/*
* JBoss, Home of Professional Open Source.
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This 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 2.1 of
* the License, or (at your option) any later version.
*
* This software 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 this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.mx.notification;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import javax.management.Notification;
import javax.management.NotificationListener;
import javax.management.ObjectName;
/**
* A notification listener used to forward notifications to listeners
* added through the mbean server.<p>
*
* The original source is replaced with the object name.
*
* @author <a href="mailto:Adrian.Brock@HappeningTimes.com">Adrian Brock</a>.
* @author <a href="mailto:telrod@e2technologies.net">Tom Elrod</a>.
* @version $Revision: 81022 $
*/
public class NotificationListenerProxy
implements InvocationHandler
{
// Constants ---------------------------------------------------
// Attributes --------------------------------------------------
/**
* The original listener
*/
private NotificationListener listener;
/**
* The object name we are proxying
*/
private ObjectName name;
/**
* The implementation method for NotificationListener
* that we want to intercept so that we can set the source
* of the Notification object.
*/
private static final String METHODNAME = "handleNotification";
/**
* Calculated hascode
*/
private final Integer hashCode;
// Static ------------------------------------------------------
public static Object newInstance(ObjectName name,
NotificationListener listener)
{
// Using set so don't have interface duplicates (which shouldn't happen anyways)
java.util.HashSet set = new java.util.HashSet();
// Walk the class heirarchy tree and get all interfaces.
Class currentClass = listener.getClass();
while(currentClass != null)
{
Class[] classInterfaces = currentClass.getInterfaces();
for(int i = 0; i < classInterfaces.length; i++)
{
set.add(classInterfaces[i]);
}
currentClass = currentClass.getSuperclass();
}
Class[] interfaces = new Class[set.size()];
interfaces = (Class[])set.toArray(interfaces);
return Proxy.newProxyInstance(listener.getClass().getClassLoader(),
interfaces,
new NotificationListenerProxy(name, listener));
}
// Constructors ------------------------------------------------
/**
* Create a new Notification Listener Proxy
*
* @param name the object name
* @param listener the original listener
*/
public NotificationListenerProxy(ObjectName name,
NotificationListener listener)
{
this.name = name;
this.listener = listener;
this.hashCode = new Integer(System.identityHashCode(this));
// Could add code to set the METHODNAME variable based
// on the method signature names from the actual listener
// interface passed (which would be done dynamically so would
// not be hard-coded), in case the NotificationListener
// method signature changes.
}
// Public ------------------------------------------------------
// implementation InvocationHandler
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable
{
String localMethodName = method.getName();
// check to see if calling handleNotification() method
if(localMethodName.equals(METHODNAME))
{
for(int x = 0; x < args.length; x++)
{
if(args[x] instanceof Notification)
{
// Forward the notification with the object name as source
// FIXME: This overwrites the original source, there is no way
// to put it back with the current spec
((Notification)args[x]).setSource(name);
}
}
}
else if (localMethodName.equals("hashCode"))
{
return proxyHashCode(proxy);
}
else if (localMethodName.equals("equals"))
{
return proxyEquals(proxy, args[0]);
}
else if (localMethodName.equals("toString"))
{
return proxyToString(proxy);
}
return method.invoke(listener, args);
}
protected Integer proxyHashCode(Object proxy)
{
return this.hashCode;
}
protected Boolean proxyEquals(Object proxy, Object other)
{
return (proxy == other ? Boolean.TRUE : Boolean.FALSE);
}
protected String proxyToString(Object proxy)
{
return proxy.getClass().getName() + '@' + Integer.toHexString(proxy.hashCode());
}
// overrides ---------------------------------------------------
// Protected ---------------------------------------------------
// Private -----------------------------------------------------
// Inner classes -----------------------------------------------
}