KeyedObjects


1   /* ===========================================================
2    * JFreeChart : a free chart 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/jfreechart/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 License 
20   * along with this library; if not, write to the Free Software Foundation, 
21   * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
22   *
23   * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
24   * in the United States and other countries.]
25   *
26   * -----------------
27   * KeyedObjects.java
28   * -----------------
29   * (C) Copyright 2003-2005, by Object Refinery Limited.
30   *
31   * Original Author:  David Gilbert (for Object Refinery Limited);
32   * Contributor(s):   -;
33   *
34   * $Id: KeyedObjects.java,v 1.5 2005/05/19 10:34:07 mungady Exp $
35   *
36   * Changes:
37   * --------
38   * 31-Oct-2002 : Version 1 (DG);
39   * 11-Jan-2005 : Minor tidy up (DG);
40   * 
41   */
42  
43  package org.jfree.data;
44  
45  import java.io.Serializable  ;
46  import java.util.Iterator  ;
47  import java.util.List  ;
48  
49  import org.jfree.util.PublicCloneable;
50  
51  /**
52   * A collection of (key, object) pairs.
53   */
54  public class KeyedObjects  implements Cloneable  , PublicCloneable, Serializable   {
55  
56      /** For serialization. */
57      private static final long serialVersionUID = 1321582394193530984L;
58      
59      /** Storage for the data. */
60      private List   data;
61  
62      /**
63       * Creates a new collection (initially empty).
64       */
65      public KeyedObjects() {
66          this.data = new java.util.ArrayList  ();
67      }
68  
69      /**
70       * Returns the number of items (values) in the collection.
71       *
72       * @return The item count.
73       */
74      public int getItemCount() {
75          return this.data.size();
76      }
77  
78      /**
79       * Returns an object.
80       *
81       * @param item  the item index (zero-based).
82       *
83       * @return The object (<code>null</code> if the index is out of range).
84       */
85      public Object   getObject(int item) {
86          Object   result = null;
87          if (item >= 0 && item < this.data.size()) {
88              KeyedObject kobj = (KeyedObject) this.data.get(item);
89              if (kobj != null) {
90                  result = kobj.getObject();
91              }
92          }
93          return result;
94      }
95  
96      /**
97       * Returns a key.
98       *
99       * @param index  the item index (zero-based).
100      *
101      * @return The row key.
102      * 
103      * @throws IndexOutOfBoundsException if <code>index</code> is out of bounds.
104      */
105     public Comparable   getKey(int index) {
106         Comparable   result = null;
107         if (index >= 0 && index < this.data.size()) {
108             KeyedObject item = (KeyedObject) this.data.get(index);
109             if (item != null) {
110                 result = item.getKey();
111             }
112         }
113         return result;
114     }
115 
116     /**
117      * Returns the index for a given key.
118      *
119      * @param key  the key.
120      *
121      * @return The index, or <code>-1</code> if the key is unrecognised.
122      */
123     public int getIndex(Comparable   key) {
124         int result = -1;
125         int i = 0;
126         Iterator   iterator = this.data.iterator();
127         while (iterator.hasNext()) {
128             KeyedObject ko = (KeyedObject) iterator.next();
129             if (ko.getKey().equals(key)) {
130                 result = i;
131             }
132             i++;
133         }
134         return result;
135     }
136 
137     /**
138      * Returns the keys.
139      *
140      * @return The keys (never <code>null</code>).
141      */
142     public List   getKeys() {
143         List   result = new java.util.ArrayList  ();
144         Iterator   iterator = this.data.iterator();
145         while (iterator.hasNext()) {
146             KeyedObject ko = (KeyedObject) iterator.next();
147             result.add(ko.getKey());
148         }
149         return result;
150     }
151 
152     /**
153      * Returns the object for a given key. If the key is not recognised, the 
154      * method should return <code>null</code>.
155      *
156      * @param key  the key.
157      *
158      * @return The object (possibly <code>null</code>).
159      */
160     public Object   getObject(Comparable   key) {
161         return getObject(getIndex(key));
162     }
163 
164     /**
165      * Adds a new object to the collection, or overwrites an existing object.  
166      * This is the same as the {@link #setObject(Comparable, Object)} method.
167      *
168      * @param key  the key.
169      * @param object  the object.
170      */
171     public void addObject(Comparable   key, Object   object) {
172         setObject(key, object);
173     }
174 
175     /**
176      * Replaces an existing object, or adds a new object to the collection.
177      * This is the same as the {@link #addObject(Comparable, Object)} 
178      * method.
179      *
180      * @param key  the key.
181      * @param object  the object.
182      */
183     public void setObject(Comparable   key, Object   object) {
184         int keyIndex = getIndex(key);
185         if (keyIndex >= 0) {
186             KeyedObject ko = (KeyedObject) this.data.get(keyIndex);
187             ko.setObject(object);
188         }
189         else {
190             KeyedObject ko = new KeyedObject(key, object);
191             this.data.add(ko);
192         }
193     }
194 
195     /**
196      * Removes a value from the collection.
197      *
198      * @param index  the index of the item to remove.
199      */
200     public void removeValue(int index) {
201         this.data.remove(index);
202     }
203 
204     /**
205      * Removes a value from the collection.
206      *
207      * @param key  the key of the item to remove.
208      */
209     public void removeValue(Comparable   key) {
210         removeValue(getIndex(key));
211     }
212     
213     /**
214      * Returns a clone of this object.
215      * 
216      * @return A clone.
217      * 
218      * @throws CloneNotSupportedException if there is a problem cloning.
219      */
220     public Object   clone() throws CloneNotSupportedException   {
221         KeyedObjects clone = (KeyedObjects) super.clone();
222         clone.data = new java.util.ArrayList  ();
223         Iterator   iterator = this.data.iterator();
224         while (iterator.hasNext()) {
225             KeyedObject ko = (KeyedObject) iterator.next();
226             clone.data.add(ko.clone());
227         }
228         return clone;      
229     }
230     
231     /**
232      * Tests if this object is equal to another.
233      *
234      * @param o  the other object.
235      *
236      * @return A boolean.
237      */
238     public boolean equals(Object   o) {
239 
240         if (o == null) {
241             return false;
242         }
243         if (o == this) {
244             return true;
245         }
246 
247         if (!(o instanceof KeyedObjects)) {
248             return false;
249         }
250 
251         KeyedObjects kos = (KeyedObjects) o;
252         int count = getItemCount();
253         if (count != kos.getItemCount()) {
254             return false;
255         }
256 
257         for (int i = 0; i < count; i++) {
258             Comparable   k1 = getKey(i);
259             Comparable   k2 = kos.getKey(i);
260             if (!k1.equals(k2)) {
261                 return false;
262             }
263             Object   o1 = getObject(i);
264             Object   o2 = kos.getObject(i);
265             if (o1 == null) {
266                 if (o2 != null) {
267                     return false;
268                 }
269             }
270             else {
271                 if (!o1.equals(o2)) {
272                     return false;
273                 }
274             }
275         }
276         return true;
277 
278     }
279     
280 }
281
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