Java 当我将QRcode转换为Base64时，结果字符串带有一个http://字符，这是不正确的

我的代码

之后，我将Base 64转换为image

如果读取，则显示二维码，并且 预期结果为1111332432br.edu.bct.pit

我如何解决这些问题？有什么想法吗

private String returnBase64FromQrCode(String content) throws IOException {
    content = "1111332432br.edu.bct.pit"; //hardcode for test
    if(!StringUtils.isEmpty(content)){
        ServletOutputStream stream = null;
        ByteArrayOutputStream os = new ByteArrayOutputStream();

        HashMap<EncodeHintType, Comparable> hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);
        hints.put(EncodeHintType.MARGIN, 2);

        try {
            QRCodeWriter writer = new QRCodeWriter();
            BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.QR_CODE, 200, 200, hints);

            BufferedImage bufferedImage = MatrixToImageWriter.toBufferedImage(bitMatrix);
            //ImageIO.write(bufferedImage, "png", os);
            MatrixToImageWriter.writeToStream(bitMatrix, "png", os);

            String resultImage = new String(Base64.encode(os.toByteArray()));

            return resultImage;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (stream != null) {
                stream.flush();
                stream.close();
            }
        }
    }
    return null;
} 

iVBORw0KGgoAAAANSUhEUgAAAMgAAADIAQAAAACFI5MzAAABHElEQVR42u2YTRbCIAyEw4pjcFNa
bsoxWDVmEtT6t5VZlFf7kM8FbTKToOivIRe5yJ/JLjaK3TfVNvAl0ZBmnwFSpdhkrpCQIWmUQ8qR
+4afFDayZ3u1RSnJkTHZ2IhHWwcy8VserCShkjbi+tTPShKjne5KQ2ynFfJFzBVh74mK5B7WYlqB
jmmIqpmK255iuVIR6AMLNfs85EJCFK9zd1eOmDca4qnXxZNR3PaICHYqAlcu8QRKQ+aCEcX261nB
q0kYc4KOw6FPmUhAwo+jxqLw0pB7NcPCrGk0JLqAx34t5hsPmd1TtJwuFzKCrjPDY+Sl0lKQ5jUt
jXncYSEe7cOLhtlMGk/nW07m6TDDnr0pfj83LiTX/wcXWU9u3z30LPQS0DQAAAAASUVORK5CYII=