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Java example source code file (JarFileFactory.java)
The JarFileFactory.java Java example source code/* * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.net.www.protocol.jar; import java.io.IOException; import java.io.FileNotFoundException; import java.net.URL; import java.net.URLConnection; import java.util.HashMap; import java.util.jar.JarFile; import java.security.Permission; import sun.net.util.URLUtil; /* A factory for cached JAR file. This class is used to both retrieve * and cache Jar files. * * @author Benjamin Renaud * @since JDK1.2 */ class JarFileFactory implements URLJarFile.URLJarFileCloseController { /* the url to file cache */ private static final HashMap<String, JarFile> fileCache = new HashMap<>(); /* the file to url cache */ private static final HashMap<JarFile, URL> urlCache = new HashMap<>(); private static final JarFileFactory instance = new JarFileFactory(); private JarFileFactory() { } public static JarFileFactory getInstance() { return instance; } URLConnection getConnection(JarFile jarFile) throws IOException { URL u; synchronized (instance) { u = urlCache.get(jarFile); } if (u != null) return u.openConnection(); return null; } public JarFile get(URL url) throws IOException { return get(url, true); } JarFile get(URL url, boolean useCaches) throws IOException { if (url.getProtocol().equalsIgnoreCase("file")) { // Deal with UNC pathnames specially. See 4180841 String host = url.getHost(); if (host != null && !host.equals("") && !host.equalsIgnoreCase("localhost")) { url = new URL("file", "", "//" + host + url.getPath()); } } JarFile result; JarFile local_result; if (useCaches) { synchronized (instance) { result = getCachedJarFile(url); } if (result == null) { local_result = URLJarFile.getJarFile(url, this); synchronized (instance) { result = getCachedJarFile(url); if (result == null) { fileCache.put(URLUtil.urlNoFragString(url), local_result); urlCache.put(local_result, url); result = local_result; } else { if (local_result != null) { local_result.close(); } } } } } else { result = URLJarFile.getJarFile(url, this); } if (result == null) throw new FileNotFoundException(url.toString()); return result; } /** * Callback method of the URLJarFileCloseController to * indicate that the JarFile is close. This way we can * remove the JarFile from the cache */ public void close(JarFile jarFile) { synchronized (instance) { URL urlRemoved = urlCache.remove(jarFile); if (urlRemoved != null) fileCache.remove(URLUtil.urlNoFragString(urlRemoved)); } } private JarFile getCachedJarFile(URL url) { assert Thread.holdsLock(instance); JarFile result = fileCache.get(URLUtil.urlNoFragString(url)); /* if the JAR file is cached, the permission will always be there */ if (result != null) { Permission perm = getPermission(result); if (perm != null) { SecurityManager sm = System.getSecurityManager(); if (sm != null) { try { sm.checkPermission(perm); } catch (SecurityException se) { // fallback to checkRead/checkConnect for pre 1.2 // security managers if ((perm instanceof java.io.FilePermission) && perm.getActions().indexOf("read") != -1) { sm.checkRead(perm.getName()); } else if ((perm instanceof java.net.SocketPermission) && perm.getActions().indexOf("connect") != -1) { sm.checkConnect(url.getHost(), url.getPort()); } else { throw se; } } } } } return result; } private Permission getPermission(JarFile jarFile) { try { URLConnection uc = getConnection(jarFile); if (uc != null) return uc.getPermission(); } catch (IOException ioe) { // gulp } return null; } } Other Java examples (source code examples)Here is a short list of links related to this Java JarFileFactory.java source code file: |
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