    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    }