在 Java Web 应用程序中消除了几个与 PermGen 相关的问题后,我达到了以下几点:
- 该应用程序在 Tomcat 6.0.32 中运行并使用 Tomcat 管理的
DataSource
DataSource
定义在$TOMCAT_HOME/conf/context.xml
- 当应用程序启动时,它会查找
DataSource
并且只有在那个时候才被DataSource
实例化; BasicDataSource
commons-dbcp的实现会加载GenericObjectPool
该类,然后启动一个java.util.Timer
- Timer 启动一个
TimerThread
GC Root 并由 Web 应用程序类加载器加载。
定时器创建的堆栈跟踪
java.util.Timer.<init>(Timer.java:123)
org.apache.tomcat.dbcp.pool.impl.GenericObjectPool.<clinit>(GenericObjectPool.java:268)
org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1172)
org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:880)
org.springframework.orm.hibernate3.LocalDataSourceConnectionProvider.getConnection(LocalDataSourceConnectionProvider.java:81)
org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:114)
org.hibernate.cfg.Configuration.buildSettingsInternal(Configuration.java:2163)
org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2159)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1383)
org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:954)
org.springframework.orm.hibernate3.LocalSessionFactoryBean.newSessionFactory(LocalSessionFactoryBean.java:855)
org.springframework.orm.hibernate3.LocalSessionFactoryBean.buildSessionFactory(LocalSessionFactoryBean.java:774)
org.springframework.orm.hibernate3.AbstractSessionFactoryBean.afterPropertiesSet(AbstractSessionFactoryBean.java:211)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1477)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1417)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
计时器显示为由 webapp 类加载器加载
我的第一个想法是让 TomcatDataSource
急切地初始化它,从而将它固定在通用类加载器中,但我发现没有办法这样做。我当然对解决这个问题的其他方法持开放态度(但 JNDI 绑定的资源需要保留)。
如何确保TimerThread
链接到 Web 应用程序类加载器?