/*
* Copyright 1999-2002,2004-2005 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.cocoon.portal.event.impl;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.avalon.framework.activity.Disposable;
import org.apache.avalon.framework.activity.Initializable;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.container.ContainerUtil;
import org.apache.avalon.framework.context.Context;
import org.apache.avalon.framework.context.ContextException;
import org.apache.avalon.framework.context.Contextualizable;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.ServiceSelector;
import org.apache.avalon.framework.service.Serviceable;
import org.apache.avalon.framework.thread.ThreadSafe;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.components.ContextHelper;
import org.apache.cocoon.portal.PortalService;
import org.apache.cocoon.portal.event.Event;
import org.apache.cocoon.portal.event.EventConverter;
import org.apache.cocoon.portal.event.EventManager;
import org.apache.cocoon.portal.event.Publisher;
import org.apache.cocoon.portal.event.Receiver;
import org.apache.cocoon.portal.event.Register;
import org.apache.cocoon.portal.event.Subscriber;
import org.apache.cocoon.portal.event.aspect.EventAspect;
import org.apache.cocoon.util.ClassUtils;
import org.apache.cocoon.util.Deprecation;
/**
* This is the default implementation of the event manager.
*
* @author <a href="mailto:cziegeler@s-und-n.de">Carsten Ziegeler</a>
* @author <a href="mailto:volker.schmitt@basf-it-services.com">Volker Schmitt</a>
*
* @version CVS $Id: DefaultEventManager.java 219049 2005-07-14 15:11:52Z cziegeler $
*/
public class DefaultEventManager
extends AbstractLogEnabled
implements EventManager,
Serviceable,
Initializable,
ThreadSafe,
Configurable,
Disposable,
Contextualizable,
Publisher, Register {
private final String rootEventType = Event.class.getName();
private Class eventClass;
/** The list of all subscribers. */
private List subscribers = new ArrayList();
/** The list of all receivers */
private Map receivers = new HashMap();
private ServiceManager manager;
private Configuration configuration;
protected EventAspectChain chain;
protected ServiceSelector aspectSelector;
protected Context context;
/** The portal service */
protected PortalService service;
/** Introspected receiver classes */
protected Map receiverClasses = new HashMap();
/**
* @see org.apache.avalon.framework.service.Serviceable#service(org.apache.avalon.framework.service.ServiceManager)
*/
public void service(ServiceManager manager) throws ServiceException {
this.manager = manager;
this.service = (PortalService)manager.lookup(PortalService.ROLE);
}
/* (non-Javadoc)
* @see org.apache.cocoon.portal.event.EventManager#getPublisher()
*/
public Publisher getPublisher() {
return this;
}
/* (non-Javadoc)
* @see org.apache.cocoon.portal.event.EventManager#getRegister()
*/
public Register getRegister() {
return this;
}
/**
* Helper method to get the current object model
*/
protected Map getObjectModel() {
return ContextHelper.getObjectModel( this.context );
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.configuration.Configurable#configure(org.apache.avalon.framework.configuration.Configuration)
*/
public void configure(Configuration conf)
throws ConfigurationException {
this.configuration = conf;
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.activity.Disposable#dispose()
*/
public void dispose() {
if (this.manager != null) {
if ( this.chain != null) {
this.chain.dispose( this.aspectSelector );
}
this.manager.release( this.aspectSelector );
this.aspectSelector = null;
this.manager.release(this.service);
this.service = null;
this.manager = null;
}
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.activity.Initializable#initialize()
*/
public void initialize()
throws Exception {
this.eventClass = Class.forName( rootEventType );
if ( this.getLogger().isDebugEnabled() ) {
this.getLogger().debug("Initialising eventClass " + eventClass);
}
// FIXME - the following configuration is not portal specific, it's global!
// subscribe all configured roles
Configuration roles = this.configuration.getChild("subscriber-roles", false);
if ( roles != null ) {
Configuration[] rolesConf = roles.getChildren("role");
for(int i=0; i<rolesConf.length;i++) {
final Configuration current = rolesConf[i];
final String name = current.getAttribute("name");
Subscriber subscriber = null;
try {
subscriber = (Subscriber) this.manager.lookup(name);
Deprecation.logger.warn("Subscriber is deprecated. Please convert the following component to a Receiver: " + subscriber.getClass().getName());
this.subscribe(subscriber);
} finally {
this.manager.release(subscriber);
}
}
}
// subscribe all configured classes
Configuration classes = this.configuration.getChild("subscriber-classes", false);
if ( classes != null ) {
Configuration[] classesConf = classes.getChildren("class");
for(int i=0; i<classesConf.length;i++) {
final Configuration current = classesConf[i];
final String name = current.getAttribute("name");
Deprecation.logger.warn("Subscriber is deprecated. Please convert the following component to a Receiver: " + name);
Subscriber subscriber = (Subscriber) ClassUtils.newInstance(name);
ContainerUtil.enableLogging(subscriber, this.getLogger());
ContainerUtil.contextualize(subscriber, this.context);
ContainerUtil.service(subscriber, this.manager );
ContainerUtil.initialize(subscriber);
this.subscribe(subscriber);
}
}
// subscribe all configured receiver roles
roles = this.configuration.getChild("receiver-roles", false);
if ( roles != null ) {
Configuration[] rolesConf = roles.getChildren("role");
for(int i=0; i<rolesConf.length;i++) {
final Configuration current = rolesConf[i];
final String name = current.getAttribute("name");
Receiver receiver = null;
try {
receiver = (Receiver) this.manager.lookup(name);
this.subscribe(receiver);
} finally {
this.manager.release(receiver);
}
}
}
// subscribe all configured receiver classes
classes = this.configuration.getChild("receiver-classes", false);
if ( classes != null ) {
Configuration[] classesConf = classes.getChildren("class");
for(int i=0; i<classesConf.length;i++) {
final Configuration current = classesConf[i];
final String name = current.getAttribute("name");
Receiver receiver = (Receiver)ClassUtils.newInstance(name);
ContainerUtil.enableLogging(receiver, this.getLogger());
ContainerUtil.contextualize(receiver, this.context);
ContainerUtil.service(receiver, this.manager );
ContainerUtil.initialize(receiver);
this.subscribe(receiver);
}
}
}
/* (non-Javadoc)
* @see org.apache.cocoon.portal.event.Publisher#publish(org.apache.cocoon.portal.event.Event)
*/
public void publish( final Event event ) {
this.send(event);
}
/* (non-Javadoc)
* @see org.apache.cocoon.portal.event.Register#subscribe(org.apache.cocoon.portal.event.Subscriber)
*/
public void subscribe( final Subscriber subscriber ) {
if ( !eventClass.isAssignableFrom( subscriber.getEventType() ) ) {
throw new RuntimeException("Invalid event type " + subscriber.getEventType()
+" for subscriber " + subscriber);
}
if ( getLogger().isDebugEnabled() ) {
getLogger().debug( "Subscribing event " + subscriber.getEventType().getName() );
}
// Add to list but prevent duplicate subscriptions
if ( !subscribers.contains( subscriber ) ) {
subscribers.add( subscriber );
if ( getLogger().isDebugEnabled() ) {
getLogger().debug( "Subscribed Event " + subscriber.getEventType().getName() );
getLogger().debug( "Subscribers now active: " + subscribers.size() );
}
}
}
/* (non-Javadoc)
* @see org.apache.cocoon.portal.event.Register#unsubscribe(org.apache.cocoon.portal.event.Subscriber)
*/
public void unsubscribe( Subscriber subscriber ) {
if ( !eventClass.isAssignableFrom( subscriber.getEventType() ) ) {
throw new RuntimeException("Invalid event type " + subscriber.getEventType()
+" for unsubscribing " + subscriber);
}
if ( subscribers.contains( subscriber ) ) {
subscribers.remove( subscriber );
if ( getLogger().isDebugEnabled() ) {
getLogger().debug( "Unsubscribed Event " + subscriber.getEventType().getName() );
getLogger().debug( "Subscribers now active: " + subscribers.size() );
}
} else {
getLogger().warn( "Subscriber " + subscriber + " not found" );
}
}
/* (non-Javadoc)
* @see org.apache.cocoon.portal.event.EventManager#processEvents()
*/
public void processEvents()
throws ProcessingException {
if ( this.configuration != null ) {
try {
this.aspectSelector = (ServiceSelector) this.manager.lookup( EventAspect.ROLE+"Selector");
this.chain = new EventAspectChain();
this.chain.configure(this.aspectSelector, this.configuration.getChild("event-aspects"));
} catch (ConfigurationException ce) {
throw new ProcessingException("Unable configure component.", ce);
} catch (ServiceException ce) {
throw new ProcessingException("Unable to lookup component.", ce);
}
this.configuration = null;
}
DefaultEventAspectContext context = new DefaultEventAspectContext(this.chain);
EventConverter converter = null;
PortalService service = null;
try {
service = (PortalService)this.manager.lookup(PortalService.ROLE);
converter = (EventConverter) this.manager.lookup(EventConverter.ROLE);
Publisher publisher = this.getPublisher();
converter.start();
// Invoke aspects
context.setEventPublisher( publisher );
context.setObjectModel(this.getObjectModel());
context.setEventConverter(converter);
context.invokeNext( service );
converter.finish();
} catch (ServiceException ce) {
throw new ProcessingException("Unable to lookup component.", ce);
} finally {
this.manager.release(converter);
this.manager.release(service);
}
}
/**
* @see org.apache.avalon.framework.context.Contextualizable#contextualize(org.apache.avalon.framework.context.Context)
*/
public void contextualize(Context context)
throws ContextException {
this.context = context;
}
/**
* @see org.apache.cocoon.portal.event.EventManager#send(org.apache.cocoon.portal.event.Event)
*/
public void send(Event event) {
if ( getLogger().isDebugEnabled() ) {
getLogger().debug("Publishing event " + event.getClass());
}
for ( Iterator e = subscribers.iterator(); e.hasNext(); ){
Subscriber subscriber = (Subscriber)e.next();
if (subscriber.getEventType().isAssignableFrom(event.getClass())
&& (subscriber.getFilter() == null || subscriber.getFilter().filter(event))) {
if ( getLogger().isDebugEnabled() ) {
getLogger().info("Informing subscriber "+subscriber+" of event "+event.getClass());
}
subscriber.inform(event);
}
}
for (Iterator re = receivers.entrySet().iterator(); re.hasNext(); ) {
final Map.Entry current = (Map.Entry)re.next();
final Receiver receiver = (Receiver)current.getKey();
final List methodInfos = (List)current.getValue();
boolean found = false;
final Iterator ci = methodInfos.iterator();
while ( !found && ci.hasNext() ) {
final MethodInfo info = (MethodInfo)ci.next();
if ( info.eventClass.isAssignableFrom(event.getClass()) ) {
if ( getLogger().isDebugEnabled() ) {
getLogger().info("Informing receiver "+receiver+" of event "+event.getClass());
}
try {
info.method.invoke(receiver, new Object[] {event, this.service});
} catch (Exception ignore) {
this.getLogger().warn("Exception during event dispatching on receiver " + receiver
+" and event " + event, ignore);
}
found = true;
}
}
}
}
protected static final class MethodInfo {
public Class eventClass;
public Method method;
}
protected synchronized List introspect(Class receiverClass) {
List result = (List)this.receiverClasses.get(receiverClass.getName());
if ( result == null ) {
result = new ArrayList();
Method[] methods = receiverClass.getMethods();
for(int i=0; i<methods.length; i++ ) {
final Method current = methods[i];
if ( current.getName().equals("inform") ) {
final Class[] params = current.getParameterTypes();
if ( params.length == 2
&& params[1].getName().equals(PortalService.class.getName())) {
if ( eventClass.isAssignableFrom( params[0] ) ) {
MethodInfo info = new MethodInfo();
info.eventClass = params[0];
info.method = current;
result.add(info);
}
}
}
}
if ( result.size() == 0 ) {
result = null;
}
}
return result;
}
/**
* @see org.apache.cocoon.portal.event.EventManager#subscribe(org.apache.cocoon.portal.event.Receiver)
*/
public void subscribe(Receiver receiver) {
List infos = this.introspect(receiver.getClass());
if ( infos == null ) {
throw new RuntimeException("Invalid event receiver type: " + receiver);
}
// Add to list but prevent duplicate subscriptions
List eventClassesForReceiver = (List)this.receivers.get(receiver);
if ( eventClassesForReceiver == null ) {
this.receivers.put(receiver, infos);
}
if ( getLogger().isDebugEnabled() ) {
for(int i=0; i<infos.size();i++) {
getLogger().debug( "Receiver " + receiver + " subscribed for event: " + ((MethodInfo)infos.get(i)).eventClass.getName() );
}
}
}
/**
* @see org.apache.cocoon.portal.event.EventManager#unsubscribe(org.apache.cocoon.portal.event.Receiver)
*/
public void unsubscribe(Receiver receiver) {
if ( getLogger().isDebugEnabled() ) {
getLogger().debug( "Receiver " + receiver + " unsubscribed.");
}
this.receivers.remove(receiver);
}
}