java 上传 MultipartFile attach 获取不到信息

attach怎么为空

@RequestMapping(value="/upload", method=RequestMethod.POST, produces="application/json;charset=UTF-8") @ResponseBody public String upload(Model model, @RequestParam("attach") MultipartFile attach, HttpServletRequest req, HttpSession session) throws IOException { System.out.println("Name:"+attach.getName()); System.out.println("ContentType:"+attach.getContentType()); System.out.println("OriginalFilename:"+attach.getOriginalFilename()); System.out.println("Size:"+attach.getSize()); System.out.println("Bytes:"+attach.getBytes()); System.out.println("Class:"+attach.getClass()); System.out.println("InputStream:"+attach.getInputStream()); return null; }

前面全部是空。空子真异常

搞定，应该这么写：@RequestParam("file") MultipartFile file