有人知道如何解决此问题吗？我尝试使用从数据库检索到的位置在Map上显示标记。尝试打开应用程序时出错。This is the error message from Logcat

这是我的密码

公共类PassengerMainscreen_Activity扩展了AppCompatActivity实现了OnMapReadyCallback {

boolean isPermissionGranted;
TextView textView;
DatabaseReference firebaseDatabase;
GoogleMap googleMap;


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

    checkpermission();
    textView = findViewById(R.id.LocEmpty);

    //RETRIEVING LOCATION FROM DATABASE
    firebaseDatabase = FirebaseDatabase.getInstance().getReference().child("Location");
    firebaseDatabase.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot snapshot) {
            Double lat = Double.valueOf(snapshot.child("latitude").getValue().toString());
            Double lng = Double.valueOf(snapshot.child("longitude").getValue().toString());
            textView.setText(lat+","+lng);

            //DISPLAYING MARKER ON THE MAP
            LatLng loc = new LatLng(lat,lng);
            googleMap.addMarker(new MarkerOptions()
                    .position(loc).title("bus"));
        }

        @Override
        public void onCancelled(@NonNull DatabaseError error) {

        }
    });


    //CHECKING GOOGLE PLAY SERVICES
    if (isPermissionGranted) {
        if (checkGooglePlayServices()) {
            SupportMapFragment supportMapFragment = SupportMapFragment.newInstance();
            getSupportFragmentManager().beginTransaction().add(R.id.CONTAINER, supportMapFragment).commit();
            supportMapFragment.getMapAsync(this);
        } else {
            Toast.makeText(this, "Google Play Services Not available", Toast.LENGTH_SHORT).show();
        }
    }
}

private boolean checkGooglePlayServices() {
    GoogleApiAvailability googleApiAvailability = GoogleApiAvailability.getInstance();
    int result = googleApiAvailability.isGooglePlayServicesAvailable(this);
    if (result == ConnectionResult.SUCCESS) {
        return true;
    } else if (googleApiAvailability.isUserResolvableError(result)) {
        Dialog dialog = googleApiAvailability.getErrorDialog(this, result, 201, new DialogInterface.OnCancelListener() {
            @Override
            public void onCancel(DialogInterface dialog) {
                Toast.makeText(PassengerMainscreen_Activity.this, "User Cancelled Dialog", Toast.LENGTH_SHORT).show();
            }
        });
        dialog.show();
    }
    return false;
}

private void checkpermission() {
    Dexter.withContext(this).withPermission(Manifest.permission.ACCESS_FINE_LOCATION).withListener(new PermissionListener() {
        @Override
        public void onPermissionGranted(PermissionGrantedResponse permissionGrantedResponse) {
            isPermissionGranted = true;
            Toast.makeText(PassengerMainscreen_Activity.this, "Permission Granted", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onPermissionDenied(PermissionDeniedResponse permissionDeniedResponse) {
            Intent intent = new Intent();
            intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
            Uri uri = Uri.fromParts("package", getPackageName(), "");
            intent.setData(uri);
            startActivity(intent);
        }

        @Override
        public void onPermissionRationaleShouldBeShown(PermissionRequest permissionRequest, PermissionToken permissionToken) {
            permissionToken.continuePermissionRequest();
        }
    }).check(); //PERMISSION END
}

@Override
public void onMapReady(@NonNull GoogleMap googleMap) {

    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;
    }
    googleMap.setMyLocationEnabled(true);

}

}
我在编写以下代码后遇到了错误：//DISPLAYING MARKER ON THE MAP LatLng loc = new LatLng(lat,lng); googleMap.addMarker(new MarkerOptions() .position(loc).title("bus"));