you can achieve this easily. you have to write code in main activity. and Main activity implements Locationlistner interface. and overload its four methods. here i'am retrieving my Longitude and Latitide co-ordinates in a textview when application started. and you have to give permission for access location in your manifest file.

as under my code.

Copypackage com.nisarg.gpsdemo;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements LocationListener {

    private LocationManager locationManager;
 private TextView textview;

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

        textview=(TextView)findViewById(R.id.textView);

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

        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.NETWORK_PROVIDER);

        onLocationChanged(location);
    }

    @Override
    public void onLocationChanged(Location location) {
        double longitude=location.getLongitude();
        double latitude=location.getLatitude();
        textview.setText("Longitude:   "+longitude+"   Latitide:  "+latitude);

    }

    @Override
    public void onStatusChanged(String s, int i, Bundle bundle) {

    }

    @Override
    public void onProviderEnabled(String s) {

    }

    @Override
    public void onProviderDisabled(String s) {

    }
}

and you have to give permission like this in manifest file.

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

And last warning. you have to give permission to your application and start mobile data and GPS before you open application. either it will be crashed.

that's it. hope it will help you. :)