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1 : dl 1.1 /*
2 : jsr166 1.22 * Copyright 1994-2007 Sun Microsystems, Inc. All Rights Reserved.
3 : jsr166 1.21 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 : dl 1.1 *
5 : jsr166 1.21 * This code is free software; you can redistribute it and/or modify it
6 :     * under the terms of the GNU General Public License version 2 only, as
7 :     * published by the Free Software Foundation. Sun designates this
8 :     * particular file as subject to the "Classpath" exception as provided
9 :     * by Sun in the LICENSE file that accompanied this code.
10 :     *
11 :     * This code is distributed in the hope that it will be useful, but WITHOUT
12 :     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 :     * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 :     * version 2 for more details (a copy is included in the LICENSE file that
15 :     * accompanied this code).
16 :     *
17 :     * You should have received a copy of the GNU General Public License version
18 :     * 2 along with this work; if not, write to the Free Software Foundation,
19 :     * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 :     *
21 :     * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 :     * CA 95054 USA or visit www.sun.com if you need additional information or
23 :     * have any questions.
24 : dl 1.1 */
25 :    
26 :     package java.util;
27 :    
28 :     /**
29 : jsr166 1.14 * The {@code Vector} class implements a growable array of
30 : dl 1.1 * objects. Like an array, it contains components that can be
31 :     * accessed using an integer index. However, the size of a
32 : jsr166 1.14 * {@code Vector} can grow or shrink as needed to accommodate
33 :     * adding and removing items after the {@code Vector} has been created.
34 : dl 1.1 *
35 : jsr166 1.9 * <p>Each vector tries to optimize storage management by maintaining a
36 : jsr166 1.14 * {@code capacity} and a {@code capacityIncrement}. The
37 :     * {@code capacity} is always at least as large as the vector
38 : dl 1.1 * size; it is usually larger because as components are added to the
39 :     * vector, the vector's storage increases in chunks the size of
40 : jsr166 1.14 * {@code capacityIncrement}. An application can increase the
41 : dl 1.1 * capacity of a vector before inserting a large number of
42 : jsr166 1.9 * components; this reduces the amount of incremental reallocation.
43 : dl 1.1 *
44 : jsr166 1.22 * <p><a name="fail-fast"/>
45 :     * The iterators returned by this class's {@link #iterator() iterator} and
46 :     * {@link #listIterator(int) listIterator} methods are <em>fail-fast</em>:
47 :     * if the vector is structurally modified at any time after the iterator is
48 :     * created, in any way except through the iterator's own
49 :     * {@link ListIterator#remove() remove} or
50 :     * {@link ListIterator#add(Object) add} methods, the iterator will throw a
51 :     * {@link ConcurrentModificationException}. Thus, in the face of
52 :     * concurrent modification, the iterator fails quickly and cleanly, rather
53 :     * than risking arbitrary, non-deterministic behavior at an undetermined
54 :     * time in the future. The {@link Enumeration Enumerations} returned by
55 :     * the {@link #elements() elements} method are <em>not</em> fail-fast.
56 : dl 1.1 *
57 :     * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed
58 :     * as it is, generally speaking, impossible to make any hard guarantees in the
59 :     * presence of unsynchronized concurrent modification. Fail-fast iterators
60 : jsr166 1.14 * throw {@code ConcurrentModificationException} on a best-effort basis.
61 : dl 1.1 * Therefore, it would be wrong to write a program that depended on this
62 :     * exception for its correctness: <i>the fail-fast behavior of iterators
63 : jsr166 1.9 * should be used only to detect bugs.</i>
64 : dl 1.1 *
65 : jsr166 1.9 * <p>As of the Java 2 platform v1.2, this class was retrofitted to
66 :     * implement the {@link List} interface, making it a member of the
67 : jsr166 1.13 * <a href="{@docRoot}/../technotes/guides/collections/index.html"> Java
68 : jsr166 1.9 * Collections Framework</a>. Unlike the new collection
69 :     * implementations, {@code Vector} is synchronized.
70 : dl 1.1 *
71 :     * @author Lee Boynton
72 :     * @author Jonathan Payne
73 :     * @see Collection
74 :     * @see List
75 :     * @see ArrayList
76 :     * @see LinkedList
77 :     * @since JDK1.0
78 :     */
79 :     public class Vector<E>
80 :     extends AbstractList<E>
81 :     implements List<E>, RandomAccess, Cloneable, java.io.Serializable
82 :     {
83 :     /**
84 :     * The array buffer into which the components of the vector are
85 :     * stored. The capacity of the vector is the length of this array buffer,
86 : jsr166 1.15 * and is at least large enough to contain all the vector's elements.
87 : dl 1.1 *
88 : jsr166 1.15 * <p>Any array elements following the last element in the Vector are null.
89 : dl 1.1 *
90 :     * @serial
91 :     */
92 :     protected Object[] elementData;
93 :    
94 :     /**
95 : jsr166 1.14 * The number of valid components in this {@code Vector} object.
96 :     * Components {@code elementData[0]} through
97 :     * {@code elementData[elementCount-1]} are the actual items.
98 : dl 1.1 *
99 :     * @serial
100 :     */
101 :     protected int elementCount;
102 :    
103 :     /**
104 :     * The amount by which the capacity of the vector is automatically
105 :     * incremented when its size becomes greater than its capacity. If
106 :     * the capacity increment is less than or equal to zero, the capacity
107 :     * of the vector is doubled each time it needs to grow.
108 :     *
109 :     * @serial
110 :     */
111 :     protected int capacityIncrement;
112 :    
113 :     /** use serialVersionUID from JDK 1.0.2 for interoperability */
114 :     private static final long serialVersionUID = -2767605614048989439L;
115 :    
116 :     /**
117 :     * Constructs an empty vector with the specified initial capacity and
118 :     * capacity increment.
119 :     *
120 :     * @param initialCapacity the initial capacity of the vector
121 :     * @param capacityIncrement the amount by which the capacity is
122 :     * increased when the vector overflows
123 : jsr166 1.15 * @throws IllegalArgumentException if the specified initial capacity
124 :     * is negative
125 : dl 1.1 */
126 :     public Vector(int initialCapacity, int capacityIncrement) {
127 : jsr166 1.23 super();
128 : dl 1.1 if (initialCapacity < 0)
129 :     throw new IllegalArgumentException("Illegal Capacity: "+
130 :     initialCapacity);
131 : jsr166 1.23 this.elementData = new Object[initialCapacity];
132 :     this.capacityIncrement = capacityIncrement;
133 : dl 1.1 }
134 :    
135 :     /**
136 :     * Constructs an empty vector with the specified initial capacity and
137 :     * with its capacity increment equal to zero.
138 :     *
139 :     * @param initialCapacity the initial capacity of the vector
140 : jsr166 1.15 * @throws IllegalArgumentException if the specified initial capacity
141 :     * is negative
142 : dl 1.1 */
143 :     public Vector(int initialCapacity) {
144 : jsr166 1.23 this(initialCapacity, 0);
145 : dl 1.1 }
146 :    
147 :     /**
148 :     * Constructs an empty vector so that its internal data array
149 : jsr166 1.14 * has size {@code 10} and its standard capacity increment is
150 : dl 1.1 * zero.
151 :     */
152 :     public Vector() {
153 : jsr166 1.23 this(10);
154 : dl 1.1 }
155 :    
156 :     /**
157 :     * Constructs a vector containing the elements of the specified
158 :     * collection, in the order they are returned by the collection's
159 :     * iterator.
160 :     *
161 :     * @param c the collection whose elements are to be placed into this
162 :     * vector
163 :     * @throws NullPointerException if the specified collection is null
164 :     * @since 1.2
165 :     */
166 :     public Vector(Collection<? extends E> c) {
167 : jsr166 1.23 elementData = c.toArray();
168 :     elementCount = elementData.length;
169 :     // c.toArray might (incorrectly) not return Object[] (see 6260652)
170 :     if (elementData.getClass() != Object[].class)
171 :     elementData = Arrays.copyOf(elementData, elementCount, Object[].class);
172 : dl 1.1 }
173 :    
174 :     /**
175 :     * Copies the components of this vector into the specified array.
176 : jsr166 1.14 * The item at index {@code k} in this vector is copied into
177 :     * component {@code k} of {@code anArray}.
178 : dl 1.1 *
179 :     * @param anArray the array into which the components get copied
180 :     * @throws NullPointerException if the given array is null
181 :     * @throws IndexOutOfBoundsException if the specified array is not
182 :     * large enough to hold all the components of this vector
183 :     * @throws ArrayStoreException if a component of this vector is not of
184 :     * a runtime type that can be stored in the specified array
185 :     * @see #toArray(Object[])
186 :     */
187 :     public synchronized void copyInto(Object[] anArray) {
188 : jsr166 1.23 System.arraycopy(elementData, 0, anArray, 0, elementCount);
189 : dl 1.1 }
190 :    
191 :     /**
192 :     * Trims the capacity of this vector to be the vector's current
193 :     * size. If the capacity of this vector is larger than its current
194 :     * size, then the capacity is changed to equal the size by replacing
195 : jsr166 1.14 * its internal data array, kept in the field {@code elementData},
196 : dl 1.1 * with a smaller one. An application can use this operation to
197 :     * minimize the storage of a vector.
198 :     */
199 :     public synchronized void trimToSize() {
200 : jsr166 1.23 modCount++;
201 :     int oldCapacity = elementData.length;
202 :     if (elementCount < oldCapacity) {
203 : dl 1.1 elementData = Arrays.copyOf(elementData, elementCount);
204 : jsr166 1.23 }
205 : dl 1.1 }
206 :    
207 :     /**
208 :     * Increases the capacity of this vector, if necessary, to ensure
209 :     * that it can hold at least the number of components specified by
210 :     * the minimum capacity argument.
211 :     *
212 :     * <p>If the current capacity of this vector is less than
213 : jsr166 1.14 * {@code minCapacity}, then its capacity is increased by replacing its
214 :     * internal data array, kept in the field {@code elementData}, with a
215 : dl 1.1 * larger one. The size of the new data array will be the old size plus
216 : jsr166 1.14 * {@code capacityIncrement}, unless the value of
217 :     * {@code capacityIncrement} is less than or equal to zero, in which case
218 : dl 1.1 * the new capacity will be twice the old capacity; but if this new size
219 : jsr166 1.14 * is still smaller than {@code minCapacity}, then the new capacity will
220 :     * be {@code minCapacity}.
221 : dl 1.1 *
222 :     * @param minCapacity the desired minimum capacity
223 :     */
224 :     public synchronized void ensureCapacity(int minCapacity) {
225 : jsr166 1.23 modCount++;
226 :     ensureCapacityHelper(minCapacity);
227 : dl 1.1 }
228 :    
229 :     /**
230 :     * This implements the unsynchronized semantics of ensureCapacity.
231 :     * Synchronized methods in this class can internally call this
232 :     * method for ensuring capacity without incurring the cost of an
233 :     * extra synchronization.
234 :     *
235 : jsr166 1.15 * @see #ensureCapacity(int)
236 : dl 1.1 */
237 :     private void ensureCapacityHelper(int minCapacity) {
238 : jsr166 1.23 int oldCapacity = elementData.length;
239 :     if (minCapacity > oldCapacity) {
240 :     Object[] oldData = elementData;
241 :     int newCapacity = (capacityIncrement > 0) ?
242 :     (oldCapacity + capacityIncrement) : (oldCapacity * 2);
243 :     if (newCapacity < minCapacity) {
244 :     newCapacity = minCapacity;
245 :     }
246 : dl 1.1 elementData = Arrays.copyOf(elementData, newCapacity);
247 : jsr166 1.23 }
248 : dl 1.1 }
249 :    
250 :     /**
251 :     * Sets the size of this vector. If the new size is greater than the
252 : jsr166 1.14 * current size, new {@code null} items are added to the end of
253 : dl 1.1 * the vector. If the new size is less than the current size, all
254 : jsr166 1.14 * components at index {@code newSize} and greater are discarded.
255 : dl 1.1 *
256 : jsr166 1.16 * @param newSize the new size of this vector
257 :     * @throws ArrayIndexOutOfBoundsException if the new size is negative
258 : dl 1.1 */
259 :     public synchronized void setSize(int newSize) {
260 : jsr166 1.23 modCount++;
261 :     if (newSize > elementCount) {
262 :     ensureCapacityHelper(newSize);
263 :     } else {
264 :     for (int i = newSize ; i < elementCount ; i++) {
265 :     elementData[i] = null;
266 :     }
267 :     }
268 :     elementCount = newSize;
269 : dl 1.1 }
270 :    
271 :     /**
272 :     * Returns the current capacity of this vector.
273 :     *
274 :     * @return the current capacity (the length of its internal
275 : jsr166 1.14 * data array, kept in the field {@code elementData}
276 : dl 1.1 * of this vector)
277 :     */
278 :     public synchronized int capacity() {
279 : jsr166 1.23 return elementData.length;
280 : dl 1.1 }
281 :    
282 :     /**
283 :     * Returns the number of components in this vector.
284 :     *
285 :     * @return the number of components in this vector
286 :     */
287 :     public synchronized int size() {
288 : jsr166 1.23 return elementCount;
289 : dl 1.1 }
290 :    
291 :     /**
292 :     * Tests if this vector has no components.
293 :     *
294 : jsr166 1.14 * @return {@code true} if and only if this vector has
295 : dl 1.1 * no components, that is, its size is zero;
296 : jsr166 1.14 * {@code false} otherwise.
297 : dl 1.1 */
298 :     public synchronized boolean isEmpty() {
299 : jsr166 1.23 return elementCount == 0;
300 : dl 1.1 }
301 :    
302 :     /**
303 :     * Returns an enumeration of the components of this vector. The
304 : jsr166 1.14 * returned {@code Enumeration} object will generate all items in
305 :     * this vector. The first item generated is the item at index {@code 0},
306 :     * then the item at index {@code 1}, and so on.
307 : dl 1.1 *
308 :     * @return an enumeration of the components of this vector
309 :     * @see Iterator
310 :     */
311 :     public Enumeration<E> elements() {
312 : jsr166 1.23 return new Enumeration<E>() {
313 :     int count = 0;
314 : dl 1.1
315 : jsr166 1.23 public boolean hasMoreElements() {
316 :     return count < elementCount;
317 :     }
318 :    
319 :     public E nextElement() {
320 :     synchronized (Vector.this) {
321 :     if (count < elementCount) {
322 :     return elementData(count++);
323 :     }
324 :     }
325 :     throw new NoSuchElementException("Vector Enumeration");
326 :     }
327 :     };
328 : dl 1.1 }
329 :    
330 :     /**
331 : jsr166 1.14 * Returns {@code true} if this vector contains the specified element.
332 :     * More formally, returns {@code true} if and only if this vector
333 :     * contains at least one element {@code e} such that
334 : dl 1.1 * <tt>(o==null&nbsp;?&nbsp;e==null&nbsp;:&nbsp;o.equals(e))</tt>.
335 :     *
336 :     * @param o element whose presence in this vector is to be tested
337 : jsr166 1.14 * @return {@code true} if this vector contains the specified element
338 : dl 1.1 */
339 :     public boolean contains(Object o) {
340 : jsr166 1.23 return indexOf(o, 0) >= 0;
341 : dl 1.1 }
342 :    
343 :     /**
344 :     * Returns the index of the first occurrence of the specified element
345 :     * in this vector, or -1 if this vector does not contain the element.
346 : jsr166 1.14 * More formally, returns the lowest index {@code i} such that
347 : dl 1.1 * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
348 :     * or -1 if there is no such index.
349 :     *
350 :     * @param o element to search for
351 :     * @return the index of the first occurrence of the specified element in
352 :     * this vector, or -1 if this vector does not contain the element
353 :     */
354 :     public int indexOf(Object o) {
355 : jsr166 1.23 return indexOf(o, 0);
356 : dl 1.1 }
357 :    
358 :     /**
359 :     * Returns the index of the first occurrence of the specified element in
360 : jsr166 1.14 * this vector, searching forwards from {@code index}, or returns -1 if
361 : dl 1.1 * the element is not found.
362 : jsr166 1.14 * More formally, returns the lowest index {@code i} such that
363 : dl 1.1 * <tt>(i&nbsp;&gt;=&nbsp;index&nbsp;&amp;&amp;&nbsp;(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i))))</tt>,
364 :     * or -1 if there is no such index.
365 :     *
366 :     * @param o element to search for
367 :     * @param index index to start searching from
368 :     * @return the index of the first occurrence of the element in
369 : jsr166 1.14 * this vector at position {@code index} or later in the vector;
370 :     * {@code -1} if the element is not found.
371 : dl 1.1 * @throws IndexOutOfBoundsException if the specified index is negative
372 :     * @see Object#equals(Object)
373 :     */
374 :     public synchronized int indexOf(Object o, int index) {
375 : jsr166 1.23 if (o == null) {
376 :     for (int i = index ; i < elementCount ; i++)
377 :     if (elementData[i]==null)
378 :     return i;
379 :     } else {
380 :     for (int i = index ; i < elementCount ; i++)
381 :     if (o.equals(elementData[i]))
382 :     return i;
383 :     }
384 :     return -1;
385 : dl 1.1 }
386 :    
387 :     /**
388 :     * Returns the index of the last occurrence of the specified element
389 :     * in this vector, or -1 if this vector does not contain the element.
390 : jsr166 1.14 * More formally, returns the highest index {@code i} such that
391 : dl 1.1 * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
392 :     * or -1 if there is no such index.
393 :     *
394 :     * @param o element to search for
395 :     * @return the index of the last occurrence of the specified element in
396 :     * this vector, or -1 if this vector does not contain the element
397 :     */
398 :     public synchronized int lastIndexOf(Object o) {
399 : jsr166 1.23 return lastIndexOf(o, elementCount-1);
400 : dl 1.1 }
401 :    
402 :     /**
403 :     * Returns the index of the last occurrence of the specified element in
404 : jsr166 1.14 * this vector, searching backwards from {@code index}, or returns -1 if
405 : dl 1.1 * the element is not found.
406 : jsr166 1.14 * More formally, returns the highest index {@code i} such that
407 : dl 1.1 * <tt>(i&nbsp;&lt;=&nbsp;index&nbsp;&amp;&amp;&nbsp;(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i))))</tt>,
408 :     * or -1 if there is no such index.
409 :     *
410 :     * @param o element to search for
411 :     * @param index index to start searching backwards from
412 :     * @return the index of the last occurrence of the element at position
413 : jsr166 1.14 * less than or equal to {@code index} in this vector;
414 : dl 1.1 * -1 if the element is not found.
415 :     * @throws IndexOutOfBoundsException if the specified index is greater
416 :     * than or equal to the current size of this vector
417 :     */
418 :     public synchronized int lastIndexOf(Object o, int index) {
419 :     if (index >= elementCount)
420 :     throw new IndexOutOfBoundsException(index + " >= "+ elementCount);
421 :    
422 : jsr166 1.23 if (o == null) {
423 :     for (int i = index; i >= 0; i--)
424 :     if (elementData[i]==null)
425 :     return i;
426 :     } else {
427 :     for (int i = index; i >= 0; i--)
428 :     if (o.equals(elementData[i]))
429 :     return i;
430 :     }
431 :     return -1;
432 : dl 1.1 }
433 :    
434 :     /**
435 : jsr166 1.15 * Returns the component at the specified index.
436 : dl 1.1 *
437 : jsr166 1.15 * <p>This method is identical in functionality to the {@link #get(int)}
438 :     * method (which is part of the {@link List} interface).
439 : dl 1.1 *
440 :     * @param index an index into this vector
441 :     * @return the component at the specified index
442 : jsr166 1.15 * @throws ArrayIndexOutOfBoundsException if the index is out of range
443 : jsr166 1.23 * ({@code index < 0 || index >= size()})
444 : dl 1.1 */
445 :     public synchronized E elementAt(int index) {
446 : jsr166 1.23 if (index >= elementCount) {
447 :     throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount);
448 :     }
449 : dl 1.1
450 : jsr166 1.22 return elementData(index);
451 : dl 1.1 }
452 :    
453 :     /**
454 : jsr166 1.14 * Returns the first component (the item at index {@code 0}) of
455 : dl 1.1 * this vector.
456 :     *
457 :     * @return the first component of this vector
458 : jsr166 1.15 * @throws NoSuchElementException if this vector has no components
459 : dl 1.1 */
460 :     public synchronized E firstElement() {
461 : jsr166 1.23 if (elementCount == 0) {
462 :     throw new NoSuchElementException();
463 :     }
464 :     return elementData(0);
465 : dl 1.1 }
466 :    
467 :     /**
468 :     * Returns the last component of the vector.
469 :     *
470 :     * @return the last component of the vector, i.e., the component at index
471 :     * <code>size()&nbsp;-&nbsp;1</code>.
472 : jsr166 1.15 * @throws NoSuchElementException if this vector is empty
473 : dl 1.1 */
474 :     public synchronized E lastElement() {
475 : jsr166 1.23 if (elementCount == 0) {
476 :     throw new NoSuchElementException();
477 :     }
478 :     return elementData(elementCount - 1);
479 : dl 1.1 }
480 :    
481 :     /**
482 : jsr166 1.14 * Sets the component at the specified {@code index} of this
483 : dl 1.1 * vector to be the specified object. The previous component at that
484 : jsr166 1.16 * position is discarded.
485 : dl 1.1 *
486 : jsr166 1.16 * <p>The index must be a value greater than or equal to {@code 0}
487 :     * and less than the current size of the vector.
488 : dl 1.1 *
489 : jsr166 1.17 * <p>This method is identical in functionality to the
490 :     * {@link #set(int, Object) set(int, E)}
491 :     * method (which is part of the {@link List} interface). Note that the
492 :     * {@code set} method reverses the order of the parameters, to more closely
493 :     * match array usage. Note also that the {@code set} method returns the
494 :     * old value that was stored at the specified position.
495 : dl 1.1 *
496 :     * @param obj what the component is to be set to
497 :     * @param index the specified index
498 : jsr166 1.17 * @throws ArrayIndexOutOfBoundsException if the index is out of range
499 : jsr166 1.23 * ({@code index < 0 || index >= size()})
500 : dl 1.1 */
501 :     public synchronized void setElementAt(E obj, int index) {
502 : jsr166 1.23 if (index >= elementCount) {
503 :     throw new ArrayIndexOutOfBoundsException(index + " >= " +
504 :     elementCount);
505 :     }
506 :     elementData[index] = obj;
507 : dl 1.1 }
508 :    
509 :     /**
510 :     * Deletes the component at the specified index. Each component in
511 :     * this vector with an index greater or equal to the specified
512 : jsr166 1.14 * {@code index} is shifted downward to have an index one
513 : dl 1.1 * smaller than the value it had previously. The size of this vector
514 : jsr166 1.15 * is decreased by {@code 1}.
515 : dl 1.1 *
516 : jsr166 1.15 * <p>The index must be a value greater than or equal to {@code 0}
517 :     * and less than the current size of the vector.
518 : dl 1.1 *
519 : jsr166 1.17 * <p>This method is identical in functionality to the {@link #remove(int)}
520 :     * method (which is part of the {@link List} interface). Note that the
521 :     * {@code remove} method returns the old value that was stored at the
522 :     * specified position.
523 : dl 1.1 *
524 :     * @param index the index of the object to remove
525 : jsr166 1.17 * @throws ArrayIndexOutOfBoundsException if the index is out of range
526 : jsr166 1.23 * ({@code index < 0 || index >= size()})
527 : dl 1.1 */
528 :     public synchronized void removeElementAt(int index) {
529 : jsr166 1.23 modCount++;
530 :     if (index >= elementCount) {
531 :     throw new ArrayIndexOutOfBoundsException(index + " >= " +
532 :     elementCount);
533 :     }
534 :     else if (index < 0) {
535 :     throw new ArrayIndexOutOfBoundsException(index);
536 :     }
537 :     int j = elementCount - index - 1;
538 :     if (j > 0) {
539 :     System.arraycopy(elementData, index + 1, elementData, index, j);
540 :     }
541 :     elementCount--;
542 :     elementData[elementCount] = null; /* to let gc do its work */
543 : dl 1.1 }
544 :    
545 :     /**
546 :     * Inserts the specified object as a component in this vector at the
547 : jsr166 1.14 * specified {@code index}. Each component in this vector with
548 :     * an index greater or equal to the specified {@code index} is
549 : dl 1.1 * shifted upward to have an index one greater than the value it had
550 : jsr166 1.15 * previously.
551 : dl 1.1 *
552 : jsr166 1.15 * <p>The index must be a value greater than or equal to {@code 0}
553 : dl 1.1 * and less than or equal to the current size of the vector. (If the
554 :     * index is equal to the current size of the vector, the new element
555 : jsr166 1.15 * is appended to the Vector.)
556 : dl 1.1 *
557 : jsr166 1.17 * <p>This method is identical in functionality to the
558 :     * {@link #add(int, Object) add(int, E)}
559 :     * method (which is part of the {@link List} interface). Note that the
560 :     * {@code add} method reverses the order of the parameters, to more closely
561 :     * match array usage.
562 : dl 1.1 *
563 :     * @param obj the component to insert
564 :     * @param index where to insert the new component
565 : jsr166 1.17 * @throws ArrayIndexOutOfBoundsException if the index is out of range
566 : jsr166 1.23 * ({@code index < 0 || index > size()})
567 : dl 1.1 */
568 :     public synchronized void insertElementAt(E obj, int index) {
569 : jsr166 1.23 modCount++;
570 :     if (index > elementCount) {
571 :     throw new ArrayIndexOutOfBoundsException(index
572 :     + " > " + elementCount);
573 :     }
574 :     ensureCapacityHelper(elementCount + 1);
575 :     System.arraycopy(elementData, index, elementData, index + 1, elementCount - index);
576 :     elementData[index] = obj;
577 :     elementCount++;
578 : dl 1.1 }
579 :    
580 :     /**
581 :     * Adds the specified component to the end of this vector,
582 :     * increasing its size by one. The capacity of this vector is
583 : jsr166 1.16 * increased if its size becomes greater than its capacity.
584 : dl 1.1 *
585 : jsr166 1.17 * <p>This method is identical in functionality to the
586 : jsr166 1.18 * {@link #add(Object) add(E)}
587 :     * method (which is part of the {@link List} interface).
588 : dl 1.1 *
589 :     * @param obj the component to be added
590 :     */
591 :     public synchronized void addElement(E obj) {
592 : jsr166 1.23 modCount++;
593 :     ensureCapacityHelper(elementCount + 1);
594 :     elementData[elementCount++] = obj;
595 : dl 1.1 }
596 :    
597 :     /**
598 :     * Removes the first (lowest-indexed) occurrence of the argument
599 :     * from this vector. If the object is found in this vector, each
600 :     * component in the vector with an index greater or equal to the
601 :     * object's index is shifted downward to have an index one smaller
602 : jsr166 1.16 * than the value it had previously.
603 : dl 1.1 *
604 : jsr166 1.18 * <p>This method is identical in functionality to the
605 :     * {@link #remove(Object)} method (which is part of the
606 :     * {@link List} interface).
607 : dl 1.1 *
608 :     * @param obj the component to be removed
609 : jsr166 1.14 * @return {@code true} if the argument was a component of this
610 :     * vector; {@code false} otherwise.
611 : dl 1.1 */
612 :     public synchronized boolean removeElement(Object obj) {
613 : jsr166 1.23 modCount++;
614 :     int i = indexOf(obj);
615 :     if (i >= 0) {
616 :     removeElementAt(i);
617 :     return true;
618 :     }
619 :     return false;
620 : dl 1.1 }
621 :    
622 :     /**
623 : jsr166 1.17 * Removes all components from this vector and sets its size to zero.
624 : dl 1.1 *
625 : jsr166 1.17 * <p>This method is identical in functionality to the {@link #clear}
626 :     * method (which is part of the {@link List} interface).
627 : dl 1.1 */
628 :     public synchronized void removeAllElements() {
629 :     modCount++;
630 : jsr166 1.23 // Let gc do its work
631 :     for (int i = 0; i < elementCount; i++)
632 :     elementData[i] = null;
633 : dl 1.1
634 : jsr166 1.23 elementCount = 0;
635 : dl 1.1 }
636 :    
637 :     /**
638 :     * Returns a clone of this vector. The copy will contain a
639 :     * reference to a clone of the internal data array, not a reference
640 : jsr166 1.14 * to the original internal data array of this {@code Vector} object.
641 : dl 1.1 *
642 :     * @return a clone of this vector
643 :     */
644 :     public synchronized Object clone() {
645 : jsr166 1.23 try {
646 :     @SuppressWarnings("unchecked")
647 :     Vector<E> v = (Vector<E>) super.clone();
648 :     v.elementData = Arrays.copyOf(elementData, elementCount);
649 :     v.modCount = 0;
650 :     return v;
651 :     } catch (CloneNotSupportedException e) {
652 :     // this shouldn't happen, since we are Cloneable
653 :     throw new InternalError();
654 :     }
655 : dl 1.1 }
656 :    
657 :     /**
658 :     * Returns an array containing all of the elements in this Vector
659 :     * in the correct order.
660 :     *
661 :     * @since 1.2
662 :     */
663 :     public synchronized Object[] toArray() {
664 :     return Arrays.copyOf(elementData, elementCount);
665 :     }
666 :    
667 :     /**
668 :     * Returns an array containing all of the elements in this Vector in the
669 :     * correct order; the runtime type of the returned array is that of the
670 :     * specified array. If the Vector fits in the specified array, it is
671 :     * returned therein. Otherwise, a new array is allocated with the runtime
672 : jsr166 1.16 * type of the specified array and the size of this Vector.
673 : dl 1.1 *
674 : jsr166 1.16 * <p>If the Vector fits in the specified array with room to spare
675 : dl 1.1 * (i.e., the array has more elements than the Vector),
676 :     * the element in the array immediately following the end of the
677 :     * Vector is set to null. (This is useful in determining the length
678 :     * of the Vector <em>only</em> if the caller knows that the Vector
679 :     * does not contain any null elements.)
680 :     *
681 :     * @param a the array into which the elements of the Vector are to
682 : jsr166 1.23 * be stored, if it is big enough; otherwise, a new array of the
683 :     * same runtime type is allocated for this purpose.
684 : dl 1.1 * @return an array containing the elements of the Vector
685 : jsr166 1.17 * @throws ArrayStoreException if the runtime type of a is not a supertype
686 : dl 1.1 * of the runtime type of every element in this Vector
687 :     * @throws NullPointerException if the given array is null
688 :     * @since 1.2
689 :     */
690 : jsr166 1.22 @SuppressWarnings("unchecked")
691 : dl 1.1 public synchronized <T> T[] toArray(T[] a) {
692 :     if (a.length < elementCount)
693 :     return (T[]) Arrays.copyOf(elementData, elementCount, a.getClass());
694 :    
695 : jsr166 1.23 System.arraycopy(elementData, 0, a, 0, elementCount);
696 : dl 1.1
697 :     if (a.length > elementCount)
698 :     a[elementCount] = null;
699 :    
700 :     return a;
701 :     }
702 :    
703 :     // Positional Access Operations
704 :    
705 : jsr166 1.22 @SuppressWarnings("unchecked")
706 :     E elementData(int index) {
707 : jsr166 1.23 return (E) elementData[index];
708 : jsr166 1.22 }
709 :    
710 : dl 1.1 /**
711 :     * Returns the element at the specified position in this Vector.
712 :     *
713 :     * @param index index of the element to return
714 :     * @return object at the specified index
715 : jsr166 1.17 * @throws ArrayIndexOutOfBoundsException if the index is out of range
716 :     * ({@code index < 0 || index >= size()})
717 : dl 1.1 * @since 1.2
718 :     */
719 :     public synchronized E get(int index) {
720 : jsr166 1.23 if (index >= elementCount)
721 :     throw new ArrayIndexOutOfBoundsException(index);
722 : dl 1.1
723 : jsr166 1.23 return elementData(index);
724 : dl 1.1 }
725 :    
726 :     /**
727 :     * Replaces the element at the specified position in this Vector with the
728 :     * specified element.
729 :     *
730 :     * @param index index of the element to replace
731 :     * @param element element to be stored at the specified position
732 :     * @return the element previously at the specified position
733 : jsr166 1.17 * @throws ArrayIndexOutOfBoundsException if the index is out of range
734 : jsr166 1.23 * ({@code index < 0 || index >= size()})
735 : dl 1.1 * @since 1.2
736 :     */
737 :     public synchronized E set(int index, E element) {
738 : jsr166 1.23 if (index >= elementCount)
739 :     throw new ArrayIndexOutOfBoundsException(index);
740 : dl 1.1
741 : jsr166 1.23 E oldValue = elementData(index);
742 :     elementData[index] = element;
743 :     return oldValue;
744 : dl 1.1 }
745 :    
746 :     /**
747 :     * Appends the specified element to the end of this Vector.
748 :     *
749 :     * @param e element to be appended to this Vector
750 : jsr166 1.14 * @return {@code true} (as specified by {@link Collection#add})
751 : dl 1.1 * @since 1.2
752 :     */
753 :     public synchronized boolean add(E e) {
754 : jsr166 1.23 modCount++;
755 :     ensureCapacityHelper(elementCount + 1);
756 :     elementData[elementCount++] = e;
757 : dl 1.1 return true;
758 :     }
759 :    
760 :     /**
761 :     * Removes the first occurrence of the specified element in this Vector
762 :     * If the Vector does not contain the element, it is unchanged. More
763 :     * formally, removes the element with the lowest index i such that
764 : jsr166 1.14 * {@code (o==null ? get(i)==null : o.equals(get(i)))} (if such
765 : dl 1.1 * an element exists).
766 :     *
767 :     * @param o element to be removed from this Vector, if present
768 :     * @return true if the Vector contained the specified element
769 :     * @since 1.2
770 :     */
771 :     public boolean remove(Object o) {
772 :     return removeElement(o);
773 :     }
774 :    
775 :     /**
776 :     * Inserts the specified element at the specified position in this Vector.
777 :     * Shifts the element currently at that position (if any) and any
778 :     * subsequent elements to the right (adds one to their indices).
779 :     *
780 :     * @param index index at which the specified element is to be inserted
781 :     * @param element element to be inserted
782 : jsr166 1.17 * @throws ArrayIndexOutOfBoundsException if the index is out of range
783 :     * ({@code index < 0 || index > size()})
784 : dl 1.1 * @since 1.2
785 :     */
786 :     public void add(int index, E element) {
787 :     insertElementAt(element, index);
788 :     }
789 :    
790 :     /**
791 :     * Removes the element at the specified position in this Vector.
792 :     * Shifts any subsequent elements to the left (subtracts one from their
793 :     * indices). Returns the element that was removed from the Vector.
794 :     *
795 : jsr166 1.18 * @throws ArrayIndexOutOfBoundsException if the index is out of range
796 :     * ({@code index < 0 || index >= size()})
797 : dl 1.1 * @param index the index of the element to be removed
798 :     * @return element that was removed
799 :     * @since 1.2
800 :     */
801 :     public synchronized E remove(int index) {
802 : jsr166 1.23 modCount++;
803 :     if (index >= elementCount)
804 :     throw new ArrayIndexOutOfBoundsException(index);
805 :     E oldValue = elementData(index);
806 :    
807 :     int numMoved = elementCount - index - 1;
808 :     if (numMoved > 0)
809 :     System.arraycopy(elementData, index+1, elementData, index,
810 :     numMoved);
811 :     elementData[--elementCount] = null; // Let gc do its work
812 : dl 1.1
813 : jsr166 1.23 return oldValue;
814 : dl 1.1 }
815 :    
816 :     /**
817 :     * Removes all of the elements from this Vector. The Vector will
818 :     * be empty after this call returns (unless it throws an exception).
819 :     *
820 :     * @since 1.2
821 :     */
822 :     public void clear() {
823 :     removeAllElements();
824 :     }
825 :    
826 :     // Bulk Operations
827 :    
828 :     /**
829 :     * Returns true if this Vector contains all of the elements in the
830 :     * specified Collection.
831 :     *
832 :     * @param c a collection whose elements will be tested for containment
833 :     * in this Vector
834 :     * @return true if this Vector contains all of the elements in the
835 : jsr166 1.23 * specified collection
836 : dl 1.1 * @throws NullPointerException if the specified collection is null
837 :     */
838 :     public synchronized boolean containsAll(Collection<?> c) {
839 :     return super.containsAll(c);
840 :     }
841 :    
842 :     /**
843 :     * Appends all of the elements in the specified Collection to the end of
844 :     * this Vector, in the order that they are returned by the specified
845 :     * Collection's Iterator. The behavior of this operation is undefined if
846 :     * the specified Collection is modified while the operation is in progress.
847 :     * (This implies that the behavior of this call is undefined if the
848 :     * specified Collection is this Vector, and this Vector is nonempty.)
849 :     *
850 :     * @param c elements to be inserted into this Vector
851 : jsr166 1.14 * @return {@code true} if this Vector changed as a result of the call
852 : dl 1.1 * @throws NullPointerException if the specified collection is null
853 :     * @since 1.2
854 :     */
855 :     public synchronized boolean addAll(Collection<? extends E> c) {
856 : jsr166 1.23 modCount++;
857 : dl 1.1 Object[] a = c.toArray();
858 :     int numNew = a.length;
859 : jsr166 1.23 ensureCapacityHelper(elementCount + numNew);
860 : dl 1.1 System.arraycopy(a, 0, elementData, elementCount, numNew);
861 :     elementCount += numNew;
862 : jsr166 1.23 return numNew != 0;
863 : dl 1.1 }
864 :    
865 :     /**
866 :     * Removes from this Vector all of its elements that are contained in the
867 :     * specified Collection.
868 :     *
869 :     * @param c a collection of elements to be removed from the Vector
870 :     * @return true if this Vector changed as a result of the call
871 :     * @throws ClassCastException if the types of one or more elements
872 :     * in this vector are incompatible with the specified
873 :     * collection (optional)
874 :     * @throws NullPointerException if this vector contains one or more null
875 :     * elements and the specified collection does not support null
876 :     * elements (optional), or if the specified collection is null
877 :     * @since 1.2
878 :     */
879 :     public synchronized boolean removeAll(Collection<?> c) {
880 :     return super.removeAll(c);
881 :     }
882 :    
883 :     /**
884 :     * Retains only the elements in this Vector that are contained in the
885 :     * specified Collection. In other words, removes from this Vector all
886 :     * of its elements that are not contained in the specified Collection.
887 :     *
888 :     * @param c a collection of elements to be retained in this Vector
889 :     * (all other elements are removed)
890 :     * @return true if this Vector changed as a result of the call
891 :     * @throws ClassCastException if the types of one or more elements
892 :     * in this vector are incompatible with the specified
893 :     * collection (optional)
894 :     * @throws NullPointerException if this vector contains one or more null
895 :     * elements and the specified collection does not support null
896 :     * elements (optional), or if the specified collection is null
897 :     * @since 1.2
898 :     */
899 :     public synchronized boolean retainAll(Collection<?> c) {
900 :     return super.retainAll(c);
901 :     }
902 :    
903 :     /**
904 :     * Inserts all of the elements in the specified Collection into this
905 :     * Vector at the specified position. Shifts the element currently at
906 :     * that position (if any) and any subsequent elements to the right
907 :     * (increases their indices). The new elements will appear in the Vector
908 :     * in the order that they are returned by the specified Collection's
909 :     * iterator.
910 :     *
911 :     * @param index index at which to insert the first element from the
912 :     * specified collection
913 :     * @param c elements to be inserted into this Vector
914 : jsr166 1.14 * @return {@code true} if this Vector changed as a result of the call
915 : jsr166 1.18 * @throws ArrayIndexOutOfBoundsException if the index is out of range
916 :     * ({@code index < 0 || index > size()})
917 : dl 1.1 * @throws NullPointerException if the specified collection is null
918 :     * @since 1.2
919 :     */
920 :     public synchronized boolean addAll(int index, Collection<? extends E> c) {
921 : jsr166 1.23 modCount++;
922 :     if (index < 0 || index > elementCount)
923 :     throw new ArrayIndexOutOfBoundsException(index);
924 : dl 1.1
925 :     Object[] a = c.toArray();
926 : jsr166 1.23 int numNew = a.length;
927 :     ensureCapacityHelper(elementCount + numNew);
928 : dl 1.1
929 : jsr166 1.23 int numMoved = elementCount - index;
930 :     if (numMoved > 0)
931 :     System.arraycopy(elementData, index, elementData, index + numNew,
932 :     numMoved);
933 : dl 1.1
934 :     System.arraycopy(a, 0, elementData, index, numNew);
935 : jsr166 1.23 elementCount += numNew;
936 :     return numNew != 0;
937 : dl 1.1 }
938 :    
939 :     /**
940 :     * Compares the specified Object with this Vector for equality. Returns
941 :     * true if and only if the specified Object is also a List, both Lists
942 :     * have the same size, and all corresponding pairs of elements in the two
943 : jsr166 1.14 * Lists are <em>equal</em>. (Two elements {@code e1} and
944 :     * {@code e2} are <em>equal</em> if {@code (e1==null ? e2==null :
945 :     * e1.equals(e2))}.) In other words, two Lists are defined to be
946 : dl 1.1 * equal if they contain the same elements in the same order.
947 :     *
948 :     * @param o the Object to be compared for equality with this Vector
949 :     * @return true if the specified Object is equal to this Vector
950 :     */
951 :     public synchronized boolean equals(Object o) {
952 :     return super.equals(o);
953 :     }
954 :    
955 :     /**
956 :     * Returns the hash code value for this Vector.
957 :     */
958 :     public synchronized int hashCode() {
959 :     return super.hashCode();
960 :     }
961 :    
962 :     /**
963 :     * Returns a string representation of this Vector, containing
964 :     * the String representation of each element.
965 :     */
966 :     public synchronized String toString() {
967 :     return super.toString();
968 :     }
969 :    
970 :     /**
971 : jsr166 1.22 * Returns a view of the portion of this List between fromIndex,
972 :     * inclusive, and toIndex, exclusive. (If fromIndex and toIndex are
973 :     * equal, the returned List is empty.) The returned List is backed by this
974 :     * List, so changes in the returned List are reflected in this List, and
975 :     * vice-versa. The returned List supports all of the optional List
976 :     * operations supported by this List.
977 : dl 1.1 *
978 : jsr166 1.22 * <p>This method eliminates the need for explicit range operations (of
979 :     * the sort that commonly exist for arrays). Any operation that expects
980 :     * a List can be used as a range operation by operating on a subList view
981 :     * instead of a whole List. For example, the following idiom
982 :     * removes a range of elements from a List:
983 :     * <pre>
984 : jsr166 1.23 * list.subList(from, to).clear();
985 : jsr166 1.22 * </pre>
986 :     * Similar idioms may be constructed for indexOf and lastIndexOf,
987 :     * and all of the algorithms in the Collections class can be applied to
988 :     * a subList.
989 :     *
990 :     * <p>The semantics of the List returned by this method become undefined if
991 :     * the backing list (i.e., this List) is <i>structurally modified</i> in
992 :     * any way other than via the returned List. (Structural modifications are
993 :     * those that change the size of the List, or otherwise perturb it in such
994 :     * a fashion that iterations in progress may yield incorrect results.)
995 :     *
996 :     * @param fromIndex low endpoint (inclusive) of the subList
997 :     * @param toIndex high endpoint (exclusive) of the subList
998 :     * @return a view of the specified range within this List
999 :     * @throws IndexOutOfBoundsException if an endpoint index value is out of range
1000 :     * {@code (fromIndex < 0 || toIndex > size)}
1001 :     * @throws IllegalArgumentException if the endpoint indices are out of order
1002 : jsr166 1.23 * {@code (fromIndex > toIndex)}
1003 : jsr166 1.22 */
1004 :     public synchronized List<E> subList(int fromIndex, int toIndex) {
1005 :     return Collections.synchronizedList(super.subList(fromIndex, toIndex),
1006 :     this);
1007 :     }
1008 :    
1009 :     /**
1010 :     * Removes from this list all of the elements whose index is between
1011 :     * {@code fromIndex}, inclusive, and {@code toIndex}, exclusive.
1012 :     * Shifts any succeeding elements to the left (reduces their index).
1013 :     * This call shortens the list by {@code (toIndex - fromIndex)} elements.
1014 :     * (If {@code toIndex==fromIndex}, this operation has no effect.)
1015 : dl 1.1 */
1016 :     protected synchronized void removeRange(int fromIndex, int toIndex) {
1017 : jsr166 1.23 modCount++;
1018 :     int numMoved = elementCount - toIndex;
1019 : dl 1.1 System.arraycopy(elementData, toIndex, elementData, fromIndex,
1020 :     numMoved);
1021 :    
1022 : jsr166 1.23 // Let gc do its work
1023 :     int newElementCount = elementCount - (toIndex-fromIndex);
1024 :     while (elementCount != newElementCount)
1025 :     elementData[--elementCount] = null;
1026 : dl 1.1 }
1027 :    
1028 :     /**
1029 : jsr166 1.14 * Save the state of the {@code Vector} instance to a stream (that
1030 : dl 1.1 * is, serialize it). This method is present merely for synchronization.
1031 :     * It just calls the default writeObject method.
1032 :     */
1033 :     private synchronized void writeObject(java.io.ObjectOutputStream s)
1034 :     throws java.io.IOException
1035 :     {
1036 : jsr166 1.23 s.defaultWriteObject();
1037 : dl 1.1 }
1038 :    
1039 :     /**
1040 : jsr166 1.22 * Returns a list iterator over the elements in this list (in proper
1041 : dl 1.1 * sequence), starting at the specified position in the list.
1042 : jsr166 1.22 * The specified index indicates the first element that would be
1043 :     * returned by an initial call to {@link ListIterator#next next}.
1044 :     * An initial call to {@link ListIterator#previous previous} would
1045 :     * return the element with the specified index minus one.
1046 :     *
1047 :     * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
1048 : dl 1.1 *
1049 :     * @throws IndexOutOfBoundsException {@inheritDoc}
1050 :     */
1051 :     public synchronized ListIterator<E> listIterator(int index) {
1052 : jsr166 1.23 if (index < 0 || index > elementCount)
1053 : dl 1.1 throw new IndexOutOfBoundsException("Index: "+index);
1054 : jsr166 1.23 return new ListItr(index);
1055 : dl 1.1 }
1056 : jsr166 1.2
1057 : dl 1.1 /**
1058 : jsr166 1.22 * Returns a list iterator over the elements in this list (in proper
1059 :     * sequence).
1060 :     *
1061 :     * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
1062 :     *
1063 :     * @see #listIterator(int)
1064 : dl 1.3 */
1065 :     public synchronized ListIterator<E> listIterator() {
1066 : jsr166 1.23 return new ListItr(0);
1067 : dl 1.3 }
1068 :    
1069 :     /**
1070 : dl 1.1 * Returns an iterator over the elements in this list in proper sequence.
1071 :     *
1072 : jsr166 1.22 * <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
1073 :     *
1074 : dl 1.1 * @return an iterator over the elements in this list in proper sequence
1075 :     */
1076 :     public synchronized Iterator<E> iterator() {
1077 : jsr166 1.23 return new Itr();
1078 : dl 1.1 }
1079 :    
1080 :     /**
1081 : jsr166 1.22 * An optimized version of AbstractList.Itr
1082 : dl 1.10 */
1083 : jsr166 1.22 private class Itr implements Iterator<E> {
1084 : jsr166 1.23 int cursor; // index of next element to return
1085 :     int lastRet = -1; // index of last element returned; -1 if no such
1086 :     int expectedModCount = modCount;
1087 : jsr166 1.22
1088 : jsr166 1.23 public boolean hasNext() {
1089 : jsr166 1.22 // Racy but within spec, since modifications are checked
1090 :     // within or after synchronization in next/previous
1091 :     return cursor != elementCount;
1092 : jsr166 1.23 }
1093 :    
1094 :     public E next() {
1095 :     synchronized (Vector.this) {
1096 :     checkForComodification();
1097 :     int i = cursor;
1098 :     if (i >= elementCount)
1099 :     throw new NoSuchElementException();
1100 :     cursor = i + 1;
1101 :     return elementData(lastRet = i);
1102 :     }
1103 :     }
1104 : jsr166 1.22
1105 : jsr166 1.23 public void remove() {
1106 :     if (lastRet == -1)
1107 :     throw new IllegalStateException();
1108 :     synchronized (Vector.this) {
1109 :     checkForComodification();
1110 :     Vector.this.remove(lastRet);
1111 :     expectedModCount = modCount;
1112 : dl 1.10 }
1113 : jsr166 1.23 cursor = lastRet;
1114 :     lastRet = -1;
1115 :     }
1116 :    
1117 :     final void checkForComodification() {
1118 :     if (modCount != expectedModCount)
1119 :     throw new ConcurrentModificationException();
1120 :     }
1121 : dl 1.10 }
1122 :    
1123 :     /**
1124 : jsr166 1.22 * An optimized version of AbstractList.ListItr
1125 : dl 1.1 */
1126 : jsr166 1.22 final class ListItr extends Itr implements ListIterator<E> {
1127 : jsr166 1.23 ListItr(int index) {
1128 :     super();
1129 :     cursor = index;
1130 :     }
1131 :    
1132 :     public boolean hasPrevious() {
1133 :     return cursor != 0;
1134 :     }
1135 :    
1136 :     public int nextIndex() {
1137 :     return cursor;
1138 :     }
1139 :    
1140 :     public int previousIndex() {
1141 :     return cursor - 1;
1142 :     }
1143 :    
1144 :     public E previous() {
1145 :     synchronized (Vector.this) {
1146 :     checkForComodification();
1147 :     int i = cursor - 1;
1148 :     if (i < 0)
1149 :     throw new NoSuchElementException();
1150 :     cursor = i;
1151 :     return elementData(lastRet = i);
1152 :     }
1153 :     }
1154 :    
1155 :     public void set(E e) {
1156 :     if (lastRet == -1)
1157 :     throw new IllegalStateException();
1158 :     synchronized (Vector.this) {
1159 :     checkForComodification();
1160 :     Vector.this.set(lastRet, e);
1161 :     }
1162 :     }
1163 :    
1164 :     public void add(E e) {
1165 :     int i = cursor;
1166 :     synchronized (Vector.this) {
1167 :     checkForComodification();
1168 :     Vector.this.add(i, e);
1169 :     expectedModCount = modCount;
1170 :     }
1171 :     cursor = i + 1;
1172 :     lastRet = -1;
1173 :     }
1174 : dl 1.1 }
1175 :     }

Doug Lea
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