Mark marker at current location after onPostExecution asynchronous task

Question

I am developing an application in which I use AsyncTask to build a marker. I am trying to build a marker on onPostExeution () for the current location and move my camera to the current location. I tried several ways to achieve this, but unfortunately the application crashes. So you can advise me to draw a marker on the current location and move my camera to this place after receiving the location update in onPostExecute ().

Here is my code -

MainActivity.java

public class MainActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener,OnMapReadyCallback {

SupportMapFragment sMapFragment;
public GoogleMap mMap;
private HttpURLConnection urlConnection = null;
private BufferedReader reader = null;
private String forecastJsonStr = null;
private String url = "my_url";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    sMapFragment = SupportMapFragment.newInstance();


    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);
    sMapFragment.getMapAsync(this);
    android.support.v4.app.FragmentManager sFM = getSupportFragmentManager();
    sFM.beginTransaction().add(R.id.Map, sMapFragment).commit();

}

//Search option

public void onMapSearch(View view) throws IOException {

    //hide button when button is pressed
    InputMethodManager inputManager = (InputMethodManager) getSystemService(this.INPUT_METHOD_SERVICE);
    inputManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);

    //preview the entered address as an Tost in bar
    EditText locationSearch = (EditText) findViewById(R.id.editText);
    String location = locationSearch.getText().toString();

    //this will animate camera and zoom 12.0f
    mMap.animateCamera(CameraUpdateFactory.zoomTo(12.0f));


    //further address search codes
    List<Address> addressList = null;

    //if nothing will be entered in the edit-text will not show a toast rather than crashing of thekha app
    if (locationSearch.getText().toString().equals("")) {
        Toast.makeText(this, "Please enter an Address", Toast.LENGTH_LONG).show();
    } else {

        //process of exception handling and finding location
        if (location != null || !location.equals("")) {
            Geocoder geocoder = new Geocoder(this);
            try {
                addressList = geocoder.getFromLocationName(location, 1);
            } catch (IOException e) {
                e.printStackTrace();
            }
            //if address is greater than one then these processes will happen

            if (addressList.size() > 0) {
                Address address = addressList.get(0);
                LatLng latLng = new LatLng(address.getLatitude(), address.getLongitude());
                mMap.addMarker(new MarkerOptions()
                        .position(latLng)
                        .title(location + " is Here ")
                        .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_BLUE)));
                mMap.animateCamera(CameraUpdateFactory.newLatLng(latLng));

                Toast.makeText(this, location + " is here, Zoom In or Zoom Out to make your Thekha Visible ", Toast.LENGTH_LONG)
                        .show(); //popup type to show entered data
            } else {
                //process where entered entry will not gonna find , this will gonna a toast to show popup

                Toast.makeText(this, "Entered Address Not Found", Toast.LENGTH_LONG).show();

            }
        }

    }
}

//Async task

ProgressDialog pd = null;

private class RetriveMarkerTask extends AsyncTask<String, Void, String> {
    private Context context;


    public RetriveMarkerTask(Context context) {
        this.context = context;
    }

    @Override
    protected void onPreExecute() {
        pd = new ProgressDialog(MainActivity.this);
        pd.setTitle("Please wait ...");
        pd.setMessage("Connecting to Loofre Network");
        pd.setCancelable(false);
        pd.show();

    }

    protected String doInBackground(String... markerGetUrl) {
        try {
            // Construct the URL for the OpenWeatherMap query
            // Possible parameters are avaiable at OWM forecast API page, at
            // http://openweathermap.org/API#forecast
            URL url1 = new URL(url);

            // Create the request to OpenWeatherMap, and open the connection
            urlConnection = (HttpURLConnection) url1.openConnection();
            urlConnection.setRequestMethod("GET");
            urlConnection.connect();

            // Read the input stream into a String
            InputStream inputStream = urlConnection.getInputStream();
            StringBuffer buffer = new StringBuffer();
            if (inputStream == null) {
                // Nothing to do.
                return null;
            }
            reader = new BufferedReader(new InputStreamReader(inputStream));

            String line;
            while ((line = reader.readLine()) != null) {
                // Since it JSON, adding a newline isn't necessary (it won't affect parsing)
                // But it does make debugging a *lot* easier if you print out the completed
                // buffer for debugging.
                buffer.append(line + "\n");
            }

            if (buffer.length() == 0) {
                // Stream was empty.  No point in parsing.
                return null;
            }
            forecastJsonStr = buffer.toString();
        } catch (IOException e) {
            Log.e("PlaceholderFragment", "Error ", e);
            // If the code didn't successfully get the weather data, there no point in attemping
            // to parse it.
            forecastJsonStr = "Error, an exception was raised.";
        } finally {
            if (urlConnection != null) {
                urlConnection.disconnect();
            }
            if (reader != null) {
                try {
                    reader.close();
                } catch (final IOException e) {
                    Log.e("PlaceholderFragment", "Error closing stream", e);
                }
            }
        }
        return forecastJsonStr;

    }

    //on post execution

    protected void onPostExecute(String markers) {


        Log.d("string response", markers);

        Toast.makeText(MainActivity.this, "Plotting Thekha", Toast.LENGTH_LONG).show();

        try {
            JSONArray jsonArray = new JSONArray(markers);
            for (int i = 0; i < jsonArray.length(); i++) {
                //create marker of each place in the json data
                JSONObject jsonObject = jsonArray.getJSONObject(i);
                String placeName = jsonObject.getString("name");
                String placeAddress = jsonObject.getString("address");
                double latitude = jsonObject.getJSONArray("latlang").getDouble(0);
                double longitude = jsonObject.getJSONArray("latlang").getDouble(1);
                LatLng loc = new LatLng(latitude, longitude);
                //marker size change code
                int height = 150;
                int width = 150;
                BitmapDrawable bitmapDrawable = (BitmapDrawable) getResources().getDrawable(R.drawable.thekhaicon);
                Bitmap b = bitmapDrawable.getBitmap();
                Bitmap smallMarker = Bitmap.createScaledBitmap(b, width, height, false);
                //marker size change code ends here
                //mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(loc, 13));

                mMap.addMarker(new MarkerOptions()
                        .icon(BitmapDescriptorFactory.fromBitmap(smallMarker))
                        .title(placeName)
                        .snippet(placeAddress)
                        .position(loc)

                );

                LatLng dwarka = new LatLng(28.570317, 77.32182);
                mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(dwarka, 13));
                mMap.addMarker(
                        new MarkerOptions()
                                .title("Wine Beer Liquor Shop, Sector 18, Noida")
                                .snippet("Sector 18, Near Centre Stage Mall, Noida")
                                .position(dwarka));
            }
            pd.dismiss();
        } catch (JSONException e) {
            e.printStackTrace();
        }

    }
}







@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

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

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();

    if (id == R.id.nav_camera) {
        // Handle the camera action
    } else if (id == R.id.nav_gallery) {

    } else if (id == R.id.nav_slideshow) {

    } else if (id == R.id.nav_manage) {

    } else if (id == R.id.call_us) {
        Intent intent = new Intent(Intent.ACTION_CALL);
        intent.setData(Uri.parse("tel:[phone]"));
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // 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 ActivityCompat#requestPermissions for more details.
            return true;
        }
        startActivity(intent);

    } else if (id == R.id.about_us) {
        Intent intent = new Intent(this,ScrollingActivity.class);
        this.startActivity(intent);

    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

@Override
public void onMapReady(GoogleMap googleMap) {
    Toast.makeText(this, "Connecting Server", Toast.LENGTH_LONG).show();
    mMap = googleMap;

    try {
        RetriveMarkerTask markerTask = new RetriveMarkerTask(MainActivity.this);
        markerTask.execute(url);
    }catch (Exception e){
        Toast.makeText(this,"Can not fetch data",Toast.LENGTH_LONG).show();
    }
    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) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // 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 ActivityCompat#requestPermissions for more details.
    }
    //tool bar and other tool related on map uiSettings
    // mMap.setMyLocationEnabled(true);
    mMap.getUiSettings().setZoomControlsEnabled(true);
    mMap.getUiSettings().setMapToolbarEnabled(true);
    mMap.getUiSettings().setMyLocationButtonEnabled(true);

}

my manifest.xml file is

<!--
     The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
     Google Maps Android API v2, but you must specify either coarse or fine
     location permissions for the 'MyLocation' functionality. 
-->
<uses-permission android:name="android.permission.CALL_PHONE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSWEVICES" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

<application
    android:name="android.support.multidex.MultiDexApplication"
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="Thekha"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name"
        android:theme="@style/AppTheme.NoActionBar"></activity>
    <!--
         The API key for Google Maps-based APIs is defined as a string resource.
         (See the file "res/values/google_maps_api.xml").
         Note that the API key is linked to the encryption key used to sign the APK.
         You need a different API key for each encryption key, including the release key that is used to
         sign the APK for publishing.
         You can define the keys for the debug and release targets in src/debug/ and src/release/.
    -->
    <meta-data
        android:name="com.google.android.geo.API_KEY"
        android:value="AIzaSyAma5WZ9H5yskkt3AsQwc3aeQOFCyc9aGo" />

    <activity android:name=".LoginActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name=".ScrollingActivity"
        android:label="@string/title_activity_scrolling"
        android:theme="@style/AppTheme.NoActionBar"></activity>
</application>

Answer 1

@ .

        public class MainActivity extends AppCompatActivity
            implements NavigationView.OnNavigationItemSelectedListener,OnMapReadyCallback {

    SupportMapFragment sMapFragment;
    public GoogleMap mMap;
    private HttpURLConnection urlConnection = null;
    private BufferedReader reader = null;
    private String forecastJsonStr = null;
    private String url = "my_url";

    @Override

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    sMapFragment = SupportMapFragment.newInstance();


    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);
    sMapFragment.getMapAsync(this);
    android.support.v4.app.FragmentManager sFM = getSupportFragmentManager();
    sFM.beginTransaction().add(R.id.Map, sMapFragment).commit();

}

//Search option

public void onMapSearch(View view) throws IOException {

    //hide button when button is pressed
    InputMethodManager inputManager = (InputMethodManager) getSystemService(this.INPUT_METHOD_SERVICE);
    inputManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);

    //preview the entered address as an Tost in bar
    EditText locationSearch = (EditText) findViewById(R.id.editText);
    String location = locationSearch.getText().toString();

    //this will animate camera and zoom 12.0f
    mMap.animateCamera(CameraUpdateFactory.zoomTo(12.0f));


    //further address search codes
    List<Address> addressList = null;

    //if nothing will be entered in the edit-text will not show a toast rather than crashing of thekha app
    if (locationSearch.getText().toString().equals("")) {
        Toast.makeText(this, "Please enter an Address", Toast.LENGTH_LONG).show();
    } else {

        //process of exception handling and finding location
        if (location != null || !location.equals("")) {
            Geocoder geocoder = new Geocoder(this);
            try {
                addressList = geocoder.getFromLocationName(location, 1);
            } catch (IOException e) {
                e.printStackTrace();
            }
            //if address is greater than one then these processes will happen

            if (addressList.size() > 0) {
                Address address = addressList.get(0);
                LatLng latLng = new LatLng(address.getLatitude(), address.getLongitude());
                mMap.addMarker(new MarkerOptions()
                        .position(latLng)
                        .title(location + " is Here ")
                        .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_BLUE)));
                mMap.animateCamera(CameraUpdateFactory.newLatLng(latLng));

                Toast.makeText(this, location + " is here, Zoom In or Zoom Out to make your Thekha Visible ", Toast.LENGTH_LONG)
                        .show(); //popup type to show entered data
            } else {
                //process where entered entry will not gonna find , this will gonna a toast to show popup

                Toast.makeText(this, "Entered Address Not Found", Toast.LENGTH_LONG).show();

            }
        }

    }
}

//Async task

ProgressDialog pd = null;

private class RetriveMarkerTask extends AsyncTask<String, Void, String> {
    private Context context;


    public RetriveMarkerTask(Context context) {
        this.context = context;
    }

    @Override
    protected void onPreExecute() {
        pd = new ProgressDialog(MainActivity.this);
        pd.setTitle("Please wait ...");
        pd.setMessage("Connecting to Loofre Network");
        pd.setCancelable(false);
        pd.show();

    }

    protected String doInBackground(String... markerGetUrl) {
        try {
            // Construct the URL for the OpenWeatherMap query
            // Possible parameters are avaiable at OWM forecast API page, at
            // http://openweathermap.org/API#forecast
            URL url1 = new URL(url);

            // Create the request to OpenWeatherMap, and open the connection
            urlConnection = (HttpURLConnection) url1.openConnection();
            urlConnection.setRequestMethod("GET");
            urlConnection.connect();

            // Read the input stream into a String
            InputStream inputStream = urlConnection.getInputStream();
            StringBuffer buffer = new StringBuffer();
            if (inputStream == null) {
                // Nothing to do.
                return null;
            }
            reader = new BufferedReader(new InputStreamReader(inputStream));

            String line;
            while ((line = reader.readLine()) != null) {
                // Since it JSON, adding a newline isn't necessary (it won't affect parsing)
                // But it does make debugging a *lot* easier if you print out the completed
                // buffer for debugging.
                buffer.append(line + "\n");
            }

            if (buffer.length() == 0) {
                // Stream was empty.  No point in parsing.
                return null;
            }
            forecastJsonStr = buffer.toString();
        } catch (IOException e) {
            Log.e("PlaceholderFragment", "Error ", e);
            // If the code didn't successfully get the weather data, there no point in attemping
            // to parse it.
            forecastJsonStr = "Error, an exception was raised.";
        } finally {
            if (urlConnection != null) {
                urlConnection.disconnect();
            }
            if (reader != null) {
                try {
                    reader.close();
                } catch (final IOException e) {
                    Log.e("PlaceholderFragment", "Error closing stream", e);
                }
            }
        }
        return forecastJsonStr;

    }

    //on post execution

    protected void onPostExecute(String markers) {


        Log.d("string response", markers);

        Toast.makeText(MainActivity.this, "Plotting Thekha", Toast.LENGTH_LONG).show();

        try {
            JSONArray jsonArray = new JSONArray(markers);
            for (int i = 0; i < jsonArray.length(); i++) {
                //create marker of each place in the json data
                JSONObject jsonObject = jsonArray.getJSONObject(i);
                String placeName = jsonObject.getString("name");
                String placeAddress = jsonObject.getString("address");
                double latitude = jsonObject.getJSONArray("latlang").getDouble(0);
                double longitude = jsonObject.getJSONArray("latlang").getDouble(1);
                LatLng loc = new LatLng(latitude, longitude);
                //marker size change code
                int height = 150;
                int width = 150;
                BitmapDrawable bitmapDrawable = (BitmapDrawable) getResources().getDrawable(R.drawable.thekhaicon);
                Bitmap b = bitmapDrawable.getBitmap();
                Bitmap smallMarker = Bitmap.createScaledBitmap(b, width, height, false);
                 mMap.clear();

                mMap.addMarker(new MarkerOptions()
                        .icon(BitmapDescriptorFactory.fromBitmap(smallMarker))
                        .title(placeName)
                        .snippet(placeAddress)
                        .position(loc));

mMap.addMarker(new MarkerOptions()
                        .icon(BitmapDescriptorFactory.fromBitmap(smallMarker))
                        .title(placeName)
                        .snippet(placeAddress)
                        .position(new LatLng(gps.getLatitude(),gps.getLongitude())));
     CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(new LatLng(gps.getLatitude(),gps.getLongitude()), 12); 
     map.animateCamera(cameraUpdate);
               }
            pd.dismiss();
        } catch (JSONException e) {
            e.printStackTrace();
        }

    }
}







@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

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

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();

    if (id == R.id.nav_camera) {
        // Handle the camera action
    } else if (id == R.id.nav_gallery) {

    } else if (id == R.id.nav_slideshow) {

    } else if (id == R.id.nav_manage) {

    } else if (id == R.id.call_us) {
        Intent intent = new Intent(Intent.ACTION_CALL);
        intent.setData(Uri.parse("tel:[phone]"));
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // 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 ActivityCompat#requestPermissions for more details.
            return true;
        }
        startActivity(intent);

    } else if (id == R.id.about_us) {
        Intent intent = new Intent(this,ScrollingActivity.class);
        this.startActivity(intent);

    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

@Override
 public void onMapReady(GoogleMap googleMap) {
        Toast.makeText(this, "Connecting Server", Toast.LENGTH_LONG).show();
        mMap = googleMap;
    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) {
                // TODO: Consider calling
                //    ActivityCompat#requestPermissions
                // 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 ActivityCompat#requestPermissions for more details.
        }
        //tool bar and other tool related on map uiSettings
        // mMap.setMyLocationEnabled(true);
        mMap.getUiSettings().setZoomControlsEnabled(true);
        mMap.getUiSettings().setMapToolbarEnabled(true);
        mMap.getUiSettings().setMyLocationButtonEnabled(true); 
    double lat=0;
    double lon=0;
          GPSTracker gps=new GPSTracker(MainActivity.this);

         if(gps.canGetLocation())
          {
             lat=gps.getLatitude();
             lon=gps.getLongitude();
             }

         try {
              LatLng myloc= new LatLng(lat,lon);
        mMap.addMarker(new MarkerOptions().position(myloc).title("Marker in my Locaiton"));
        mMap.moveCamera(CameraUpdateFactory.newLatLng(myloc));
            RetriveMarkerTask markerTask = new RetriveMarkerTask(MainActivity.this);
            markerTask.execute(url);
        }catch (Exception e){
            Toast.makeText(this,"Can not fetch data",Toast.LENGTH_LONG).show();
        }


    }

GPSTracker.java.

import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
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;

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;
                // 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;
    }

}