Sample Code to fetch location on Android using FusedLocationProviderClient

LocationActivity.java

package com.domain.apps.smileyview;

import android.Manifest;
import android.annotation.SuppressLint;
import android.content.IntentSender;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.common.api.ResolvableApiException;
import com.google.android.gms.location.FusedLocationProviderClient;
import com.google.android.gms.location.LocationAvailability;
import com.google.android.gms.location.LocationCallback;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationResult;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.location.LocationSettingsRequest;
import com.google.android.gms.location.LocationSettingsResponse;
import com.google.android.gms.location.SettingsClient;
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.android.gms.tasks.Task;

//See https://github.com/codepath/android_guides/wiki/Retrieving-Location-with-LocationServices-API

public class LocationActivity extends AppCompatActivity {

    private static final String TAG = "LocationActivity";
    TextView lastLocation, locUpdate;
    FusedLocationProviderClient fusedClient;
    private LocationRequest mRequest;
    private LocationCallback mCallback;

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


        mCallback = new LocationCallback() {
            //This callback is where we get "streaming" location updates. We can check things like accuracy to determine whether
            //this latest update should replace our previous estimate.
            @Override
            public void onLocationResult(LocationResult locationResult) {
                if (locationResult == null) {
                    Log.d(TAG, "locationResult null");
                    return;
                }
                Log.d(TAG, "received " + locationResult.getLocations().size() + " locations");
                for (Location loc : locationResult.getLocations()) {
                    locUpdate.append("\n"+ loc.getProvider() + ":Accu:(" + loc.getAccuracy() + "). Lat:" + loc.getLatitude() + ",Lon:" + loc.getLongitude());
                }
            }

            @Override
            public void onLocationAvailability(LocationAvailability locationAvailability) {
                Log.d(TAG, "locationAvailability is " + locationAvailability.isLocationAvailable());
                super.onLocationAvailability(locationAvailability);
            }
        };

        //permissions
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION)
                != PackageManager.PERMISSION_GRANTED) {
            //request permission.
            //However check if we need to show an explanatory UI first
            if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.ACCESS_COARSE_LOCATION)) {
                showRationale();
            } else {
                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION,
                        Manifest.permission.ACCESS_NETWORK_STATE}, 2);
            }
        } else {
            //we already have the permission. Do any location wizardry now
            locationWizardry();
        }

    }

    @SuppressLint("MissingPermission")
    private void locationWizardry() {
        fusedClient = LocationServices.getFusedLocationProviderClient(this);
        //Initially, get last known location. We can refine this estimate later
        fusedClient.getLastLocation().addOnSuccessListener(new OnSuccessListener<Location>() {
            @Override
            public void onSuccess(Location location) {
                if (location != null) {
                    String loc = location.getProvider() + ":Accu:(" + location.getAccuracy() + "). Lat:" + location.getLatitude() + ",Lon:" + location.getLongitude();
                    lastLocation.setText(loc);
                }
            }
        });


        //now for receiving constant location updates:
        createLocRequest();
        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
                .addLocationRequest(mRequest);

        //This checks whether the GPS mode (high accuracy,battery saving, device only) is set appropriately for "mRequest". If the current settings cannot fulfil
        //mRequest(the Google Fused Location Provider determines these automatically), then we listen for failutes and show a dialog box for the user to easily
        //change these settings.
        SettingsClient client = LocationServices.getSettingsClient(LocationActivity.this);
        Task<LocationSettingsResponse> task = client.checkLocationSettings(builder.build());
        task.addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                if (e instanceof ResolvableApiException) {
                    // Location settings are not satisfied, but this can be fixed
                    // by showing the user a dialog.
                    try {
                        // Show the dialog by calling startResolutionForResult(),
                        // and check the result in onActivityResult().
                        ResolvableApiException resolvable = (ResolvableApiException) e;
                        resolvable.startResolutionForResult(LocationActivity.this, 500);
                    } catch (IntentSender.SendIntentException sendEx) {
                        // Ignore the error.
                    }
                }
            }
        });

        //actually start listening for updates: See on Resume(). It's done there so that conveniently we can stop listening in onPause
    }

    @Override
    protected void onResume() {
        super.onResume();
        startLocationUpdates();
    }

    @Override
    protected void onPause() {
        super.onPause();
        fusedClient.removeLocationUpdates(mCallback);
    }

    @SuppressLint("MissingPermission")
    protected void startLocationUpdates() {
        fusedClient.requestLocationUpdates(mRequest, mCallback, null);
    }


    protected void createLocRequest() {
        mRequest = new LocationRequest();
        mRequest.setInterval(10000);//time in ms; every ~10 seconds
        mRequest.setFastestInterval(5000);
        mRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    }


    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode) {
            case 2: {
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    Toast.makeText(this, "Thanks bud", Toast.LENGTH_SHORT).show();
                    locationWizardry();
                } else {
                    Toast.makeText(this, "C'mon man we really need this", Toast.LENGTH_SHORT).show();
                }
            }
            break;
            default:
                break;
        }
    }



    private void showRationale() {
        AlertDialog dialog = new AlertDialog.Builder(this).setMessage("We need this, Just suck it up and grant us the" +
                "permission :)").setPositiveButton("Sure", (dialogInterface, i) ->
        {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, 2);
            dialogInterface.dismiss();
        })
                .create();
        dialog.show();
    }



}