json:
{"updated_at":1551780617,"attr":{"uptime_h":3,"uptime_m":17},"did":"GBBxjJYAxE4apkxwEzR3"}
Map rMap = (Map) JSON.parse("{"updated_at":1551780617,"attr":{"uptime_h":3,"uptime_m":17},"did":"GBBxjJYAxE4apkxwEzR3"} ");
在提取出 rMap.get("attr"); 时得到的是:{"uptime_h":3,"uptime_m":17}
但我要得到里面的东西,直接用字符串不好搞,我把它转为json 提取:
Map rMap2 = (Map) JSON.parse((String)rMap.get("attr"));
结果就报错了: com.alibaba.fastjson.JSONObject cannot be cast to java.lang.String
原因是:改map提取出来的对象不能转为String,而要通过它的方法 toString 来转化:
String str = map.get("attr").toString();
System.out.println("ddd===" + str);
Map rMap = (Map) JSON.parse(str);
System.out.println(rMap.get("uptime_h"));
OK!!!
原文地址:https://www.cnblogs.com/zhumengdexiaobai/p/10480550.html
时间: 2024-10-15 13:24:26