Before couple of months, I created GPSTracker library to help me to get GPS locations. In case you need to view GPSTracker > getLocation

Demo

AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

Activity

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity {

    TextView textview;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.geo_locations);

        // check if GPS enabled
        GPSTracker gpsTracker = new GPSTracker(this);

        if (gpsTracker.getIsGPSTrackingEnabled())
        {
            String stringLatitude = String.valueOf(gpsTracker.latitude);
            textview = (TextView)findViewById(R.id.fieldLatitude);
            textview.setText(stringLatitude);

            String stringLongitude = String.valueOf(gpsTracker.longitude);
            textview = (TextView)findViewById(R.id.fieldLongitude);
            textview.setText(stringLongitude);

            String country = gpsTracker.getCountryName(this);
            textview = (TextView)findViewById(R.id.fieldCountry);
            textview.setText(country);

            String city = gpsTracker.getLocality(this);
            textview = (TextView)findViewById(R.id.fieldCity);
            textview.setText(city);

            String postalCode = gpsTracker.getPostalCode(this);
            textview = (TextView)findViewById(R.id.fieldPostalCode);
            textview.setText(postalCode);

            String addressLine = gpsTracker.getAddressLine(this);
            textview = (TextView)findViewById(R.id.fieldAddressLine);
            textview.setText(addressLine);
        }
        else
        {
            // can't get location
            // GPS or Network is not enabled
            // Ask user to enable GPS/network in settings
            gpsTracker.showSettingsAlert();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.varna_lab_geo_locations, menu);
        return true;
    }
}

GPS Tracker

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 {

    // Get Class Name
    private static String TAG = GPSTracker.class.getName();

    private final Context mContext;

    // flag for GPS Status
    boolean isGPSEnabled = false;

    // flag for network status
    boolean isNetworkEnabled = false;

    // flag for GPS Tracking is enabled 
    boolean isGPSTrackingEnabled = false;

    Location location;
    double latitude;
    double longitude;

    // How many Geocoder should return our GPSTracker
    int geocoderMaxResults = 1;

    // 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;

    // Store LocationManager.GPS_PROVIDER or LocationManager.NETWORK_PROVIDER information
    private String provider_info;

    public GPSTracker(Context context) {
        this.mContext = context;
        getLocation();
    }

    /**
     * Try to get my current location by GPS or Network Provider
     */
    public void 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);

            // Try to get location if you GPS Service is enabled
            if (isGPSEnabled) {
                this.isGPSTrackingEnabled = true;

                Log.d(TAG, "Application use GPS Service");

                /*
                 * This provider determines location using
                 * satellites. Depending on conditions, this provider may take a while to return
                 * a location fix.
                 */

                provider_info = LocationManager.GPS_PROVIDER;

            } else if (isNetworkEnabled) { // Try to get location if you Network Service is enabled
                this.isGPSTrackingEnabled = true;

                Log.d(TAG, "Application use Network State to get GPS coordinates");

                /*
                 * This provider determines location based on
                 * availability of cell tower and WiFi access points. Results are retrieved
                 * by means of a network lookup.
                 */
                provider_info = LocationManager.NETWORK_PROVIDER;

            } 

            // Application can use GPS or Network Provider
            if (!provider_info.isEmpty()) {
                locationManager.requestLocationUpdates(
                    provider_info,
                    MIN_TIME_BW_UPDATES,
                    MIN_DISTANCE_CHANGE_FOR_UPDATES, 
                    this
                );

                if (locationManager != null) {
                    location = locationManager.getLastKnownLocation(provider_info);
                    updateGPSCoordinates();
                }
            }
        }
        catch (Exception e)
        {
            //e.printStackTrace();
            Log.e(TAG, "Impossible to connect to LocationManager", e);
        }
    }

    /**
     * Update GPSTracker latitude and longitude
     */
    public void updateGPSCoordinates() {
        if (location != null) {
            latitude = location.getLatitude();
            longitude = location.getLongitude();
        }
    }

    /**
     * GPSTracker latitude getter and setter
     * @return latitude
     */
    public double getLatitude() {
        if (location != null) {
            latitude = location.getLatitude();
        }

        return latitude;
    }

    /**
     * GPSTracker longitude getter and setter
     * @return
     */
    public double getLongitude() {
        if (location != null) {
            longitude = location.getLongitude();
        }

        return longitude;
    }

    /**
     * GPSTracker isGPSTrackingEnabled getter.
     * Check GPS/wifi is enabled
     */
    public boolean getIsGPSTrackingEnabled() {

        return this.isGPSTrackingEnabled;
    }

    /**
     * Stop using GPS listener
     * Calling this method will stop using GPS in your app
     */
    public void stopUsingGPS() {
        if (locationManager != null) {
            locationManager.removeUpdates(GPSTracker.this);
        }
    }

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

        //Setting Dialog Title
        alertDialog.setTitle(R.string.GPSAlertDialogTitle);

        //Setting Dialog Message
        alertDialog.setMessage(R.string.GPSAlertDialogMessage);

        //On Pressing Setting button
        alertDialog.setPositiveButton(R.string.action_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(R.string.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<Address>
     */
    public List<Address> getGeocoderAddress(Context context) {
        if (location != null) {

            Geocoder geocoder = new Geocoder(context, Locale.ENGLISH);

            try {
                /**
                 * Geocoder.getFromLocation - Returns an array of Addresses 
                 * that are known to describe the area immediately surrounding the given latitude and longitude.
                 */
                List<Address> addresses = geocoder.getFromLocation(latitude, longitude, this.geocoderMaxResults);

                return addresses;
            } catch (IOException e) {
                //e.printStackTrace();
                Log.e(TAG, "Impossible to connect to Geocoder", e);
            }
        }

        return null;
    }

    /**
     * Try to get AddressLine
     * @return null or addressLine
     */
    public String getAddressLine(Context context) {
        List<Address> 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<Address> 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<Address> 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<Address> 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 onStatusChanged(String provider, int status, Bundle extras) {
    }

    @Override
    public void onProviderEnabled(String provider) {
    }

    @Override
    public void onProviderDisabled(String provider) {
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}

Note

If the method / answer doesn't work. You need to use the official Google Provider: FusedLocationProviderApi.

Article: Getting the Last Known Location

I think that if the null pointer exception really happens within the if() block, at the getLatitude() call, this means the reference to the Location object that you just tested is no longer valid.

So I would try to copy the location object before using it, like this:

       public void onLocationChanged(Location location) {
            Location copyOfLocation = new Location(location);
            updateWithNewLocation(copyOfLocation );
        }

Haven't tested this, and I don't remember seeing this problem before...

--Edit--

Wait, the exception has moved since your last edit... Well your location is null probably because the system has no previous location to give you. Try going outside with your phone, power on the GPS, launch Google Maps until the GPS icon in the notification bar does not blink anymore, quit Maps, go back inside and try your app again.

-- Edit 2--

There are two conditions for getLastKnownLocation to work:

• the location provider must be powered on (must use the Android preferences panel to turn the GPS on)
• the system must have computed a position with the required provider sometime in the past

Else it will return null

try this code:

locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    // Define the criteria how to select the locatioin provider -> use
    // default
    Criteria criteria = new Criteria();
    provider = locationManager.getBestProvider(criteria, false);
    Location location = locationManager.getLastKnownLocation(provider);

    // Initialize the location fields
    if (location != null) {
      System.out.println("Provider " + provider + " has been selected.");
      onLocationChanged(location);
    } else {
      latituteField.setText("Location not available");
      longitudeField.setText("Location not available");
      System.out.println("Location not avilable");
    }
  }

  /* Request updates at startup */
  @Override
  protected void onResume() {
    super.onResume();
    locationManager.requestLocationUpdates(provider, 400, 1, this);
  }

  /* Remove the locationlistener updates when Activity is paused */
  @Override
  protected void onPause() {
    super.onPause();
    locationManager.removeUpdates(this);
  }

  @Override
  public void onLocationChanged(Location location) {
    double lat = (double) (location.getLatitude());
    double lng = (double) (location.getLongitude());
    latituteField.setText(String.valueOf(lat));
    longitudeField.setText(String.valueOf(lng));
    Log.i(TAG, "Lattitude:" +lat);
    Log.i(TAG, "Longitude:" +lng);
  }

GPS_PROVIDER does not work in bound place. So if gps_provider is enabled but you get null location you can replace provider from gps to NETWORK_PROVIDER.

you can use the LocationListener class to get the coordinates while on the move.

use the following to get the coordiates when not on the move.

LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);    
Location location = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);  

if(location == null){
    LAT = 0.0;
    LONG = 0.0;
    loc.setText("No Location");
}

for an indepth discussion --

http://www.devx.com/wireless/Article/39239/1954

onLocationChanged gets called every time when your location updates , so keep & update a global value and take that value on your Button click to do what you want

 private LatLng latLng;

       @Override
        public void onLocationChanged(Location location) {
        if(location!=null){
         latLng = new LatLng(location.getLatitude(), location.getLongitude()); }
    }

or based on time or distance you can get the location as well use android.location.LocationListener() see Edit for that,

If you want to manually call onLocationChanged after a time period even the location is not changed use below

 LocationRequest  mLocationRequest = new LocationRequest();
    mLocationRequest.setInterval(30000); //5 seconds
    mLocationRequest.setFastestInterval(30000); //3 seconds
    mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
    //mLocationRequest.setSmallestDisplacement(0.1F); //1/10 meter

    if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        return;
    }
    LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);

Edit : This is the location listener you can use this separately without the above if you want

    private LocationManager locationManager;
    private android.location.LocationListener myLocationListener;

    public void checkLocation() {

        String serviceString = Context.LOCATION_SERVICE;
        locationManager = (LocationManager) getSystemService(serviceString);


        if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return;
        }


        myLocationListener = new android.location.LocationListener() {
            public void onLocationChanged(Location locationListener) {

                if (isGPSEnabled(YourActivityName.this)) {
                    if (locationListener != null) {
                        if (ActivityCompat.checkSelfPermission(YourActivityName.this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(YourActivityName.this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                            return;
                        }

                        if (locationManager != null) {
                            location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
                            if (location != null) {
                                latitude = location.getLatitude();
                                longitude = location.getLongitude();
                            }
                        }
                    }
                } else if (isInternetConnected(YourActivityName.this)) {
                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }



            }

            public void onProviderDisabled(String provider) {

            }

            public void onProviderEnabled(String provider) {

            }

            public void onStatusChanged(String provider, int status, Bundle extras) {

            }
        }; 

locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 1, myLocationListener); 
}

isInternetConnected method

public static boolean isInternetConnected(Context ctx) {
        ConnectivityManager connectivityMgr = (ConnectivityManager) ctx
                .getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo wifi = connectivityMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
        NetworkInfo mobile = connectivityMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
        // Check if wifi or mobile network is available or not. If any of them is
        // available or connected then it will return true, otherwise false;
        if (wifi != null) {
            if (wifi.isConnected()) {
                return true;
            }
        }
        if (mobile != null) {
            if (mobile.isConnected()) {
                return true;
            }
        }
        return false;
    }

isGpsEnabled method

  public boolean isGPSEnabled(Context mContext) {
        LocationManager locationManager = (LocationManager) mContext.getSystemService(Context.LOCATION_SERVICE);
        return locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
    }

Note : Now do not get confuse. There are 3 ways mentioned here.

1.use onLocationChanged automatically

2. use onLocationChanged manually

3. use android.location.LocationListener() added the full implementation (this will not help you to learn but to get a data. Go through these lines and understand them by searching what happen actually )

You have a mistake in your manifest file. Correct one is:

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

This is the code for getting user current latitude and longitude using geo coading in Android:

        public class HomeActivity extends Activity implements LocationListener{
    public static Context mContext;
    private double latitude, longitude;
     public LocationManager mLocManager;
    // *******This is the new Code start on 11/4/2011 at 3 o'clock
    
    
    /**
     * This is the Home Button if user Login then it is move to TennisAppActivity otherwise move to Login  
     *
     */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        mContext=this;
        super.onCreate(savedInstanceState);
        setContentView(R.layout.homelayout);
        

        mLocManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
         
        mLocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0,
                this);
        mLocManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0,
                0, this);
        locationUpdate();
        ((Button) this.findViewById(R.id.ButtonHome))
                .setOnClickListener(new OnClickListener() {
                    public void onClick(View arg0) {
                        
                            startActivity(new Intent(HomeActivity.this,
                                    DefaultDisplay.class));
                        
                    }
                });

        ((Button) this.findViewById(R.id.ButtonProfile))
                .setOnClickListener(new OnClickListener() {

                    public void onClick(View arg0) {
                        if (GUIStatics.boolLoginStatus) {
                            startActivity(new Intent(HomeActivity.this,
                                    MyProfile.class));
                        } else {
                            Intent intent=new Intent(HomeActivity.this,
                                    Login.class);
                            intent.putExtra("moveTo","MyProfile");
                            startActivity(intent);
                        }
                    }
                });

        ((Button) this.findViewById(R.id.ButtonNotifications))
                .setOnClickListener(new OnClickListener() {

                    public void onClick(View arg0) {
                        if (GUIStatics.boolLoginStatus) {
                            startActivity(new Intent(HomeActivity.this,
                                    ShowAllNotificationActiviry.class));
                        } else {
                            Intent intent=new Intent(HomeActivity.this,
                                    Login.class);
                            intent.putExtra("moveTo","ShowAllNotificationActiviry");
                            startActivity(intent);
                        }
                    }
                });

        ((Button) this.findViewById(R.id.ButtonFavorites))
                .setOnClickListener(new OnClickListener() {

                    public void onClick(View arg0) {
                        if (GUIStatics.boolLoginStatus) {
                            startActivity(new Intent(HomeActivity.this,
                                    FavoritesActivity.class));
                        } else {
                            Intent intent=new Intent(HomeActivity.this,
                                    Login.class);
                            intent.putExtra("moveTo","FavoritesActivity");
                            startActivity(intent);
                        }
                    }
                });

                ((Button) this.findViewById(R.id.ButtonMore))
                .setOnClickListener(new OnClickListener() {
                    public void onClick(View arg0) {
                            startActivity(new Intent(HomeActivity.this,
                                    MoreListActivity.class));
                    }
                });

    }
    
    public void locationUpdate()
    {
        CellLocation.requestLocationUpdate();
    }
    
    
    public void getAddress(double lat, double lng) {
        Geocoder geocoder = new Geocoder(HomeActivity.mContext, Locale.getDefault());
        try {
            List<Address> addresses = geocoder.getFromLocation(lat, lng, 1);
            Address obj = addresses.get(0);
            String add = obj.getAddressLine(0);
            GUIStatics.currentAddress = obj.getSubAdminArea() + ","
                    + obj.getAdminArea();
            GUIStatics.latitude = obj.getLatitude();
            GUIStatics.longitude = obj.getLongitude();
            GUIStatics.currentCity= obj.getSubAdminArea();
            GUIStatics.currentState= obj.getAdminArea();
            add = add + "\n" + obj.getCountryName();
            add = add + "\n" + obj.getCountryCode();
            add = add + "\n" + obj.getAdminArea();
            add = add + "\n" + obj.getPostalCode();
            add = add + "\n" + obj.getSubAdminArea();
            add = add + "\n" + obj.getLocality();
            add = add + "\n" + obj.getSubThoroughfare();

            Log.v("IGA", "Address" + add);
            // Toast.makeText(this, "Address=>" + add,
            // Toast.LENGTH_SHORT).show();

            // TennisAppActivity.showDialog(add);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            Toast.makeText(this, e.getMessage(), Toast.LENGTH_SHORT).show();
        }
    }
    
    

    public void onLocationChanged(Location location) {
        latitude = location.getLatitude();
        longitude = location.getLongitude();
        GUIStatics.latitude=location.getLatitude();
        GUIStatics.longitude= location.getLongitude();
        Log.v("Test", "IGA" + "Lat" + latitude + "   Lng" + longitude);
        //mLocManager.r
         
        getAddress(latitude, longitude);
        if(location!=null)
        {
            
        mLocManager.removeUpdates(this);
        }
        // Toast.makeText(this, "Lat" + latitude + "   Lng" + longitude,
        // Toast.LENGTH_SHORT).show();
    }


    public void onProviderDisabled(String arg0) {
        // TODO Auto-generated method stub
        Toast.makeText(HomeActivity.this, "Gps Disabled", Toast.LENGTH_SHORT).show();
        Intent intent = new Intent(
                android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS);
        startActivity(intent);
    }


    public void onProviderEnabled(String arg0) {
        // TODO Auto-generated method stub
        
    }


    public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
         if(arg1 == 
                LocationProvider.TEMPORARILY_UNAVAILABLE) { 
                                        Toast.makeText(HomeActivity.this, 
                "LocationProvider.TEMPORARILY_UNAVAILABLE", 
                Toast.LENGTH_SHORT).show(); 
                            } 
                            else if(arg1== LocationProvider.OUT_OF_SERVICE) { 
                                        Toast.makeText(HomeActivity.this, 
                "LocationProvider.OUT_OF_SERVICE", Toast.LENGTH_SHORT).show(); 
                            } 
        
    }
}