The first startup error com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Every time the computer is restarted or when the project is started the next day after standby, an error will be reported:

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

I searched the Internet for the reason, and the basic operation is as follows:

 

My mysql version:

It is to change the timeout time of mysql. A blog post I refer to is as follows:

https://www.cnblogs.com/ergexy/p/11100932.html