after login a button create that shows my location

import android.content.Intent;
import android.os.AsyncTask;
import android.os.Handler;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;


public class MainActivity extends ActionBarActivity {
    EditText UsernameEt, PasswordEt;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        UsernameEt = (EditText)findViewById(R.id.etUserName);
        PasswordEt = (EditText)findViewById(R.id.etPassword);
    }

    public void OnLogin(View view) {
        String username = UsernameEt.getText().toString();
        String password = PasswordEt.getText().toString();
        String type = "login";
        BackgroundWorker backgroundWorker = new BackgroundWorker(this);
        AsyncTask<String, Void, String> execute = backgroundWorker.execute(type, username, password);

    }

    public void registerB(View view) {
        Intent intent = new Intent(MainActivity.this,RegisterActivity.class);
        startActivity(intent);
    }private Boolean exit = false;
    @Override

    public void onBackPressed(){
        if (exit) {
            finish();
        }
        else {
            Toast.makeText(this, "Press Back again to Exit.",
                    Toast.LENGTH_SHORT).show();
            exit = true;
            new Handler().postDelayed(new Runnable() {

                @Override
                public void run() {
                    // TODO Auto-generated method stub
                    Intent a = new Intent(Intent.ACTION_MAIN);
                    a.addCategory(Intent.CATEGORY_HOME);
                    a.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                    startActivity(a);
                }
            }, 1000);

//Backgroundworker class//


public class BackgroundWorker extends AsyncTask<String,Void,String> {

    Context ctx;
    AlertDialog alertDialog;
    BackgroundWorker (Context ctx) {

        this.ctx=ctx;
    }
    @Override
    protected String doInBackground(String... params) {
        String type = params[0];
        String login_url = "http://localhost/~myprojec//login.php";
        String register_url = "http://localhost/~myprojec//register.php";
        if(type.equals("login")) try {
            String user_name = params[1];
            String password = params[2];
            URL url = new URL(login_url);
            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
            httpURLConnection.setRequestMethod("POST");
            httpURLConnection.setDoOutput(true);
            httpURLConnection.setDoInput(true);
            OutputStream outputStream = httpURLConnection.getOutputStream();
            BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
            String post_data = URLEncoder.encode("user_name", "UTF-8") + "=" + URLEncoder.encode(user_name, "UTF-8") + "&"
                    + URLEncoder.encode("password", "UTF-8") + "=" + URLEncoder.encode(password, "UTF-8");
            bufferedWriter.write(post_data);
            bufferedWriter.flush();
            bufferedWriter.close();
            outputStream.close();
            InputStream inputStream = httpURLConnection.getInputStream();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "iso-8859-1"));
            String result = "";
            String line = "";
            while ((line = bufferedReader.readLine()) != null) {
                result += line;
            }
            bufferedReader.close();
            inputStream.close();
            httpURLConnection.disconnect();
            return result;
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }else if(type.equals("register")){
            try {
                String name = params[1];
                String surname = params[2];
                String age = params[3];
                String username = params[4];
                String password = params[5];
                URL url = new URL(register_url);
                HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                httpURLConnection.setRequestMethod("POST");
                httpURLConnection.setDoOutput(true);
                httpURLConnection.setDoInput(true);
                OutputStream outputStream = httpURLConnection.getOutputStream();
                BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
                String post_data = URLEncoder.encode("name", "UTF-8") + "=" + URLEncoder.encode(name, "UTF-8") + "&"
                + URLEncoder.encode("surname", "UTF-8") + "=" + URLEncoder.encode(surname, "UTF-8") + "&"
                + URLEncoder.encode("age", "UTF-8") + "=" + URLEncoder.encode(age, "UTF-8") + "&"
                + URLEncoder.encode("username", "UTF-8") + "=" + URLEncoder.encode(username, "UTF-8") + "&"
                        + URLEncoder.encode("password", "UTF-8") + "=" + URLEncoder.encode(password, "UTF-8");
                bufferedWriter.write(post_data);
                bufferedWriter.flush();
                bufferedWriter.close();
                outputStream.close();
                InputStream inputStream = httpURLConnection.getInputStream();
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "iso-8859-1"));
                String result = "";
                String line = "";
                while ((line = bufferedReader.readLine()) != null) {
                    result += line;
                }
                bufferedReader.close();
                inputStream.close();
                httpURLConnection.disconnect();
                return result;
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    @Override
    protected void onPreExecute() {

        alertDialog = new AlertDialog.Builder(ctx).create();
        alertDialog.setTitle("Login Information....");
    }

    @Override
    protected void onPostExecute(String result) {
        if(result == null)
        {
            // do what you want to do
        }else if (result.contains("Incorrect username/password!! Try again")){
            Toast.makeText(ctx, result, Toast.LENGTH_LONG).show();
        }

        else if(result.contains("login success !!!!! Welcome user")) // msg you get from success like "Login Success"
        {
            Toast.makeText(ctx, result, Toast.LENGTH_LONG).show();
            Intent i = new Intent(ctx,TextActivity.class);
            ctx.startActivity(i);


        }else if(result.contains("Registerd succesfully")){
            Toast.makeText(ctx, result, Toast.LENGTH_LONG).show();
            Intent i = new Intent(ctx,MainActivity.class);
            ctx.startActivity(i);
        };
    }

//TextActivity//
import android.app.Activity;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.CountDownTimer;
import android.os.Handler;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class TextActivity extends AppCompatActivity {
    GPSTracker gps;
    Button locationBt;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_location);
        locationBt = (Button) findViewById(R.id.locationBt);

        locationBt.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {


                if (gps.canGetLocation()) {
                    double latitude = gps.getLatitude();
                    double longitude = gps.getLongitude();

                    Toast.makeText(
                            getApplicationContext(),
                            "Your Location is -\nLat: " + latitude + "\nLong: "
                                    + longitude, Toast.LENGTH_LONG).show();
                } else {
                    gps.showSettingsAlert();
                }

            }

        });

    }
    private Boolean exit = false;
    @Override

    public void onBackPressed() {
        if (exit) {
            finish(); // finish activity
        } else {
            Toast.makeText(this, "Press Back again to Exit.",
                    Toast.LENGTH_SHORT).show();
            exit = true;

            new Handler().postDelayed(new Runnable() {
                @Override
                public void run() {
                    exit = false;
                    Intent a = new Intent(Intent.ACTION_MAIN);
                    a.addCategory(Intent.CATEGORY_HOME);
                    a.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                    startActivity(a);
                }
            }, 3 * 1000);



        }
    }



        }
}}

//Gpstracker//

import android.Manifest;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
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.support.v4.app.ActivityCompat;
import android.telephony.SmsManager;
import android.util.Log;

public class GPSTracker extends Service implements LocationListener {


    private final Context context;

    boolean isGPSEnabled = false;
    boolean isNetworkEnabled = false;
    boolean canGetLocation = false;

    Location location;

    double latitude;
    double longitude;


    private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10;
    private static final long MIN_TIME_BW_UPDATES = 1000 * 60 ;

    protected LocationManager locationManager;

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

    public Location getLocation() {
        try {
            locationManager = (LocationManager) context.getSystemService(LOCATION_SERVICE);

            isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);

            isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

            if (!isGPSEnabled && !isNetworkEnabled) {
            } else {
                this.canGetLocation = true;

                if (isNetworkEnabled) {

                    locationManager.requestLocationUpdates(
                            LocationManager.NETWORK_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);

                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);

                        if (location != null) {

                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }

                }

                if (isGPSEnabled) {
                    if (location == null) {
                        locationManager.requestLocationUpdates(
                                LocationManager.GPS_PROVIDER,
                                MIN_TIME_BW_UPDATES,
                                MIN_DISTANCE_CHANGE_FOR_UPDATES, this);

                        if (locationManager != null) {
                            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, 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.
                                return location;
                            }
                            location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

                            if (location != null) {
                                latitude = location.getLatitude();
                                longitude = location.getLongitude();
                            }
                        }
                    }
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        return location;
    }


    public void stopUsingGPS() {
        if (locationManager != null)
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, 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.
                return;
            }
    }

    public double getLatitude() {
        if(location != null) {
            latitude = location.getLatitude();
        }
        return latitude;
    }

    public double getLongitude() {
        if(location != null) {
            longitude = location.getLongitude();
        }

        return longitude;
    }

    public boolean canGetLocation() {
        return this.canGetLocation;
    }

     public void showSettingsAlert() {
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(context);

        alertDialog.setTitle("GPS is settings");

       alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");

        alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {

            @Override
          public void onClick(DialogInterface dialog, int which) {
               Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
          context.startActivity(intent);
            }
        });

        alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {

           @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });

        alertDialog.show();
   }

    @Override
    public void onLocationChanged(final Location location) {

        updateWithNewLocation(location);
        SendSms(location);

    }

    private void updateWithNewLocation(Location location) {

    }

    public void SendSms(Location location){

        String phoneNo = ("+8801732986828");



        String locationText = "This is my location.. plz help."+"Latitude-"+location.getLatitude() +" "+ "and"+ " "+"Longitude"+" "+ location.getLongitude();
        SmsManager smsManager = SmsManager.getDefault();
        smsManager.sendTextMessage(phoneNo, null,locationText , null, null);
    }



    @Override
    public void onProviderDisabled(String arg0) {
        // TODO Auto-generated method stub

    }

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

    }

    @Override
    public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
        // TODO Auto-generated method stub

    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return null;
    }



}