How to get last known location for Location manager in Android?

Question

I am using simple location manager object to get lastKnownLocation() of device but getting null object in

Answer 1

The thing i use to get Location with Name of the place is

GPSTracker gpsTracker = new GPSTracker(CameraActivity.this);
String stringLatitude = "", stringLongitude = "", nameOfLocation="";
    if (gpsTracker.canGetLocation()) {
        stringLatitude = String.valueOf(gpsTracker.latitude);
        stringLongitude = String.valueOf(gpsTracker.longitude);
        nameOfLocation = ConvertPointToLocation(stringLatitude,stringLongitude);
    }

public String ConvertPointToLocation(String Latitude, String Longitude) {
    String address = "";
    Geocoder geoCoder = new Geocoder(getBaseContext(), Locale.getDefault());
    try {
        List
 addresses = geoCoder.getFromLocation(
                Float.parseFloat(Latitude), Float.parseFloat(Longitude), 1);

        if (addresses.size() > 0) {
            for (int index = 0; index < addresses.get(0)
                    .getMaxAddressLineIndex(); index++)
                address += addresses.get(0).getAddressLine(index) + " ";
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

    return address;
}

GPSTracker.java

package in.appology.lss;

import java.io.IOException;
import java.util.List;
import java.util.Locale;

import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.util.Log;

/**
 * Create this Class from tutorial :
 * http://www.androidhive.info/2012/07/android-gps-location-manager-tutorial
 * 
 * For Geocoder read this :
 * http://stackoverflow.com/questions/472313/android-reverse
 * -geocoding-getfromlocation
 * 
 */

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;

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; // 10
                                                                // metters

// The minimum time beetwen 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);
                    updateGPSCoordinates();
                }
            }

            // 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();
                    }
                }
            }
        }
    } 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(GPSTracker.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;
}

/**
 * Function to show settings alert dialog
 */
public void showSettingsAlert() {
    AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

    // Setting Dialog Title
    alertDialog.setTitle("GPS");

    // Setting Dialog Message
    alertDialog
            .setMessage("Please enable location in settings for accurate results!");

    // On Pressing Setting button
    alertDialog.setPositiveButton("Settings",
            new DialogInterface.OnClickListener() {
                @Override
                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() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.cancel();
                }
            });

    alertDialog.show();
}

/**
 * Get list of address by latitude and longitude
 * 
 * @return null or List

 */
public List
 getGeocoderAddress(Context context) {
    if (location != null) {
        Geocoder geocoder = new Geocoder(context, Locale.ENGLISH);
        try {
            List
 addresses = geocoder.getFromLocation(latitude,
                    longitude, 1);
            return addresses;
        } catch (IOException e) {
            // e.printStackTrace();
            Log.e("Error : Geocoder", "Impossible to connect to Geocoder",
                    e);
        }
    }

    return null;
}

/**
 * Try to get AddressLine
 * 
 * @return null or addressLine
 */
public String getAddressLine(Context context) {
    List
 addresses = getGeocoderAddress(context);
    if (addresses != null && addresses.size() > 0) {
        Address address = addresses.get(0);
        String addressLine = address.getAddressLine(0);

        return addressLine;
    } else {
        return null;
    }
}

/**
 * Try to get Locality
 * 
 * @return null or locality
 */
public String getLocality(Context context) {
    List
 addresses = getGeocoderAddress(context);
    if (addresses != null && addresses.size() > 0) {
        Address address = addresses.get(0);
        String locality = address.getLocality();

        return locality;
    } else {
        return null;
    }
}

/**
 * Try to get Postal Code
 * 
 * @return null or postalCode
 */
public String getPostalCode(Context context) {
    List
 addresses = getGeocoderAddress(context);
    if (addresses != null && addresses.size() > 0) {
        Address address = addresses.get(0);
        String postalCode = address.getPostalCode();

        return postalCode;
    } else {
        return null;
    }
}

/**
 * Try to get CountryName
 * 
 * @return null or postalCode
 */
public String getCountryName(Context context) {
    List
 addresses = getGeocoderAddress(context);
    if (addresses != null && addresses.size() > 0) {
        Address address = addresses.get(0);
        String countryName = address.getCountryName();

        return countryName;
    } else {
        return null;
    }
}

@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 intent) {
    return null;
}
}