Spring boot connection MySQL long time not connected after error ' com.mysql.cj.core.exceptions.ConnectionIsClosedException:No operations allowed after Connection closed. ' Solution

Error:com.mysql.cj.core.exceptions.ConnectionIsClosedException: No operations allowed after connection closed.

Adding &autoReconnect=true does not help, this option appears to be valid only for versions prior to MySQL 5.

Reason

MySQL server default "Wait_timeout" is 8 hours, which means that a connection idle for more than 8 hours, MySQL will automatically disconnect the connection. This is the problem, in the C3P0 pools connections if idle for more than 8 hours, MySQL will disconnect it, and c3p0 do not know that the connection has failed, if there is a client request connection, C3P0 the failure of the connection to the client, will cause the above exception.

Solutions

Http://www.cnblogs.com/hemingwang0902/archive/2012/03/15/2397620.html

Temporary Solutions

Because the above method needs to modify the database, but I do not want to change the database. So:
Modify the driver to connect to MySQL (Modify application.properties):
From

spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver

Switch

spring.datasource.driverClassName=com.mysql.jdbc.Driver

Spring boot connection MySQL long time not connected after error ' com.mysql.cj.core.exceptions.ConnectionIsClosedException:No operations allowed after Connection closed. ' Solution