Getting current location on Android

Question

I want to find out where my location is currently on the device connected to my computer, but since my location has not changed, it does not fall into the onLocationChanged function and therefore returns location = null. How do I enter the onLocationChanged function?

@Override
public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;
    mMap.setOnMapLongClickListener(this);

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

        locationListener = new LocationListener() {
            @Override
           public void onLocationChanged(Location location) {
            LatLng userLocation = new LatLng(location.getLatitude(), location.getLongitude());
           mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(userLocation, 15));
            }
            @Override
            public void onStatusChanged(String s, int i, Bundle bundle) {
            }

            @Override
            public void onProviderEnabled(String s) {
            }

            @Override
            public void onProviderDisabled(String s) {
            }
        };

Answer 1

Like Sai suggested, you can use the fused location provider to retrieve the device's last known location which will display your current location.

Check out the working code sample below:

import android.Manifest;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Bundle;

import androidx.annotation.NonNull;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.fragment.app.FragmentActivity;

import com.google.android.gms.location.FusedLocationProviderClient;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private FusedLocationProviderClient fusedLocationClient;
    private GoogleMap mMap;

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

        fusedLocationClient = LocationServices.getFusedLocationProviderClient(this);

        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        if (mapFragment != null) {
            mapFragment.getMapAsync(this);
        }
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        if (checkPermissions()) {
            mMap.setMyLocationEnabled(true);
        }

        fusedLocationClient.getLastLocation()
                .addOnSuccessListener(this, new OnSuccessListener<Location>() {
                    @Override
                    public void onSuccess(Location location) {
                        if (location != null) {
                            System.out.println("current location: " + location.toString());
                        } else {
                            System.out.println("current location is null");
                        }
                    }
                }).addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                System.out.println("error trying to get current location");
                e.printStackTrace();
            }
        });
    }

    private boolean checkPermissions() {
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
            return true;
        } else {
            requestPermissions();
            return false;
        }
    }

    private void requestPermissions() {
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                1);
    }
}

Hope it helps!