ajax传递json数据，springmvc后台就收json数据

  var json = {"token":token};//封装json数据
         $.ajax({
             url:‘‘,
             data:JSON.stringify(json),//封装成json
             dataType:"JSON",
             type:"POST",
             async:false,
             cache:false,
             contentType:‘application/json;charset=UTF-8‘,//必须添加
             success:function(data){


             },
             error:function(data){
                 textmsg("请求错误，请联系客服人员！");
             }
         });

@ResponseBody
    @RequestMapping("checkLogin")
    public  String checkLogin(HttpServletRequest request,HttpServletResponse response,@RequestBody JSONObject jsonObject){
        System.out.println("----------------i am checkLogin");
        String token  = jsonObject.get("token")==null?"":jsonObject.getString("token");
        //或者使用 String token = request.getParameter("token")==null?"":request.getParameter("token");
}