报错内容：
17:55:55.038 [main] ERROR c.z.h.p.HikariPool - [throwPoolInitializationException,587] - HikariPool-1 - Exception during pool initialization.
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.