001 /*
002 * Copyright 2005 Stephen J. McConnell
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
013 * implied.
014 *
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019 package net.dpml.tools.info;
020
021 import java.net.URI;
022 import java.util.Properties;
023
024 import net.dpml.library.info.AbstractDirective;
025
026 /**
027 * The ListenerDirective is an immutable descriptor used to define
028 * a build listener to be attached to an Ant project.
029 *
030 * @author <a href="http://www.dpml.net">Digital Product Meta Library</a>
031 * @version 1.1.3
032 */
033 public final class ListenerDirective extends AbstractDirective implements Comparable
034 {
035 private final String m_name;
036 private final int m_priority;
037 private final URI m_uri;
038 private final String m_classname;
039
040 /**
041 * Creation of a new listener directive.
042 * @param name the listener name
043 * @param priority the listener priority
044 * @param uri the listener codebase
045 * @param classname optional classname of the plugin instantiation target
046 * @param properties supplimentary properties
047 * @exception NullPointerException if name or dependencies are null
048 * @exception IllegalStateException if both classname and urn values are null
049 */
050 public ListenerDirective(
051 String name, int priority, URI uri, String classname, Properties properties )
052 throws NullPointerException, IllegalStateException
053 {
054 super( properties );
055 if( null == name )
056 {
057 throw new NullPointerException( "name" );
058 }
059 if( null == uri )
060 {
061 if( null == classname )
062 {
063 final String error =
064 "Listener definition ["
065 + name
066 + "] does not declare a classname or uri value.";
067 throw new IllegalStateException( error );
068 }
069 }
070 m_priority = priority;
071 m_name = name;
072 m_uri = uri;
073 m_classname = classname;
074 }
075
076 /**
077 * Return the listener name.
078 * @return the listener name
079 */
080 public String getName()
081 {
082 return m_name;
083 }
084
085 /**
086 * Return the listener priority.
087 * @return the priority value
088 */
089 public int getPriority()
090 {
091 return m_priority;
092 }
093
094 /**
095 * Return the listener codebase uri.
096 * @return the urn
097 */
098 public URI getURI()
099 {
100 return m_uri;
101 }
102
103 /**
104 * Return the listener codebase uri as a string.
105 * @return the uri value
106 */
107 public String getURISpec()
108 {
109 if( null == m_uri )
110 {
111 return null;
112 }
113 else
114 {
115 return m_uri.toASCIIString();
116 }
117 }
118
119 /**
120 * Get the listener classname.
121 *
122 * @return the classname of the listener
123 */
124 public String getClassname()
125 {
126 return m_classname;
127 }
128
129 /**
130 * Compares this <code>ListenerDirective</code> object to another object.
131 * If the object is an <code>ListenerDirective</code>, this function behaves
132 * like <code>compareTo(Integer)</code>. Otherwise, it throws a
133 * <code>ClassCastException</code>.
134 *
135 * @param other the <code>Object</code> to be compared.
136 * @return the value <code>0</code> if the argument is a
137 * <code>ListenerDirective</code> with a priority numerically equal to this
138 * <code>ListenerDirective</code>; a value less than <code>0</code>
139 * if the argument is a <code>ListenerDirective</code> numerically
140 * greater than this <code>ListenerDirective</code>; and a value
141 * greater than <code>0</code> if the argument is a
142 * <code>ListenerDirective</code> numerically less than this
143 * <code>ListenerDirective</code>.
144 * @exception ClassCastException if the argument is not an
145 * <code>ListenerDirective</code>.
146 * @see java.lang.Comparable
147 */
148 public int compareTo( Object other ) throws ClassCastException
149 {
150 ListenerDirective directive = (ListenerDirective) other;
151 Integer p1 = new Integer( m_priority );
152 Integer p2 = new Integer( directive.getPriority() );
153 return p1.compareTo( p2 );
154 }
155
156 /**
157 * Compare this object with another for equality.
158 * @param other the other object
159 * @return true if equal
160 */
161 public boolean equals( Object other )
162 {
163 if( super.equals( other ) && ( other instanceof ListenerDirective ) )
164 {
165 ListenerDirective object = (ListenerDirective) other;
166 if( !equals( m_name, object.m_name ) )
167 {
168 return false;
169 }
170 else if( m_priority != object.m_priority )
171 {
172 return false;
173 }
174 else
175 {
176 return equals( m_uri, object.m_uri );
177 }
178 }
179 else
180 {
181 return false;
182 }
183 }
184
185 /**
186 * Compute the hash value.
187 * @return the hashcode value
188 */
189 public int hashCode()
190 {
191 int hash = super.hashCode();
192 hash ^= super.hashValue( m_name );
193 hash ^= super.hashValue( m_uri );
194 hash ^= m_priority;
195 return hash;
196 }
197 }