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

        //Flash
        hasFlash = getApplicationContext().getPackageManager()
                .hasSystemFeature( PackageManager.FEATURE_CAMERA_FLASH);
        if (!hasFlash) {
            // device doesn't support flash
            // Show alert message and close the application
            AlertDialog alert = new AlertDialog.Builder(Custom_CameraActivity.this)
                    .create();
            alert.setTitle("Error");
            alert.setMessage("Sorry, your device doesn't support flash light!");
            alert.setButton("OK", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    // closing the application
                    finish();
                }
            });
            alert.show();
            return;
        }


        getWindow().addFlags( WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON );
        context = this;

        mCamera = Camera.open();
        mCamera.setDisplayOrientation( 90 );
        camerapreview = (LinearLayout) findViewById( R.id.camera_preview );
        mCameraPreview = new CameraPreview( context, mCamera );
        camerapreview.addView( mCameraPreview );

        capture = (ImageButton) findViewById( R.id.button_capture );
        capture.setOnClickListener( new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                    mCamera.takePicture( null, null, mPicture );
            }
        } );

        switchCamera = (ImageButton) findViewById(R.id.btnSwitch);
        switchCamera.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //get the number of cameras
                int camerasNumber = Camera.getNumberOfCameras();
                if (camerasNumber > 1) {
                    //release the old camera instance
                    //switch camera, from the front and the back and vice versa

                    releaseCamera();
                    chooseCamera();
                } else {


                }
            }
        });

        flash= (ImageButton)findViewById( R.id.bulb ) ;
        flash.setOnClickListener( new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(isFlashOn){
                    turnOffFlash();
                }else{
                    turnOnFlash();
                }
            }
        } );

        mCamera.startPreview();
        //initializeCamera();
    }

    private void turnOnFlash() {
        if (isFlashOn) {
            if (mCamera != null || params != null) {
                return;
            }
            params = mCamera.getParameters();
            params.setFlashMode( Camera.Parameters.FLASH_MODE_OFF);
            mCamera.setParameters(params);
            mCamera.stopPreview();
            isFlashOn = false;
        }
    }

    private void turnOffFlash() {

       if(!isFlashOn) {
            if (mCamera == null || params == null) {
                return;
            }
            params = mCamera.getParameters();
            ((Camera.Parameters) params).setFlashMode( Camera.Parameters.FLASH_MODE_TORCH);
           mCamera.setParameters(params);
           mCamera.startPreview();
            isFlashOn = true;

        }

    }

    private void initializeCamera() {
        int cameraId= findBackFacingCamera();
        if(cameraId >= 0){
            mCamera= Camera.open(cameraId);
            mCamera.setDisplayOrientation( 180 );
            mPicture=getPictureCallBack();
            mCameraPreview.refreshCamera( mCamera );
        }
    }


    private int findFrontFacingCamera() {
        int cameraId = -1;
        // Search for the front facing camera
        int numberOfCameras = Camera.getNumberOfCameras();

        for (int i = 0; i < numberOfCameras; i++) {
            Camera.CameraInfo info = new Camera.CameraInfo();
            Camera.getCameraInfo(i, info);
            if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
                cameraId = i;
                cameraBack = false;
                break;
            }
        }
        return cameraId;

    }

    private int findBackFacingCamera() {
        int cameraId = -1;
        //Search for the back facing camera
        //get the number of cameras
        int numberOfCameras = Camera.getNumberOfCameras();
        //for every camera check
        for (int i = 0; i < numberOfCameras; i++) {
            Camera.CameraInfo info = new Camera.CameraInfo();
            Camera.getCameraInfo(i, info);
            if (info.facing == Camera.CameraInfo.CAMERA_FACING_BACK) {
                cameraId = i;
                cameraBack = true;
                break;

            }

        }
        return cameraId;
    }

    @Override
    protected void onResume() {
        super.onResume();
        if(mCamera== null){
            mCamera = Camera.open();
            mCamera.setDisplayOrientation( 90 );
            mPicture= getPictureCallBack();
            mCameraPreview.refreshCamera(mCamera);
            Log.d("nu","null");
        }else{
            Log.d("nu","no null");
        }
    }

    public void chooseCamera() {
        //if the camera preview is the front
        if (cameraBack) {
            int cameraId = findFrontFacingCamera();
            if (cameraId >= 0) {
                //open the backFacingCamera
                //set a picture callback
                //refresh the preview

                mCamera = Camera.open(cameraId);
                mCamera.setDisplayOrientation(90);
                mPicture = getPictureCallBack();
                mCameraPreview.refreshCamera(mCamera);
            }
        } else {
            int cameraId = findBackFacingCamera();
            if (cameraId >= 0) {
                //open the backFacingCamera
                //set a picture callback
                //refresh the preview
                mCamera = Camera.open(cameraId);
                mCamera.setDisplayOrientation(90);
                mPicture = getPictureCallBack();
                mCameraPreview.refreshCamera(mCamera);
            }
        }
    }

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

    private void releaseCamera() {
        if(mCamera != null){
            mCamera.stopPreview();
            mCamera.setPreviewCallback( null );
            mCamera.release();
            mCamera= null;
        }
    }
    private Camera.PictureCallback getPictureCallBack() {
        Camera.PictureCallback picture = new Camera.PictureCallback() {
            @Override
            public void onPictureTaken(byte[] data, Camera camera) {
                bitmap = BitmapFactory.decodeByteArray( data,0,data.length );
                Intent intent= new Intent(Custom_CameraActivity.this,Display.class);
                startActivity( intent );
            }
        };
        return  picture;
    }

}

public class CameraPreview extends SurfaceView implements
        SurfaceHolder.Callback {
    private SurfaceHolder mHolder;
    private Camera mCamera;


    // Constructor that obtains context and camera
    @SuppressWarnings("deprecation")
    public CameraPreview(Context context, Camera camera) {
        super(context);
        this.mCamera = camera;
        this.mHolder = this.getHolder();
        this.mHolder.addCallback(this);
        this.mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        try {
            // create the surface and start camera preview
            if (mCamera == null) {
                mCamera.setPreviewDisplay(holder);
                mCamera.startPreview();
            }
        } catch (IOException e) {
            Log.d(VIEW_LOG_TAG, "Error setting camera preview: " + e.getMessage());
        }
    }

    public void refreshCamera(Camera camera){
        if(mHolder.getSurface()== null){
            return;
        }
        try{
            mCamera.stopPreview();
        }catch (Exception e){

        }
        setCamera(camera);
        try{
            mCamera.setPreviewDisplay( mHolder );
            mCamera.startPreview();
        }catch (Exception e){
            Log.d(VIEW_LOG_TAG,"Error Starting camera preview: " +e.getMessage());

        }
    }

    private void setCamera(Camera camera) {
        mCamera = camera;
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder surfaceHolder) {

    }

    @Override
    public void surfaceChanged(SurfaceHolder Holder, int format,
                               int width, int height) {
        // start preview with new settings
       refreshCamera( mCamera );

    }


}

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate( savedInstanceState );
    setContentView( R.layout.activity_display );

    image = findViewById( R.id.imageView );
    scancode=findViewById( R.id.scan );
    scancode.setOnClickListener( this );

    image.setImageBitmap( Custom_CameraActivity.bitmap);
    saveImage(Custom_CameraActivity.bitmap);


private String  saveImage(Bitmap mybitmap) {
    ByteArrayOutputStream bytes = new ByteArrayOutputStream(  );
    mybitmap.compress( Bitmap.CompressFormat.JPEG,90,bytes );
    File file= new File( Environment.getExternalStorageDirectory() + IMAGE_DIRECTORY );
    if(!file.exists() ){
        Log.d("dirrrrrr","" + file.mkdirs());
        file.mkdirs();
    }
    try{
        File f = new File( file, Calendar.getInstance().getTimeInMillis() + ".jpg");
        f.createNewFile();
        FileOutputStream fo = new FileOutputStream( f );
        fo.write( bytes.toByteArray() );
        MediaScannerConnection.scanFile( this,new String[]{f.getPath()} ,
                new String[]{"image/jpeg"},null);
        fo.close();
        Log.d( "TAG","File Saved:: ---- " + f.getAbsolutePath() );
        return f.getAbsolutePath();
    }catch(IOException e1){
        e1.printStackTrace();
    }
    return "";
}