Develop Reference

Get String from Location Android

I found a great function which gives me possibility to get Location quickly.
After that i want to display its (longitude and latitude) but it doest work still i get 0.0 / 0.0.
here's code
What should i do if i want display this latitude and longitude mostly I'm interested in function getLastKnownLocation because i want display this data without using GPS or Internet
public class MainActivity extends Activity implements OnClickListener
{
private static final long MIN_TIME_BW_UPDATES = 0;
private static final float MIN_DISTANCE_CHANGE_FOR_UPDATES = 0;
public EditText lokalizacja;
public Button pobierz;
private static Context context;
LocationManager locationManager;
// 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
public static Context getContext()
{
return context;
}
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lokalizacja = (EditText) findViewById(R.id.editText1);
pobierz = (Button) findViewById(R.id.button1);
pobierz.setOnClickListener(this);
}
#Override
public void onClick(View v)
{
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 && !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, (LocationListener) this);
Log.d("Network", "Network Enabled");
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, (LocationListener) this);
Log.d("GPS", "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();
}
String napis = String.valueOf(latitude+ "\n" + longitude);
lokalizacja.setText(napis);
return location;
}
}

As flow never enter the else part due the following condition
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider is enabled
} else {
You need to have condition something like this
if (!isGPSEnabled || !isNetworkEnabled) {
// no network provider is enabled
} else {
or first check for GPS and then after network

For the first time, for getting your current location, you want to enable gps or network in your device. After getting lat and lng create a preference and save these values to preference. So make some changes in your getLocation() method.
If gps and network are disable try to return the saved value from preference.

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<meta-data
android:name="com.google.android.gms.version"
android:value="#integer/google_play_services_version" />

GPS location changing in Android application

I've followed this tutorial for GPS tracking in Android application with this class:
GPSTracker.java
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;
}
#Override
public void onLocationChanged(Location location) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
#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 this is the Activity using the previous class:
AndroidGPSTrackingActivity.java
package com.example.gpstracking;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class AndroidGPSTrackingActivity extends Activity {
Button btnShowLocation;
// GPSTracker class
GPSTracker gps;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
btnShowLocation = (Button) findViewById(R.id.btnShowLocation);
// show location button click event
btnShowLocation.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
// create class object
gps = new GPSTracker(AndroidGPSTrackingActivity.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();
}
}
});
}
}
How can I receive new position updates from the AndroidGPSTrackingActivity.java ?
How can I get latitude and longitude in AndroidGPSTrackingActivity taken by onLocationChanged that is in GPSTracker class ?
many thanks

I can't write comments yet, so I try here:
I would create a Handler in your Activity and assign it to the the GPSTracker Class:
Handler handler = new Handler(){
#Override
public void handleMessage(Message msg) {
// new GPS Informations
// get it by gps.getLatitude() for example
};
};
gps = new GPSTracker(AndroidGPSTrackingActivity.this, handler);
In your GPSTracker Class you have to change the constructor of course:
Handler mHandler;
public GPSTracker(Context context, Handler handler){
...
this.mHandler = handler;
}
And then, just send the info, that the location has changed to your activity:
#Override
public void onLocationChanged(Location location) {
latitude = location.getLatitude();
longitude = location.getLongitude();
mHandler.sendEmptyMessage(0);
}

Android GPS using old locations

Im trying to learn more about location services in android and am attempting to build an app which can locate an Android device and send it's latitude and longitude to a server. I've had everything working as expected for a while, but am still being bothered by a small bug. When I send the command from the server to locate the device the first time, the device returns a recent, but old, location such as a road I drove on the same day.
On the second time the device receives a command from the server to locate the device, the device returns an accurate location.
Here is the relevant code:
LocationTracker.java
public class LocationTracker extends Service implements LocationListener {
//flag for GPS Status
boolean isGPSEnabled = false;
//flag for network status
boolean isNetworkEnabled = false;
boolean canGetLocation = false;
Location location;
double latitude;
double longitude;
//The minimum distance to change updates in metters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10*1000; //10,000 meters
//The minimum time beetwen updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 10000; // 10,000 minutes
//Declaring a Location Manager
protected LocationManager locationManager;
public void fetchLocation(Context context) {
getLocation(context);
if (canGetLocation())
{
String stringLatitude = String.valueOf(latitude);
String stringLongitude = String.valueOf(longitude);
Log.i("Location: ", stringLatitude + " " + stringLongitude);
new MyAsyncTask().execute(stringLatitude, stringLongitude);
}
else
{
// can't get location
// GPS or Network is not enabled
// Ask user to enable GPS/network in settings
Log.i("Error: ", "Cannot get location");
}
}
public Location getLocation(Context context)
{
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 && !isNetworkEnabled)
{
// no network provider is enabled
}
else
{
this.canGetLocation = true;
//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);
updateGPSCoordinates();
}
}
}
//If no GPS, get location from Network Provider
if (isNetworkEnabled && !isGPSEnabled)
{
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);
updateGPSCoordinates();
}
}
}
}
catch (Exception e)
{
//e.printStackTrace();
Log.e("Error : Location", "Impossible to connect to LocationManager", e);
}
return location;
}
public void updateGPSCoordinates()
{
if (location != null)
{
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
*/
public void stopUsingGPS()
{
if (locationManager != null)
{
locationManager.removeUpdates(LocationTracker.this);
}
}
/**
* Function to get latitude
*/
public double getLatitude()
{
if (location != null)
{
latitude = location.getLatitude();
}
return latitude;
}
/**
* Function to get longitude
*/
public double getLongitude()
{
if (location != null)
{
longitude = location.getLongitude();
}
return longitude;
}
/**
* Function to check GPS/wifi enabled
*/
public boolean canGetLocation()
{
return this.canGetLocation;
}
#Override
public void onLocationChanged(Location location)
{
double newLat = location.getLatitude();
double newLong = location.getLongitude();
String stringNewLatitude = String.valueOf(newLat);
String stringNewLongitude = String.valueOf(newLong);
Log.i("New Location: ", stringNewLatitude + " " + stringNewLongitude);
new MyAsyncTask().execute(stringNewLatitude, stringNewLongitude);
}
#Override
public void onProviderDisabled(String provider)
{
}
#Override
public void onProviderEnabled(String provider)
{
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras)
{
}
public IBinder onBind(Intent intent)
{
return null;
}
Why is my location updating as an old location the first time it tries, and a correct location on the second time?
Also note that I would also like to remove requestLocationUpdates seen here:
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
because it causes a handler on dead thread warning, but when I removed it my device stopped acquiring my location. This may be part of the problem.
I would greatly appreciate any help!

It's because you're using getLastKnownLocation().
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
getLastKnownLocation(String Provider) :
Returns a Location indicating the data from the last known location fix obtained from the given provider.
This can be done without starting the provider. Note that this location could be out-of-date, for example if the device was turned off and moved to another location.

Get current latitude and longitude in the string

I am trying to get latitude and longitude but sometime network is available but I am not getting value of latitude and longitude. I am using MyLocationListener class and put condition all but some time value is not getting.
protected void showCurrentLocation()
{
Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null)
{
counter++;
latitude=location.getLatitude();
longitude=location.getLongitude();
altitude=location.getAltitude();
}
}
private class MyLocationListener implements LocationListener
{
#Override
public void onLocationChanged(Location location)
{
counter++;
latitude=location.getLatitude();
longitude=location.getLongitude();
altitude=location.getAltitude();
}
#Override
public void onStatusChanged(String s, int i, Bundle b)
{
}
#Override
public void onProviderDisabled(String s)
{
}
#Override
public void onProviderEnabled(String s)
{
}
}

Here Best way to get Longitude Latitude:
/** PROCESS for Get Longitude and Latitude **/
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
// Define a listener that responds to location updates
LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
// Called when a new location is found by the network location provider.
longitude = String.valueOf(location.getLongitude());
latitude = String.valueOf(location.getLatitude());
Log.d("msg", "changed Loc : "+longitude + ":"+latitude);
}
public void onStatusChanged(String provider, int status, Bundle extras) {}
public void onProviderEnabled(String provider) {}
public void onProviderDisabled(String provider) {}
};
// getting GPS status
isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
// check if GPS enabled
if(isGPSEnabled){
Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(location != null)
{
longitude = String.valueOf(location.getLongitude());
latitude = String.valueOf(location.getLatitude());
Log.d("msg", "Loc : "+longitude + ":"+latitude);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
}else
{
/*
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setCostAllowed(true);
String provider = locationManager.getBestProvider(criteria, true);
*/
location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if(location != null)
{
longitude = String.valueOf(location.getLongitude());
latitude = String.valueOf(location.getLatitude());
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
}else
{
longitude = "0.00";
latitude = "0.00";
}
}
}
if device is not able to get currentLocation using GPS then it'll be take fron NetworkProvider or else it'll take 0,0 as my requirement but you can modify as per your requirement
May it'll helpful to you.
Happy Coding :D

See, this is a very common problem. In order to have exact Latitude and Longitude ,You must use GPS also it must me activated on the mobile device but GPS too have some limitations. GPS works most efficiently under open sky. you will not have a clear range inside a building. So try your code under open sky and check the response.

onLocationChanged only called once, not update automatically

In android app want to get the location by button click here is my 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 = 0; // 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;
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;
}
public void onLocationChanged(Location location) {
this.location=location;
}
public void onProviderDisabled(String provider) {
}
public void onProviderEnabled(String provider) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
}
and my call function that get the Latitude,Longitude from above code.
double lat = gps.getLatitude();
double log = gps.getLongitude();
but its only give the same location even the place is changed.
any one help me...thanks in advance..

I looked in your code and it seems correct in all way. Can you please try it by making minimum distance to 0 as you have given min. distance 10 meter and may be you didn't moved at that much rate and your service may be taking min. distance as primary point instead of min. time.
#Dynamo: requestupdatelocation call the onLocationChanged callback method. It is not totally depending on the location assignment. location value will change as per the user location updates.
Here question is that "onLocationChanged" callback method is not getting call on given parameter.

Try this
public void onLocationChanged(Location location) {
this.location = location;
}
and also try reducing the MIN_DISTANCE_CHANGE_FOR_UPDATES to a least value.

Your code seems correct. The only reason I could think of is that device is not able to get the locations. It takes a few minutes for the device to get a lock on your location so try giving it some time.
You can use adb shell dumpsys location to check which apps have a location listener registered and if your app is among them. It will also tell you when was the last time android got a location update. Also try running any other location app to see if this problem is with your app or the environment.