001 /*
002 * Copyright 2004-2005 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.metro.data;
020
021 import java.net.URI;
022 import java.net.URISyntaxException;
023
024 import net.dpml.component.Directive;
025
026 import net.dpml.lang.Value;
027 import net.dpml.lang.Construct;
028
029 /**
030 * A <code>ValueDirective</code> represents a single constructed argument value. The directive
031 * holds a classname (default value of <code>java.lang.String</code>) and possible sub-directives.
032 * The directives value is established by creating a new instance using the classname
033 * together with the values directived from the sub-sidiary directives as constructor arguments.
034 *
035 * <p><b>XML</b></p>
036 * <p>A value is a nested structure containing a string value or contructor parameter arguments.</p>
037 * <pre>
038 * <font color="gray"><-- Simple string param declaration --></font>
039 *
040 * <value><font color="darkred">London</font></value>
041 *
042 * <font color="gray"><-- Typed value declaration --></font>
043 *
044 * <value class="<font color="darkred">java.io.File</font>"><font color="darkred">./home</font></value>
045 *
046 * <font color="gray"><-- Multi-argument parameter declaration --></font>
047 *
048 * <value class="<font color="darkred">MyClass</font>">
049 * <value class="<font color="darkred">java.io.File</font>"><font color="darkred">./home</font></value>
050 * <value><font color="darkred">London</font></value>
051 * </value>
052 * </pre>
053 *
054 * @author <a href="http://www.dpml.net">Digital Product Meta Library</a>
055 * @version 1.0.1
056 */
057 public final class ValueDirective extends Construct implements Directive
058 {
059 //--------------------------------------------------------------------------
060 // static
061 //--------------------------------------------------------------------------
062
063 /**
064 * Serial version identifier.
065 */
066 static final long serialVersionUID = 1L;
067
068 //--------------------------------------------------------------------------
069 // constructors
070 //--------------------------------------------------------------------------
071
072 /**
073 * Create a new construct using the default java.lang.String class as the base type.
074 * @param value the construct value
075 */
076 public ValueDirective( String value )
077 {
078 super( value );
079 }
080
081 /**
082 * Create a new construct using a supplied target defintion. The target argument
083 * may be either a classname or a symbolic reference in the form ${[key]}. If the
084 * argument is symbolic it resolved relative to a context map supplied by the
085 * application resolving construct values.
086 *
087 * @param target a classname or symbolic reference
088 * @param value the construct value
089 */
090 public ValueDirective( String target, String value )
091 {
092 super( target, value );
093 }
094
095 /**
096 * Create a new construct using a supplied target defintion. The target argument
097 * may be either a classname or a symbolic reference in the form ${[key]}. If the
098 * argument is symbolic it is resolved relative to a context map supplied by the
099 * application resolving construct values. If the construct value is symbolic
100 * the implementation will attempt to expand the reference relative to a context
101 * map (if supplied) otherwise the implementation will attempt to expand the value
102 * using system properties.
103 *
104 * @param target a classname or symbolic reference
105 * @param method the method to invoke on the target
106 * @param value the construct value
107 */
108 public ValueDirective( String target, String method, String value )
109 {
110 super( target, method, value );
111 }
112
113 /**
114 * Create a new construct using a supplied target defintion. The target argument
115 * may be either a classname or a symbolic reference in the form ${[key]}. If the
116 * argument is symbolic it is resolved relative to a context map supplied by the
117 * application resolving construct values. Instance values resolved from the
118 * supplied Value[] will be used as constructor arguments when resolving the target.
119 *
120 * @param target the construct classname
121 * @param args an array of unresolved parameter values
122 */
123 public ValueDirective( String target, Value[] args )
124 {
125 super( target, args );
126 }
127
128 /**
129 * Create a new construct using a supplied target defintion. The target argument
130 * may be either a classname or a symbolic reference in the form ${[key]}. If the
131 * argument is symbolic it is resolved relative to a context map supplied by the
132 * application resolving construct values. Instance values resolved from the
133 * supplied Value[] will be used as method arguments when resolving the target.
134 *
135 * @param target the construct classname
136 * @param method the method to invoke on the target
137 * @param args an array of unresolved parameter values
138 */
139 public ValueDirective( String target, String method, Value[] args )
140 {
141 super( target, method, args );
142 }
143
144 //--------------------------------------------------------------------------
145 // ValueDirective
146 //--------------------------------------------------------------------------
147
148 /**
149 * Test if the supplied object is equal to this object.
150 * @param other the object to compare with this instance
151 * @return TRUE if the supplied object is equal to this object
152 */
153 public boolean equals( Object other )
154 {
155 boolean equals = super.equals( other );
156 if( null == other )
157 {
158 return false;
159 }
160 if( !( other instanceof ValueDirective ) )
161 {
162 return false;
163 }
164 else
165 {
166 ValueDirective directive = (ValueDirective) other;
167 if( !getPartHandlerURI().equals( directive.getPartHandlerURI() ) )
168 {
169 return false;
170 }
171 return super.equals( other );
172 }
173 }
174
175 /**
176 * Return the hashcode for the instance.
177 * @return the instance hashcode
178 */
179 public int hashCode()
180 {
181 int hash = super.hashCode();
182 hash ^= getPartHandlerURI().hashCode();
183 return hash;
184 }
185
186 //--------------------------------------------------------------------------
187 // Part
188 //--------------------------------------------------------------------------
189
190 /**
191 * Return the part handler uri.
192 * @return the uri of the part handler
193 */
194 public URI getPartHandlerURI()
195 {
196 return PART_HANDLER_URI;
197 }
198
199 private static final URI PART_HANDLER_URI = setupURI( "artifact:part:dpml/metro/dpml-metro-runtime#1.0.1" );
200
201 /**
202 * Internal utility to create a static uri.
203 * @param spec the uri spec
204 * @return the uri
205 */
206 protected static URI setupURI( String spec )
207 {
208 try
209 {
210 return new URI( spec );
211 }
212 catch( URISyntaxException ioe )
213 {
214 return null;
215 }
216 }
217 }