Solution for cocould not execute query MySQL database not accessed for more than 8 hours

Hibernate uses the connection pool of c3p0 to configure c3p0. 1. Import the c3p0. jar package. You can also download it from the Internet. 2. Add <property name = "c3p0. acquire_increment"> 1 </property> to the hibernate. cfg. xml configuration file. <Property name = "c3p0. idle_test_period"> 100 </property> <Property name = "c3p0. max_size"> 5 </property> <Property name = "c3p0. max_statements"> 0 </property> <Property name = "c3p0. min_size"> 2 </property> <Property name = "c3p0. Timeout"> 90 </property> <Property name = "c3p0. preferredtestquery"> select 1 from user where id = 1 </property> <Property name = "c3p0. idleconnectiontestperiod"> 18000 </property> <Property name = "c3p0. maxidletime"> 25000 </property> <Property name = "c3p0. testconnectiononcheckout"> true </property> 3. Restart tomcat to solve the problem. After you restart tomcat, you will be prompted to warn c3p0connectionprovider: 210-both hibernate-style property 'hibernate. c3p0. max_size 'and c3p0-style property' c3p0. max_size 'have been set in hibernate. properties. hibernate-style property 'hibernate. c3p0. max_size 'will be used and c3p0-style properties' c3p0. max_size 'will be ignored! Solution: Replace "c3p0. max_size" with "hibernate. c3p0. max_size". I found a lot on the Internet. I don't know if this solution works. No error is reported.