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      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     private JarFile getCachedJarFile(URL url) {
    121         assert Thread.holdsLock(instance);
    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 }
    164