001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
006     *
007     * Project Info:  http://www.jfree.org/jfreechart/index.html
008     *
009     * This library is free software; you can redistribute it and/or modify it 
010     * under the terms of the GNU Lesser General Public License as published by 
011     * the Free Software Foundation; either version 2.1 of the License, or 
012     * (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but 
015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
017     * License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this library; if not, write to the Free Software
021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
022     * USA.  
023     *
024     * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
025     * in the United States and other countries.]
026     *
027     * -----------------
028     * ChartDeleter.java
029     * -----------------
030      * (C) Copyright 2002-2007, by Richard Atkinson and Contributors.
031     *
032     * Original Author:  Richard Atkinson;
033     * Contributor(s):   -;
034     *
035     * Changes
036     * -------
037     * 19-Aug-2002 : Version 1;
038     * 17-Oct-2002 : Fixed errors reported by Checkstyle (DG);
039     * ------------- JFREECHART 1.0.x ---------------------------------------------
040     * 02-Feb-2007 : Removed author tags all over JFreeChart sources (DG);
041     *
042     */
043    package org.jfree.chart.servlet;
044    
045    import java.io.File;
046    import java.io.Serializable;
047    import java.util.Iterator;
048    import java.util.List;
049    
050    import javax.servlet.http.HttpSessionBindingEvent;
051    import javax.servlet.http.HttpSessionBindingListener;
052    
053    /**
054     * Used for deleting charts from the temporary directory when the users session
055     * expires.
056     */
057    public class ChartDeleter implements HttpSessionBindingListener, Serializable {
058    
059        /** The chart names. */
060        private List chartNames = new java.util.ArrayList();
061    
062        /**
063         * Blank constructor.
064         */
065        public ChartDeleter() {
066            super();
067        }
068    
069        /**
070         * Add a chart to be deleted when the session expires
071         *
072         * @param filename  the name of the chart in the temporary directory to be 
073         *                  deleted.
074         */
075        public void addChart(String filename) {
076            this.chartNames.add(filename);
077        }
078    
079        /**
080         * Checks to see if a chart is in the list of charts to be deleted
081         *
082         * @param filename  the name of the chart in the temporary directory.
083         *
084         * @return A boolean value indicating whether the chart is present in the 
085         *         list.
086         */
087        public boolean isChartAvailable(String filename) {
088            return (this.chartNames.contains(filename));
089        }
090    
091        /**
092         * Binding this object to the session has no additional effects.
093         *
094         * @param event  the session bind event.
095         */
096        public void valueBound(HttpSessionBindingEvent event) {
097            return;
098        }
099    
100        /**
101         * When this object is unbound from the session (including upon session
102         * expiry) the files that have been added to the ArrayList are iterated
103         * and deleted.
104         *
105         * @param event  the session unbind event.
106         */
107        public void valueUnbound(HttpSessionBindingEvent event) {
108    
109            Iterator iter = this.chartNames.listIterator();
110            while (iter.hasNext()) {
111                String filename = (String) iter.next();
112                File file = new File(
113                    System.getProperty("java.io.tmpdir"), filename
114                );
115                if (file.exists()) {
116                    file.delete();
117                }
118            }
119            return;
120    
121        }
122    
123    }