入参数据示例:

{
    "respCode": "0000",
    "respMsg": "请求成功",
    "bizSeqNo": "22022120001184432418054888526616",
    "transTime": "20220221180548",
    "success": true,
    "tokenArr": [
        {
            "value": "xxxx",
            "expire_in": 96,
            "expire_time": "20220221180724"
        }
    ]
}

取出其中的value值

String req = "这里是入参";
//1.先转换成map
Map map = JSON.parseObject(req, Map.class);
//2.取出数组
JSONArray tokenArr = (JSONArray) map.get("tokenArr");
//3.把数组的第一个转换成map
HashMap tokenArrMap = JSON.parseObject(
				tokenArr.getString(0), HashMap.class);
//4.取出value
String value = (String) tokenArrMap.get("value");