is that latitude and longitude shows 0.0 on clicking the button.
Can anone help? Thank you :)
you didn't call getLocation() method
if(gps.canGetLocation())
{
gps.getLocation();
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
// \n is for new line
Toast.makeText(getApplicationContext(), "Your Location is - \nLat: "
+ latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
}
The function getLastKnownLocation() is returning null. I would recommend waiting for a fresh location to get called in onLocationChanged() and use that location object.
Also, you aren't properly using the Service class. You basically created a wrapper around the LocationManager. If you want to know how to use a Service properly, check out this tutorial.

Android LocationManager :- Error Showing Progress Dialog

I am working on an application where I need to fetch the users current location. I am following this tutorial to achieve my goal http://www.androidhive.info/2012/07/android-gps-location-manager-tutorial/. This code works perfectly for me but there is some delay in fetching the co-ordinates. I want to show a progress dialog until the co-ordinates are fetched.
I found a similar question asked here Android show progress dialog while waiting for location
But I don’t follow the accepted answer. I tried it but it didn’t work for me …
My Problem :
1.When the application first starts with GPS Setting on, the ProgressDialog is infinite. That is, it doesn't dismiss.
Once the locations co-ordinates are found, the application crashes.
Errors :
For the 2nd problem is NullPointerException. Somehow the application is not able to find the dialog at the main activity. (inside onLocationChanged()).
Please help.
My code :
Main Activity :-
public class AndroidGPSTrackingActivity extends Activity {
Button btnShowLocation;
// GPSTracker class
GPSTracker gps;
ProgressDialog dialog;
TextView tv_addressView;
Location loc;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
tv_addressView = (TextView)findViewById(R.id.tv_address);
btnShowLocation = (Button) findViewById(R.id.btnShowLocation);
// show location button click event
btnShowLocation.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0)
{
if(loc == null)
{
dialog = ProgressDialog.show(
AndroidGPSTrackingActivity.this,
"Getting Co-ordinates",
"Please Wait ...");
}
});
}
#Override
protected void onResume()
{
super.onResume();
gps = new GPSTracker(getApplicationContext(),AndroidGPSTrackingActivity.this);
loc = gps.getLocation();
if(gps.canGetLocation())
{
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
Log.d("Got","Lat = "+latitude+"\nLong = "+longitude);
}
else
{
gps.showSettingsAlert();
}
}
public void dismissDialog()
{
if(dialog.isShowing()) {
dialog.dismiss();
}
}
public void upDateUI(String result)
{
tv_addressView.setText(result);
}
}
GPSTracker.java
public class GPSTracker extends Service implements LocationListener {
ProgressDialog dialog;
private final Context mContext;
boolean isGPSEnabled = false;
boolean isNetworkEnabled = false;
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
AndroidGPSTrackingActivity callingActivity;
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10;
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1;
protected LocationManager locationManager;
public GPSTracker(Context context, AndroidGPSTrackingActivity activity)
{
this.mContext = context;
this.callingActivity = activity;
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;
}
public Location returnLocation()
{
return location;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS(){
if(locationManager != null){
//dialog.dismiss();
locationManager.removeUpdates(GPSTracker.this);
}
}
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
* #return boolean
* */
public boolean canGetLocation()
{
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(callingActivity);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
#Override
public void onLocationChanged(Location location) {
callingActivity.dismissDialog();
}
#Override
public void onProviderDisabled(String provider) {
stopUsingGPS();
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
}
Try this
public final class GPSTracker implements LocationListener {
private final Context mContext;
// flag for GPS status
public boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 1; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;
public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}
/**
* Function to get the user's current location
*
* #return
*/
public Location getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(Context.LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
Log.v("isGPSEnabled", "=" + isGPSEnabled);
// getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
Log.v("isNetworkEnabled", "=" + isNetworkEnabled);
if (isGPSEnabled == false && isNetworkEnabled == false) {
// no network provider is enabled
} else {
this.canGetLocation = true;
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();
}
}
}
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
location=null;
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;
}
/**
* Stop using GPS listener Calling this function will stop using GPS in your
* app
* */
public void stopUsingGPS() {
if (locationManager != null) {
locationManager.removeUpdates(GPSTracker.this);
}
}
/**
* Function to get latitude
* */
public double getLatitude() {
if (location != null) {
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude() {
if (location != null) {
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
*
* #return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog On pressing Settings button will
* lauch Settings Options
* */
public void showSettingsAlert() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog
.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(
Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
#Override
public void onLocationChanged(Location location) {
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
}

Loppers Android Error

Hello i have one class in android
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 5; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 30 * 1; // 1 minute
// Declaring a Location Manager
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 est� activado el gps
showSettingsAlert();
} 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;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(GPSTracker.this);
}
}
//Function to get latitude
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
//Function to get longitude
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
* #return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
new AlertDialog.Builder(mContext)
//.setIcon(android.R.drawable.ic_dialog_alert)
.setTitle("Activar GPS")
.setMessage("El GPS no esta habilitado. �Desea Activarlo?")
.setPositiveButton("Si", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
//TO DO
}
} )
.show();
}
#Override
public void onLocationChanged(Location location) {
this.location = location;
}
#Override
public void onProviderDisabled(String provider) {
showSettingsAlert();
}
#Override
public void onProviderEnabled(String provider) {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("Activar GPS");
// Setting Dialog Message
alertDialog.setMessage("El GPS esta habilitado.");
// Showing Alert Message
// alertDialog.show();
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
}
its work and return gps but when im call in another class im send error for lopper.prepare
java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
getLocation(GPSTracker.java:69)
(GPSTracker.java:47)
where have a error?
regards!
I think the solution is simple. Why do you extend Service. I have seen many implementations of GPSTracker, have used one myself too and there is no need to extend any class. Just get rid of the "extends Service" part and all methods that come from extending service and you will be OK. Whenever you need location data create a GPSTracker object.
If you want to get notified when the tracker gets the data than just create an interface and implement it in the Activity. After that do this:
listener.onInterfaceMethod(location);

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