休眠：關閉會話工廠不關閉c3p0連接池

Question

我最近開始在應用程序中使用hibernate和c3p0作爲ORM。但是，當我關閉會話工廠時，連接池不會自動關閉！這是唯一的地方在我的應用程序，我做任何事情與會議。

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(); 
     } 
    } 

這是我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> 

注意，對於非常短的空閒連接它，它的唯一的方式的原因，我發現還沒有讓我的集成測試通過。他們打開和關閉會話工廠很多，因此我總是用完連接。當我們處於項目的開始階段時，我認爲從長遠來看這不是一個非常可持續的策略。

一個「有趣」的事情要注意的是，儘管我將初始連接池設置爲1，但c3p0仍嘗試在開始時打開兩個連接。我的猜測是某種隱藏的會話不會關閉（但是在哪裏？打敗我）。

那麼，如何才能讓煩人的連接池關閉？

附加信息： 我如何創建和銷燬我的會話工廠

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的版本：4.1.10.Final
• C3P0版本：0.9.1.2

Answer 1

我同樣的問題，併成功地使用瞭解決辦法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(); 
} 

你必須引用hibernate-c3p0-4.x.x jar。

Answer 2

我有同樣的問題，併成功地運用了ehnanced（2014年1月）的變通提供in this bug report：

private static boolean closeSessionFactoryIfC3P0ConnectionProvider(SessionFactory factory) { 

    boolean done = false; 
    if(factory instanceof SessionFactoryImpl) { 
     SessionFactoryImpl sf = (SessionFactoryImpl)factory; 
     ConnectionProvider conn = sf.getConnectionProvider(); 
     if(conn instanceof C3P0ConnectionProvider) { 
      ((C3P0ConnectionProvider)conn).close(); 
      try { 
       Thread.sleep(2000); //Let give it time...it is enough...probably 
      } catch (InterruptedException e) { 
       e.printStackTrace(); 
      } 
      done = true; 
     } 
     factory.close(); 
    } 
    return done; 

} 

您必須引用休眠-c3p0-4.x.x罐子。