JAVA+HttpServletRequest文件上传

public Result fileUp(HttpServletRequest request) {
        RowsVo vo = new RowsVo();
        MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
        MultipartFile file = multipartRequest.getFile("ImFileName");
        if (file.getOriginalFilename().equals("")) {
            vo.setCode("201");
            vo.setMessage("请选择一个文件");
            return vo;
        }
        String suffix = file.getOriginalFilename().toString().split("\\.")[1];
        if (!suffix.equals("xls") && !suffix.equals("xlsx")) {
            vo.setCode("201");
            vo.setMessage("文件类型不符");
            return vo;
        }
        double fileSize = (file.getSize() / 1024) / 1024;
        if (fileSize > 20) {
            vo.setCode("201");
            vo.setMessage("请上传小于20MB的文件");
            return vo;
        }
        System.out.println("文件大小:" + (file.getSize() / 1024) / 1024 + "MB");
        Date date = new Date();
        SimpleDateFormat df = new SimpleDateFormat("yyyyMM");
        SimpleDateFormat df1 = new SimpleDateFormat("yyyyMMHHmmss");
        String rootPath = ClassUtils.getDefaultClassLoader().getResource("").getPath();
        String path = "public/FileUpload/Logistics/" + df.format(date);
        String fileName = df1.format(date) + "." + suffix;
      try {
//创建要保存文件的路径
            File dirFile = new File(rootPath + path, fileName);
            if (!dirFile.exists()) {
                dirFile.mkdirs();
            }
            //将文件写入创建的路径
            file.transferTo(dirFile);
            vo.setCode("200");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return vo;
    }