alfresco-community-repo/source/java/org/alfresco/repo/management/SafeApplicationEventMulticaster.java
Brian Remmington dc87333db5 Migrate codebase onto Spring 3.0.5. There is an issue with using annotation based test cases that I haven't got to the bottom of yet. I have posted on the SpringSource forum here:
http://forum.springsource.org/showthread.php?111842-ConfigurationClassPostProcessor-IllegalStateException-when-starting-test-case

As a workaround I have converted all such test cases so that they simply use the "normal" BaseSpringTest super class. Fortunately there were only eight or nine such classes.

Although I have run quite a number of tests on the result I haven't run every test there is, so there may be some fallout.

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@28904 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261
2011-07-10 21:42:21 +00:00

400 lines
15 KiB
Java

/*
* Copyright (C) 2005-2010 Alfresco Software Limited.
*
* This file is part of Alfresco
*
* Alfresco is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Alfresco is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
*/
package org.alfresco.repo.management;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.Executor;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ApplicationEventMulticaster;
import org.springframework.context.event.ContextClosedEvent;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.context.event.GenericApplicationListenerAdapter;
import org.springframework.context.event.SmartApplicationListener;
import org.springframework.core.OrderComparator;
/**
* Abstract implementation of the {@link ApplicationEventMulticaster} interface,
* providing the basic listener registration facility.
*
* <p>
* Doesn't permit multiple instances of the same listener by default, as it
* keeps listeners in a linked Set. The collection class used to hold
* ApplicationListener objects can be overridden through the "collectionClass"
* bean property.
*
* <p>
* Implementing ApplicationEventMulticaster's actual {@link #multicastEvent}
* method is left to subclasses. {@link SimpleApplicationEventMulticaster}
* simply multicasts all events to all registered listeners, invoking them in
* the calling thread. Alternative implementations could be more sophisticated
* in those respects.
*
* @author Juergen Hoeller
* @since 1.2.3
* @see #getApplicationListeners(ApplicationEvent)
* @see SimpleApplicationEventMulticaster
*/
public class SafeApplicationEventMulticaster implements ApplicationEventMulticaster, ApplicationContextAware
{
private final Log log = LogFactory.getLog(SafeApplicationEventMulticaster.class);
private final ListenerRetriever defaultRetriever = new ListenerRetriever(false);
private final Map<ListenerCacheKey, ListenerRetriever> retrieverCache = new ConcurrentHashMap<ListenerCacheKey, ListenerRetriever>();
private ApplicationContext appContext;
private Executor taskExecutor;
/** Has the application started? */
private boolean isApplicationStarted;
/** The queued events that can't be broadcast until the application is started. */
private List<ApplicationEvent> queuedEvents = new LinkedList<ApplicationEvent>();
/**
* Set the TaskExecutor to execute application listeners with.
* <p>
* Default is a SyncTaskExecutor, executing the listeners synchronously in
* the calling thread.
* <p>
* Consider specifying an asynchronous TaskExecutor here to not block the
* caller until all listeners have been executed. However, note that
* asynchronous execution will not participate in the caller's thread
* context (class loader, transaction association) unless the TaskExecutor
* explicitly supports this.
*
* @see org.springframework.core.task.SyncTaskExecutor
* @see org.springframework.core.task.SimpleAsyncTaskExecutor
*/
public void setTaskExecutor(Executor taskExecutor)
{
this.taskExecutor = taskExecutor;
}
/**
* Return the current TaskExecutor for this multicaster.
*/
protected Executor getTaskExecutor()
{
return this.taskExecutor;
}
public void addApplicationListener(ApplicationListener listener)
{
synchronized (this.defaultRetriever)
{
this.defaultRetriever.applicationListeners.add(listener);
this.retrieverCache.clear();
}
}
public void addApplicationListenerBean(String listenerBeanName)
{
synchronized (this.defaultRetriever)
{
this.defaultRetriever.applicationListenerBeans.add(listenerBeanName);
this.retrieverCache.clear();
}
}
public void removeApplicationListener(ApplicationListener listener)
{
synchronized (this.defaultRetriever)
{
this.defaultRetriever.applicationListeners.remove(listener);
this.retrieverCache.clear();
}
}
public void removeApplicationListenerBean(String listenerBeanName)
{
synchronized (this.defaultRetriever)
{
this.defaultRetriever.applicationListenerBeans.remove(listenerBeanName);
this.retrieverCache.clear();
}
}
public void removeAllListeners()
{
synchronized (this.defaultRetriever)
{
this.defaultRetriever.applicationListeners.clear();
this.defaultRetriever.applicationListenerBeans.clear();
this.retrieverCache.clear();
}
}
private BeanFactory getBeanFactory()
{
if (this.appContext == null)
{
throw new IllegalStateException("ApplicationEventMulticaster cannot retrieve listener beans "
+ "because it is not associated with a BeanFactory");
}
return this.appContext;
}
@Override
public void multicastEvent(ApplicationEvent event)
{
if (event instanceof ContextRefreshedEvent && event.getSource() == this.appContext)
{
this.isApplicationStarted = true;
for (ApplicationEvent queuedEvent : this.queuedEvents)
{
multicastEventInternal(queuedEvent);
}
this.queuedEvents.clear();
multicastEventInternal(event);
}
else if (event instanceof ContextClosedEvent && event.getSource() == this.appContext)
{
this.isApplicationStarted = false;
multicastEventInternal(event);
}
else if (this.isApplicationStarted)
{
multicastEventInternal(event);
}
else
{
this.queuedEvents.add(event);
}
}
@SuppressWarnings("unchecked")
protected void multicastEventInternal(final ApplicationEvent event) {
for (final ApplicationListener listener : getApplicationListeners(event)) {
Executor executor = getTaskExecutor();
if (executor != null) {
executor.execute(new Runnable() {
public void run() {
listener.onApplicationEvent(event);
}
});
}
else {
listener.onApplicationEvent(event);
}
}
}
/**
* Return a Collection containing all ApplicationListeners.
*
* @return a Collection of ApplicationListeners
* @see org.springframework.context.ApplicationListener
*/
protected Collection<ApplicationListener> getApplicationListeners()
{
return this.defaultRetriever.getApplicationListeners();
}
/**
* Return a Collection of ApplicationListeners matching the given event
* type. Non-matching listeners get excluded early.
*
* @param event
* the event to be propagated. Allows for excluding non-matching
* listeners early, based on cached matching information.
* @return a Collection of ApplicationListeners
* @see org.springframework.context.ApplicationListener
*/
protected Collection<ApplicationListener> getApplicationListeners(ApplicationEvent event)
{
Class<? extends ApplicationEvent> eventType = event.getClass();
Class sourceType = event.getSource().getClass();
ListenerCacheKey cacheKey = new ListenerCacheKey(eventType, sourceType);
ListenerRetriever retriever = this.retrieverCache.get(cacheKey);
if (retriever != null)
{
return retriever.getApplicationListeners();
}
else
{
retriever = new ListenerRetriever(true);
LinkedList<ApplicationListener> allListeners = new LinkedList<ApplicationListener>();
synchronized (this.defaultRetriever)
{
if (!this.defaultRetriever.applicationListenerBeans.isEmpty())
{
BeanFactory beanFactory = getBeanFactory();
for (String listenerBeanName : this.defaultRetriever.applicationListenerBeans)
{
ApplicationListener listener = beanFactory.getBean(listenerBeanName, ApplicationListener.class);
if (supportsEvent(listener, eventType, sourceType))
{
retriever.applicationListenerBeans.add(listenerBeanName);
allListeners.add(listener);
}
}
}
for (ApplicationListener listener : this.defaultRetriever.applicationListeners)
{
if (!allListeners.contains(listener) && supportsEvent(listener, eventType, sourceType))
{
retriever.applicationListeners.add(listener);
allListeners.add(listener);
}
}
OrderComparator.sort(allListeners);
this.retrieverCache.put(cacheKey, retriever);
}
if (log.isDebugEnabled())
{
log.debug(allListeners.toString());
}
return allListeners;
}
}
/**
* Determine whether the given listener supports the given event.
* <p>
* The default implementation detects the {@link SmartApplicationListener}
* interface. In case of a standard {@link ApplicationListener}, a
* {@link GenericApplicationListenerAdapter} will be used to introspect the
* generically declared type of the target listener.
*
* @param listener
* the target listener to check
* @param eventType
* the event type to check against
* @param sourceType
* the source type to check against
* @return whether the given listener should be included in the candidates
* for the given event type
*/
protected boolean supportsEvent(ApplicationListener listener, Class<? extends ApplicationEvent> eventType,
Class sourceType)
{
SmartApplicationListener smartListener = (listener instanceof SmartApplicationListener ? (SmartApplicationListener) listener
: new GenericApplicationListenerAdapter(listener));
return (smartListener.supportsEventType(eventType) && smartListener.supportsSourceType(sourceType));
}
/**
* Cache key for ListenerRetrievers, based on event type and source type.
*/
private static class ListenerCacheKey
{
private final Class eventType;
private final Class sourceType;
public ListenerCacheKey(Class eventType, Class sourceType)
{
this.eventType = eventType;
this.sourceType = sourceType;
}
@Override
public boolean equals(Object other)
{
if (this == other)
{
return true;
}
ListenerCacheKey otherKey = (ListenerCacheKey) other;
return (this.eventType.equals(otherKey.eventType) && this.sourceType.equals(otherKey.sourceType));
}
@Override
public int hashCode()
{
return this.eventType.hashCode() * 29 + this.sourceType.hashCode();
}
}
/**
* Helper class that encapsulates a specific set of target listeners,
* allowing for efficient retrieval of pre-filtered listeners.
* <p>
* An instance of this helper gets cached per event type and source type.
*/
private class ListenerRetriever
{
public final Set<ApplicationListener> applicationListeners;
public final Set<String> applicationListenerBeans;
private final boolean preFiltered;
public ListenerRetriever(boolean preFiltered)
{
this.applicationListeners = new LinkedHashSet<ApplicationListener>();
this.applicationListenerBeans = new LinkedHashSet<String>();
this.preFiltered = preFiltered;
}
public Collection<ApplicationListener> getApplicationListeners()
{
LinkedList<ApplicationListener> allListeners = new LinkedList<ApplicationListener>();
if (!this.applicationListenerBeans.isEmpty())
{
BeanFactory beanFactory = getBeanFactory();
for (String listenerBeanName : this.applicationListenerBeans)
{
ApplicationListener listener = beanFactory.getBean(listenerBeanName, ApplicationListener.class);
allListeners.add(listener);
}
}
for (ApplicationListener listener : this.applicationListeners)
{
if (this.preFiltered || !allListeners.contains(listener))
{
allListeners.add(listener);
}
}
OrderComparator.sort(allListeners);
if (log.isDebugEnabled())
{
log.debug(allListeners.toString());
}
return allListeners;
}
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException
{
this.appContext = applicationContext;
}
}