Why Location manager returns null? - android

I am developing an app where users will be reporting field Incidences.
The Incident location(longitude and latitude) is important for mapping purposes.
For better, i want to use GPS provider only.
In my activity, i have a nested class for getting location information.
private class myGPSTracker extends Service implements LocationListener {
public myGPSTracker() {
getLocation();
}
public Location getLocation() {
try {
locationManager = (LocationManager) context
.getSystemService(LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
//isNetworkEnabled = locationManager
// .isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled ) {
// no network provider is enabled
showSettingsAlert();
canGetLocation = true;
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if ( ActivityCompat.checkSelfPermission(ReportIncident.this, android.Manifest.permission.ACCESS_FINE_LOCATION ) != PackageManager.PERMISSION_GRANTED ) {
ActivityCompat.requestPermissions(ReportIncident.this, new String[] { android.Manifest.permission.ACCESS_FINE_LOCATION }, ACCESS_FINE_LOCATION );
}
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();
}
}
}
}
} else {
canGetLocation = true;
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if ( ContextCompat.checkSelfPermission(ReportIncident.this, android.Manifest.permission.ACCESS_FINE_LOCATION ) != PackageManager.PERMISSION_GRANTED ) {
ActivityCompat.requestPermissions(ReportIncident.this, new String[] { android.Manifest.permission.ACCESS_FINE_LOCATION }, ACCESS_FINE_LOCATION );
}
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;
}
/**
* 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;
}
public double getAltitude()
{
if(location != null){
altitude = location.getAltitude();
}
// return longitude
return altitude;
}
/**
* Function to check GPS/wifi enabled
* #return boolean
* */
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
#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;
}
public String getAddress()
{
Geocoder geocoder =
new Geocoder(context, Locale.getDefault());
// Create a list to contain the result address
List<Address> addresses = null;
try {
/*
* Return 1 address.
*/
addresses = geocoder.getFromLocation(this.getLatitude(),
this.getLongitude(), 1);
} catch (Exception e1) {
e1.printStackTrace();
return ("Un Known place!");
}
// If the reverse geocode returned an address
if (addresses != null && addresses.size() > 0) {
// Get the first address
Address address = addresses.get(0);
/*
* Format the first line of address (if available),
* city, and country name.
*/
String addressText = String.format(
"%s, %s, %s",
// If there's a street address, add it
address.getMaxAddressLineIndex() > 0 ?
address.getAddressLine(0) : "",
// Locality is usually a city
address.getLocality(),
// The country of the address
address.getCountryName());
// Return the text
return addressText;
} else {
return "Un known place";
}
}
}
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(ReportIncident.this);
// Setting Dialog Title
alertDialog.setTitle("GPS 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);
context.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();
}
In my Activity, i try to get location information by
gpstracker=new myGPSTracker();
Incidents incidents =new Incidents();
incidents.setId(new Date().getTime());
incidents.setIncidentdate(new Date().getTime());
incidents.setPlaceName("Some Thing");
incidents.setAltitude(gpstracker.getAltitude());
incidents.setMyLat(gpstracker.getLatitude());
incidents.setMyLongtitude(gpstracker.getLongitude());
When i run the app, i get 0 for longitude and latitude, and i also debugged and found out the location manager is null.
Here is the complete code for the activity.
public class ReportIncident extends Activity {
Button bb;
double mylat;
double mylong;
String myplace;
double myalt;
EditText editText;
private Context context;
//private Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
private myGPSTracker gpstracker;
Location location; // location
double latitude; // latitude
double longitude; // longitude
double altitude;
// 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;
private static final int ACCESS_FINE_LOCATION = 200;
//private Activity activity;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.add_incident);
context=getApplicationContext();
gpstracker=new myGPSTracker();
editText=(EditText)findViewById(R.id.txtReportIncident);
bb=(Button)findViewById(R.id.btnReport);
bb.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String mydescription=editText.getText().toString().trim();
if(TextUtils.isEmpty(mydescription))
{
editText.setError("Field can not be blank");
return;
}
Incidents incidents =new Incidents();
incidents.setId(new Date().getTime());
incidents.setIncidentdate(new Date().getTime());
incidents.setPlaceName("Some Thing");
incidents.setAltitude(gpstracker.getAltitude());
incidents.setMyLat(gpstracker.getLatitude());
incidents.setMyLongtitude(gpstracker.getLongitude());
incidents.setIncidentDescription(mydescription);
new AddIncidentAsyncTask(getApplicationContext()).execute(incidents);
editText.setText("");
}
});
}
What is missing?
Any help will be highly appreciated.
Ronald

Related

Android - Gps location change distance

I am trying to make a Speedometer app that will get location every 5 sec interval. calculate the distance and get the user velocity, but my initial data is showing a high value firstly without even moving the phone and than then being kind of random value. please check my code.
MainActivity.java
public class MainActivity extends Activity {
private static final int REQUEST_CODE_PERMISSION = 2;
String mPermission = Manifest.permission.ACCESS_FINE_LOCATION;
TextView tvRunning, tvMax;
int maxv = 0;
// GPSTracker class
GPSTracker gps;
GPSTracker GPSTrackerBefore = new GPSTracker(MainActivity.this);
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tvRunning = (TextView) findViewById(R.id.tvRunnung);
tvMax = (TextView) fin
dViewById(R.id.tvMax);
try {
if (ActivityCompat.checkSelfPermission(this, mPermission)
!= MockPackageManager.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();
}
//----------------initializing the first gps----------------//
if(GPSTrackerBefore.canGetLocation){
GPSTrackerBefore.getLocation();
}
final Handler ha = new Handler();
ha.postDelayed(new Runnable() {
#Override
public void run() {
//call function
[enter image description here][1]
gps = new GPSTracker(MainActivity.this);
// check if GPS enabled
if (gps.canGetLocation()) {
double lon2 = gps.getLongitude(), lat2 = gps.getLatitude();
double lon1 = GPSTrackerBefore.getLongitude(), lat1 = GPSTrackerBefore.getLatitude();
int R = 6371; // km
double x = (lon2 - lon1) * Math.cos((lat1 + lat2) / 2);
double y = (lat2 - lat1);
int d = (int) Math.sqrt(x * x + y * y) * R;
int v=d/5; //this is the velocity divided by interval time
Toast.makeText(getApplicationContext(), String.valueOf(v), Toast.LENGTH_SHORT).show();
// Toast.makeText(getApplicationContext(),
// gps.getLatitude()+"||"+gps.getLongitude()+
// "\n"+GPSTrackerBefore.getLatitude()+"||"+GPSTrackerBefore.getLongitude(),
// Toast.LENGTH_SHORT).show();
GPSTrackerBefore = gps;
tvRunning.setText(String.valueOf(v));
if (v > maxv) {
maxv = v;
tvMax.setText(String.valueOf(maxv));
}
} else {
// can't get location
// GPS or Network is not enabled
// Ask user to enable GPS/network in settings
gps.showSettingsAlert();
}
ha.postDelayed(this, 5000);
}
}, 5000);
}
}
GPSTracker.java
package bytebiters.com.speedo;
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 = 1; // 1 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 3000 ; // 1 sec
// 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
* */
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;
}
}
In GPSTracker, attempting to read latitude or longitude will return 0 if there is no location available. You need multiple readings before you attempt to estimate speed using your method.
Code aside, GPS coordinates are inherently noisy (the position is not known exactly). There will always be errors in a speed measurement that result from noise in the position estimation. There are more sophisticated methods for estimating speed and location from noisy measurements such as the Kalman Filter.

Get geo locations repeatedly (after every.. 1 minute )

I am calling toast message in AndroidGPSTrackingActivity.class. how to fetch geo locations after every 1 minutes.. With below code I am getting only once
public class AndroidGPSTrackingActivity extends Activity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
gps = new GPSTracker(AndroidGPSTrackingActivity.this);
// check if GPS enabled
if (gps.canGetLocation()) {
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
Toast.makeText( getApplicationContext(),"Your Locion is - \nLat: " + latitude
+ "\nLog: " + longitude, Toast.LENGTH_LONG).show();
System.out.println("respmaillati::;;"+latitude);
} else {
gps.showSettingsAlert();
}
}
in manifest I given
<service android:name=".GPSTracker" />
Code:
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 = 100 * 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
* */
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(GPSTracker.this);
}
}
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
System.out.println("responsel:::"+latitude);
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
System.out.println("responsel:::"+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;
}
}
Try this!
Wrap the toast code in a method and call it recursively using Handler and Runnable:
public class AndroidGPSTrackingActivity extends Activity {
Handler showLocationHandler;
Runnable showLocationRunnable;
private static final int DELAY_TIME = 1000 * 60; //delay time - 1 minute
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
gps = new GPSTracker(AndroidGPSTrackingActivity.this);
showLocationHandler = new Handler();
showLocationRunnable = new Runnable() {
#Override
public void run() {
showLatLongToast();
}
};
//call the method once
showLatLongToast();
}
public void showLatLongToast() {
if (gps.canGetLocation()) {
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
Toast.makeText(getApplicationContext(), "Your Locion is - \nLat: " + latitude
+ "\nLog: " + longitude, Toast.LENGTH_LONG).show();
System.out.println("respmaillati::;;" + latitude);
} else {
gps.showSettingsAlert();
}
//call the same method after some delay
showLocationHandler.postDelayed(showLocationRunnable, DELAY_TIME);
}
#Override
protected void onDestroy() {
super.onDestroy();
//kill this runnable when ever you want to stop displaying toast like this
showLocationHandler.removeCallbacks(showLocationRunnable);
}
}

Android GPS tracks wrong location

In my app I want to show user's current location and if location is changed it will show an alert message to change the location. The problem is that it shows location chahnge message even when the phone's GPS is off. What might be the reason?
Here's my code:
protected void onResume() {
/**
* get saved Location from shared preference
*
*/
SharedPreferences sPrefs = PreferenceManager
.getDefaultSharedPreferences(Activity_Home.this);
String getL = sPrefs.getString(Utility.KEY_USER_LAT, "0.000000");
String getLo = sPrefs.getString(Utility.KEY_USER_LONG, "0.000000");
getLat = Double.parseDouble(getL);
getLog = Double.parseDouble(getLo);
gps = new GpsTracker(Activity_Home.this);
/**
* Get user current latitude and longitude and match them to stored
* latitude and longitude if distance between these latitude then Pop up
* will be show
*
* #author Ankit
*/
if (gps.canGetLocation()) {
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
System.out.println("Latitude is " + getLat);
if (getLat > 0.0) {
Location locationA = new Location("point A");
locationA.setLatitude(getLat);
locationA.setLongitude(getLog);
Location locationB = new Location("point B");
locationB.setLatitude(latitude);
locationB.setLongitude(longitude);
distance = locationA.distanceTo(locationB);
// Toast.makeText(Activity_Home.this,
// "Distance is :"+Double.toString(distance),
// Toast.LENGTH_LONG).show();
distance = distance / 1000000;
int getDistance = (int) (distance * 1000000);
System.out.println("Distance is " + getDistance);
if (getDistance > 100) {
showWarningMessage();
}
}
String lat = String.valueOf(latitude);
String lon = String.valueOf(longitude);
SharedPreferences sPref = PreferenceManager
.getDefaultSharedPreferences(Activity_Home.this);
SharedPreferences.Editor sEdit = sPref.edit();
sEdit.putString(Utility.KEY_USER_LAT, lat);
sEdit.putString(Utility.KEY_USER_LONG, lon);
sEdit.commit();
} else {
gps.showSettingsAlert();
}
super.onResume();
}
// Method for show an Alert dialog for user if user's location changed''
public void showWarningMessage() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(
Activity_Home.this);
alertDialog.setCancelable(false);
// Setting Dialog Title
alertDialog.setTitle("Location Changed");
// Setting Dialog Message
alertDialog
.setMessage("It seems your location has changed, would you like to change the Branch now?");
// On pressing Settings button
alertDialog.setPositiveButton("Yes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Activity_Home.this,
Activity_Settings.class);
startActivity(intent);
dialog.cancel();
}
});
// on pressing cancel button
alertDialog.setNegativeButton("No",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
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 = 100; // 100 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);
System.out.println("=====isGPSEnabled:
"+isGPSEnabled+"====isNetworkEnabled: "+isNetworkEnabled);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider is enabled
System.out.println("=====notgps");
} 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
* */
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);
alertDialog.setCancelable(false);
// Setting Dialog Title
alertDialog.setTitle("Enable GPS");
// 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();
// alertDialog.;
}
#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;
}
}
Here is one sample code for find location check this if it works for you
public static void LocationFind() {
try {
if (Skyhook) {
_xps.getXPSLocation(null,
// note we convert _period to seconds
(int) (_period / 1000), _desiredXpsAccuracy, _callback);
// _xps.getLocation(null, _streetAddressLookup, _callback);
} else {
Criteria criteria = new Criteria();
criteria.setBearingRequired(false);
criteria.setCostAllowed(true);
criteria.setPowerRequirement(Criteria.POWER_LOW);
criteria.setAltitudeRequired(false);
criteria.setAccuracy(Criteria.ACCURACY_FINE);
LocationManager locationManager = (LocationManager) mcontext.getSystemService(Context.LOCATION_SERVICE);
isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
// Getting network status
isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, locationListener);
// Log.d("Network", "Network");
if (locationManager != null) {
lastknownlocations = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (lastknownlocations != null) {
lat = lastknownlocations.getLatitude();
lng = lastknownlocations.getLongitude();
}
}
}
if (isGPSEnabled) {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, locationListener);
// Log.d("Network", "Network");
if (locationManager != null) {
lastknownlocations = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (lastknownlocations != null) {
lat = lastknownlocations.getLatitude();
lng = lastknownlocations.getLongitude();
}
}
}
if (lat == 0.0 && lng == 0.0) {
lng = lastknownlocations.getLongitude();
lat = lastknownlocations.getLatitude();
}
getAddressFromLatLong(lat, lng);
}
} catch (Exception e) {
e.printStackTrace();
}
}
Try out with this service class. This sends updates to method sendLocationDataToProcess(Location location) whenever there is a different of 10 meters with respect to last location
public class AppLocationService extends Service implements GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener,
LocationListener{
private LocationRequest locationRequest;
private GoogleApiClient googleApiClient;
private Context appContext;
private boolean currentlyProcessingLocation = false;
private int mInterval=0;
private final int CONNTIMEOUT=50000;
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
appContext=getApplicationContext();
Toast.makeText(getBaseContext(), "Location Service Started", Toast.LENGTH_SHORT)
.show();
if (!currentlyProcessingLocation) {
currentlyProcessingLocation = true;
startTracking();
}
return START_STICKY;
}
private void startTracking() {
if (GooglePlayServicesUtil.isGooglePlayServicesAvailable(this) == ConnectionResult.SUCCESS) {
Log.v(Constants.BLL_LOG, "ConnectionResult SUCCESS");
googleApiClient = new GoogleApiClient.Builder(this)
.addApi(LocationServices.API)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build();
if (!googleApiClient.isConnected() || !googleApiClient.isConnecting()) {
googleApiClient.connect();
}else{
Log.v(Constants.BLL_LOG, "NOT connected googleApiClient.connect()");
}
} else {
Log.v(Constants.BLL_LOG, "unable to connect to google play services.");
}
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
public AppLocationService() {
}
#Override
public void onConnected(Bundle bundle) {
Log.v(Constants.BLL_LOG,"onConnected");
locationRequest = LocationRequest.create();
locationRequest.setInterval(mInterval * 1000); // milliseconds
locationRequest.setFastestInterval(mInterval * 1000);
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
locationRequest.setSmallestDisplacement(MIN_DISTANCE_CHANGE_FOR_UPDATES);//dostance change
int permissionCheck = ContextCompat.checkSelfPermission(appContext, Manifest.permission.ACCESS_COARSE_LOCATION);
if (permissionCheck!= PackageManager.PERMISSION_DENIED)
LocationServices.FusedLocationApi.requestLocationUpdates(googleApiClient, locationRequest, this);
}
#Override
public void onConnectionSuspended(int i) {
Log.v(Constants.BLL_LOG,"onConnectionSuspended");
}
#Override
public void onLocationChanged(Location location) {
Log.v(Constants.BLL_LOG, "onLocationChanged position: " + location.getLatitude() + ", " + location.getLongitude() + " accuracy: " + location.getAccuracy());
Log.v(Constants.BLL_LOG, "onLocationChanged position: location.getAccuracy()= "+location.getAccuracy());
sendLocationDataToProcess(location);
}
#Override
public void onConnectionFailed(ConnectionResult connectionResult) {
Log.v(Constants.BLL_LOG,"onConnectionFailed");
}
void sendLocationDataToProcess(Location location){
//Do your logic with Location data
}
#Override
public void onDestroy() {
super.onDestroy();
if (googleApiClient != null && googleApiClient.isConnected()) {
googleApiClient.disconnect();
}
}
}

Not getting current location properly

I am new to android. I am developing an application which displays users current latitude and longitude even without using internet.
It works fine but the latitude and longitude changes everytime i refersh or start the app again... Please help me.. Why is it so?/
This is my GPSTracker class
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; // 5 minutes
// 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) {
// if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// public void requestPermissions(#NonNull String[] permissions, int requestCode)
// 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 Activity#requestPermissions for more details.
return;
}
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;
}
}
and in MainActivity
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.app_bar);
toolbar.setTitle("PWD_GPSFinder");
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
lat1 = (TextView) findViewById(R.id.latitude);
long1 = (TextView) findViewById(R.id.longitude);
exit = (Button) findViewById(R.id.button);
exit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
finish();
}
});
refresh = (Button) findViewById(R.id.buttonRefresh);
refresh.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
gps = new GPSTracker(MainActivity.this);
// check if GPS enabled
if(gps.canGetLocation()){
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
lat1.setText(""+latitude);
long1.setText(""+longitude);
}else{
// can't get location
// GPS or Network is not enabled
// Ask user to enable GPS/network in settings
gps.showSettingsAlert();
}
}
});
gps = new GPSTracker(MainActivity.this);
// check if GPS enabled
if(gps.canGetLocation()){
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
lat1.setText(""+latitude);
long1.setText(""+longitude);
// \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();
}
}
Have a look at http://developer.android.com/guide/topics/location/strategies.html ... it helped me understand geolocation states in Android recently.

Always getting Same latitude and longitude

i have problem with this code please if some one help me to fix the problem
PROBLEM IS WHEN I START THE APP FIRST TIME IT GET LAT AND LONG AND AFTER THAT ALWAYS SAME LAT AND LONG , so please tell me how it could get new lat long if i change the locations , thanks
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 = 0; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 0; // 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
* */
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) {
Toast.makeText(mContext,"Location changed: Lat: " + location.getLatitude() + " Lng: "
+ location.getLongitude(), Toast.LENGTH_SHORT).show();
}
#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 are not updating your location member.Modify onLocationChanged as-
#Override
public void onLocationChanged(Location location) {
this.location = location;//update your location member with current location
}
It should be assign a value following
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 0; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 0; // 1 minute

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