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Java > Open Source Codes > org > jfree > xml > factory > objects > ClassFactoryImpl


1 /* ========================================================================
2  * JCommon : a free general purpose class library for the Java(tm) platform
3  * ========================================================================
4  *
5  * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
6  *
7  * Project Info: http://www.jfree.org/jcommon/index.html
8  *
9  * This library is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU Lesser General Public License as published by
11  * the Free Software Foundation; either version 2.1 of the License, or
12  * (at your option) any later version.
13  *
14  * This library is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
17  * License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with this library; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
22  * USA.
23  *
24  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
25  * in the United States and other countries.]
26  *
27  * ---------------------
28  * ClassFactoryImpl.java
29  * ---------------------
30  * (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
31  *
32  * Original Author: Thomas Morgner;
33  * Contributor(s): David Gilbert (for Object Refinery Limited);
34  *
35  * $Id: ClassFactoryImpl.java,v 1.6 2006/01/25 23:15:03 taqua Exp $
36  *
37  * Changes (from 19-Feb-2003)
38  * -------------------------
39  * 19-Feb-2003 : Added standard header and Javadocs (DG);
40  * 29-Apr-2003 : Distilled from the JFreeReport project and moved into JCommon
41  * 29-Jul-2004 : Replaced 'enum' variable name (reserved word in JDK 1.5) (DG);
42  *
43  */
44
45 package org.jfree.xml.factory.objects;
46
47 import java.util.HashMap JavaDoc;
48 import java.util.Iterator JavaDoc;
49
50 import org.jfree.util.Configuration;
51 import org.jfree.util.ClassComparator;
52 /**
53  * An abstract class that implements the {@link ClassFactory} interface.
54  *
55  * @author Thomas Morgner.
56  */
57 public abstract class ClassFactoryImpl implements ClassFactory {
58
59     /** Storage for the classes. */
60     private HashMap JavaDoc classes;
61     /** A class comparator for searching the super class */
62     private ClassComparator comparator;
63     /** The parser/report configuration */
64     private Configuration config;
65
66     /**
67      * Creates a new class factory.
68      */
69     public ClassFactoryImpl() {
70         this.classes = new HashMap JavaDoc();
71         this.comparator = new ClassComparator();
72     }
73
74     /**
75      * Returns the class comparator used to sort the super classes of an object.
76      *
77      * @return the class comparator.
78      */
79     public ClassComparator getComparator() {
80         return this.comparator;
81     }
82
83     /**
84      * Returns an object-description for a class.
85      *
86      * @param c the class.
87      *
88      * @return An object description.
89      */
90     public ObjectDescription getDescriptionForClass(final Class JavaDoc c) {
91         final ObjectDescription od = (ObjectDescription) this.classes.get(c);
92         if (od == null) {
93             return null;
94         }
95         return od.getInstance();
96     }
97
98     /**
99      * Returns the most concrete object-description for the super class of a class.
100      *
101      * @param d the class.
102      * @param knownSuperClass a known supported superclass or null, if no superclass
103      * is known yet.
104      *
105      * @return The object description.
106      */
107     public ObjectDescription getSuperClassObjectDescription
108         (final Class JavaDoc d, ObjectDescription knownSuperClass) {
109
110         if (d == null) {
111             throw new NullPointerException JavaDoc("Description class must not be null.");
112         }
113         final Iterator JavaDoc iterator = this.classes.keySet().iterator();
114         while (iterator.hasNext()) {
115             final Class JavaDoc keyClass = (Class JavaDoc) iterator.next();
116             if (keyClass.isAssignableFrom(d)) {
117                 final ObjectDescription od = (ObjectDescription) this.classes.get(keyClass);
118                 if (knownSuperClass == null) {
119                     knownSuperClass = od;
120                 }
121                 else {
122                     if (this.comparator.isComparable
123                         (knownSuperClass.getObjectClass(), od.getObjectClass())) {
124                         if (this.comparator.compare
125                             (knownSuperClass.getObjectClass(), od.getObjectClass()) < 0) {
126                             knownSuperClass = od;
127                         }
128                     }
129                 }
130             }
131         }
132         if (knownSuperClass == null) {
133             return null;
134         }
135         return knownSuperClass.getInstance();
136     }
137
138     /**
139      * Registers an object description with the factory.
140      *
141      * @param key the key.
142      * @param od the object description.
143      */
144     protected void registerClass(final Class JavaDoc key, final ObjectDescription od) {
145         this.classes.put(key, od);
146         if (this.config != null) {
147             od.configure(this.config);
148         }
149     }
150
151     /**
152      * Returns an iterator that provides access to the registered object definitions.
153      *
154      * @return The iterator.
155      */
156     public Iterator JavaDoc getRegisteredClasses() {
157         return this.classes.keySet().iterator();
158     }
159
160
161     /**
162      * Configures this factory. The configuration contains several keys and
163      * their defined values. The given reference to the configuration object
164      * will remain valid until the report parsing or writing ends.
165      * <p>
166      * The configuration contents may change during the reporting.
167      *
168      * @param config the configuration, never null
169      */
170     public void configure(final Configuration config) {
171         if (config == null) {
172             throw new NullPointerException JavaDoc("The given configuration is null");
173         }
174         if (this.config != null) {
175             // already configured ... ignored
176 return;
177         }
178
179         this.config = config;
180         final Iterator JavaDoc it = this.classes.values().iterator();
181         while (it.hasNext()) {
182             final ObjectDescription od = (ObjectDescription) it.next();
183             od.configure(config);
184         }
185     }
186
187     /**
188      * Returns the currently set configuration or null, if none was set.
189      *
190      * @return the configuration.
191      */
192     public Configuration getConfig() {
193         return this.config;
194     }
195
196     /**
197      * Tests for equality.
198      *
199      * @param o the object to test.
200      *
201      * @return A boolean.
202      */
203     public boolean equals(final Object JavaDoc o) {
204         if (this == o) {
205             return true;
206         }
207         if (!(o instanceof ClassFactoryImpl)) {
208             return false;
209         }
210
211         final ClassFactoryImpl classFactory = (ClassFactoryImpl) o;
212
213         if (!this.classes.equals(classFactory.classes)) {
214             return false;
215         }
216
217         return true;
218     }
219
220     /**
221      * Returns a hash code.
222      *
223      * @return A hash code.
224      */
225     public int hashCode() {
226         return this.classes.hashCode();
227     }
228 }
229
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