private void upload(List multipartFiles) throws Exception {
        for (MultipartFile multipartFile : multipartFiles) {
            String fileName = multipartFile.getOriginalFilename();
            String filePath = "F:/test";
            String fileTotalName = filePath + File.separator + fileName;
            File f = new File(fileTotalName);
            multipartFile.transferTo(f);
        }
    }

    @PostMapping("upload")
    public R upload(HttpServletRequest request) throws Exception {
        List files = new ArrayList<>();
        MultipartHttpServletRequest multipartHttpServletRequest = (MultipartHttpServletRequest) request;
        Iterator a = multipartHttpServletRequest.getFileNames();//返回的数量与前端input数量相同, 返回的字符串即为前端input标签的name
        while (a.hasNext()) {
            String name = a.next();
            List multipartFiles = multipartHttpServletRequest.getFiles(name);//获取单个input标签上传的文件，可能为多个
            files.addAll(multipartFiles);
        }
        upload(files);
        return R.success();
    }