add qr pdf

    private File urlToImg(String urlImg) throws Exception {
        URL url=new URL(urlImg);
        URLConnection connection = null;

        connection = url.openConnection();

        InputStream in = null;
        in = connection.getInputStream();

        FileOutputStream fos = null;

        File factura = null;
        fos = new FileOutputStream(factura=new File("downloaded.jpg"));

        byte[] buf = new byte[512];
        while (true) {
            int len = in.read(buf);
            if (len == -1)
                {break;}
            fos.write(buf, 0, len);
        }
        in.close();fos.flush();fos.close();

        return factura;
    }

    private BufferedImage crearQR(String datos, int ancho, int altura) throws WriterException {
        BitMatrix matrix;
        Writer escritor = new QRCodeWriter();
        matrix = escritor.encode(datos, BarcodeFormat.QR_CODE, ancho, altura);

        BufferedImage imagen = new BufferedImage(ancho, altura, BufferedImage.TYPE_INT_RGB);

        for(int y = 0; y < altura; y++) {
            for(int x = 0; x < ancho; x++) {
                int grayValue = (matrix.get(x, y) ? 0 : 1) & 0xff;
                imagen.setRGB(x, y, (grayValue == 0 ? 0 : 0xFFFFFF));
            }
        }

        return imagen;
    }


    private void concatenarFotos(String urlTemplateFactura){
        try {

            File facturaTemplate = urlToImg(urlTemplateFactura);

            BufferedImage biUno = ImageIO.read(facturaTemplate);//1240x1755
            BufferedImage biDos = crearQR("https://www.google.com/",200,200);

            BufferedImage biResultado = new BufferedImage(biUno.getWidth(), biUno.getHeight(), BufferedImage.TYPE_INT_ARGB);

            Graphics g = biResultado.getGraphics();
            g.drawImage(biUno, 0, 0, null);
            g.drawImage(biDos, biUno.getWidth()/2, biUno.getHeight()-(biUno.getHeight()/4), null);


            //ImageIO.write(biResultado, "PNG", new File("resultado.png"));

            //~*~*~*~*~*~*~asigna la img generada como template del pdf:~*~*~*~*~*~*~
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            ImageIO.write(biResultado, "gif", baos);
            this.image = Image.getInstance(baos.toByteArray());

            logger.info("----------------------Imagenes concatenadas correctamente----------------------");
        }

        catch(Exception e) {
            logger.info("----------------------Error al momento de concatenar las imgs----------------------");
            System.out.println(e.getMessage());
        }
    }