1 /*
   2  * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package sun.net.www.protocol.jar;
  27 
  28 import java.io.IOException;
  29 import java.io.FileNotFoundException;
  30 import java.net.URL;
  31 import java.net.URLConnection;
  32 import java.util.HashMap;
  33 import java.util.jar.JarFile;
  34 import java.security.Permission;
  35 import sun.net.util.URLUtil;
  36 
  37 /* A factory for cached JAR file. This class is used to both retrieve
  38  * and cache Jar files.
  39  *
  40  * @author Benjamin Renaud
  41  * @since JDK1.2
  42  */
  43 class JarFileFactory implements URLJarFile.URLJarFileCloseController {
  44 
  45     /* the url to file cache */
  46     private static final HashMap<String, JarFile> fileCache = new HashMap<>();
  47 
  48     /* the file to url cache */
  49     private static final HashMap<JarFile, URL> urlCache = new HashMap<>();
  50 
  51     private static final JarFileFactory instance = new JarFileFactory();
  52 
  53     private JarFileFactory() { }
  54 
  55     public static JarFileFactory getInstance() {
  56         return instance;
  57     }
  58 
  59     URLConnection getConnection(JarFile jarFile) throws IOException {
  60         URL u;
  61         synchronized (instance) {
  62             u = urlCache.get(jarFile);
  63         }
  64         if (u != null)
  65             return u.openConnection();
  66 
  67         return null;
  68     }
  69 
  70     public JarFile get(URL url) throws IOException {
  71         return get(url, true);
  72     }
  73 
  74     JarFile get(URL url, boolean useCaches) throws IOException {
  75 
  76         JarFile result;
  77         JarFile local_result;
  78 
  79         if (useCaches) {
  80             synchronized (instance) {
  81                 result = getCachedJarFile(url);
  82             }
  83             if (result == null) {
  84                 local_result = URLJarFile.getJarFile(url, this);
  85                 synchronized (instance) {
  86                     result = getCachedJarFile(url);
  87                     if (result == null) {
  88                         fileCache.put(URLUtil.urlNoFragString(url), local_result);
  89                         urlCache.put(local_result, url);
  90                         result = local_result;
  91                     } else {
  92                         if (local_result != null) {
  93                             local_result.close();
  94                         }
  95                     }
  96                 }
  97             }
  98         } else {
  99             result = URLJarFile.getJarFile(url, this);
 100         }
 101         if (result == null)
 102             throw new FileNotFoundException(url.toString());
 103 
 104         return result;
 105     }
 106 
 107     /**
 108      * Callback method of the URLJarFileCloseController to
 109      * indicate that the JarFile is close. This way we can
 110      * remove the JarFile from the cache
 111      */
 112     public void close(JarFile jarFile) {
 113         synchronized (instance) {
 114             URL urlRemoved = urlCache.remove(jarFile);
 115             if( urlRemoved != null)
 116                 fileCache.remove(URLUtil.urlNoFragString(urlRemoved));
 117         }
 118     }
 119 
 120     // must be called while holding the 'instance' lock
 121     private JarFile getCachedJarFile(URL url) {
 122         JarFile result = fileCache.get(URLUtil.urlNoFragString(url));
 123 
 124         /* if the JAR file is cached, the permission will always be there */
 125         if (result != null) {
 126             Permission perm = getPermission(result);
 127             if (perm != null) {
 128                 SecurityManager sm = System.getSecurityManager();
 129                 if (sm != null) {
 130                     try {
 131                         sm.checkPermission(perm);
 132                     } catch (SecurityException se) {
 133                         // fallback to checkRead/checkConnect for pre 1.2
 134                         // security managers
 135                         if ((perm instanceof java.io.FilePermission) &&
 136                             perm.getActions().indexOf("read") != -1) {
 137                             sm.checkRead(perm.getName());
 138                         } else if ((perm instanceof
 139                             java.net.SocketPermission) &&
 140                             perm.getActions().indexOf("connect") != -1) {
 141                             sm.checkConnect(url.getHost(), url.getPort());
 142                         } else {
 143                             throw se;
 144                         }
 145                     }
 146                 }
 147             }
 148         }
 149         return result;
 150     }
 151 
 152     private Permission getPermission(JarFile jarFile) {
 153         try {
 154             URLConnection uc = getConnection(jarFile);
 155             if (uc != null)
 156                 return uc.getPermission();
 157         } catch (IOException ioe) {
 158             // gulp
 159         }
 160 
 161         return null;
 162     }
 163 }