引入依赖Jar

 <dependency>
  <groupId>com.google.zxing</groupId>
  <artifactId>core</artifactId>
  <version>3.4.0</version>
</dependency>
<dependency>
  <groupId>com.google.zxing</groupId>
  <artifactId> javase </artifactId>
  <version>3.4.0</version>
</dependency>  

二维码图片生成工具类

方法drawQRCode（），根据内容直接生成，同时可以指定生成二维码图片的宽度和高度

方法draw Logo QRCode（），根据内容生成，支持在二维码中间带上logo。

 public class QRCodeUtils {
     private  final  static  Logger logger = LoggerFactory.getLogger(QRCodeUtils.class);
    /**
     * 二维码图片格式
     */
    private final static String PNG_FORMAT = "png";
    private final static String UTF8 = "utf-8";
    /**
     * 二维码图片背景颜色，黑色
     */
    public static int QR_COLOR = 0xFF000000;
    /**
     * 二维码图片颜色，白色
     */
    public static int BG_WHITE = 0xFFFFFFFF;

    /**
     * 根据二维码内容生成二维码
     *
     * @param url         二维码内容
     * @param imageWidth  图片宽度
     * @param imageHeight 图片高度
     * @return
     */
    public static String drawQRCode(String url, int imageWidth, int imageHeight) {
        if (StringUtils.isEmpty(url)) {
            return null;
        }
        try (
                ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        ) {
            QRCodeWriter writer = new QRCodeWriter();
            BitMatrix bm = writer.encode(url,  Barcode Format.QR_CODE, imageWidth, imageHeight, HINTS);
            MatrixToImageWriter.writeToStream(bm, PNG_FORMAT, outStream);
            return new String(Base64.encodeBase64(outStream.toByteArray()), UTF8);
        } catch ( Exception  e) {
            logger.error("生成二维码失败:" + e.getMessage());
        }
        return null;
    }

    /**
     * 生成带logo的二维码图片
     *
     * @param logoUrl     logo图片地址
     * @param qrUrl       二维码地址
     * @param imageWidth  图片宽度
     * @param imageHeight 图片高度
     * @return
     */
    public static String drawLogoQRCode(String logoUrl, String qrUrl, int imageWidth, int imageHeight) {
        try {
            MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
            // 参数顺序分别为：编码内容，编码类型，生成图片宽度，生成图片高度，设置参数
            BitMatrix bm = multiFormatWriter.encode(qrUrl, BarcodeFormat.QR_CODE, imageWidth, imageHeight, HINTS);
            BufferedImage image = new BufferedImage(imageWidth, imageHeight, BufferedImage.TYPE_INT_RGB);
            // 开始利用二维码数据创建 Bitmap 图片，分别设为黑（0xFFFFFFFF）白（0xFF000000）两色
            for (int x = 0; x < imageWidth; x++) {
                for (int y = 0; y < imageHeight; y++) {
                    image.setRGB(x, y, bm.get(x, y) ? QR_COLOR : BG_WHITE);
                }
            }
            add logo Image(logoUrl, image);
            image.flush();
            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
            ImageIO.write(image, PNG_FORMAT, outputStream);
            return new String(Base64.encodeBase64(outputStream.toByteArray()), UTF8);
        } catch (Exception e) {
            logger.error("drawLogoQRCode error" + e.getMessage());
        }
        return "";
    }

    private static  void  addLogoImage(String logoUrl, final BufferedImage image) throws IOException {
        BufferedImage logoBuff = null;
        if (logoUrl.startsWith("http")) {
            // 构建绘图对象
             InputStream  logoFileInputStream = new URL(logoUrl).openStream();
            logoBuff = ImageIO.read(logoFileInputStream);
        } else {
             File  logoFile = new File(logoUrl);
            if (logoFile. exists ()) {
                logoBuff = ImageIO.read(logoFile);
            }
        }
        Graphics2D g = image.createGraphics();
        int width = image.getWidth();
        int height = image.getHeight();
        g.drawImage(logoBuff, width * 2 / 5, height * 2 / 5, width * 2 / 10, height * 2 / 10, null);
        g.dispose();
        logoBuff.flush();
    }

    /**
     * 用于设置QR二维码参数
     */
    private static Map<EncodeHintType, Object> HINTS = new HashMap<EncodeHintType, Object>() {
        {
            // 设置QR二维码的纠错级别（H为最高级别）具体级别信息
            put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
            // 设置编码方式
            put(EncodeHintType.CHARACTER_SET, UTF8);
            put(EncodeHintType.MARGIN, 0);
        }
    };
}
  

使用及效果

 String logo = "#34;;
String url = "#34;;
//String urlPath = QRCodeUtils.drawLogoQRCode(logo, url, 400, 400);
String urlPath = QRCodeUtils.drawQRCode(url, 400, 400);
String bas464 = "data:image/png;base64," + urlPath;
return bas464;  

 <img src=“{base64内容}” />