    001    /* ===========================================================
    002     * JFreeChart : a free chart library for the Java(tm) platform
    003     * ===========================================================
    004     *
    005     * (C) Copyright 2000-2005, 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     * DisplayChart.java
    029     * -----------------
    030     * (C) Copyright 2002-2005, by Richard Atkinson and Contributors.
    031     *
    032     * Original Author:  Richard Atkinson;
    033     * Contributor(s):   David Gilbert (for Object Refinery Limited);
    034     *
    035     * $Id: DisplayChart.java,v 1.2.2.1 2005/10/25 20:58:06 mungady Exp $
    036     *
    037     * Changes
    038     * -------
    039     * 19-Aug-2002 : Version 1;
    040     * 09-Mar-2005 : Added facility to serve up "one time" charts - see
    041     *               ServletUtilities.java (DG);
    042     *
    043     */
    044
    045    package org.jfree.chart.servlet;
    046
    047    import java.io.File;
    048    import java.io.IOException;
    049
    050    import javax.servlet.ServletException;
    051    import javax.servlet.http.HttpServlet;
    052    import javax.servlet.http.HttpServletRequest;
    053    import javax.servlet.http.HttpServletResponse;
    054    import javax.servlet.http.HttpSession;
    055
    056    /**
    057     * Servlet used for streaming charts to the client browser from the temporary
    058     * directory.  You need to add this servlet and mapping to your deployment
    059     * descriptor (web.xml) in order to get it to work.  The syntax is as follows:
    060     * <xmp>
    061     * <servlet>
    062     *    <servlet-name>DisplayChart</servlet-name>
    063     *    <servlet-class>org.jfree.chart.servlet.DisplayChart</servlet-class>
    064     * </servlet>
    065     * <servlet-mapping>
    066     *     <servlet-name>DisplayChart</servlet-name>
    067     *     <url-pattern>/servlet/DisplayChart</url-pattern>
    068     * </servlet-mapping>
    069     * </xmp>
    070     *
    071     * @author Richard Atkinson
    072     */
    073    public class DisplayChart extends HttpServlet {
    074
    075        /**
    076         * Default constructor.
    077         */
    078        public DisplayChart() {
    079            super();
    080        }
    081
    082        /**
    083         * Init method.
    084         *
    085         * @throws ServletException never.
    086         */
    087        public void init() throws ServletException {
    088            return;
    089        }
    090
    091        /**
    092         * Service method.
    093         *
    094         * @param request  the request.
    095         * @param response  the response.
    096         *
    097         * @throws ServletException ??.
    098         * @throws IOException ??.
    099         */
    100        public void service(HttpServletRequest request,
    101                            HttpServletResponse response)
    102                throws ServletException, IOException {
    103
    104            HttpSession session = request.getSession();
    105            String filename = request.getParameter("filename");
    106
    107            if (filename == null) {
    108                throw new ServletException("Parameter 'filename' must be supplied");
    109            }
    110
    111            //  Replace ".." with ""
    112            //  This is to prevent access to the rest of the file system
    113            filename = ServletUtilities.searchReplace(filename, "..", "");
    114
    115            //  Check the file exists
    116            File file = new File(System.getProperty("java.io.tmpdir"), filename);
    117            if (!file.exists()) {
    118                throw new ServletException(
    119                    "File '" + file.getAbsolutePath() + "' does not exist"
    120                );
    121            }
    122
    123            //  Check that the graph being served was created by the current user
    124            //  or that it begins with "public"
    125            boolean isChartInUserList = false;
    126            ChartDeleter chartDeleter = (ChartDeleter) session.getAttribute(
    127                "JFreeChart_Deleter"
    128            );
    129            if (chartDeleter != null) {
    130                isChartInUserList = chartDeleter.isChartAvailable(filename);
    131            }
    132
    133            boolean isChartPublic = false;
    134            if (filename.length() >= 6) {
    135                if (filename.substring(0, 6).equals("public")) {
    136                    isChartPublic = true;
    137                }
    138            }
    139
    140            boolean isOneTimeChart = false;
    141            if (filename.startsWith(ServletUtilities.getTempOneTimeFilePrefix())) {
    142                isOneTimeChart = true;
    143            }
    144
    145            if (isChartInUserList || isChartPublic || isOneTimeChart) {
    146                //  Serve it up
    147                ServletUtilities.sendTempFile(file, response);
    148                if (isOneTimeChart) {
    149                    file.delete();
    150                }
    151            }
    152            else {
    153                throw new ServletException("Chart image not found");
    154            }
    155            return;
    156        }
    157
    158    }