MapsActivity.java

package com.example.mapstracker;

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

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.Build;
import android.os.Bundle;
import android.widget.Toast;

import com.google.android.gms.maps.CameraUpdateFactory;
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.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private GoogleMap mMap;
    LocationManager lm;
    LocationListener ll;

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if(requestCode ==1 ){
            if(grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {


                    lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, ll);
                }
            }
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }


    /**
     * Manipulates the map once available.
     * This callback is triggered when the map is ready to be used.
     * This is where we can add markers or lines, add listeners or move the camera. In this case,
     * we just add a marker near Sydney, Australia.
     * If Google Play services is not installed on the device, the user will be prompted to install
     * it inside the SupportMapFragment. This method will only be triggered once the user has
     * installed Google Play services and returned to the app.
     */
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;
        lm = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
        ll = new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                LatLng userlocation = new LatLng(location.getLatitude(),location.getLongitude());
                mMap.clear();
                mMap.addMarker(new MarkerOptions().position(userlocation).title("Your Location"));
                mMap.moveCamera(CameraUpdateFactory.newLatLng(userlocation));

            }

            @Override
            public void onStatusChanged(String provider, int status, Bundle extras) {

            }

            @Override
            public void onProviderEnabled(String provider) {

            }

            @Override
            public void onProviderDisabled(String provider) {

            }
        };
        if (Build.VERSION.SDK_INT < 23) {
            lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, ll);
        }else{
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED && ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)!= PackageManager.PERMISSION_GRANTED) {

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

         else{
                lm.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,ll);
                Location lastknown = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
                LatLng userlocation = new LatLng(lastknown.getLatitude(),lastknown.getLongitude());
                mMap.clear();
                mMap.addMarker(new MarkerOptions().position(userlocation).title("Your Location"));
                mMap.moveCamera(CameraUpdateFactory.newLatLng(userlocation));
         }

        }
        // Add a marker in Sydney and move the camera

    }
}