urlrefresher.java

来自「jetspeed源代码」· Java 代码 · 共 104 行

/*
 * Copyright 2000-2004 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.jetspeed.daemon.impl.util.diskcachedaemon;

//jetspeed stuff
import org.apache.jetspeed.om.registry.PortletEntry;
import org.apache.jetspeed.services.logging.JetspeedLogFactoryService;
import org.apache.jetspeed.services.logging.JetspeedLogger;
import org.apache.jetspeed.services.Registry;
import org.apache.jetspeed.services.urlmanager.URLFetcher;

//Java stuff
import java.util.Enumeration;

/**
<p>
URLRefresher that checks if a URL is updated remotely.  If it is then it will
pull the new URL down and try to reinstantiate all Portlets that depend on this
URL.
</p>

@author <A HREF="mailto:[e-mail]">Kevin A. Burton</A>
@version $Id: URLRefresher.java,v 1.16 2004/02/23 02:47:00 jford Exp $
*/
public class URLRefresher implements Runnable {

    private String url = null;
    
    /**
     * Static initialization of the logger for this class
     */
    private static final JetspeedLogger logger = JetspeedLogFactoryService.getLogger(URLRefresher.class.getName());
    
    /**
    default constructor
    */
    public URLRefresher( String url ) {
        
        this.url = url;
        
    }
    
    /**
    Used within the ThreadPool... IE Runnable interface.
    */
    public void run() {
        
        try {

            //only update this if the URL on which it is based is newer 
            //than the one on disk.
            if(URLFetcher.refresh(url)) {
                //now make sure that the entry that depends on this HREF
                //is updated in the PortletFactory.
                
                
                //create a Runnable for updating this Portlet in the cache.
                    
                Enumeration enum = Registry.get(Registry.PORTLET).getEntries();
                    
                while( enum.hasMoreElements() ) {
                    PortletEntry entry = (PortletEntry)enum.nextElement();
                    
                    if ( (entry.getURL()!= null) && entry.getURL().equals(url) )
                    {
                        try
                        {
                            PortletRefresher pr = new PortletRefresher( entry );
                        
                            //now put this Instantiator in the ThreadPool so that 
                            //it can execute.
                            //SGP Trying to intersperse CPU intensive tasks with
                            // network intensive tasks
                            pr.run();
                            //ThreadPool.process( pr );
                        }
                        catch (Throwable t)
                        {
                            //FIXME: Put it in the bad URL list
                            logger.info( "DiskCacheDaemon: Error refreshing: " + url ); 
                        }
                    }
                }
            }
        } catch ( Throwable t ) {
            logger.error("Error refreshing URL", t);
        }
    }
}