I need to use GPS programmatically to get the current position. How can I achieve it?
#1 building
I created a small application with step-by-step instructions to get the GPS coordinates of the current location.
Complete sample source code On Android " Get current location coordinate, city name .
See how it works:
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What we need to do is add this permission to the manifest file:
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> -
And create a LocationManager instance as follows:
LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); Check if GPS is enabled.
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Then implement LocationListener and get the coordinates:
LocationListener locationListener = new MyLocationListener(); locationManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 5000, 10, locationListener); This is the sample code to do this
/*---------- Listener class to get coordinates ------------- */ private class MyLocationListener implements LocationListener { @Override public void onLocationChanged(Location loc) { editLocation.setText(""); pb.setVisibility(View.INVISIBLE); Toast.makeText( getBaseContext(), "Location changed: Lat: " + loc.getLatitude() + " Lng: " + loc.getLongitude(), Toast.LENGTH_SHORT).show(); String longitude = "Longitude: " + loc.getLongitude(); Log.v(TAG, longitude); String latitude = "Latitude: " + loc.getLatitude(); Log.v(TAG, latitude); /*------- To get city name from coordinates -------- */ String cityName = null; Geocoder gcd = new Geocoder(getBaseContext(), Locale.getDefault()); List<Address> addresses; try { addresses = gcd.getFromLocation(loc.getLatitude(), loc.getLongitude(), 1); if (addresses.size() > 0) { System.out.println(addresses.get(0).getLocality()); cityName = addresses.get(0).getLocality(); } } catch (IOException e) { e.printStackTrace(); } String s = longitude + "\n" + latitude + "\n\nMy Current City is: " + cityName; editLocation.setText(s); } @Override public void onProviderDisabled(String provider) {} @Override public void onProviderEnabled(String provider) {} @Override public void onStatusChanged(String provider, int status, Bundle extras) {} }
#2 building
This is additional information for other answers.
Because Android has
GPS_PROVIDER and NETWORK_PROVIDER
You can register both and get events from two onLocationChanged(Location location). So far so good. The question now is whether we need two results or whether we should achieve the best. As far as I know, GPS? Provider results have better accuracy than network? Provider.
Let's define the Location field:
private Location currentBestLocation = null;
Before we start listening for location changes, we implement the following methods. This method returns the last known location between GPS and the network. For this method, it's better to be new.
/** * @return the last know best location */ private Location getLastBestLocation() { Location locationGPS = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER); Location locationNet = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER); long GPSLocationTime = 0; if (null != locationGPS) { GPSLocationTime = locationGPS.getTime(); } long NetLocationTime = 0; if (null != locationNet) { NetLocationTime = locationNet.getTime(); } if ( 0 < GPSLocationTime - NetLocationTime ) { return locationGPS; } else { return locationNet; } }
Every time we retrieve a new location, we compare it with the previous results.
... static final int TWO_MINUTES = 1000 * 60 * 2; ...
I added a new method to onLocationChanged:
@Override public void onLocationChanged(Location location) { makeUseOfNewLocation(location); if(currentBestLocation == null){ currentBestLocation = location; } .... } /** * This method modify the last know good location according to the arguments. * * @param location The possible new location. */ void makeUseOfNewLocation(Location location) { if ( isBetterLocation(location, currentBestLocation) ) { currentBestLocation = location; } } .... /** Determines whether one location reading is better than the current location fix * @param location The new location that you want to evaluate * @param currentBestLocation The current location fix, to which you want to compare the new one. */ protected boolean isBetterLocation(Location location, Location currentBestLocation) { if (currentBestLocation == null) { // A new location is always better than no location return true; } // Check whether the new location fix is newer or older long timeDelta = location.getTime() - currentBestLocation.getTime(); boolean isSignificantlyNewer = timeDelta > TWO_MINUTES; boolean isSignificantlyOlder = timeDelta < -TWO_MINUTES; boolean isNewer = timeDelta > 0; // If it's been more than two minutes since the current location, use the new location, // because the user has likely moved. if (isSignificantlyNewer) { return true; // If the new location is more than two minutes older, it must be worse. } else if (isSignificantlyOlder) { return false; } // Check whether the new location fix is more or less accurate int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation.getAccuracy()); boolean isLessAccurate = accuracyDelta > 0; boolean isMoreAccurate = accuracyDelta < 0; boolean isSignificantlyLessAccurate = accuracyDelta > 200; // Check if the old and new location are from the same provider boolean isFromSameProvider = isSameProvider(location.getProvider(), currentBestLocation.getProvider()); // Determine location quality using a combination of timeliness and accuracy if (isMoreAccurate) { return true; } else if (isNewer && !isLessAccurate) { return true; } else if (isNewer && !isSignificantlyLessAccurate && isFromSameProvider) { return true; } return false; } // Checks whether two providers are the same private boolean isSameProvider(String provider1, String provider2) { if (provider1 == null) { return provider2 == null; } return provider1.equals(provider2); } ....
#3 building
You can find the location through GPS? Provider or network? Provider.
In Android Location service Summary.
This is an example of trying to find a location using GPS. If your GPS is not available, try using the network to find a location.
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 = 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; 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 latitude/longitude 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/Wi-Fi enabled * @return boolean * */ public boolean canGetLocation() { return this.canGetLocation; } /** * Function to show settings alert dialog. * On pressing the Settings button it will launch 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 the 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 the 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; } }
Activity - Android gpstrangkingactivity.java
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(); } } }); } }
Layout - main.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <Button android:id="@+id/btnShowLocation" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Show Location" android:layout_centerVertical="true" android:layout_centerHorizontal="true"/> </RelativeLayout>
AndroidManifest.xml
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> <uses-permission android:name="android.permission.INTERNET" />
#4 building
class MyLocation { Timer timer1; LocationManager lm; LocationResult locationResult; boolean gps_enabled = false; boolean network_enabled = false; public boolean getLocation(Context context, LocationResult result) { // I use LocationResult callback class to pass location value from // MyLocation to user code. locationResult = result; if (lm == null) lm = (LocationManager) context .getSystemService(Context.LOCATION_SERVICE); // Exceptions will be thrown if the provider is not permitted. try { gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER); } catch (Exception ex) { } try { network_enabled = lm .isProviderEnabled(LocationManager.NETWORK_PROVIDER); } catch (Exception ex) { } // Don't start listeners if no provider is enabled. if (!gps_enabled && !network_enabled) return false; if (gps_enabled) lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps); if (network_enabled) lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork); timer1 = new Timer(); timer1.schedule(new GetLastLocation(), 5000); return true; } LocationListener locationListenerGps = new LocationListener() { public void onLocationChanged(Location location) { timer1.cancel(); locationResult.gotLocation(location); lm.removeUpdates(this); lm.removeUpdates(locationListenerNetwork); } public void onProviderDisabled(String provider) { } public void onProviderEnabled(String provider) { } public void onStatusChanged(String provider, int status, Bundle extras) { } }; LocationListener locationListenerNetwork = new LocationListener() { public void onLocationChanged(Location location) { timer1.cancel(); locationResult.gotLocation(location); lm.removeUpdates(this); lm.removeUpdates(locationListenerGps); } public void onProviderDisabled(String provider) { } public void onProviderEnabled(String provider) { } public void onStatusChanged(String provider, int status, Bundle extras) { } }; class GetLastLocation extends TimerTask { @Override public void run() { lm.removeUpdates(locationListenerGps); lm.removeUpdates(locationListenerNetwork); Location net_loc = null, gps_loc = null; if (gps_enabled) gps_loc = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER); if (network_enabled) net_loc = lm .getLastKnownLocation(LocationManager.NETWORK_PROVIDER); // If there are both values, use the latest one. if (gps_loc != null && net_loc != null) { if (gps_loc.getTime() > net_loc.getTime()) locationResult.gotLocation(gps_loc); else locationResult.gotLocation(net_loc); return; } if (gps_loc != null) { locationResult.gotLocation(gps_loc); return; } if (net_loc != null) { locationResult.gotLocation(net_loc); return; } locationResult.gotLocation(null); } } public static abstract class LocationResult { public abstract void gotLocation(Location location); } }
I hope this can help you
#5 building
If you want to create a new location project for Android, you should use the new Google Play Location services. It's more accurate and easier to use.
I am engaged in Open source GPS Tracker project Gpstrangler has been for many years. I recently updated it to handle Android, iOS, Windows Phone and Java ME Regular update of mobile phone. It is fully functional, can meet your needs, and has MIT License .
The Android project in gpstrangler uses the new Google Play service, with two server stacks( ASP.NET and PHP )Allows you to track these phones.