FileServlet


1   /*
2    * FileServlet is part of the Cofax content management system library.
3    *
4    * This library is free software; you can redistribute it and/or
5    * modify it under the terms of the GNU Lesser General Public
6    * License as published by the Free Software Foundation; either
7    * version 2.1 of the License, or (at your option) any later version.
8    *
9    * This library is distributed in the hope that it will be useful,
10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   * Lesser General Public License for more details.
13   * 
14   * You should have received a copy of the GNU Lesser General Public
15   * License along with this library; if not, write to the Free Software
16   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
17   *
18   * Please see http://www.cofax.org for contact information and other related informaion.
19   * 
20   * $Header: /cvsroot/cofax/cofax/src/org/cofax/cds/FileServlet.java,v 1.4.2.1 2006/12/11 16:19:29 fxrobin Exp $
21   */
22  
23  package org.cofax.cds;
24  
25  import java.io.*;
26  import java.util.*;
27  import java.text.*;
28  import javax.servlet.*;
29  import javax.servlet.http.*;
30  
31  /**
32   * A simple servlet for dynamically returning static files.
33   * 
34   * @author kmartino
35   * @created April 22, 2002
36   */
37  public class FileServlet extends HttpServlet {
38  
39      /**
40       * Returns a string containing information about the author, version, and
41       * copyright of the servlet.
42       * 
43       * @return The servletInfo value
44       */
45      public String   getServletInfo() {
46          return "servlet similar to a standard httpd";
47      }
48  
49      /**
50       * Services a single request from the client.
51       * 
52       * @param req
53       *            the servlet request
54       * @param res
55       *            Description of the Parameter
56       * @exception ServletException
57       *                when an exception has occurred
58       * @exception IOException
59       *                Description of the Exception
60       */
61      public void service(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
62  
63          boolean headOnly;
64  
65          if (req.getMethod().equalsIgnoreCase("get")) {
66              headOnly = false;
67          } else if (!req.getMethod().equalsIgnoreCase("head")) {
68              headOnly = true;
69          } else {
70              res.sendError(HttpServletResponse.SC_NOT_IMPLEMENTED);
71              return;
72          }
73  
74          // FX : to change file name delivery
75          // 29/03/2006
76  
77          String   path = req.getRequestURI();
78          String   pathInfo = req.getPathInfo();
79  
80          String   aliasPattern = "/_alias_/";
81  
82          if (path != null && path.indexOf(aliasPattern) > 0) {
83  
84              CDSServlet.cofaxLog("this is an alias file : " + path);
85              path = path.replaceAll(aliasPattern, "/");
86              String   reste = path;
87  
88              CDSServlet.cofaxLog("removing alias part : " + reste);
89  
90              int i = reste.lastIndexOf("/");
91              String   filename = reste.substring(i + 1);
92              reste = reste.substring(0, i);
93  
94              CDSServlet.cofaxLog("got the filename : " + filename + " - rest : " + reste);
95  
96              /*
97               * i = reste.lastIndexOf("/"); String extension =
98               * reste.substring(i+1); reste = reste.substring(0,i);
99               * 
100              * 
101              * CDSServlet.cofaxLog("got the extension : "+ extension + " - rest : " +
102              * reste);
103              */
104 
105             i = reste.lastIndexOf("/");
106             String   fileOnDisk = reste.substring(i + 1);
107             reste = reste.substring(0, i);
108 
109             CDSServlet.cofaxLog("got the file on disk : " + fileOnDisk + " - rest : " + reste);
110 
111             path = reste + "/" + fileOnDisk;
112 
113             CDSServlet.cofaxLog("real file : " + path);
114 
115             res.setHeader("Content-Disposition", "attachment; filename=" + filename + ";");
116         }
117 
118         // For security disallow any path's with dots in them.
119         if (path == null || path.charAt(0) != '/') {
120             res.sendError(HttpServletResponse.SC_BAD_REQUEST);
121             return;
122         }
123         if (path.indexOf("/../") != -1 || path.endsWith("/..")) {
124             res.sendError(HttpServletResponse.SC_FORBIDDEN);
125             return;
126         }
127 
128         // we need to strip the context path from the BEGINNING
129         // of the path to continue
130         String   stripMe = req.getContextPath();
131         int stripMeLen = stripMe.length();
132         path = path.substring(stripMeLen);
133 
134         // Make a version without the leading /.
135         String   pathname = path.substring(1);
136         if (pathname.length() == 0) {
137             pathname = "./";
138         }
139         dispatchPathname(req, res, headOnly, path, pathname);
140 
141     }
142 
143     /**
144      * Description of the Method
145      * 
146      * @param req
147      *            Description of the Parameter
148      * @param res
149      *            Description of the Parameter
150      * @param headOnly
151      *            Description of the Parameter
152      * @param path
153      *            Description of the Parameter
154      * @param pathname
155      *            Description of the Parameter
156      * @exception IOException
157      *                Description of the Exception
158      */
159     private void dispatchPathname(HttpServletRequest req, HttpServletResponse res, boolean headOnly, String   path, String   pathname) throws IOException {
160 
161         String   filename = pathname.replace('/', File.separatorChar);
162         if (filename.charAt(filename.length() - 1) == File.separatorChar) {
163             filename = filename.substring(0, filename.length() - 1);
164         }
165 
166         filename = getServletContext().getRealPath(filename);
167 
168         File file = new File(filename);
169         if (file.exists()) {
170             if (!file.isDirectory()) {
171                 serveFile(req, res, headOnly, path, filename, file);
172             } else {
173                 if (pathname.charAt(pathname.length() - 1) != '/') {
174                     redirectDirectory(req, res, path, file);
175                 } else {
176                     String   indexFilename = filename + File.separatorChar + "index.html";
177                     File indexFile = new File(indexFilename);
178                     if (indexFile.exists()) {
179                         serveFile(req, res, headOnly, path, indexFilename, indexFile);
180                     } else {
181                         serveDirectory(req, res, headOnly, path, filename, file);
182                     }
183                 }
184             }
185         } else {
186             if (pathname.endsWith("/index.html")) {
187                 dispatchPathname(req, res, headOnly, path, pathname.substring(0, pathname.length() - 10));
188             } else if (pathname.equals("index.html")) {
189                 dispatchPathname(req, res, headOnly, path, "./");
190             } else {
191                 res.sendError(HttpServletResponse.SC_NOT_FOUND);
192             }
193         }
194     }
195 
196     /**
197      * Description of the Method
198      * 
199      * @param req
200      *            Description of the Parameter
201      * @param res
202      *            Description of the Parameter
203      * @param headOnly
204      *            Description of the Parameter
205      * @param path
206      *            Description of the Parameter
207      * @param filename
208      *            Description of the Parameter
209      * @param file
210      *            Description of the Parameter
211      * @exception IOException
212      *                Description of the Exception
213      */
214     protected void serveFile(HttpServletRequest req, HttpServletResponse res, boolean headOnly, String   path, String   filename, File file) throws IOException {
215 
216         if (!file.canRead()) {
217             res.sendError(HttpServletResponse.SC_FORBIDDEN);
218             return;
219         }
220 
221         // Handle If-Modified-Since.
222         res.setStatus(HttpServletResponse.SC_OK);
223         long lastMod = file.lastModified();
224         String   ifModSinceStr = req.getHeader("If-Modified-Since");
225         long ifModSince = -1;
226 
227         if (ifModSinceStr != null) {
228             int semi = ifModSinceStr.indexOf(';');
229             if (semi != -1) {
230                 ifModSinceStr = ifModSinceStr.substring(0, semi);
231             }
232             try {
233                 ifModSince = DateFormat.getDateInstance().parse(ifModSinceStr).getTime();
234             } catch (Exception   ignore) {
235             }
236         }
237 
238         if (ifModSince != -1 && ifModSince >= lastMod) {
239             res.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
240             headOnly = true;
241         }
242 
243         res.setContentType(getServletContext().getMimeType(filename));
244         res.setContentLength((int) file.length());
245         res.setDateHeader("Last-Modified", lastMod);
246         OutputStream out = res.getOutputStream();
247         if (!headOnly) {
248             InputStream in = new FileInputStream(file);
249             copyStream(in, out);
250             in.close();
251         }
252         out.close();
253     }
254 
255     /**
256      * Copy a file from in to out. Sub-classes can override this in order to do
257      * filtering of some sort.
258      * 
259      * @param in
260      *            Description of the Parameter
261      * @param out
262      *            Description of the Parameter
263      * @exception IOException
264      *                Description of the Exception
265      */
266     public void copyStream(InputStream in, OutputStream out) throws IOException {
267         byte buf[] = new byte[2048];
268         int cnt = 0;
269         int n;
270         try {
271             while ((n = in.read(buf)) != -1) {
272                 out.write(buf, 0, n);
273             }
274         } catch (IOException e) {
275         }
276     }
277 
278     /**
279      * Description of the Method
280      * 
281      * @param req
282      *            Description of the Parameter
283      * @param res
284      *            Description of the Parameter
285      * @param headOnly
286      *            Description of the Parameter
287      * @param path
288      *            Description of the Parameter
289      * @param filename
290      *            Description of the Parameter
291      * @param file
292      *            Description of the Parameter
293      * @exception IOException
294      *                Description of the Exception
295      */
296     private void serveDirectory(HttpServletRequest req, HttpServletResponse res, boolean headOnly, String   path, String   filename, File file) throws IOException {
297         if (!file.canRead()) {
298             res.sendError(HttpServletResponse.SC_FORBIDDEN);
299             return;
300         }
301         res.setStatus(HttpServletResponse.SC_OK);
302         res.setContentType("text/html");
303         OutputStream out = res.getOutputStream();
304         if (!headOnly) {
305             PrintStream p = new PrintStream(new BufferedOutputStream(out));
306             p.println("<HTML><HEAD>");
307             p.println("<TITLE>Index of " + path + "</TITLE>");
308             p.println("</HEAD><BODY BGCOLOR=\"#ffffff\">");
309             p.println("<H2>Index of " + path + "</H2>");
310             p.println("<PRE>");
311             p.println("mode     bytes  last-changed  name");
312             p.println("<HR>");
313             String  [] names = file.list();
314 
315             for (int i = 0; i < names.length; ++i) {
316                 String   aFilename = filename + File.separatorChar + names[i];
317                 File aFile = new File(aFilename);
318                 String   aFileType;
319                 if (aFile.isDirectory()) {
320                     aFileType = "d";
321                 } else if (aFile.isFile()) {
322                     aFileType = "-";
323                 } else {
324                     aFileType = "?";
325                 }
326                 String   aFileRead = (aFile.canRead() ? "r" : "-");
327                 String   aFileWrite = (aFile.canWrite() ? "w" : "-");
328                 String   aFileExe = "-";
329                 String   aFileSize = Long.toString(aFile.length());
330                 String   aFileDate = new Date(aFile.lastModified()).toString();
331                 String   aFileDirsuf = (aFile.isDirectory() ? "/" : "");
332                 String   aFileSuf = (aFile.isDirectory() ? "/" : "");
333                 p.println(aFileType + aFileRead + aFileWrite + aFileExe + "  " + aFileSize + "  " + aFileDate + "  " + "<A HREF=\"" + names[i] + aFileDirsuf
334                         + "\">" + names[i] + aFileSuf + "</A>");
335             }
336             p.println("</PRE>");
337             p.println("<HR>");
338             p.println("</BODY></HTML>");
339             p.flush();
340         }
341         out.close();
342     }
343 
344     /**
345      * Description of the Method
346      * 
347      * @param req
348      *            Description of the Parameter
349      * @param res
350      *            Description of the Parameter
351      * @param path
352      *            Description of the Parameter
353      * @param file
354      *            Description of the Parameter
355      * @exception IOException
356      *                Description of the Exception
357      */
358     protected void redirectDirectory(HttpServletRequest req, HttpServletResponse res, String   path, File file) throws IOException {
359         res.sendRedirect(path + "/");
360     }
361 
362 }
363
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