URLRefresher xref

This project has retired. For details please refer to its Attic page.
URLRefresher xref

1   /*
2    * Copyright 2000-2004 The Apache Software Foundation.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.apache.jetspeed.daemon.impl.util.diskcachedaemon;
18  
19  //jetspeed stuff
20  import org.apache.jetspeed.om.registry.PortletEntry;
21  import org.apache.jetspeed.services.logging.JetspeedLogFactoryService;
22  import org.apache.jetspeed.services.logging.JetspeedLogger;
23  import org.apache.jetspeed.services.Registry;
24  import org.apache.jetspeed.services.urlmanager.URLFetcher;
25  
26  //Java stuff
27  import java.util.Enumeration;
28  
29  /***
30  <p>
31  URLRefresher that checks if a URL is updated remotely.  If it is then it will
32  pull the new URL down and try to reinstantiate all Portlets that depend on this
33  URL.
34  </p>
35  
36  @author <A HREF="mailto:burton@apache.org">Kevin A. Burton</A>
37  @version $Id: URLRefresher.java,v 1.16 2004/02/23 02:47:00 jford Exp $
38  */
39  public class URLRefresher implements Runnable {
40  
41      private String url = null;
42      
43      /***
44       * Static initialization of the logger for this class
45       */
46      private static final JetspeedLogger logger = JetspeedLogFactoryService.getLogger(URLRefresher.class.getName());
47      
48      /***
49      default constructor
50      */
51      public URLRefresher( String url ) {
52          
53          this.url = url;
54          
55      }
56      
57      /***
58      Used within the ThreadPool... IE Runnable interface.
59      */
60      public void run() {
61          
62          try {
63  
64              //only update this if the URL on which it is based is newer 
65              //than the one on disk.
66              if(URLFetcher.refresh(url)) {
67                  //now make sure that the entry that depends on this HREF
68                  //is updated in the PortletFactory.
69                  
70                  
71                  //create a Runnable for updating this Portlet in the cache.
72                      
73                  Enumeration enum = Registry.get(Registry.PORTLET).getEntries();
74                      
75                  while( enum.hasMoreElements() ) {
76                      PortletEntry entry = (PortletEntry)enum.nextElement();
77                      
78                      if ( (entry.getURL()!= null) && entry.getURL().equals(url) )
79                      {
80                          try
81                          {
82                              PortletRefresher pr = new PortletRefresher( entry );
83                          
84                              //now put this Instantiator in the ThreadPool so that 
85                              //it can execute.
86                              //SGP Trying to intersperse CPU intensive tasks with
87                              // network intensive tasks
88                              pr.run();
89                              //ThreadPool.process( pr );
90                          }
91                          catch (Throwable t)
92                          {
93                              //FIXME: Put it in the bad URL list
94                              logger.info( "DiskCacheDaemon: Error refreshing: " + url ); 
95                          }
96                      }
97                  }
98              }
99          } catch ( Throwable t ) {
100             logger.error("Error refreshing URL", t);
101         }
102     }
103 }