2021-02-13 11:35:13.970 ERROR 8044 --- [ restartedMain] com.zaxxer.hikari.pool.HikariPool : 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.
at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174) ~[mysql-connector-java-8.0.22.jar:8.0.22]
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Caused by: com.mysql.cj.exceptions.CJCommunicationsException: 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.
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Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure解決策：MySQLサービスを起動する。
