Question

I have a configuration listener that creates a Hibernate session when a user hits the application. I’m getting an error from the contextDestroyed method. Can anyone help me with this? Here is the method that’s causing the problem.

public void contextDestroyed(ServletContextEvent arg0) {
    this.sessionFactory.close();
}

Here are the error messages on my console.

SEVERE: Exception sending context initialized event to listener instance of class com.configuration.ConfigurationListener
java.lang.NoClassDefFoundError: org/apache/commons/collections/SequencedHashMap
    at org.hibernate.mapping.Table.<init>(Table.java:32)
    at org.hibernate.cfg.Mappings.addTable(Mappings.java:120)
    at org.hibernate.cfg.HbmBinder.bindRootPersistentClassCommonValues(HbmBinder.java:251)
    at org.hibernate.cfg.HbmBinder.bindRootClass(HbmBinder.java:236)
    at org.hibernate.cfg.HbmBinder.bindRoot(HbmBinder.java:152)
    at org.hibernate.cfg.Configuration.add(Configuration.java:362)
    at org.hibernate.cfg.Configuration.addInputStream(Configuration.java:400)
    at org.hibernate.cfg.Configuration.addResource(Configuration.java:449)
    at org.hibernate.cfg.Configuration.parseMappingElement(Configuration.java:1263)
    at org.hibernate.cfg.Configuration.parseSessionFactory(Configuration.java:1235)
    at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1217)
    at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1184)
    at org.hibernate.cfg.Configuration.configure(Configuration.java:1112)
    at org.hibernate.cfg.Configuration.configure(Configuration.java:1098)
    at com.configuration.ConfigurationListener.contextInitialized(ConfigurationListener.java:19)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3830)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4337)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
    at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
    at org.apache.catalina.core.StandardService.start(StandardService.java:516)
    at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:566)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.collections.SequencedHashMap
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1358)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204)
    ... 30 more
Jun 25, 2012 5:21:59 PM org.apache.catalina.core.StandardContext start
SEVERE: Error listenerStart
Jun 25, 2012 5:21:59 PM org.apache.catalina.core.StandardContext start
SEVERE: Context [/ghs1986] startup failed due to previous errors
Jun 25, 2012 5:21:59 PM org.apache.catalina.core.StandardContext listenerStop
SEVERE: Exception sending context destroyed event to listener instance of class com.configuration.ConfigurationListener
java.lang.NullPointerException
    at com.configuration.ConfigurationListener.contextDestroyed(ConfigurationListener.java:25)
    at org.apache.catalina.core.StandardContext.listenerStop(StandardContext.java:3869)
    at org.apache.catalina.core.StandardContext.stop(StandardContext.java:4503)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4367)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
    at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
    at org.apache.catalina.core.StandardService.start(StandardService.java:516)
    at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:566)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)

Answer 1

The main problem isn’t in the contextDestroy method. The problem is in your classpath. You’re missing the apache commons collections jar in the classpath. Hibernate depends on it and fails with

java.lang.ClassNotFoundException: org.apache.commons.collections.SequencedHashMap.

This causes later the listener’s contextDestoryed method to be invoked. That methods, tries to close() its sessionFactory. But sessionFactory was never initialized since Hibernate never made it up because of the aforementioned ClassNotFoundException.

It’s all written in the pasted console log.