spring mvc ajax

controller 处理请求的代码

@ResponseBody
    @RequestMapping(value = "ajax", produces = "application/json")
    public String ajax(HttpServletRequest request,HttpServletResponse response)
    {
        String getString=request.getParameter("ajaxSendMessage");
        System.out.println(getString);
        response.setContentType("application/json");
        return "{\"answer\":\"" + getString + "\"}"; 
    }

 

ajax代码

<script type="text/javascript">
          $.ajax({
              type:'POST',
              url:'/helloworld/helloworld/ajax',      //请求的url
              data:{
                  ajaxSendMessage:'I was posted from ajax'
              },
              success:function(msg){
                  alert(msg.answer);
              }

          })
  </script>