/*
* Copyright (C) 2005-2009 Alfresco Software Limited.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program 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 General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* As a special exception to the terms and conditions of version 2.0 of
* the GPL, you may redistribute this Program in connection with Free/Libre
* and Open Source Software ("FLOSS") applications as described in Alfresco's
* FLOSS exception. You should have received a copy of the text describing
* the FLOSS exception, and it is also available here:
* http://www.alfresco.com/legal/licensing"
*/
package org.alfresco.repo.management.subsystems;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.util.TreeSet;
import org.springframework.beans.BeansException;
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.ContextRefreshedEvent;
/**
* A default {@link ChildApplicationContextManager} implementation that manages a 'chain' of
* {@link ChildApplicationContextFactory} objects, perhaps corresponding to the components of a chained subsystem such
* as authentication. As with other {@link PropertyBackedBean}s, can be stopped, reconfigured, started and tested. Its
* one special chain
property allows an ordered list of {@link ChildApplicationContextFactory} objects to
* be managed. This property is a comma separated list with the format:
*
* - <id1>:<typeName1>,<id2>:<typeName2>,...,<idn>:<typeNamen>
*
* See {@link ChildApplicationContextManager} for the meanings of <id> and <typeName>. In the enterprise edition,
* this property is editable at runtime via JMX. If a new <id> is included in the list then a new
* {@link ChildApplicationContextFactory} will be brought into existence. Similarly, if one is removed from the list,
* then the corresponding instance will be destroyed. For Alfresco community edition, the chain is best configured
* through the {@link #setDefaultChain(String)} method via Spring configuration.
*
* @author dward
*/
public class DefaultChildApplicationContextManager extends AbstractPropertyBackedBean implements
ApplicationContextAware, ApplicationListener, ChildApplicationContextManager
{
/** The name of the special property that holds the ordering of child instance names. */
private static final String ORDER_PROPERTY = "chain";
/** The parent. */
private ApplicationContext parent;
/** The default type name. */
private String defaultTypeName;
/** The default chain. */
private String defaultChain;
/** The instance ids. */
private List instanceIds = new ArrayList(10);
/** The child application contexts. */
private Map childApplicationContexts = new TreeMap();
/** The auto start. */
private boolean autoStart;
/**
* Instantiates a new default child application context manager.
*/
public DefaultChildApplicationContextManager()
{
setId("manager");
}
/*
* (non-Javadoc)
* @see org.springframework.context.ApplicationContextAware#setApplicationContext(org.springframework.context.
* ApplicationContext)
*/
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException
{
this.parent = applicationContext;
}
/**
* Sets the default type name. This is used when a type name is not included after an instance ID in a chain string.
*
* @param defaultTypeName
* the new default type name
*/
public void setDefaultTypeName(String defaultTypeName)
{
this.defaultTypeName = defaultTypeName;
}
/**
* Configures the default chain of {@link ChildApplicationContextFactory} instances. May be set on initialization by
* the Spring container.
*
* @param defaultChain
* a comma separated list in the following format:
*
* - <id1>:<typeName1>,<id2>:<typeName2>,...,<idn>:<typeNamen>
*
*/
public void setDefaultChain(String defaultChain)
{
this.defaultChain = defaultChain;
}
/**
* Indicates whether all child application contexts should be started on startup of the parent application context.
*
* @param autoStart
* true
if all child application contexts should be started on startup of the parent
* application context
*/
public void setAutoStart(boolean autoStart)
{
this.autoStart = autoStart;
}
/*
* (non-Javadoc)
* @see org.alfresco.repo.management.subsystems.AbstractPropertyBackedBean#afterPropertiesSet()
*/
@Override
public void afterPropertiesSet() throws Exception
{
if (this.defaultChain != null && this.defaultChain.length() > 0)
{
// Use the first type as the default, unless one is specified explicitly
if (this.defaultTypeName == null)
{
updateOrder(this.defaultChain, AbstractPropertyBackedBean.DEFAULT_ID);
this.defaultTypeName = this.childApplicationContexts.get(this.instanceIds.get(0)).getTypeName();
}
else
{
updateOrder(this.defaultChain, this.defaultTypeName);
}
}
else if (this.defaultTypeName == null)
{
setDefaultTypeName(AbstractPropertyBackedBean.DEFAULT_ID);
}
super.afterPropertiesSet();
}
/*
* (non-Javadoc)
* @see org.alfresco.repo.management.subsystems.PropertyBackedBean#start()
*/
public void start()
{
// Nothing to do
}
/*
* (non-Javadoc)
* @see org.alfresco.repo.management.subsystems.PropertyBackedBean#stop()
*/
public void stop()
{
// Nothing to do
}
/*
* (non-Javadoc)
* @see org.alfresco.repo.management.subsystems.AbstractPropertyBackedBean#destroy(boolean)
*/
@Override
public void destroy(boolean permanent)
{
super.destroy(permanent);
// Cascade the destroy / shutdown
for (String id : this.instanceIds)
{
ChildApplicationContextFactory factory = this.childApplicationContexts.get(id);
factory.destroy(permanent);
}
}
/*
* (non-Javadoc)
* @see org.alfresco.repo.management.subsystems.PropertyBackedBean#getProperty(java.lang.String)
*/
public synchronized String getProperty(String name)
{
if (!name.equals(DefaultChildApplicationContextManager.ORDER_PROPERTY))
{
return null;
}
return getOrderString();
}
/*
* (non-Javadoc)
* @see org.alfresco.repo.management.subsystems.PropertyBackedBean#getPropertyNames()
*/
public Set getPropertyNames()
{
return Collections.singleton(DefaultChildApplicationContextManager.ORDER_PROPERTY);
}
/*
* (non-Javadoc)
* @see org.alfresco.repo.management.subsystems.PropertyBackedBean#setProperty(java.lang.String, java.lang.String)
*/
public synchronized void setProperty(String name, String value)
{
if (!name.equals(DefaultChildApplicationContextManager.ORDER_PROPERTY))
{
throw new IllegalStateException("Illegal attempt to write to property \"" + name + "\"");
}
updateOrder(value, this.defaultTypeName);
}
/*
* (non-Javadoc)
* @see org.alfresco.repo.management.ChildApplicationContextManager#getInstanceIds()
*/
public synchronized Collection getInstanceIds()
{
return Collections.unmodifiableList(this.instanceIds);
}
/*
* (non-Javadoc)
* @see org.alfresco.repo.management.ChildApplicationContextManager#getApplicationContext(java.lang.String)
*/
public synchronized ApplicationContext getApplicationContext(String id)
{
ChildApplicationContextFactory child = this.childApplicationContexts.get(id);
return child == null ? null : child.getApplicationContext();
}
/*
* (non-Javadoc)
* @see
* org.springframework.context.ApplicationListener#onApplicationEvent(org.springframework.context.ApplicationEvent)
*/
public void onApplicationEvent(ApplicationEvent event)
{
if (this.autoStart && event instanceof ContextRefreshedEvent && event.getSource() == this.parent)
{
for (String instance : getInstanceIds())
{
getApplicationContext(instance);
}
}
}
/**
* Gets the order string.
*
* @return the order string
*/
private String getOrderString()
{
StringBuilder orderString = new StringBuilder(100);
for (String id : this.instanceIds)
{
if (orderString.length() > 0)
{
orderString.append(",");
}
orderString.append(id).append(':').append(this.childApplicationContexts.get(id).getTypeName());
}
return orderString.toString();
}
/**
* Updates the order from a comma or whitespace separated string.
*
* @param orderString
* the order as a comma or whitespace separated string
* @param defaultTypeName
* the default type name
*/
private void updateOrder(String orderString, String defaultTypeName)
{
try
{
StringTokenizer tkn = new StringTokenizer(orderString, ", \t\n\r\f");
List newInstanceIds = new ArrayList(tkn.countTokens());
while (tkn.hasMoreTokens())
{
String instance = tkn.nextToken();
int sepIndex = instance.indexOf(':');
String id = sepIndex == -1 ? instance : instance.substring(0, sepIndex);
String typeName = sepIndex == -1 || sepIndex + 1 >= instance.length() ? defaultTypeName : instance
.substring(sepIndex + 1);
newInstanceIds.add(id);
// Look out for new or updated children
ChildApplicationContextFactory factory = this.childApplicationContexts.get(id);
// If we have the same instance ID but a different type, treat that as a destroy and remove
if (factory != null && !factory.getTypeName().equals(typeName))
{
factory.destroy(true);
factory = null;
}
if (factory == null)
{
this.childApplicationContexts.put(id, new ChildApplicationContextFactory(this.parent,
getRegistry(), getCategory(), typeName, "managed$" + id));
}
}
// Destroy any children that have been removed
Set idsToRemove = new TreeSet(this.childApplicationContexts.keySet());
idsToRemove.removeAll(newInstanceIds);
for (String id : idsToRemove)
{
ChildApplicationContextFactory factory = this.childApplicationContexts.remove(id);
factory.destroy(true);
}
this.instanceIds = newInstanceIds;
}
catch (RuntimeException e)
{
throw e;
}
catch (Exception e)
{
throw new RuntimeException(e);
}
}
}