<dependency>
   <groupId>com.google.zxing</groupId>
   <artifactId>core</artifactId>
   <version>3.3.3</version>
   <scope>compile</scope>
</dependency>
<dependency>
   <groupId>com.google.zxing</groupId>
   <artifactId>javase</artifactId>
   <version>3.3.3</version>
   <scope>compile</scope>
</dependency>

其次，Controller的写法（生成二维码并以流的形式输出到浏览器）

@RequestMapping("/test")
public void dowanload(HttpServletRequest request,HttpServletResponse response) throws Exception {
    //二维码中包含的信息
    String content = "姓名:十二余n博客：https://www.cnblogs.com/jing5464";
    Map<EncodeHintType, Object> hints = new HashMap<EncodeHintType, Object>();
    // 指定编码格式
    hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
    // 指定纠错级别(L--7%,M--15%,Q--25%,H--30%)
    hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
    // 编码内容,编码类型(这里指定为二维码),生成图片宽度,生成图片高度,设置参数
    BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, 200, 200, hints);
    //设置请求头
    response.setHeader("Content-Type","application/octet-stream");
    response.setHeader("Content-Disposition", "attachment;filename=" + "十二余的二维码.png");
    OutputStream outputStream = response.getOutputStream();
    MatrixToImageWriter.writeToStream(bitMatrix, "png", outputStream);
    outputStream.flush();
    outputStream.close();
}

最后，访问地址：http://ip地址+端口号+访问方法路径
　　　如：http://1.0.0.1:9090/test