错误：The driver has not received any packets from the server.

用 mysql 8.*的依赖去连接 mysql 5 时报错

The driver has not received any packets from the server.

解决：

// 将这个url改为 下面一个解决
url: jdbc:mysql://192.168.200.130:3306/gulimall_pms?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf8&useSSL=true

url: jdbc:mysql://192.168.200.130:3306/gulimall_pms?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf8&useSSL=false

也就是将useSSL改为false