$.ajax({

    		type:"post",

    		url:"../classsetting/addCounselor.do",

    		data:{"cLassid": cLassid, "userid": userid},

    		dataType:"json",

//    		contentType:"application/json;charset=UTF-8",

    		async:false,

    		success:function(data){

    		              ......

    		},error:function(jqXHR, textStatus, errorThrown){

    			.......

    		}

       });

        @RequestMapping(value = "addCounselor.do" )

	public @ResponseBody int insertCounselor(HttpServletRequest request) {

		String classid  = request.getParameter("cLassid");//编辑编号

		String counselor  = request.getParameter("userid");//辅导员的 userID
　　　　　　　　　 //拿不到 ajax的 参数！！！！ 原因在下面

	    int i = sysClassService.updateClassCounselor(counselor,classid);

		return i;

	}