@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    RequestUserPermission requestUserPermission = new RequestUserPermission(this);
    requestUserPermission.verifyStoragePermissions();
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        createSoundPoolWithBuilder();
    } else {
        createSoundPoolWithConstructor();
    }
    soundPool.setOnLoadCompleteListener(this);
    sound = soundPool.load(this, R.raw.click, 1);
    mySwitch = (Switch) findViewById(R.id.my_switch);
    mySwitch.setChecked(false);
    mySwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) {
            if (isChecked) {
                setFlashLigthOn();
            } else {
                setFlashLightOff();
            }
        }
    });

    boolean isCameraFlash = getApplicationContext().getPackageManager()
            .hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);
    if (!isCameraFlash) {
        showCameraAlert();
    } else {
        camera = Camera.open();
    }
}

private void showCameraAlert() {
    new AlertDialog.Builder(this)
            .setTitle(R.string.error_title)
            .setMessage(R.string.error_text)
            .setPositiveButton(R.string.exit_message, new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {
                    finish();
                }
            })
            .setIcon(android.R.drawable.ic_dialog_alert)
            .show();
}

@TargetApi(Build.VERSION_CODES.LOLLIPOP)
protected void createSoundPoolWithBuilder() {
    AudioAttributes attributes = new AudioAttributes.Builder()
            .setUsage(AudioAttributes.USAGE_GAME)
            .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
            .build();
    soundPool = new SoundPool.Builder().setAudioAttributes(attributes).setMaxStreams(1).build();
}

@SuppressWarnings("deprecation")
protected void createSoundPoolWithConstructor() {
    soundPool = new SoundPool(1, AudioManager.STREAM_MUSIC, 0);
}

private void setFlashLigthOn() {
    soundPool.play(sound, 1, 1, 0, 0, 1);
    new Thread(new Runnable() {
        @Override
        public void run() {
            if (camera != null) {
                parameters = camera.getParameters();
                if (parameters != null) {
                    List supportedFlashModes = parameters.getSupportedFlashModes();
                    if (supportedFlashModes.contains(Parameters.FLASH_MODE_TORCH)) {
                        parameters.setFlashMode(Parameters.FLASH_MODE_TORCH);
                        //   } else if (supportedFlashModes.contains(Parameters.FLASH_MODE_ON)) {
                        // parameters.setFlashMode(Parameters.FLASH_MODE_ON);
                    } else camera = null;
                    if (camera != null) {
                        try {
                            camera.setParameters(parameters);
                            camera.startPreview();
                        } catch (RuntimeException f) {

                        }
                        try {
                            camera.setPreviewTexture(new SurfaceTexture(0));
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
        }
    }).start();
}

private void setFlashLightOff() {
    soundPool.play(sound, 1, 1, 0, 0, 1);
    new Thread(new Runnable() {
        @Override
        public void run() {
            if (camera != null) {
                parameters.setFlashMode(Parameters.FLASH_MODE_OFF);
                camera.setParameters(parameters);
                camera.stopPreview();
            }
        }
    }).start();
}

private void releaseCamera() {
    if (camera != null) {
        camera.release();
        camera = null;
    }
}

@Override
protected void onStop() {
    super.onStop();
    //  releaseCamera();
}

@Override
protected void onPause() {
    super.onPause();
    //releaseCamera();
    // mySwitch.setChecked(false);
}

@Override
protected void onResume() {
    super.onResume();
    if (camera == null) {
        camera = Camera.open();
    } else {
        setFlashLigthOn();
    }
    // mySwitch.setChecked(false);
}

@Override
protected void onStart() {
    super.onStart();
    camera = Camera.open();

}

@Override
public void onLoadComplete(SoundPool soundPool, int i, int i1) {

}