ajax请求springmvc成功后仍然执行error模块

1.前台

 $.ajax({             method:'post',             data:jsonStr,             url:'xxxxx/good',             contentType: "application/json; charset=utf-8",             dataType: "json",              success:function(result){             },             error: function(XMLHttpRequest, textStatus, errorThrown) {                 alert(XMLHttpRequest.status);                 alert(XMLHttpRequest.readyState);                 alert(textStatus);             }         });

2.springmvc

    @ResponseBody    @RequestMapping(value={"good",""})    public String savetobt(@RequestBody String jsonStr){        List<BigDelay> list=JsonUtil.fromJson(jsonStr, List.class);        return "";    }

3.出现问题
ajax请求springmvc成功后仍然执行error模块，分别弹出200， 4，parsererror
3.问题原因
springmvc返回的结果不是json类型的数据
4.解决办法：改返回类型

    @ResponseBody    @RequestMapping(value={"good",""})    public String savetobt(@RequestBody String jsonStr){        List<BigDelay> list=JsonUtil.fromJson(jsonStr, List.class);        System.out.println(list);        String jsonResult=JsonUtil.toJson("");        return jsonResult;    }