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     * $Id: DisplayChart.java,v 1.2.2.3 2007/02/02 15:03:19 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     * ------------- JFREECHART 1.0.x ---------------------------------------------
043     * 02-Feb-2007 : Removed author tags all over JFreeChart sources (DG);
044     *
045     */
046    
047    package org.jfree.chart.servlet;
048    
049    import java.io.File;
050    import java.io.IOException;
051    
052    import javax.servlet.ServletException;
053    import javax.servlet.http.HttpServlet;
054    import javax.servlet.http.HttpServletRequest;
055    import javax.servlet.http.HttpServletResponse;
056    import javax.servlet.http.HttpSession;
057    
058    /**
059     * Servlet used for streaming charts to the client browser from the temporary
060     * directory.  You need to add this servlet and mapping to your deployment 
061     * descriptor (web.xml) in order to get it to work.  The syntax is as follows:
062     * <xmp>
063     * <servlet>
064     *    <servlet-name>DisplayChart</servlet-name>
065     *    <servlet-class>org.jfree.chart.servlet.DisplayChart</servlet-class>
066     * </servlet>
067     * <servlet-mapping>
068     *     <servlet-name>DisplayChart</servlet-name>
069     *     <url-pattern>/servlet/DisplayChart</url-pattern>
070     * </servlet-mapping>
071     * </xmp>
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("File '" + file.getAbsolutePath() 
119                        + "' does not exist");
120            }
121    
122            //  Check that the graph being served was created by the current user
123            //  or that it begins with "public"
124            boolean isChartInUserList = false;
125            ChartDeleter chartDeleter = (ChartDeleter) session.getAttribute(
126                    "JFreeChart_Deleter");
127            if (chartDeleter != null) {
128                isChartInUserList = chartDeleter.isChartAvailable(filename);
129            }
130    
131            boolean isChartPublic = false;
132            if (filename.length() >= 6) {
133                if (filename.substring(0, 6).equals("public")) {
134                    isChartPublic = true;
135                }
136            }
137            
138            boolean isOneTimeChart = false;
139            if (filename.startsWith(ServletUtilities.getTempOneTimeFilePrefix())) {
140                isOneTimeChart = true;   
141            }
142    
143            if (isChartInUserList || isChartPublic || isOneTimeChart) {
144                //  Serve it up
145                ServletUtilities.sendTempFile(file, response);
146                if (isOneTimeChart) {
147                    file.delete();   
148                }
149            }
150            else {
151                throw new ServletException("Chart image not found");
152            }
153            return;
154        }
155    
156    }