破坏资源失败：com.mchange.v2.c3p0.impl.NewPooledConnection@67a781cc

Question

我的c3p0配置如下，有时我在控制台中收到以下错误消息。为什么我会收到这个？

        <property name="hibernate.c3p0.min_size">5</property>
        <property name="hibernate.c3p0.max_size">100</property>
        <property name="hibernate.c3p0.timeout">300</property>
        <property name="hibernate.c3p0.max_statements">50</property>
        <property name="hibernate.c3p0.idle_test_period">3000</property>
        <property name="current_session_context_class">thread</property>
        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>

Hibernate配置

私有静态SessionFactory SessionFactory=buildSessionFactory（）；

private static SessionFactory buildSessionFactory() {
    try {
        System.err.println("in session Facotry");
        Configuration configuration = new Configuration();
        return configuration.configure().buildSessionFactory(
                new StandardServiceRegistryBuilder().applySettings(configuration.getProperties())
                .build());
    } catch (HibernateException ex) {
        System.err.println("Initial SessionFactory creation failed." + ex);
        throw new ExceptionInInitializerError(ex);
    }
}

public static SessionFactory getSessionFactory() {
    return sessionFactory;
}

错误

INFO:   WARN - Failed to destroy resource: com.mchange.v2.c3p0.impl.NewPooledConnection@67a781cc
 30 Jun 2014 11:57:59java.lang.IllegalStateException: This web container has not yet been started
    at org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1652)
    at org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1611)
    at com.mchange.v2.c3p0.stmt.GooGooStatementCache.synchronousDestroyStatement(GooGooStatementCache.java:413)
    at com.mchange.v2.c3p0.stmt.GooGooStatementCache.closeAll(GooGooStatementCache.java:351)
    at com.mchange.v2.c3p0.impl.NewPooledConnection.closeAllCachedStatements(NewPooledConnection.java:598)
    at com.mchange.v2.c3p0.impl.NewPooledConnection.close(NewPooledConnection.java:468)
    at com.mchange.v2.c3p0.impl.NewPooledConnection.close(NewPooledConnection.java:191)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.destroyResource(C3P0PooledConnectionPool.java:470)
    at com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask.run(BasicResourcePool.java:964)
    at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)

Answer 1

因此，这是一个类加载器问题，可能与应用程序热重新部署时仍在运行的过时池有关。以下是一些建议：

>

确保应用程序关闭时，hibernate SessionFactory在某个钩子中完全关闭，例如在SessionContextListener中。关闭SessionFactory应该在它所需的类仍然处于活动状态时清理池。这是最好的做法，因为除了您看到的消息之外，如果您在应用程序重启后让旧应用程序实例的池保持活动状态，那么您正在泄漏资源（线程、连接）。

升级到c3p0-0.9.5-pre8，并尝试将设置设置为hibernate.c3p0.contextClassLoaderSource到库。看见http://www.mchange.com/projects/c3p0/#contextClassLoaderSource确保将c3p0的两个jar文件放在应用程序服务器级lib目录中，而不是war文件或其他归档文件的附属目录中。