Servlet 3.0 + Spring 3.2 + Multipart无法正常工作

Question

我对servlet 3.0规范和Spring 3.2并不熟悉。我只是想通过从jsp中获取<input type="file">的输入来读取excel文件。下面是我的控制器类。 request.getParts().size()始终为0.当我在firebug中看到网络面板时，会将一些内容发送到服务器。

@Controller
@RequestMapping("/upload")
@MultipartConfig
public class FileUploadController {
    @RequestMapping(value = "/file", method = RequestMethod.POST)
    public ModelAndView readFileData(HttpServletRequest request,
            HttpServletResponse response) throws IOException, ServletException {
        System.out.println(request.getParts().size());
        Part filePart = request.getPart("datafile"); 
        String filename = getFilename(filePart);
//the below two lines are dummy. ignore it
        String message = "Hello World, Spring 3.0!";
        return new ModelAndView("hello", "message", message);
    }
}

不知道我哪里弄错了。请帮助。感谢。