获取RestResultResponse返回的值

Springboot项目，需要调其他服务的接口，返回值类型是RestResultResponse

打断点的结果集是这个

打印出来的getData():

[{id=3336b624-8474-4dd9-bd5b-c7358687c877, paraNo=104, para=PostponeDay, paraName=卡启用延期天数, visible=1, editType=INPUT_NUMBER, maxLength=5, minValue=12, dictCode=null, defaultValue=0, bid=3369d1ff47a7a8bcda6fe86a90cff642, bvisible=1, calter=1, balter=1, bparaValue=12, vmodule=CLB, nmaxValue=99999, nprecision=0, vdesc=会员卡启用延期天数(天)}]

无法取到值

RestResultResponse mapRestResultResponse = feign.doSearch(student);
JSONArray json = (JSONArray) JSON.toJSON(mapRestResultResponse.getData());
for (int i = 0; i < json.size(); i++) {
    com.alibaba.fastjson.JSONObject obj = json.getJSONObject(i);
    System.err.println(obj.getString("nmaxValue"));   //成功取到值
}