Error-no operations allowed after connection closed. org.hibernate.exception.jdbcconnectionexception:could not Execute Queryat Org.hibernate.exception.SQLStateConverter.convert (sqlstateconverter.java:74) at Org.hibernate.exception.JDBCExceptionHelper.convert (jdbcexceptionhelper.java:43) at Org.hibernate.loader.Loader.doList (loader.java:2148) at Org.hibernate.loader.Loader.listIgnoreQueryCache ( loader.java:2029) at Org.hibernate.loader.Loader.list (loader.java:2024) at Org.hibernate.loader.hql.QueryLoader.list (queryloader.java:375) at Org.hibernate.hql.ast.QueryTranslatorImpl.list (querytranslatorimpl.java:308) at Org.hibernate.engine.query.HQLQueryPlan.performList (hqlqueryplan.java:153) at Org.hibernate.impl.SessionImpl.list (sessionimpl.java:1106) at Org.hibernate.impl.QueryImpl.list (Queryimpl.java : 79) Analysis, the reason for this exception is: MySQL server default "Wait_timeout" is 8 hours, that is, 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. A) There are 3 ways to solve the: increase wait_timeout time. Reduce the lifetime of connection in connection pools. Test the effectiveness of connection in connection pools. b) Specific solutions:
1, change the JDBC driver, Jdbc3.1.0-alpha and previous versions of this issue, download the new JDBC Driver 2, use Hibernate configuration: Hibernate: <property name= " Connection.autoreconnect ">true</property> <!--This is the most important--<property name=" Connection.autoreconnectforpools ">true</property> <property name=" Connection.is-connection-validation-required ">true</property> Add the above property to resolve this issue, If you do not use a persistence management framework such as Hibernate, you can add autoreconnect=true to the MySQL URL to resolve it. The reason is simple. Shutting down connections after the end of a database operation is the right thing to do, no big deal. As for the appearance:No operations allowed after connection closed。 The reason for this problem is only one, you here and the database connection connection is a static, program sharing this one connection. So the first time on the database operation is not a problem, when the connection closed, the second time also want to operate the database connection certainly does not exist.
Com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException:No operations allowed after connection closed.
