安卓开发null对象

Question

问题遇到的现象和发生背景

问题相关代码，请勿粘贴截图

{"total":2,"rows":[{"searchValue":null,"createBy":null,"createTime":"2022-07-07 20:06:25","updateBy":null,"updateTime":null,"remark":null,"params":{},"id":9802,"appType":"park","title":"123","content":"123456","userId":1119471},{"searchValue":null,"createBy":null,"createTime":"2022-07-07 19:38:10","updateBy":null,"updateTime":null,"remark":null,"params":{},"id":9801,"appType":"park","title":"123","content":"123","userId":1119471}],"code":200,"msg":"查询成功"}
服务端返回的结果
String s=response.body().string();

feetlistBean= new Gson().fromJson(s, FeetlistBean.class);
将结果转换为bean对象，然后调用报错

运行结果及报错内容

我的解答思路和尝试过的方法

我想要达到的结果