| /* FileURLLoader.java -- a URLLoader for file URLs |
| Copyright (C) 2006 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.java.net.loader; |
| |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.net.URL; |
| import java.net.URLClassLoader; |
| import java.net.URLStreamHandlerFactory; |
| import java.util.StringTokenizer; |
| |
| /** |
| * A <code>FileURLLoader</code> is a type of <code>URLLoader</code> |
| * only loading from file url. |
| */ |
| public final class FileURLLoader extends URLLoader |
| { |
| File dir; //the file for this file url |
| |
| public FileURLLoader(URLClassLoader classloader, |
| URLStreamHandlerCache cache, |
| URLStreamHandlerFactory factory, |
| URL url, URL absoluteUrl) |
| { |
| super(classloader, cache, factory, url, absoluteUrl); |
| dir = new File(absoluteUrl.getFile()); |
| } |
| |
| /** get resource with the name "name" in the file url */ |
| public Resource getResource(String name) |
| { |
| try |
| { |
| // Make sure that all components in name are valid by walking through |
| // them |
| File file = walkPathComponents(name); |
| |
| if (file == null) |
| return null; |
| |
| return new FileResource(this, file); |
| } |
| catch (IOException e) |
| { |
| // Fall through... |
| } |
| return null; |
| } |
| |
| /** |
| * Walk all path tokens and check them for validity. At no moment, we are |
| * allowed to reach a directory located "above" the root directory, stored |
| * in "dir" property. We are also not allowed to enter a non existing |
| * directory or a non directory component (plain file, symbolic link, ...). |
| * An empty or null path is valid. Pathnames components are separated by |
| * <code>File.separatorChar</code> |
| * |
| * @param resourceFileName the name to be checked for validity. |
| * @return the canonical file pointed by the resourceFileName or null if the |
| * walking failed |
| * @throws IOException in case of issue when creating the canonical |
| * resulting file |
| * @see File#separatorChar |
| */ |
| private File walkPathComponents(String resourceFileName) throws IOException |
| { |
| StringTokenizer stringTokenizer = new StringTokenizer(resourceFileName, File.separator); |
| File currentFile = dir; |
| int tokenCount = stringTokenizer.countTokens(); |
| |
| for (int i = 0; i < tokenCount - 1; i++) |
| { |
| String currentToken = stringTokenizer.nextToken(); |
| |
| // If we are at the root directory and trying to go up, the walking is |
| // finished with an error |
| if ("..".equals(currentToken) && currentFile.equals(dir)) |
| return null; |
| |
| currentFile = new File(currentFile, currentToken); |
| |
| // If the current file doesn't exist or is not a directory, the walking is |
| // finished with an error |
| if (! (currentFile.exists() && currentFile.isDirectory())) |
| return null; |
| |
| } |
| |
| // Treat the last token differently, if it exists, because it does not need |
| // to be a directory |
| if (tokenCount > 0) |
| { |
| String currentToken = stringTokenizer.nextToken(); |
| |
| if ("..".equals(currentToken) && currentFile.equals(dir)) |
| return null; |
| |
| currentFile = new File(currentFile, currentToken); |
| |
| // If the current file doesn't exist, the walking is |
| // finished with an error |
| if (! currentFile.exists()) |
| return null; |
| } |
| |
| return currentFile.getCanonicalFile(); |
| } |
| } |