/*
============================================================================
The Apache Software License, Version 1.1
============================================================================
Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
Redistribution and use in source and binary forms, with or without modifica-
tion, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
3. The end-user documentation included with the redistribution, if any, must
include the following acknowledgment: "This product includes software
developed by the Apache Software Foundation (http://www.apache.org/)."
Alternately, this acknowledgment may appear in the software itself, if
and wherever such third-party acknowledgments normally appear.
4. The names "Jakarta", "Avalon", "Excalibur" and "Apache Software Foundation"
must not be used to endorse or promote products derived from this software
without prior written permission. For written permission, please contact
apache@apache.org.
5. Products derived from this software may not be called "Apache", nor may
"Apache" appear in their name, without prior written permission of the
Apache Software Foundation.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
This software consists of voluntary contributions made by many individuals
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Apache Software Foundation, please see <http://www.apache.org/>.
*/
package org.apache.avalon.excalibur.monitor.impl;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import org.apache.avalon.excalibur.monitor.Monitor;
import org.apache.avalon.excalibur.monitor.Resource;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
/**
* The AbstractMonitor class is a useful base class which all Monitors
* can extend. The particular monitoring policy is defined by the particular
* implementation.
*
* @author <a href="mailto:bloritsch@apache.org">Berin Loritsch</a>
* @author <a href="mailto:peter at apache.org">Peter Donald</a>
* @version $Id: AbstractMonitor.java,v 1.11 2003/05/23 17:41:04 bloritsch Exp $
*/
public abstract class AbstractMonitor
implements Monitor
{
/**
* The set of resources that the monitor is monitoring.
*/
private Map m_resources = new HashMap();
/**
* Add an array of resources to monitor.
*
* @param resources the resources to monitor
*/
public final void addResources( final Resource[] resources )
{
for( int i = 0; i < resources.length; i++ )
{
addResource( resources[ i ] );
}
}
/**
* Add a resource to monitor. The resource key referenced in the other
* interfaces is derived from the resource object.
*/
public final void addResource( final Resource resource )
{
synchronized( m_resources )
{
final String resourceKey = resource.getResourceKey();
if( m_resources.containsKey( resourceKey ) )
{
final Resource original =
(Resource)m_resources.get( resourceKey );
original.addPropertyChangeListenersFrom( resource );
}
else
{
m_resources.put( resourceKey, resource );
}
}
}
/**
* Find a monitored resource. If no resource is available, return null
*/
public Resource getResource( final String key )
{
synchronized( m_resources )
{
return (Resource)m_resources.get( key );
}
}
/**
* Remove a monitored resource by key.
*/
public final void removeResource( final String key )
{
synchronized( m_resources )
{
final Resource resource =
(Resource)m_resources.remove( key );
resource.removeAllPropertyChangeListeners();
}
}
/**
* Remove a monitored resource by reference.
*/
public final void removeResource( final Resource resource )
{
removeResource( resource.getResourceKey() );
}
/**
* Return an array containing all the resources currently monitored.
*
* @return an array containing all the resources currently monitored.
*/
protected Resource[] getResources()
{
final Collection collection = m_resources.values();
return (Resource[])collection.toArray( new Resource[ collection.size() ] );
}
/**
* Scan through all resources to determine if they have changed.
*/
protected void scanAllResources()
{
final long currentTestTime = System.currentTimeMillis();
final Resource[] resources = getResources();
for( int i = 0; i < resources.length; i++ )
{
resources[ i ].testModifiedAfter( currentTestTime );
}
}
}