错误
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure
The last packet successfully received from the server was 45,555 milliseconds ago. The last packet sent successfully to the server was 319 milliseconds ago.
排查思路
我的数据库用的是mysql8，经排查，linux服务器因为黑客攻击导致数据库关闭了，启动数据库即可。