KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > commons > discovery > resource > classes > DiscoverClasses


1 /*
2  * ====================================================================
3  *
4  * The Apache Software License, Version 1.1
5  *
6  * Copyright (c) 1999-2002 The Apache Software Foundation. All rights
7  * reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  * notice, this list of conditions and the following disclaimer.
15  *
16  * 2. Redistributions in binary form must reproduce the above copyright
17  * notice, this list of conditions and the following disclaimer in
18  * the documentation and/or other materials provided with the
19  * distribution.
20  *
21  * 3. The end-user documentation included with the redistribution, if
22  * any, must include the following acknowlegement:
23  * "This product includes software developed by the
24  * Apache Software Foundation (http://www.apache.org/)."
25  * Alternately, this acknowlegement may appear in the software itself,
26  * if and wherever such third-party acknowlegements normally appear.
27  *
28  * 4. The names "The Jakarta Project", "Commons", and "Apache Software
29  * Foundation" must not be used to endorse or promote products derived
30  * from this software without prior written permission. For written
31  * permission, please contact apache@apache.org.
32  *
33  * 5. Products derived from this software may not be called "Apache"
34  * nor may "Apache" appear in their names without prior written
35  * permission of the Apache Group.
36  *
37  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
38  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
39  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
40  * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
41  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
43  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
44  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
45  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
46  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
47  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
48  * SUCH DAMAGE.
49  * ====================================================================
50  *
51  * This software consists of voluntary contributions made by many
52  * individuals on behalf of the Apache Software Foundation. For more
53  * information on the Apache Software Foundation, please see
54  * <http://www.apache.org/>.
55  *
56  */

57
58 package org.apache.commons.discovery.resource.classes;
59
60 import java.net.URL JavaDoc;
61 import java.util.Vector JavaDoc;
62
63 import org.apache.commons.discovery.ResourceClass;
64 import org.apache.commons.discovery.ResourceClassDiscover;
65 import org.apache.commons.discovery.ResourceNameListener;
66 import org.apache.commons.discovery.log.DiscoveryLogFactory;
67 import org.apache.commons.discovery.resource.ClassLoaders;
68 import org.apache.commons.logging.Log;
69
70
71 /**
72  * The findResources() method will check every loader.
73  *
74  * @author Richard A. Sitze
75  * @author Craig R. McClanahan
76  * @author Costin Manolache
77  * @author James Strachan
78  */

79 public class DiscoverClasses extends ResourceClassDiscoverImpl
80     implements ResourceClassDiscover, ResourceNameListener
81 {
82     private static Log log = DiscoveryLogFactory.newLog(DiscoverClasses.class);
83     public static void setLog(Log _log) {
84         log = _log;
85     }
86
87     /** Construct a new resource discoverer
88      */

89     public DiscoverClasses() {
90         super();
91     }
92     
93     /** Construct a new resource discoverer
94      */

95     public DiscoverClasses(ClassLoaders classLoaders) {
96         super(classLoaders);
97     }
98     
99     public boolean find(String JavaDoc className) {
100         final String JavaDoc resourceName = className.replace('.','/') + ".class";
101         
102         if (log.isDebugEnabled())
103             log.debug("find: className='" + className + "'");
104
105         Vector JavaDoc history = new Vector JavaDoc();
106
107         for (int idx = 0; idx < getClassLoaders().size(); idx++) {
108             ClassLoader JavaDoc loader = getClassLoaders().get(idx);
109             URL JavaDoc url = loader.getResource(resourceName);
110             if (url != null) {
111                 if (!history.contains(url)) {
112                     history.addElement(url);
113                     if (!notifyListener(new ResourceClass(className,
114                                                           url,
115                                                           loader)))
116                         return false;
117                 } else {
118                     if (log.isDebugEnabled())
119                         log.debug("find: duplicate URL='" + url + "'");
120                 }
121             } else {
122                 if (log.isDebugEnabled())
123                     log.debug("find: '" + resourceName + "' not found with loader: " + loader);
124             }
125         }
126         
127         return true;
128     }
129     
130     public boolean found(String JavaDoc className) {
131         return find(className);
132     }
133 }
134
Popular Tags