001 /*
002 Licensed to the Apache Software Foundation (ASF) under one
003 or more contributor license agreements. See the NOTICE file
004 distributed with this work for additional information
005 regarding copyright ownership. The ASF licenses this file
006 to you under the Apache License, Version 2.0 (the
007 "License"); you may not use this file except in compliance
008 with the License. You may obtain a copy of the License at
009
010 http://www.apache.org/licenses/LICENSE-2.0
011
012 Unless required by applicable law or agreed to in writing,
013 software distributed under the License is distributed on an
014 "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 KIND, either express or implied. See the License for the
016 specific language governing permissions and limitations
017 under the License.
018 */
019 package org.apache.wiki.rss;
020
021
022 import java.io.BufferedWriter;
023 import java.io.File;
024 import java.io.FileOutputStream;
025 import java.io.IOException;
026 import java.io.OutputStreamWriter;
027 import java.io.Reader;
028 import java.io.StringReader;
029 import java.io.Writer;
030
031 import org.apache.log4j.Logger;
032 import org.apache.wiki.WatchDog;
033 import org.apache.wiki.WikiBackgroundThread;
034 import org.apache.wiki.WikiEngine;
035 import org.apache.wiki.util.FileUtil;
036
037 /**
038 * Runs the RSS generation thread.
039 * FIXME: MUST be somewhere else, this is not a good place.
040 */
041 public class RSSThread extends WikiBackgroundThread
042 {
043 static Logger log = Logger.getLogger( RSSThread.class );
044
045 private final File m_rssFile;
046 private final RSSGenerator m_generator;
047
048 private WatchDog m_watchdog;
049
050 /**
051 * Create a new RSS thread.
052 *
053 * @param engine A WikiEngine to own this thread.
054 * @param rssFile A File to write the RSS data to.
055 * @param rssInterval How often the RSS should be generated.
056 */
057 public RSSThread( WikiEngine engine, File rssFile, int rssInterval )
058 {
059 super( engine, rssInterval );
060 m_generator = engine.getRSSGenerator();
061 m_rssFile = rssFile;
062 setName("JSPWiki RSS Generator");
063 log.debug( "RSS file will be at "+m_rssFile.getAbsolutePath() );
064 log.debug( "RSS refresh interval (seconds): "+rssInterval );
065 }
066
067 /**
068 * {@inheritDoc}
069 */
070 @Override
071 public void startupTask() throws Exception
072 {
073 m_watchdog = getEngine().getCurrentWatchDog();
074 }
075
076 /**
077 * Runs the RSS generator thread.
078 * If a previous RSS generation operation encountered a
079 * file I/O or other error, this method will turn off generation.
080 * <code>false</code>.
081 * @see java.lang.Thread#run()
082 * @throws Exception All exceptions are thrown upwards.
083 */
084 @Override
085 public void backgroundTask() throws Exception
086 {
087 if ( m_generator.isEnabled() )
088 {
089 Writer out = null;
090 Reader in = null;
091
092 m_watchdog.enterState( "Generating RSS feed", 60 );
093
094 try
095 {
096 //
097 // Generate RSS file, output it to
098 // default "rss.rdf".
099 //
100 log.debug("Regenerating RSS feed to "+m_rssFile);
101
102 String feed = m_generator.generate();
103
104 in = new StringReader(feed);
105 out = new BufferedWriter( new OutputStreamWriter( new FileOutputStream( m_rssFile ), "UTF-8") );
106
107 FileUtil.copyContents( in, out );
108 }
109 catch( IOException e )
110 {
111 log.error("Cannot generate RSS feed to "+m_rssFile.getAbsolutePath(), e );
112 m_generator.setEnabled( false );
113 }
114 finally
115 {
116 try
117 {
118 if( in != null ) in.close();
119 if( out != null ) out.close();
120 }
121 catch( IOException e )
122 {
123 log.fatal("Could not close I/O for RSS", e );
124 m_generator.setEnabled( false );
125 }
126 m_watchdog.exitState();
127 }
128
129 }
130 }
131
132 }