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Java > Open Source Codes > org > apache > avalon > meta > info > ExtensionDescriptor


1 /*
2
3  ============================================================================
4                    The Apache Software License, Version 1.1
5  ============================================================================
6
7  Copyright (C) 1999-2002 The Apache Software Foundation. All rights reserved.
8
9  Redistribution and use in source and binary forms, with or without modifica-
10  tion, are permitted provided that the following conditions are met:
11
12  1. Redistributions of source code must retain the above copyright notice,
13     this list of conditions and the following disclaimer.
14
15  2. Redistributions in binary form must reproduce the above copyright notice,
16     this list of conditions and the following disclaimer in the documentation
17     and/or other materials provided with the distribution.
18
19  3. The end-user documentation included with the redistribution, if any, must
20     include the following acknowledgment: "This product includes software
21     developed by the Apache Software Foundation (http://www.apache.org/)."
22     Alternately, this acknowledgment may appear in the software itself, if
23     and wherever such third-party acknowledgments normally appear.
24
25  4. The names "Jakarta", "Apache Avalon", "Avalon Framework" and
26     "Apache Software Foundation" must not be used to endorse or promote
27     products derived from this software without prior written
28     permission. For written permission, please contact apache@apache.org.
29
30  5. Products derived from this software may not be called "Apache", nor may
31     "Apache" appear in their name, without prior written permission of the
32     Apache Software Foundation.
33
34  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
35  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
36  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
37  APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
38  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
39  DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
40  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
41  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
42  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
43  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44
45  This software consists of voluntary contributions made by many individuals
46  on behalf of the Apache Software Foundation. For more information on the
47  Apache Software Foundation, please see <http://www.apache.org/>.
48
49 */
50
51 package org.apache.avalon.meta.info;
52
53 import java.util.Properties JavaDoc;
54
55 /**
56  * A descriptor that describes a name and inteface of a lifecycle stage.
57  *
58  * @author <a HREF="mailto:dev@avalon.apache.org">Avalon Development Team</a>
59  * @version $Revision: 1.5 $ $Date: 2003/07/18 08:26:29 $
60  */
61 public final class ExtensionDescriptor extends Descriptor
62 {
63     /**
64      * The extension identifier.
65      */
66     private final String JavaDoc m_urn;
67
68     /**
69      * Creation of an extension descriptor without attributes.
70      * @param urn the extension identifier
71      * @exception NullPointerException if the urn identifer is null
72      */
73     public ExtensionDescriptor( final String JavaDoc urn )
74             throws NullPointerException JavaDoc
75     {
76         this( urn, null );
77     }
78
79     /**
80      * Creation of a extension descriptor with attributes.
81      * @param urn the extension identifier
82      * @param attributes a set of attributes to associate with the extension
83      * @exception NullPointerException if the supplied urn is null
84      */
85     public ExtensionDescriptor( final String JavaDoc urn,
86                                 final Properties JavaDoc attributes )
87             throws NullPointerException JavaDoc
88     {
89         super( attributes );
90
91         if ( null == urn )
92         {
93             throw new NullPointerException JavaDoc( "urn" );
94         }
95
96         m_urn = urn;
97     }
98
99     /**
100      * Return the interface reference
101      *
102      * @return the reference.
103      */
104     public String JavaDoc getKey()
105     {
106         return m_urn;
107     }
108
109    /**
110     * Test is the supplied object is equal to this object.
111     * @return true if the object are equivalent
112     */
113     public boolean equals(Object JavaDoc other)
114     {
115         if( other instanceof ExtensionDescriptor )
116         {
117             if( super.equals( other ) )
118             {
119                 return m_urn.equals( ((ExtensionDescriptor)other).m_urn );
120             }
121         }
122         return false;
123     }
124
125    /**
126     * Return the hashcode for the object.
127     * @return the hashcode value
128     */
129     public int hashCode()
130     {
131         int hash = super.hashCode();
132         hash >>>= 17;
133         hash ^= m_urn.hashCode();
134         return hash;
135     }
136
137    /**
138     * Return a stringified representation of the instance.
139     * @return the string representation
140     */
141     public String JavaDoc toString()
142     {
143         return "[extension " + getKey() + "]";
144     }
145
146 }
147
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