1 /*
   2  * Copyright (c) 2015, 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.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 import java.io.File;
  25 import java.io.IOException;
  26 import java.net.URL;
  27 import java.nio.file.Files;
  28 import java.security.AllPermission;
  29 import java.security.Permissions;
  30 import java.security.ProtectionDomain;
  31 import java.util.Map;
  32 import java.util.concurrent.ConcurrentHashMap;
  33 
  34 
  35 /**
  36  * A custom ClassLoader to load the concrete LoggerFinder class
  37  * with all permissions.
  38  *
  39  * @author danielfuchs
  40  */
  41 public class CustomSystemClassLoader extends ClassLoader {
  42 
  43 
  44     final ConcurrentHashMap<String, Class<?>> classes = new ConcurrentHashMap<>();
  45 
  46     public CustomSystemClassLoader() {
  47         super();
  48     }
  49     public CustomSystemClassLoader(ClassLoader parent) {
  50         super(parent);
  51     }
  52 
  53     private Class<?> defineFinderClass(String name)
  54         throws ClassNotFoundException {
  55         Class<?> loggerFinderClass = classes.get(name);
  56         if (loggerFinderClass != null) return loggerFinderClass;
  57         final Object obj = getClassLoadingLock(name);
  58         synchronized(obj) {
  59             loggerFinderClass = classes.get(name);
  60             if (loggerFinderClass != null) return loggerFinderClass;
  61 
  62             URL url = this.getClass().getProtectionDomain().getCodeSource().getLocation();
  63             File file = new File(url.getPath(), name+".class");
  64             if (file.canRead()) {
  65                 try {
  66                     byte[] b = Files.readAllBytes(file.toPath());
  67                     Permissions perms = new Permissions();
  68                     perms.add(new AllPermission());
  69                     loggerFinderClass = defineClass(
  70                             name, b, 0, b.length, new ProtectionDomain(
  71                             this.getClass().getProtectionDomain().getCodeSource(),
  72                             perms));
  73                     System.out.println("Loaded " + name);
  74                     classes.put(name, loggerFinderClass);
  75                     return loggerFinderClass;
  76                 } catch (Throwable ex) {
  77                     ex.printStackTrace();
  78                     throw new ClassNotFoundException(name, ex);
  79                 }
  80             } else {
  81                 throw new ClassNotFoundException(name,
  82                         new IOException(file.toPath() + ": can't read"));
  83             }
  84         }
  85     }
  86 
  87     @Override
  88     public synchronized Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
  89         if (name.equals("LogProducerFinder") || name.startsWith("LogProducerFinder$")) {
  90             Class<?> c = defineFinderClass(name);
  91             if (resolve) {
  92                 resolveClass(c);
  93             }
  94             return c;
  95         }
  96         return super.loadClass(name, resolve);
  97     }
  98 
  99     @Override
 100     protected Class<?> findClass(String name) throws ClassNotFoundException {
 101         if (name.equals("LogProducerFinder") || name.startsWith("LogProducerFinder$")) {
 102             return defineFinderClass(name);
 103         }
 104         return super.findClass(name);
 105     }
 106 
 107 }