public class MainActivity extends AppCompatActivity {

    public static final int CAMERA_PERM_CODE = 101;
    public static final int CAMERA_REQUEST_CODE = 102;
    ImageView selectedImage;
    Button cameraBtn;
    String currentPhotoPath;

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

        selectedImage = findViewById(R.id.displayImageView);
        cameraBtn = findViewById(R.id.cameraBtn);

        // Open Camera
        cameraBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                verifyPermissions();
            }
        });
    }

    private void verifyPermissions(){
        String[] permissions = {Manifest.permission.READ_EXTERNAL_STORAGE,
                Manifest.permission.WRITE_EXTERNAL_STORAGE,
                Manifest.permission.CAMERA};

        if(ContextCompat.checkSelfPermission(this.getApplicationContext(),
                permissions[0]) == PackageManager.PERMISSION_GRANTED
                && ContextCompat.checkSelfPermission(this.getApplicationContext(),
                permissions[1]) == PackageManager.PERMISSION_GRANTED
                && ContextCompat.checkSelfPermission(this.getApplicationContext(),
                permissions[2]) == PackageManager.PERMISSION_GRANTED){
            dispatchTakePictureIntent();
        }else{
            ActivityCompat.requestPermissions(this,
                    permissions,
                    CAMERA_PERM_CODE);
        }
    }
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if(requestCode == CAMERA_PERM_CODE){
            if(grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
                dispatchTakePictureIntent();
            }else {
                Toast.makeText(this, "Camera Permission is Required to Use camera.", Toast.LENGTH_SHORT).show();
            }
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(requestCode == CAMERA_REQUEST_CODE){
            if(resultCode == Activity.RESULT_OK){
                File f = new File(currentPhotoPath);
                selectedImage.setImageURI(Uri.fromFile(f));
                Log.d("tag", "ABsolute Url of Image is " + Uri.fromFile(f));

                Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
                Uri contentUri = Uri.fromFile(f);
                mediaScanIntent.setData(contentUri);
                this.sendBroadcast(mediaScanIntent);
            }

        }
    }

    private File createImageFile() throws IOException {
        // Create an image file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        String imageFileName = "JPEG_" + timeStamp + "_";
//        File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
        File storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
        File image = File.createTempFile(
                imageFileName,  /* prefix */
                ".jpg",         /* suffix */
                storageDir      /* directory */
        );

        // Save a file: path for use with ACTION_VIEW intents
        currentPhotoPath = image.getAbsolutePath();
        return image;
    }

    private void dispatchTakePictureIntent() {
        Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        // Ensure that there's a camera activity to handle the intent
        if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
            // Create the File where the photo should go
            File photoFile = null;
            try {
                photoFile = createImageFile();
            } catch (IOException ex) {

            }
            // Continue only if the File was successfully created
            if (photoFile != null) {
                Uri photoURI = FileProvider.getUriForFile(this,
                        "com.example.android.fileprovider",
                        photoFile);
                takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
                startActivityForResult(takePictureIntent, CAMERA_REQUEST_CODE);
            }
        }
    }
}