我最近开始在我的应用程序中使用 hibernate 和 c3p0 作为 ORM。但是，当我关闭 session 工厂时，连接池并没有自行关闭!这是我的应用程序中也是唯一的地方，我可以在其中对 session 执行任何操作。

    StatelessSession session = null;
    Transaction transaction = null;


    try {
        session = sessionFactory.openStatelessSession();
        transaction = session.beginTransaction();

        List<Thingy> list = session.getNamedQuery("getAvailableThingy").list();

        transaction.commit();
        return list;

    } catch (Exception error) { 
        if (transaction != null) {
            transaction.rollback();
        }
        throw error;
    } finally {
        if (session != null) {
            session.close();
        }
    }

这是我的hibernate.cfg.xml配置文件

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">


<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
        <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
        <property name="javax.persistence.validation.mode">none</property>
        <property name="hibernate.connection.release_mode">after_transaction</property>

        <property name="hibernate.c3p0.minPoolSize">1</property>
        <property name="hibernate.c3p0.maxPoolSize">2</property>
        <property name="hibernate.c3p0.acquireIncrement">1</property>
        <property name="hibernate.c3p0.initialPoolSize">1</property>
        <property name="hibernate.c3p0.timeout">30</property>
        <property name="hibernate.c3p0.maxIdleTimeExcessConnections">5</property>
        <property name="hibernate.c3p0.idleConnectionTestPeriod">300</property>
    </session-factory>
</hibernate-configuration>

请注意，空闲连接非常短的原因是它是我发现尚未通过集成测试的唯一方法。他们经常打开和关闭 session 工厂，因此我总是用完连接。由于我们还处于项目初期，我想从长远来看，这不是一个非常可持续的战略。

需要注意的一个“有趣”的事情是，尽管我将初始连接池设置为一个，但 c3p0 仍然尝试在启动时打开两个连接。我的猜测是某个地方有某种隐藏的 session 不会关闭(但是在哪里？打败我)。

那么我怎样才能让烦人的连接池自行关闭呢？

附加信息: 我如何创建和销毁我的 session 工厂

import static com.google.common.base.Preconditions.*;

import javax.inject.Inject;
import javax.inject.Provider;
import javax.inject.Singleton;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.inject.Provides;


@Singleton 
public class PostgisConnection implements Provider<SessionFactory>, AutoCloseable {
    private final Logger logger = LoggerFactory.getLogger(getClass());
    private final ConnectionInfo connectionInfo;
    private SessionFactory sessionFactory = null;

    @Inject 
    public PostgisConnection(ConnectionInfo connectionInfo) {
        this.connectionInfo = connectionInfo;
    }

    public AutoCloseable open() {
        checkState(sessionFactory == null, "Connections to postgis are already open");

        logger.info("Creating sessionFactory for connection to postgis: {}", connectionInfo.getJdbcUrl());
        sessionFactory = newPostgisSessionFactory(connectionInfo);

        return this;
    }

    @Override
    public void close() throws Exception {
        try {
            if (sessionFactory != null) {
                logger.info("Closing sessionFactory for postgis: {}", connectionInfo.getJdbcUrl());
                sessionFactory.close();
                checkState(sessionFactory.isClosed(), "Session factory should be closed at this point");
            }
        } catch (Exception error) {
            logger.error("Error closing SessionFactory", error);
        }
    }

    @Provides 
    public SessionFactory get() {
        return sessionFactory;
    }

    public static SessionFactory newPostgisSessionFactory(ConnectionInfo connectionInfo) {
        Configuration configuration = configurationWith(connectionInfo);
        return configuration.buildSessionFactory(registryFrom(configuration));
    }

    private static Configuration configurationWith(ConnectionInfo connectionInfo) {
        Configuration configuration = new Configuration();
        setConnectionInfo(connectionInfo, configuration);
        configuration.addURL(PostgisConnection.class.getResource("mapping.hbm.xml"));
        configuration.configure(PostgisConnection.class.getResource("hibernate.cfg.xml"));

        return configuration;
    }

    private static void setConnectionInfo(ConnectionInfo connectionInfo, Configuration configuration) {
        configuration.setProperty("hibernate.connection.url", connectionInfo.getJdbcUrl());
        configuration.setProperty("hibernate.connection.username", connectionInfo.getUsername());
        configuration.setProperty("hibernate.connection.password", connectionInfo.getPassword());
    }

    private static ServiceRegistry registryFrom(Configuration configuration) {
        return new ServiceRegistryBuilder()
                .applySettings(configuration.getProperties())
                .buildServiceRegistry();
    }

}

• hibernate 版本:4.1.10.Final
• C3p0 版本:0.9.1.2

最佳答案

我遇到了同样的问题并成功使用了提供的解决方法 in this bug report :

private void closeSessionFactory(SessionFactory factory) { 
   if(factory instanceof SessionFactoryImpl) {
      SessionFactoryImpl sf = (SessionFactoryImpl)factory;
      ConnectionProvider conn = sf.getConnectionProvider();
      if(conn instanceof C3P0ConnectionProvider) { 
        ((C3P0ConnectionProvider)conn).close(); 
      }
   }
   factory.close();
}

您必须引用 hibernate-c3p0-4.x.x jar。

关于java - hibernate : closing the session factory does not close the c3p0 connection pool，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15298437/