google maps application error - how to fix that?

Question

I was trying to make google map application but when i try to build the app it gives me a weird error on some casting sentences please help the error the error 1 the androidstudio can not find R Class

This is the map activity where i am loading the map.............................................................................................................................

public class MapActivity extends AppCompatActivity implements OnMapReadyCallback {


    public void onMapReady(GoogleMap googleMap) {
        Toast.makeText(this, "Map is Ready", Toast.LENGTH_SHORT).show();
        Log.d(TAG, "Map is Ready");
        mMap = googleMap;
        if (mLocationPermissionGranted)
        {
            getDeviceLocation();
            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;
            }
            mMap.setMyLocationEnabled(true);
            mMap.getUiSettings().setMyLocationButtonEnabled(false);
            init();
        }

    }
    private static final String TAG = "MapActivity";
    private static final String FINE_LOCATION = Manifest.permission.ACCESS_FINE_LOCATION;
    private static final String COARSE_LOCATION = Manifest.permission.ACCESS_COARSE_LOCATION;
    private Boolean mLocationPermissionGranted = false;
    private static final int LOCATON_PERMISSION_REQUEST_CODE = 1234;
    private static final float DEFAULT_ZOOM= 15f;
    private GoogleMap mMap;
    private FusedLocationProviderClient mFusedLocationProviderClient;
    private EditText mSearchText;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_map);
        mSearchText = (EditText) findViewById(R.id.input_search);

        getLocationPermission();

       /* MobileAds.initialize(this,"ca-app-pub-3940256099942544~3347511713");
        mAdView = (AdView)findViewById(R.id.adView);
        AdRequest adRequest = new AdRequest.Builder().addTestDevice("7B0B6DDFA6EB4A71955387A3EA155884").build();
        mAdView.loadAd(adRequest);*/

    }

    private void init()
    {
        Log.d(TAG,"initializing map");
        mSearchText.setOnEditorActionListener(new TextView.OnEditorActionListener()
        {
            @Override
            public boolean onEditorAction(TextView v, int actionId, KeyEvent event)
            {
                if(actionId== EditorInfo.IME_ACTION_SEARCH || actionId==EditorInfo.IME_ACTION_DONE
                        ||actionId==KeyEvent.ACTION_DOWN || actionId== KeyEvent.KEYCODE_ENTER)
                {
                    geoLocate();

                }
                return false;
            }
        });
    }
    private void geoLocate()
    {
        Log.d(TAG,"locating");
        String searchString = mSearchText.getText().toString();
        Geocoder geocoder = new Geocoder(MapActivity.this);
        List<Address> list = new ArrayList<>();
        try
        {
            list = geocoder.getFromLocationName(searchString,1);


        }
        catch(IOException e)
        {
            Log.e(TAG,"IOException"+ e.getMessage());

        }
        if(list.size()>0)
        {
            Address address = list.get(0);
            Log.d(TAG,"found location" + address.toString());
           // Toast.makeText(this,address.toString(),Toast.LENGTH_SHORT).show();
        }
    }
    private void getDeviceLocation()
    {
        Log.d(TAG,"GetDeviceLocation");
        mFusedLocationProviderClient= LocationServices.getFusedLocationProviderClient(this);
        try
        {
            if(mLocationPermissionGranted)
            {
                Task location = mFusedLocationProviderClient.getLastLocation();
                location.addOnCompleteListener(new OnCompleteListener()
                {
                    @Override
                    public void onComplete(@NonNull Task task)
                    {
                        if(task.isSuccessful())
                        {
                            Log.d(TAG,"location found");
                            Location CurrentLocation = (Location) task.getResult();
                            moveCamera(new LatLng(CurrentLocation.getLatitude(),CurrentLocation.getLongitude()),DEFAULT_ZOOM);
                        }
                        else
                        {
                            Log.d(TAG,"location not found");
                            Toast.makeText(MapActivity.this,"unable to find location",Toast.LENGTH_SHORT).show();
                        }

                    }
                });

            }
        }catch (SecurityException e)
        {
            Log.e(TAG,"security exception"+e.getMessage());

        }
    }
    private void moveCamera(LatLng latlng,float zoom)
    {
        Log.d(TAG,"move camera to location lat:"+latlng.latitude + ",lng" + latlng.longitude);
        mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latlng,zoom));

    }
    private void initMap()
    {
        Log.d(TAG,"initializing map");
        SupportMapFragment mapFragment = (SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.map);
        mapFragment.getMapAsync(MapActivity.this);
    }
    private void getLocationPermission()
    {
        Log.d(TAG,"Getting permission");

        String[] permissions = {Manifest.permission.ACCESS_FINE_LOCATION,Manifest.permission.ACCESS_COARSE_LOCATION};
        if(ContextCompat.checkSelfPermission(this.getApplicationContext(),FINE_LOCATION)==PackageManager.PERMISSION_GRANTED)
        {
            if(ContextCompat.checkSelfPermission(this.getApplicationContext(),COARSE_LOCATION)==PackageManager.PERMISSION_GRANTED)
            {
                mLocationPermissionGranted = true;
                initMap();

            }
            else
            {

                ActivityCompat.requestPermissions(this,permissions,LOCATON_PERMISSION_REQUEST_CODE);
            }

        }
        else
        {

            ActivityCompat.requestPermissions(this,permissions,LOCATON_PERMISSION_REQUEST_CODE);
        }


    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults)
    {
        Log.d(TAG,"onRequestPermissionsResult:called");
       // super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        mLocationPermissionGranted = false;
                switch(requestCode)
                {
                    case LOCATON_PERMISSION_REQUEST_CODE:
                    {
                        if(grantResults.length>0 )
                        {
                            for(int i = 0 ; i < grantResults.length;i++)
                            {
                                if(grantResults[i]!= PackageManager.PERMISSION_GRANTED)
                                {

                                    mLocationPermissionGranted = false;
                                    Log.d(TAG,"onRequestPermissionsResult:failed");
                                    return;
                                }
                            }
                            Log.d(TAG,"onRequestPermissionsResult:granted");
                            mLocationPermissionGranted= true;
                            initMap();
                        }
                    }
                }

    }



}

Answer 1

In Android Studio

Go to Build -> Clean Project Project It surely will work.If not restart Android Studio