springmvc的MultipartFile参数如果不上传文件报错的问题

 @RequestMapping(value = "/updateInformation",method = RequestMethod.POST)
     @ResponseBody
     public Boolean updateInformation(Commodity commodity, HttpServletRequest request)throws Exception {
         MultipartFile file = null;
         boolean isMultipart = ServletFileUpload.isMultipartContent(request);
         if (isMultipart){
             MultipartHttpServletRequest multipartRequest = WebUtils.getNativeRequest(request, MultipartHttpServletRequest.class);
             file = multipartRequest.getFile("file");
         }
       }

commodity是pojo类
出错是的代码是这样的

  @RequestMapping(value = "/updateInformation",method = RequestMethod.POST)
    @ResponseBody
    public Boolean updateInformation(@RequestParam("file") MultipartFile file,Commodity commodity, HttpServletRequest request)throws Exception {
       }

　　后台报错为; Required request part 'file' is not present

　　页面报错为：  Request method 'GET' not supported