java.lang.String cannot be cast to com.alibaba.fastjson.JSONArray
https://blog.csdn.net/angelofmersy/article/details/52355017
https://blog.csdn.net/Hello_World_QWP/article/details/90692167
JSONObject常用方法
https://www.cnblogs.com/zjdxr-up/p/9736755.html