1 /*
2 * Redistribution and use of this software and associated documentation ("Software"), with or
3 * without modification, are permitted provided that the following conditions are met:
4 *
5 * 1. Redistributions of source code must retain copyright statements and notices. Redistributions
6 * must also contain a copy of this document.
7 *
8 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
9 * conditions and the following disclaimer in the documentation and/or other materials provided with
10 * the distribution.
11 *
12 * 3. The name "Exolab" must not be used to endorse or promote products derived from this Software
13 * without prior written permission of Intalio, Inc. For written permission, please contact
14 * info@exolab.org.
15 *
16 * 4. Products derived from this Software may not be called "Exolab" nor may "Exolab" appear in
17 * their names without prior written permission of Intalio, Inc. Exolab is a registered trademark of
18 * Intalio, Inc.
19 *
20 * 5. Due credit should be given to the Exolab Project (http://www.exolab.org/).
21 *
22 * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
24 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTALIO, INC. OR ITS
25 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
28 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
29 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 * Copyright 2002 (C) Intalio, Inc. All Rights Reserved.
32 *
33 * $Id$
34 */
35 package org.exolab.castor.xml.util;
36
37 import org.exolab.castor.xml.XMLFieldDescriptor;
38
39 /**
40 * A class which represents a collection of XMLFieldDescriptor instances.
41 *
42 * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
43 * @version $Revision$ $Date: 2005-12-13 14:58:48 -0700 (Tue, 13 Dec 2005) $
44 * @see java.util.List
45 * @see java.util.Collection
46 */
47 public class XMLFieldDescriptors {
48
49 private static final int DEFAULT_SIZE = 11;
50
51 private XMLFieldDescriptor[] _elements;
52
53 /**
54 * The next available location in the elements array.
55 */
56 private int _elementCount = 0;
57
58 /**
59 * Creates a new XMLFieldDescriptors with the default Size.
60 */
61 public XMLFieldDescriptors() {
62 _elements = new XMLFieldDescriptor[DEFAULT_SIZE];
63 } // -- XMLFieldDescriptors
64
65 /**
66 * Creates a new XMLFieldDescriptors with the given size.
67 *
68 * @param size the initial size of the internal collection.
69 */
70 public XMLFieldDescriptors(int size) {
71 _elements = new XMLFieldDescriptor[size];
72 } // -- XMLFieldDescriptors
73
74 /**
75 * Adds the specified XMLFieldDescriptor to the collection. If the specified XMLFieldDescriptor is
76 * already contained in the collection, it will not be re-added, false will be returned.
77 *
78 * @param descriptor the XMLFieldDescriptor to add
79 * @return true if the descriptor is added, false otherwise.
80 */
81 public boolean add(XMLFieldDescriptor descriptor) {
82
83 for (int i = 0; i < _elementCount; i++) {
84 if (_elements[i] == descriptor)
85 return false;
86 }
87 if (_elementCount == _elements.length)
88 increaseSize();
89 _elements[_elementCount++] = descriptor;
90 return true;
91 } // -- add
92
93 /**
94 * Removes all descriptors from this collection.
95 */
96 public void clear() {
97 for (int i = 0; i < _elementCount; i++) {
98 _elements[i] = null;
99 }
100 _elementCount = 0;
101 } // -- clear
102
103 public Object clone() {
104 Object obj = null;
105 try {
106 obj = super.clone();
107 } catch (CloneNotSupportedException e) {
108 // this should never happen
109 }
110 return obj;
111 } // -- clone
112
113 /**
114 * Returns true if the specified descriptor is contained in this collection. If the descriptor is
115 * null, then if this collection contains a null value, true will be returned.
116 *
117 * @param descriptor the XMLFieldDescriptor to search the list for
118 * @return true if specified descriptor is contained in the list
119 **/
120 public boolean contains(XMLFieldDescriptor descriptor) {
121 return (indexOf(descriptor) >= 0);
122 } // -- contains
123
124 /**
125 * Compares the specified object with this list for equality. Returns true if and only if the
126 * specified Object is a list and all of its associated elements are equal to the elements of this
127 * list
128 *
129 * @return true if the given object is considered equal to this list.
130 */
131 public boolean equals(Object obj) {
132 if (obj == null)
133 return false;
134 if (obj == this)
135 return true;
136 if (!(obj instanceof XMLFieldDescriptors))
137 return false;
138 XMLFieldDescriptors descs = (XMLFieldDescriptors) obj;
139 if (descs._elementCount != _elementCount)
140 return false;
141 for (int i = 0; i < _elementCount; i++) {
142 Object e1 = get(i);
143 Object e2 = descs._elements[i];
144 if (!((e1 == null) ? (e2 == null) : e1.equals(e2)))
145 return false;
146 }
147 return true;
148 } // -- equals
149
150 /**
151 * Returns the XMLFieldDescriptor at the specified position in this list.
152 *
153 * @param index the position of the descriptor to return
154 * @exception IndexOutOfBoundsException
155 */
156 public XMLFieldDescriptor get(int index) throws IndexOutOfBoundsException {
157 if ((index < 0) || index >= _elementCount) {
158 throw new IndexOutOfBoundsException();
159 }
160 return _elements[index];
161 } // -- get
162
163 /**
164 * As defined by the JDK 1.2 API spec:<BR>
165 * Returns the hash code value for this list. The hash code of a list is defined to be the result
166 * of the following calculation: <BR>
167 * <code>
168 * hashCode = 1;
169 * Iterator i = list.iterator();
170 * while (i.hasNext()) {
171 * Object obj = i.next();
172 * hashCode = 31*hashCode + (obj==null ? 0 : obj.hashCode());
173 * }
174 * </code>
175 *
176 * @return the hash code value for this list
177 */
178 public int hashCode() {
179 int hashCode = 1;
180 for (int i = 0; i < _elementCount; i++) {
181 Object obj = _elements[i];
182 hashCode = 31 * hashCode + (obj == null ? 0 : obj.hashCode());
183 }
184 return hashCode;
185 } // -- hashCode
186
187 /**
188 * Returns the index of the first occurrence of the specified XMLFieldDescriptor, or -1 if the
189 * descriptor is not contained in the collection.
190 *
191 * @param descriptor the XMLFieldDescriptor to get the index of
192 */
193 public int indexOf(XMLFieldDescriptor descriptor) {
194 if (descriptor == null) {
195 for (int i = 0; i < _elementCount; i++) {
196 if (_elements[i] == null)
197 return i;
198 }
199 } else {
200 for (int i = 0; i < _elementCount; i++) {
201 if (descriptor.equals(_elements[i]))
202 return i;
203 }
204 }
205 return -1;
206 } // -- indexOf
207
208 /**
209 * Returns true if there are no descriptors in the collection.
210 *
211 * @return true if the collection is empty.
212 */
213 public boolean isEmpty() {
214 return (_elementCount == 0);
215 } // -- isEmpty
216
217 /**
218 * Removes the descriptor at the specified index from the list.
219 *
220 * @param index the position in the list to remove the descriptor from.
221 * @return the descriptor that was removed from the list.
222 */
223 public XMLFieldDescriptor remove(int index) {
224
225 if ((index < 0) || (index > _elementCount))
226 return null;
227 XMLFieldDescriptor desc = _elements[index];
228 shiftDown(index + 1);
229 --_elementCount;
230 return desc;
231 } // -- remove
232
233 /**
234 * Removes the given XMLFieldDescriptor from the list.
235 *
236 * @param descriptor the XMLFieldDescriptor to remove from the list.
237 * @return true if the descriptor was removed from the list.
238 */
239 public boolean remove(XMLFieldDescriptor descriptor) {
240 int index = indexOf(descriptor);
241 if (index > -1) {
242 remove(index);
243 return true;
244 }
245 return false;
246 } // -- remove
247
248 /**
249 * Reduces the capacity of the internal buffer to the current size freeing up unused memory.
250 */
251 public void trimToSize() {
252 if (_elements.length == _elementCount)
253 return;
254 XMLFieldDescriptor[] pointer = _elements;
255 _elements = new XMLFieldDescriptor[_elementCount];
256 System.arraycopy(pointer, 0, _elements, 0, _elementCount);
257 pointer = null;
258 } // -- trimToSize
259
260 /**
261 * Returns the number of descriptors in the list.
262 *
263 * @return the number of descriptors in the list.
264 */
265 public int size() {
266 return _elementCount;
267 } // -- size
268
269 /**
270 * Returns an array containing all of the descriptors in this list in proper sequence.
271 *
272 * @return the array of descriptors of this List
273 */
274 public XMLFieldDescriptor[] toArray() {
275 XMLFieldDescriptor[] objArray = new XMLFieldDescriptor[_elementCount];
276 System.arraycopy(_elements, 0, objArray, 0, _elementCount);
277 return objArray;
278 } // -- toArray
279
280 /**
281 * Returns an array containing all of the descriptors in this list in proper sequence.
282 *
283 * @return the array of descriptors of this list.
284 */
285 public XMLFieldDescriptor[] toArray(XMLFieldDescriptor[] dst) {
286 return toArray(dst, 0);
287 } // -- toArray
288
289 /**
290 * Returns an array containing all of the elements in this list in proper sequence.
291 *
292 * @return the array of descriptors of this list.
293 */
294 public XMLFieldDescriptor[] toArray(XMLFieldDescriptor[] dst, int offset) {
295
296 XMLFieldDescriptor[] objArray = null;
297
298 if (dst.length >= _elementCount)
299 objArray = dst;
300 else {
301 objArray = new XMLFieldDescriptor[_elementCount];
302 }
303 System.arraycopy(_elements, 0, objArray, offset, _elementCount);
304 return objArray;
305 } // -- toArray
306
307
308 // -------------------/
309 // - Private Methods -/
310 // -------------------/
311
312 /**
313 * Basically the same as a vector, increase the list by a factor of its initial size
314 */
315 private void increaseSize() {
316 XMLFieldDescriptor[] pointer = _elements;
317 int length = (pointer.length > 0) ? pointer.length : 1;
318 _elements = new XMLFieldDescriptor[(length * 3) / 2 + 1];
319 System.arraycopy(pointer, 0, _elements, 0, pointer.length);
320 pointer = null;
321 } // -- increaseSize
322
323 /**
324 * Shifts all elements at the specified index to down by 1
325 */
326 private void shiftDown(int index) {
327 if ((index <= 0) || (index >= _elementCount))
328 return;
329 System.arraycopy(_elements, index, _elements, index - 1, _elementCount - index);
330 // clean up for gc
331 _elements[_elementCount - 1] = null;
332 } // -- shiftDown
333
334 } // -- XMLFieldDescriptors