/*
* Copyright 2002-2004 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.avalon.excalibur.monitor.impl;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import org.apache.avalon.excalibur.monitor.Resource;
/**
* A passive monitor will check the reosurce each time it
* is accessed.
*
* @author <a href="mailto:dev@avalon.apache.org">Avalon Development Team</a>
* @version $Revision: 1.5 $ $Date: 2004/02/28 11:47:35 $
*/
public class PassiveMonitor
extends AbstractMonitor
{
private Map m_lastModified = Collections.synchronizedMap( new HashMap() );
/**
* Find a monitored resource. If no resource is available, return null
*/
public final Resource getResource( final String key )
{
final Resource resource = super.getResource( key );
if( resource != null )
{
final Long lastModified = (Long)m_lastModified.get( key );
if( lastModified != null )
{
resource.testModifiedAfter( lastModified.longValue() );
}
m_lastModified.put( key,
new Long( System.currentTimeMillis() ) );
}
return resource;
}
}