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Java > Open Source Codes > com > db4o > test > util > ExcludingClassLoader


1 /* Copyright (C) 2004 - 2006 db4objects Inc. http://www.db4o.com
2
3 This file is part of the db4o open source object database.
4
5 db4o is free software; you can redistribute it and/or modify it under
6 the terms of version 2 of the GNU General Public License as published
7 by the Free Software Foundation and as clarified by db4objects' GPL
8 interpretation policy, available at
9 http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
10 Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
11 Suite 350, San Mateo, CA 94403, USA.
12
13 db4o is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation, Inc.,
20 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */

21 package com.db4o.test.util;
22
23 import java.net.*;
24 import java.util.*;
25
26 public class ExcludingClassLoader extends URLClassLoader {
27     private Vector excludedNames;
28     
29     public ExcludingClassLoader(ClassLoader JavaDoc parent,Vector excludedNames) {
30         super(new URL[]{},parent);
31         this.excludedNames=excludedNames;
32     }
33     
34     protected synchronized Class JavaDoc loadClass(String JavaDoc name, boolean resolve) throws ClassNotFoundException JavaDoc {
35         if(excludedNames.contains(name)) {
36             throw new ClassNotFoundException JavaDoc(name);
37         }
38         return super.loadClass(name, resolve);
39     }
40     
41     public static void main(String JavaDoc[] args) throws Exception JavaDoc {
42         ClassLoader JavaDoc parent=ExcludingClassLoader.class.getClassLoader();
43         String JavaDoc excName=ExcludingClassLoader.class.getName();
44         Vector excluded=new Vector();
45         ClassLoader JavaDoc incLoader=new ExcludingClassLoader(parent,excluded);
46         System.out.println(incLoader.loadClass(excName));
47         excluded.add(excName);
48         try {
49             System.out.println(incLoader.loadClass(excName));
50         }
51         catch(ClassNotFoundException JavaDoc exc) {
52             System.out.println("Ok, not found.");
53         }
54     }
55 }
56
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