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 * DisplayChart.java
029 * -----------------
030 * (C) Copyright 2002-2008, 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
045package org.jfree.chart.servlet;
046
047import java.io.File;
048import java.io.IOException;
049
050import javax.servlet.ServletException;
051import javax.servlet.http.HttpServlet;
052import javax.servlet.http.HttpServletRequest;
053import javax.servlet.http.HttpServletResponse;
054import 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 */
071public 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}