@ResponseBody
@RequestMapping(method = RequestMethod.GET, value = "/{productId}/ean")
public ResponseEntity<?> getProductEAN(@PathVariable String productId) throws WriterException, IOException {
    Product product = repository.findOne(productId);
    if (product == null) {
        return ResponseEntity.notFound().build();
    }
    EAN13Writer ean13Writer = new EAN13Writer();
    BitMatrix matrix = ean13Writer.encode(product.getEan(), BarcodeFormat.EAN_13, 300, 200);
    BufferedImage bufferedImage = MatrixToImageWriter.toBufferedImage(matrix);
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    ImageIO.write(bufferedImage, "png", baos);
    byte[] imageData = baos.toByteArray();
    ByteArrayResource byteArrayResource = new ByteArrayResource(imageData);
    return ResponseEntity.ok().contentType(MediaType.IMAGE_PNG).body(byteArrayResource);
}
 

public static BufferedImage generateEAN13BarcodeImage(String barcodeText) throws Exception {
    EAN13Writer barcodeWriter = new EAN13Writer();
    BitMatrix bitMatrix = barcodeWriter.encode(barcodeText, BarcodeFormat.EAN_13, 300, 150);

    return MatrixToImageWriter.toBufferedImage(bitMatrix);
}