jurt/com/sun/star/comp/loader/RegistrationClassFinder.java

   1 /*
   2  * This file is part of the LibreOffice project.
   3  *
   4  * This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this
   6  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   7  *
   8  * This file incorporates work covered by the following license notice:
   9  *
  10  *   Licensed to the Apache Software Foundation (ASF) under one or more
  11  *   contributor license agreements. See the NOTICE file distributed
  12  *   with this work for additional information regarding copyright
  13  *   ownership. The ASF licenses this file to you under the Apache
  14  *   License, Version 2.0 (the "License"); you may not use this file
  15  *   except in compliance with the License. You may obtain a copy of
  16  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  17  */
  18
  19 package com.sun.star.comp.loader;
  20
  21 import com.sun.star.lib.unoloader.UnoClassLoader;
  22 import com.sun.star.lib.util.WeakMap;
  23 import java.io.IOException;
  24 import java.net.URL;
  25 import java.net.URLClassLoader;
  26 import java.util.jar.Attributes;
  27
  28 final class RegistrationClassFinder {
  29     public static Class<?> find(String locationUrl)
  30         throws ClassNotFoundException, IOException
  31     {
  32         synchronized (map) {
  33             Class<?> c = (Class<?>) WeakMap.getValue(map.get(locationUrl));
  34             if (c != null) {
  35                 return c;
  36             }
  37         }
  38         URL url = new URL(locationUrl);
  39         Attributes attr = UnoClassLoader.getJarMainAttributes(url);
  40         String name = attr == null
  41             ? null : attr.getValue("RegistrationClassName");
  42         if (name == null) {
  43             return null;
  44         }
  45         ClassLoader cl1 = RegistrationClassFinder.class.getClassLoader();
  46         ClassLoader cl2;
  47         if (cl1 instanceof UnoClassLoader) {
  48             cl2 = ((UnoClassLoader) cl1).getClassLoader(url, attr);
  49         } else {
  50             cl2 = URLClassLoader.newInstance(new URL[] { url }, cl1);
  51         }
  52         Class<?> c = cl2.loadClass(name);
  53         synchronized (map) {
  54             Class<?> c2 = (Class<?>) WeakMap.getValue(map.get(locationUrl));
  55             if (c2 != null) {
  56                 return c2;
  57             }
  58             map.put(locationUrl, c);
  59         }
  60         return c;
  61     }
  62
  63     private RegistrationClassFinder() {} // do not instantiate
  64
  65     private static final WeakMap map = new WeakMap();
  66 }