如何关闭上下文卸载连接池？ [英] How to shutdown connection pool on context unload?

问题描述

在开发了几个webapps之后，所有的spring都有类似的连接池，hibernate和c3p0作为connectionpool我想调查一下我每次注意到的问题：
连接池保持连接，直到关闭tomcat（或者你的应用服务器） 。

今天我用这四个依赖关系创建了最基本的项目：

  org.springframework：spring-web 
 org.springframework：spring-orm 
 org.hibernate：hibernate-core 
 c3p0：c3p0 
  

（加上特定的JDBC驱动程序）。

我的web.xml只创建一个ContextLoaderListener

 < context-param>设置应用程序上下文。 
< param-name> contextConfigLocation< / param-name> 
< param-value> 
 /WEB-INF/applicationContext.xml 
< / param-value> 
< / context-param> 
 
< listener> 
< listener-class> 
 org.springframework.web.context.ContextLoaderListener 
< / listener-class> 
< / listener> 
  

应用程序上下文由两个bean组成 - 数据源和会话工厂：

 < bean id =sessionFactoryclass =org.springframework.orm.hibernate4.LocalSessionFactoryBean> 
< property name =dataSourceref =dataSource/> 
< / bean> 
 
< bean id =dataSourceclass =com.mchange.v2.c3p0.ComboPooledDataSource> 
< property name =driverClass> 
< value> org.postgresql.Driver< / value> 
< / property> 
< property name =jdbcUrl> 
<值> jdbc：postgresql：// localhost / mydb< /值> 
< / property> 
< property name =user> 
<值> usr< /值> 
< / property> 
< property name =password> 
<值> pwd< /值> 
< / property> 
< / bean> 
  

当我启动webapp并查看jconsole的MBeans或检查我的DBMS的打开连接时，我注意到

问题：当我告诉tomcat停止webapp时，它们仍然存在！

我创建了另一个ServletContextListener，它只实现了contextDestroyed方法，并以编程方式关闭sessionFactory（并且还注销了也未自动完成的JDBC驱动程序）。
代码是：

  @Override 
 public void contextDestroyed（ServletContextEvent sce）{
 
 ... 
 sessionFactory（）。close（）; 
 
 //取消注册sql驱动程序
枚举< Driver> drivers = DriverManager.getDrivers（）; 
 while（drivers.hasMoreElements（））{
 Driver driver = drivers.nextElement（）; 
尝试{
 DriverManager.deregisterDriver（driver）; 
 log.info（deregistering jdbc driver：+ driver）; 
} catch（SQLException e）{
 log.error（error deregistering jdbc driver：+ driver，e）; 
} 
} 
} 
  

但是，真的吗？有没有内置的机制，我不知道？

解决方案

你有没有试图指定销毁方法？ / p>

 < bean class =com.mchange.v2.c3p0.ComboPooledDataSourcedestroy-method =close> 
  

after developing several webapps that all had a similar setup with spring, hibernate and c3p0 as connectionpool I wanted to investigate a problem that i noticed everytime: Connectionpool keeps the connections until you shutdown tomcat (or your application server).

Today i create the most basic project I could with these four dependencies:

org.springframework:spring-web
org.springframework:spring-orm
org.hibernate:hibernate-core
c3p0:c3p0

(plus the specific JDBC driver).

My web.xml only creates a ContextLoaderListener that sets up the application context.

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>
        /WEB-INF/applicationContext.xml
    </param-value>
</context-param>

<listener>
    <listener-class>
        org.springframework.web.context.ContextLoaderListener
    </listener-class>
</listener>

application context consists of two beans - datasource and session factory:

<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
</bean>

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
    <property name="driverClass">
        <value>org.postgresql.Driver</value>
    </property>
    <property name="jdbcUrl">
        <value>jdbc:postgresql://localhost/mydb</value>
    </property>
    <property name="user">
        <value>usr</value>
    </property>
    <property name="password">
        <value>pwd</value>
    </property>
</bean>

When i start the webapp and either look into jconsole's MBeans or check my DBMS for open connections i notice the three initial connections made by c3p0.

PROBLEM: When i tell tomcat to stop the webapp, they still remain!

I created another ServletContextListener that only has the contextDestroyed method implemented and programatically shuts down the sessionFactory (and also deregisters the JDBC drivers which is also not done automatically). Code is:

@Override
public void contextDestroyed(ServletContextEvent sce) {

    ...
    sessionFactory().close();

    // deregister sql driver(s)
    Enumeration<Driver> drivers = DriverManager.getDrivers();
    while (drivers.hasMoreElements()) {
        Driver driver = drivers.nextElement();
        try {
            DriverManager.deregisterDriver(driver);
            log.info("deregistering jdbc driver: " + driver);
        } catch (SQLException e) {
            log.error("error deregistering jdbc driver: " + driver, e);
        }
    }
}

But is that really it? Is there no built-in mechanism that I am not aware of?

解决方案

Have you tried to specify the destroy-method?

<bean class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">

这篇关于如何关闭上下文卸载连接池？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！