    001    /* ===========================================================
    002     * JFreeChart : a free chart library for the Java(tm) platform
    003     * ===========================================================
    004     *
    005     * (C) Copyright 2000-2008, 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 2002-2008, 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
    044    package org.jfree.chart.servlet;
    045
    046    import java.io.File;
    047    import java.io.Serializable;
    048    import java.util.Iterator;
    049    import java.util.List;
    050
    051    import javax.servlet.http.HttpSessionBindingEvent;
    052    import javax.servlet.http.HttpSessionBindingListener;
    053
    054    /**
    055     * Used for deleting charts from the temporary directory when the users session
    056     * expires.
    057     */
    058    public class ChartDeleter implements HttpSessionBindingListener, Serializable {
    059
    060        /** The chart names. */
    061        private List chartNames = new java.util.ArrayList();
    062
    063        /**
    064         * Blank constructor.
    065         */
    066        public ChartDeleter() {
    067            super();
    068        }
    069
    070        /**
    071         * Add a chart to be deleted when the session expires
    072         *
    073         * @param filename  the name of the chart in the temporary directory to be
    074         *                  deleted.
    075         */
    076        public void addChart(String filename) {
    077            this.chartNames.add(filename);
    078        }
    079
    080        /**
    081         * Checks to see if a chart is in the list of charts to be deleted
    082         *
    083         * @param filename  the name of the chart in the temporary directory.
    084         *
    085         * @return A boolean value indicating whether the chart is present in the
    086         *         list.
    087         */
    088        public boolean isChartAvailable(String filename) {
    089            return (this.chartNames.contains(filename));
    090        }
    091
    092        /**
    093         * Binding this object to the session has no additional effects.
    094         *
    095         * @param event  the session bind event.
    096         */
    097        public void valueBound(HttpSessionBindingEvent event) {
    098            return;
    099        }
    100
    101        /**
    102         * When this object is unbound from the session (including upon session
    103         * expiry) the files that have been added to the ArrayList are iterated
    104         * and deleted.
    105         *
    106         * @param event  the session unbind event.
    107         */
    108        public void valueUnbound(HttpSessionBindingEvent event) {
    109
    110            Iterator iter = this.chartNames.listIterator();
    111            while (iter.hasNext()) {
    112                String filename = (String) iter.next();
    113                File file = new File(
    114                    System.getProperty("java.io.tmpdir"), filename
    115                );
    116                if (file.exists()) {
    117                    file.delete();
    118                }
    119            }
    120            return;
    121
    122        }
    123
    124    }