001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert 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 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * -----------------
028 * ChartDeleter.java
029 * -----------------
030  * (C) Copyright 2002-present, by Richard Atkinson and Contributors.
031 *
032 * Original Author:  Richard Atkinson;
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.chart.servlet;
038
039import java.io.File;
040import java.io.Serializable;
041import java.util.Iterator;
042import java.util.List;
043
044import javax.servlet.http.HttpSessionBindingEvent;
045import javax.servlet.http.HttpSessionBindingListener;
046
047/**
048 * Used for deleting charts from the temporary directory when the users session
049 * expires.
050 */
051public class ChartDeleter implements HttpSessionBindingListener, Serializable {
052
053    /** The chart names. */
054    private final List chartNames = new java.util.ArrayList();
055
056    /**
057     * Blank constructor.
058     */
059    public ChartDeleter() {
060        super();
061    }
062
063    /**
064     * Add a chart to be deleted when the session expires
065     *
066     * @param filename  the name of the chart in the temporary directory to be
067     *                  deleted.
068     */
069    public void addChart(String filename) {
070        this.chartNames.add(filename);
071    }
072
073    /**
074     * Checks to see if a chart is in the list of charts to be deleted
075     *
076     * @param filename  the name of the chart in the temporary directory.
077     *
078     * @return A boolean value indicating whether the chart is present in the
079     *         list.
080     */
081    public boolean isChartAvailable(String filename) {
082        return (this.chartNames.contains(filename));
083    }
084
085    /**
086     * Binding this object to the session has no additional effects.
087     *
088     * @param event  the session bind event.
089     */
090    @Override
091    public void valueBound(HttpSessionBindingEvent event) {
092        // nothing to do
093    }
094
095    /**
096     * When this object is unbound from the session (including upon session
097     * expiry) the files that have been added to the ArrayList are iterated
098     * and deleted.
099     *
100     * @param event  the session unbind event.
101     */
102    @Override
103    public void valueUnbound(HttpSessionBindingEvent event) {
104        Iterator iter = this.chartNames.listIterator();
105        while (iter.hasNext()) {
106            String filename = (String) iter.next();
107            File file = new File(
108                System.getProperty("java.io.tmpdir"), filename
109            );
110            if (file.exists()) {
111                file.delete();
112            }
113        }
114    }
115
116}