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1   package org.apache.maven.surefire.booter;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  import java.net.URL;
23  import java.net.URLClassLoader;
24  import java.util.HashSet;
25  import java.util.Set;
26  
27  /**
28   * Loads classes from jar files added via {@link #addURL(URL)}.
29   */
30  public class IsolatedClassLoader
31      extends URLClassLoader
32  {
33      private final ClassLoader parent = ClassLoader.getSystemClassLoader();
34  
35      private final Set<URL> urls = new HashSet<URL>();
36  
37      private final String roleName;
38  
39      private boolean childDelegation = true;
40  
41      private static final URL[] EMPTY_URL_ARRAY = new URL[0];
42  
43      public IsolatedClassLoader( ClassLoader parent, boolean childDelegation, String roleName )
44      {
45          super( EMPTY_URL_ARRAY, parent );
46  
47          this.childDelegation = childDelegation;
48  
49          this.roleName = roleName;
50      }
51  
52      /**
53       * @deprecated this method will use {@link java.io.File} instead of {@link URL} in the next
54       * major version.
55       */
56      @Override
57      @Deprecated
58      public void addURL( URL url )
59      {
60          // avoid duplicates
61          // todo avoid URL due to calling equals method may cause some overhead due to resolving host or file.
62          if ( !urls.contains( url ) )
63          {
64              super.addURL( url );
65              urls.add( url );
66          }
67      }
68  
69      @Override
70      public synchronized Class loadClass( String name )
71          throws ClassNotFoundException
72      {
73          if ( childDelegation )
74          {
75              Class<?> c = findLoadedClass( name );
76  
77              if ( c == null )
78              {
79                  try
80                  {
81                      c = findClass( name );
82                  }
83                  catch ( ClassNotFoundException e )
84                  {
85                      if ( parent == null )
86                      {
87                          throw e;
88                      }
89                      else
90                      {
91                          c = parent.loadClass( name );
92                      }
93                  }
94              }
95  
96              return c;
97          }
98          else
99          {
100             return super.loadClass( name );
101         }
102     }
103 
104     @Override
105     public String toString()
106     {
107         return "IsolatedClassLoader{roleName='" + roleName + "'}";
108     }
109 }