//
// ========================================================================
// Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package org.eclipse.jetty.servlet.listener;
import java.lang.reflect.Field;
import java.util.Iterator;
import java.util.concurrent.ConcurrentHashMap;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import org.eclipse.jetty.util.Loader;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
/**
* ELContextCleaner
*
* Clean up BeanELResolver when the context is going out
* of service:
*
* See http://java.net/jira/browse/GLASSFISH-1649
* See https://bugs.eclipse.org/bugs/show_bug.cgi?id=353095
*/
public class ELContextCleaner implements ServletContextListener
{
private static final Logger LOG = Log.getLogger(ELContextCleaner.class);
public void contextInitialized(ServletContextEvent sce)
{
}
public void contextDestroyed(ServletContextEvent sce)
{
try
{
//Check that the BeanELResolver class is on the classpath
Class beanELResolver = Loader.loadClass(this.getClass(), "javax.el.BeanELResolver");
//Get a reference via reflection to the properties field which is holding class references
Field field = getField(beanELResolver);
//Get rid of references
purgeEntries(field);
LOG.debug("javax.el.BeanELResolver purged");
}
catch (ClassNotFoundException e)
{
//BeanELResolver not on classpath, ignore
}
catch (SecurityException e)
{
LOG.warn("Cannot purge classes from javax.el.BeanELResolver", e);
}
catch (IllegalArgumentException e)
{
LOG.warn("Cannot purge classes from javax.el.BeanELResolver", e);
}
catch (IllegalAccessException e)
{
LOG.warn("Cannot purge classes from javax.el.BeanELResolver", e);
}
catch (NoSuchFieldException e)
{
LOG.debug("Not cleaning cached beans: no such field javax.el.BeanELResolver.properties");
}
}
protected Field getField (Class beanELResolver)
throws SecurityException, NoSuchFieldException
{
if (beanELResolver == null)
return null;
return beanELResolver.getDeclaredField("properties");
}
protected void purgeEntries (Field properties)
throws IllegalArgumentException, IllegalAccessException
{
if (properties == null)
return;
if (!properties.isAccessible())
properties.setAccessible(true);
ConcurrentHashMap map = (ConcurrentHashMap) properties.get(null);
if (map == null)
return;
Iterator<Class> itor = map.keySet().iterator();
while (itor.hasNext())
{
Class clazz = itor.next();
LOG.debug("Clazz: "+clazz+" loaded by "+clazz.getClassLoader());
if (Thread.currentThread().getContextClassLoader().equals(clazz.getClassLoader()))
{
itor.remove();
LOG.debug("removed");
}
else
LOG.debug("not removed: "+"contextclassloader="+Thread.currentThread().getContextClassLoader()+"clazz's classloader="+clazz.getClassLoader());
}
}
}