常遇到的bug

1. Property or field ‘moduleId’ cannot be found on null
   https://blog.csdn.net/fansili/article/details/78285991
   2. Java中常见报错处理方法（500、404）
      https://blog.csdn.net/qq_40136594/article/details/83187238
      3.Result Maps collection does not contain value for 错误
      https://blog.csdn.net/sunguoqiang1213/article/details/82345747