    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     * DisplayChart.java
    029     * -----------------
    030     * (C) Copyright 2002-2007, by Richard Atkinson and Contributors.
    031     *
    032     * Original Author:  Richard Atkinson;
    033     * Contributor(s):   David Gilbert (for Object Refinery Limited);
    034     *
    035     * Changes
    036     * -------
    037     * 19-Aug-2002 : Version 1;
    038     * 09-Mar-2005 : Added facility to serve up "one time" charts - see
    039     *               ServletUtilities.java (DG);
    040     * ------------- JFREECHART 1.0.x ---------------------------------------------
    041     * 02-Feb-2007 : Removed author tags all over JFreeChart sources (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    public class DisplayChart extends HttpServlet {
    072
    073        /**
    074         * Default constructor.
    075         */
    076        public DisplayChart() {
    077            super();
    078        }
    079
    080        /**
    081         * Init method.
    082         *
    083         * @throws ServletException never.
    084         */
    085        public void init() throws ServletException {
    086            return;
    087        }
    088
    089        /**
    090         * Service method.
    091         *
    092         * @param request  the request.
    093         * @param response  the response.
    094         *
    095         * @throws ServletException ??.
    096         * @throws IOException ??.
    097         */
    098        public void service(HttpServletRequest request,
    099                            HttpServletResponse response)
    100                throws ServletException, IOException {
    101
    102            HttpSession session = request.getSession();
    103            String filename = request.getParameter("filename");
    104
    105            if (filename == null) {
    106                throw new ServletException("Parameter 'filename' must be supplied");
    107            }
    108
    109            //  Replace ".." with ""
    110            //  This is to prevent access to the rest of the file system
    111            filename = ServletUtilities.searchReplace(filename, "..", "");
    112
    113            //  Check the file exists
    114            File file = new File(System.getProperty("java.io.tmpdir"), filename);
    115            if (!file.exists()) {
    116                throw new ServletException("File '" + file.getAbsolutePath()
    117                        + "' does not exist");
    118            }
    119
    120            //  Check that the graph being served was created by the current user
    121            //  or that it begins with "public"
    122            boolean isChartInUserList = false;
    123            ChartDeleter chartDeleter = (ChartDeleter) session.getAttribute(
    124                    "JFreeChart_Deleter");
    125            if (chartDeleter != null) {
    126                isChartInUserList = chartDeleter.isChartAvailable(filename);
    127            }
    128
    129            boolean isChartPublic = false;
    130            if (filename.length() >= 6) {
    131                if (filename.substring(0, 6).equals("public")) {
    132                    isChartPublic = true;
    133                }
    134            }
    135
    136            boolean isOneTimeChart = false;
    137            if (filename.startsWith(ServletUtilities.getTempOneTimeFilePrefix())) {
    138                isOneTimeChart = true;
    139            }
    140
    141            if (isChartInUserList || isChartPublic || isOneTimeChart) {
    142                //  Serve it up
    143                ServletUtilities.sendTempFile(file, response);
    144                if (isOneTimeChart) {
    145                    file.delete();
    146                }
    147            }
    148            else {
    149                throw new ServletException("Chart image not found");
    150            }
    151            return;
    152        }
    153
    154    }