SpringMVC中关于ModelAttribute的问题

首先确定能断点进入update方法中。 

Enumeration e = request.getParameterNames();
        while (e.hasMoreElements())
        {
            Object object = (Object) e.nextElement();
            System.out.println(object);
        }
关掉后获取不到，就像上面说的，request里面没有东西,session里面也没有，

现在代码是这样的

@RequestMapping(params="id", method = RequestMethod.PUT, produces = "text/html")
 public String update(Model uiModel, HttpServletRequest httpServletRequest
         ,@RequestParam("id")JobKey key) throws SchedulerException {
     Enumeration<?> em = httpServletRequest.getAttributeNames();
     System.out.print("httpServletRequest: ");
     if(em.hasMoreElements()){
         System.out.println(em.nextElement());
     }
     Enumeration<?> session = httpServletRequest.getSession().getAttributeNames();
     System.out.print("httpServletSession: ");
     if(session.hasMoreElements()){
         System.out.println(session.nextElement());
     }
     System.out.print("uiModel: ");
     Set<String> map = uiModel.asMap().keySet();
     for (String string : map) {
         Object o = uiModel.asMap().get(string);
         System.out.println(o);
     }
结果是：

httpServletRequest: CharacterEncodingFilter.FILTERED

httpServletSession:

uiModel: