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1 : dl 1.1 /*
2 :     * %W% %E%
3 :     *
4 :     * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
5 :     * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6 :     */
7 :    
8 :     package java.util;
9 :     import java.util.*; // for javadoc (till 6280605 is fixed)
10 :    
11 :     /**
12 :     * The <code>Vector</code> class implements a growable array of
13 :     * objects. Like an array, it contains components that can be
14 :     * accessed using an integer index. However, the size of a
15 :     * <code>Vector</code> can grow or shrink as needed to accommodate
16 :     * adding and removing items after the <code>Vector</code> has been created.<p>
17 :     *
18 :     * Each vector tries to optimize storage management by maintaining a
19 :     * <code>capacity</code> and a <code>capacityIncrement</code>. The
20 :     * <code>capacity</code> is always at least as large as the vector
21 :     * size; it is usually larger because as components are added to the
22 :     * vector, the vector's storage increases in chunks the size of
23 :     * <code>capacityIncrement</code>. An application can increase the
24 :     * capacity of a vector before inserting a large number of
25 :     * components; this reduces the amount of incremental reallocation. <p>
26 :     *
27 :     * As of the Java 2 platform v1.2, this class has been retrofitted to
28 :     * implement List, so that it becomes a part of Java's collection framework.
29 :     * Unlike the new collection implementations, Vector is synchronized.<p>
30 :     *
31 :     * The Iterators returned by Vector's iterator and listIterator
32 :     * methods are <em>fail-fast</em>: if the Vector is structurally modified
33 :     * at any time after the Iterator is created, in any way except through the
34 :     * Iterator's own remove or add methods, the Iterator will throw a
35 :     * ConcurrentModificationException. Thus, in the face of concurrent
36 :     * modification, the Iterator fails quickly and cleanly, rather than risking
37 :     * arbitrary, non-deterministic behavior at an undetermined time in the future.
38 :     * The Enumerations returned by Vector's elements method are <em>not</em>
39 :     * fail-fast.
40 :     *
41 :     * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed
42 :     * as it is, generally speaking, impossible to make any hard guarantees in the
43 :     * presence of unsynchronized concurrent modification. Fail-fast iterators
44 :     * throw <tt>ConcurrentModificationException</tt> on a best-effort basis.
45 :     * Therefore, it would be wrong to write a program that depended on this
46 :     * exception for its correctness: <i>the fail-fast behavior of iterators
47 :     * should be used only to detect bugs.</i><p>
48 :     *
49 :     * This class is a member of the
50 :     * <a href="{@docRoot}/../guide/collections/index.html">
51 :     * Java Collections Framework</a>.
52 :     *
53 :     * @author Lee Boynton
54 :     * @author Jonathan Payne
55 :     * @version %I%, %G%
56 :     * @see Collection
57 :     * @see List
58 :     * @see ArrayList
59 :     * @see LinkedList
60 :     * @since JDK1.0
61 :     */
62 :     public class Vector<E>
63 :     extends AbstractList<E>
64 :     implements List<E>, RandomAccess, Cloneable, java.io.Serializable
65 :     {
66 :     /**
67 :     * The array buffer into which the components of the vector are
68 :     * stored. The capacity of the vector is the length of this array buffer,
69 :     * and is at least large enough to contain all the vector's elements.<p>
70 :     *
71 :     * Any array elements following the last element in the Vector are null.
72 :     *
73 :     * @serial
74 :     */
75 :     protected Object[] elementData;
76 :    
77 :     /**
78 :     * The number of valid components in this <tt>Vector</tt> object.
79 :     * Components <tt>elementData[0]</tt> through
80 :     * <tt>elementData[elementCount-1]</tt> are the actual items.
81 :     *
82 :     * @serial
83 :     */
84 :     protected int elementCount;
85 :    
86 :     /**
87 :     * The amount by which the capacity of the vector is automatically
88 :     * incremented when its size becomes greater than its capacity. If
89 :     * the capacity increment is less than or equal to zero, the capacity
90 :     * of the vector is doubled each time it needs to grow.
91 :     *
92 :     * @serial
93 :     */
94 :     protected int capacityIncrement;
95 :    
96 :     /** use serialVersionUID from JDK 1.0.2 for interoperability */
97 :     private static final long serialVersionUID = -2767605614048989439L;
98 :    
99 :     /**
100 :     * Constructs an empty vector with the specified initial capacity and
101 :     * capacity increment.
102 :     *
103 :     * @param initialCapacity the initial capacity of the vector
104 :     * @param capacityIncrement the amount by which the capacity is
105 :     * increased when the vector overflows
106 :     * @exception IllegalArgumentException if the specified initial capacity
107 :     * is negative
108 :     */
109 :     public Vector(int initialCapacity, int capacityIncrement) {
110 :     super();
111 :     if (initialCapacity < 0)
112 :     throw new IllegalArgumentException("Illegal Capacity: "+
113 :     initialCapacity);
114 :     this.elementData = new Object[initialCapacity];
115 :     this.capacityIncrement = capacityIncrement;
116 :     }
117 :    
118 :     /**
119 :     * Constructs an empty vector with the specified initial capacity and
120 :     * with its capacity increment equal to zero.
121 :     *
122 :     * @param initialCapacity the initial capacity of the vector
123 :     * @exception IllegalArgumentException if the specified initial capacity
124 :     * is negative
125 :     */
126 :     public Vector(int initialCapacity) {
127 :     this(initialCapacity, 0);
128 :     }
129 :    
130 :     /**
131 :     * Constructs an empty vector so that its internal data array
132 :     * has size <tt>10</tt> and its standard capacity increment is
133 :     * zero.
134 :     */
135 :     public Vector() {
136 :     this(10);
137 :     }
138 :    
139 :     /**
140 :     * Constructs a vector containing the elements of the specified
141 :     * collection, in the order they are returned by the collection's
142 :     * iterator.
143 :     *
144 :     * @param c the collection whose elements are to be placed into this
145 :     * vector
146 :     * @throws NullPointerException if the specified collection is null
147 :     * @since 1.2
148 :     */
149 :     public Vector(Collection<? extends E> c) {
150 : jsr166 1.6 elementData = c.toArray();
151 :     elementCount = elementData.length;
152 :     // c.toArray might (incorrectly) not return Object[] (see 6260652)
153 :     if (elementData.getClass() != Object[].class)
154 :     elementData = Arrays.copyOf(elementData, elementCount, Object[].class);
155 : dl 1.1 }
156 :    
157 :     /**
158 :     * Copies the components of this vector into the specified array.
159 :     * The item at index <tt>k</tt> in this vector is copied into
160 :     * component <tt>k</tt> of <tt>anArray</tt>.
161 :     *
162 :     * @param anArray the array into which the components get copied
163 :     * @throws NullPointerException if the given array is null
164 :     * @throws IndexOutOfBoundsException if the specified array is not
165 :     * large enough to hold all the components of this vector
166 :     * @throws ArrayStoreException if a component of this vector is not of
167 :     * a runtime type that can be stored in the specified array
168 :     * @see #toArray(Object[])
169 :     */
170 :     public synchronized void copyInto(Object[] anArray) {
171 :     System.arraycopy(elementData, 0, anArray, 0, elementCount);
172 :     }
173 :    
174 :     /**
175 :     * Trims the capacity of this vector to be the vector's current
176 :     * size. If the capacity of this vector is larger than its current
177 :     * size, then the capacity is changed to equal the size by replacing
178 :     * its internal data array, kept in the field <tt>elementData</tt>,
179 :     * with a smaller one. An application can use this operation to
180 :     * minimize the storage of a vector.
181 :     */
182 :     public synchronized void trimToSize() {
183 :     modCount++;
184 :     int oldCapacity = elementData.length;
185 :     if (elementCount < oldCapacity) {
186 :     elementData = Arrays.copyOf(elementData, elementCount);
187 :     }
188 :     }
189 :    
190 :     /**
191 :     * Increases the capacity of this vector, if necessary, to ensure
192 :     * that it can hold at least the number of components specified by
193 :     * the minimum capacity argument.
194 :     *
195 :     * <p>If the current capacity of this vector is less than
196 :     * <tt>minCapacity</tt>, then its capacity is increased by replacing its
197 :     * internal data array, kept in the field <tt>elementData</tt>, with a
198 :     * larger one. The size of the new data array will be the old size plus
199 :     * <tt>capacityIncrement</tt>, unless the value of
200 :     * <tt>capacityIncrement</tt> is less than or equal to zero, in which case
201 :     * the new capacity will be twice the old capacity; but if this new size
202 :     * is still smaller than <tt>minCapacity</tt>, then the new capacity will
203 :     * be <tt>minCapacity</tt>.
204 :     *
205 :     * @param minCapacity the desired minimum capacity
206 :     */
207 :     public synchronized void ensureCapacity(int minCapacity) {
208 :     modCount++;
209 :     ensureCapacityHelper(minCapacity);
210 :     }
211 :    
212 :     /**
213 :     * This implements the unsynchronized semantics of ensureCapacity.
214 :     * Synchronized methods in this class can internally call this
215 :     * method for ensuring capacity without incurring the cost of an
216 :     * extra synchronization.
217 :     *
218 :     * @see java.util.Vector#ensureCapacity(int)
219 :     */
220 :     private void ensureCapacityHelper(int minCapacity) {
221 :     int oldCapacity = elementData.length;
222 :     if (minCapacity > oldCapacity) {
223 :     Object[] oldData = elementData;
224 :     int newCapacity = (capacityIncrement > 0) ?
225 :     (oldCapacity + capacityIncrement) : (oldCapacity * 2);
226 :     if (newCapacity < minCapacity) {
227 :     newCapacity = minCapacity;
228 :     }
229 :     elementData = Arrays.copyOf(elementData, newCapacity);
230 :     }
231 :     }
232 :    
233 :     /**
234 :     * Sets the size of this vector. If the new size is greater than the
235 :     * current size, new <code>null</code> items are added to the end of
236 :     * the vector. If the new size is less than the current size, all
237 :     * components at index <code>newSize</code> and greater are discarded.
238 :     *
239 :     * @param newSize the new size of this vector
240 :     * @throws ArrayIndexOutOfBoundsException if new size is negative
241 :     */
242 :     public synchronized void setSize(int newSize) {
243 :     modCount++;
244 :     if (newSize > elementCount) {
245 :     ensureCapacityHelper(newSize);
246 :     } else {
247 :     for (int i = newSize ; i < elementCount ; i++) {
248 :     elementData[i] = null;
249 :     }
250 :     }
251 :     elementCount = newSize;
252 :     }
253 :    
254 :     /**
255 :     * Returns the current capacity of this vector.
256 :     *
257 :     * @return the current capacity (the length of its internal
258 :     * data array, kept in the field <tt>elementData</tt>
259 :     * of this vector)
260 :     */
261 :     public synchronized int capacity() {
262 :     return elementData.length;
263 :     }
264 :    
265 :     /**
266 :     * Returns the number of components in this vector.
267 :     *
268 :     * @return the number of components in this vector
269 :     */
270 :     public synchronized int size() {
271 :     return elementCount;
272 :     }
273 :    
274 :     /**
275 :     * Tests if this vector has no components.
276 :     *
277 :     * @return <code>true</code> if and only if this vector has
278 :     * no components, that is, its size is zero;
279 :     * <code>false</code> otherwise.
280 :     */
281 :     public synchronized boolean isEmpty() {
282 :     return elementCount == 0;
283 :     }
284 :    
285 :     /**
286 :     * Returns an enumeration of the components of this vector. The
287 :     * returned <tt>Enumeration</tt> object will generate all items in
288 :     * this vector. The first item generated is the item at index <tt>0</tt>,
289 :     * then the item at index <tt>1</tt>, and so on.
290 :     *
291 :     * @return an enumeration of the components of this vector
292 :     * @see Enumeration
293 :     * @see Iterator
294 :     */
295 :     public Enumeration<E> elements() {
296 :     return new Enumeration<E>() {
297 :     int count = 0;
298 :    
299 :     public boolean hasMoreElements() {
300 :     return count < elementCount;
301 :     }
302 :    
303 :     public E nextElement() {
304 :     synchronized (Vector.this) {
305 :     if (count < elementCount) {
306 :     return (E)elementData[count++];
307 :     }
308 :     }
309 :     throw new NoSuchElementException("Vector Enumeration");
310 :     }
311 :     };
312 :     }
313 :    
314 :     /**
315 :     * Returns <tt>true</tt> if this vector contains the specified element.
316 :     * More formally, returns <tt>true</tt> if and only if this vector
317 :     * contains at least one element <tt>e</tt> such that
318 :     * <tt>(o==null&nbsp;?&nbsp;e==null&nbsp;:&nbsp;o.equals(e))</tt>.
319 :     *
320 :     * @param o element whose presence in this vector is to be tested
321 :     * @return <tt>true</tt> if this vector contains the specified element
322 :     */
323 :     public boolean contains(Object o) {
324 :     return indexOf(o, 0) >= 0;
325 :     }
326 :    
327 :     /**
328 :     * Returns the index of the first occurrence of the specified element
329 :     * in this vector, or -1 if this vector does not contain the element.
330 :     * More formally, returns the lowest index <tt>i</tt> such that
331 :     * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
332 :     * or -1 if there is no such index.
333 :     *
334 :     * @param o element to search for
335 :     * @return the index of the first occurrence of the specified element in
336 :     * this vector, or -1 if this vector does not contain the element
337 :     */
338 :     public int indexOf(Object o) {
339 :     return indexOf(o, 0);
340 :     }
341 :    
342 :     /**
343 :     * Returns the index of the first occurrence of the specified element in
344 :     * this vector, searching forwards from <tt>index</tt>, or returns -1 if
345 :     * the element is not found.
346 :     * More formally, returns the lowest index <tt>i</tt> such that
347 :     * <tt>(i&nbsp;&gt;=&nbsp;index&nbsp;&amp;&amp;&nbsp;(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 :     * @param index index to start searching from
352 :     * @return the index of the first occurrence of the element in
353 :     * this vector at position <tt>index</tt> or later in the vector;
354 :     * <tt>-1</tt> if the element is not found.
355 :     * @throws IndexOutOfBoundsException if the specified index is negative
356 :     * @see Object#equals(Object)
357 :     */
358 :     public synchronized int indexOf(Object o, int index) {
359 :     if (o == null) {
360 :     for (int i = index ; i < elementCount ; i++)
361 :     if (elementData[i]==null)
362 :     return i;
363 :     } else {
364 :     for (int i = index ; i < elementCount ; i++)
365 :     if (o.equals(elementData[i]))
366 :     return i;
367 :     }
368 :     return -1;
369 :     }
370 :    
371 :     /**
372 :     * Returns the index of the last occurrence of the specified element
373 :     * in this vector, or -1 if this vector does not contain the element.
374 :     * More formally, returns the highest index <tt>i</tt> such that
375 :     * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
376 :     * or -1 if there is no such index.
377 :     *
378 :     * @param o element to search for
379 :     * @return the index of the last occurrence of the specified element in
380 :     * this vector, or -1 if this vector does not contain the element
381 :     */
382 :     public synchronized int lastIndexOf(Object o) {
383 :     return lastIndexOf(o, elementCount-1);
384 :     }
385 :    
386 :     /**
387 :     * Returns the index of the last occurrence of the specified element in
388 :     * this vector, searching backwards from <tt>index</tt>, or returns -1 if
389 :     * the element is not found.
390 :     * More formally, returns the highest index <tt>i</tt> such that
391 :     * <tt>(i&nbsp;&lt;=&nbsp;index&nbsp;&amp;&amp;&nbsp;(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 :     * @param index index to start searching backwards from
396 :     * @return the index of the last occurrence of the element at position
397 :     * less than or equal to <tt>index</tt> in this vector;
398 :     * -1 if the element is not found.
399 :     * @throws IndexOutOfBoundsException if the specified index is greater
400 :     * than or equal to the current size of this vector
401 :     */
402 :     public synchronized int lastIndexOf(Object o, int index) {
403 :     if (index >= elementCount)
404 :     throw new IndexOutOfBoundsException(index + " >= "+ elementCount);
405 :    
406 :     if (o == null) {
407 :     for (int i = index; i >= 0; i--)
408 :     if (elementData[i]==null)
409 :     return i;
410 :     } else {
411 :     for (int i = index; i >= 0; i--)
412 :     if (o.equals(elementData[i]))
413 :     return i;
414 :     }
415 :     return -1;
416 :     }
417 :    
418 :     /**
419 :     * Returns the component at the specified index.<p>
420 :     *
421 :     * This method is identical in functionality to the get method
422 :     * (which is part of the List interface).
423 :     *
424 :     * @param index an index into this vector
425 :     * @return the component at the specified index
426 :     * @exception ArrayIndexOutOfBoundsException if the <tt>index</tt>
427 :     * is negative or not less than the current size of this
428 :     * <tt>Vector</tt> object.
429 :     * @see #get(int)
430 :     * @see List
431 :     */
432 :     public synchronized E elementAt(int index) {
433 :     if (index >= elementCount) {
434 :     throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount);
435 :     }
436 :    
437 :     return (E)elementData[index];
438 :     }
439 :    
440 :     /**
441 :     * Returns the first component (the item at index <tt>0</tt>) of
442 :     * this vector.
443 :     *
444 :     * @return the first component of this vector
445 :     * @exception NoSuchElementException if this vector has no components
446 :     */
447 :     public synchronized E firstElement() {
448 :     if (elementCount == 0) {
449 :     throw new NoSuchElementException();
450 :     }
451 :     return (E)elementData[0];
452 :     }
453 :    
454 :     /**
455 :     * Returns the last component of the vector.
456 :     *
457 :     * @return the last component of the vector, i.e., the component at index
458 :     * <code>size()&nbsp;-&nbsp;1</code>.
459 :     * @exception NoSuchElementException if this vector is empty
460 :     */
461 :     public synchronized E lastElement() {
462 :     if (elementCount == 0) {
463 :     throw new NoSuchElementException();
464 :     }
465 :     return (E)elementData[elementCount - 1];
466 :     }
467 :    
468 :     /**
469 :     * Sets the component at the specified <code>index</code> of this
470 :     * vector to be the specified object. The previous component at that
471 :     * position is discarded.<p>
472 :     *
473 :     * The index must be a value greater than or equal to <code>0</code>
474 :     * and less than the current size of the vector. <p>
475 :     *
476 :     * This method is identical in functionality to the set method
477 :     * (which is part of the List interface). Note that the set method reverses
478 :     * the order of the parameters, to more closely match array usage. Note
479 :     * also that the set method returns the old value that was stored at the
480 :     * specified position.
481 :     *
482 :     * @param obj what the component is to be set to
483 :     * @param index the specified index
484 :     * @exception ArrayIndexOutOfBoundsException if the index was invalid
485 :     * @see #size()
486 :     * @see List
487 :     * @see #set(int, java.lang.Object)
488 :     */
489 :     public synchronized void setElementAt(E obj, int index) {
490 :     if (index >= elementCount) {
491 :     throw new ArrayIndexOutOfBoundsException(index + " >= " +
492 :     elementCount);
493 :     }
494 :     elementData[index] = obj;
495 :     }
496 :    
497 :     /**
498 :     * Deletes the component at the specified index. Each component in
499 :     * this vector with an index greater or equal to the specified
500 :     * <code>index</code> is shifted downward to have an index one
501 :     * smaller than the value it had previously. The size of this vector
502 :     * is decreased by <tt>1</tt>.<p>
503 :     *
504 :     * The index must be a value greater than or equal to <code>0</code>
505 :     * and less than the current size of the vector. <p>
506 :     *
507 :     * This method is identical in functionality to the remove method
508 :     * (which is part of the List interface). Note that the remove method
509 :     * returns the old value that was stored at the specified position.
510 :     *
511 :     * @param index the index of the object to remove
512 :     * @exception ArrayIndexOutOfBoundsException if the index was invalid
513 :     * @see #size()
514 :     * @see #remove(int)
515 :     * @see List
516 :     */
517 :     public synchronized void removeElementAt(int index) {
518 :     modCount++;
519 :     if (index >= elementCount) {
520 :     throw new ArrayIndexOutOfBoundsException(index + " >= " +
521 :     elementCount);
522 :     }
523 :     else if (index < 0) {
524 :     throw new ArrayIndexOutOfBoundsException(index);
525 :     }
526 :     int j = elementCount - index - 1;
527 :     if (j > 0) {
528 :     System.arraycopy(elementData, index + 1, elementData, index, j);
529 :     }
530 :     elementCount--;
531 :     elementData[elementCount] = null; /* to let gc do its work */
532 :     }
533 :    
534 :     /**
535 :     * Inserts the specified object as a component in this vector at the
536 :     * specified <code>index</code>. Each component in this vector with
537 :     * an index greater or equal to the specified <code>index</code> is
538 :     * shifted upward to have an index one greater than the value it had
539 :     * previously. <p>
540 :     *
541 :     * The index must be a value greater than or equal to <code>0</code>
542 :     * and less than or equal to the current size of the vector. (If the
543 :     * index is equal to the current size of the vector, the new element
544 :     * is appended to the Vector.)<p>
545 :     *
546 :     * This method is identical in functionality to the add(Object, int) method
547 :     * (which is part of the List interface). Note that the add method reverses
548 :     * the order of the parameters, to more closely match array usage.
549 :     *
550 :     * @param obj the component to insert
551 :     * @param index where to insert the new component
552 :     * @exception ArrayIndexOutOfBoundsException if the index was invalid
553 :     * @see #size()
554 :     * @see #add(int, Object)
555 :     * @see List
556 :     */
557 :     public synchronized void insertElementAt(E obj, int index) {
558 :     modCount++;
559 :     if (index > elementCount) {
560 :     throw new ArrayIndexOutOfBoundsException(index
561 :     + " > " + elementCount);
562 :     }
563 :     ensureCapacityHelper(elementCount + 1);
564 :     System.arraycopy(elementData, index, elementData, index + 1, elementCount - index);
565 :     elementData[index] = obj;
566 :     elementCount++;
567 :     }
568 :    
569 :     /**
570 :     * Adds the specified component to the end of this vector,
571 :     * increasing its size by one. The capacity of this vector is
572 :     * increased if its size becomes greater than its capacity. <p>
573 :     *
574 :     * This method is identical in functionality to the add(Object) method
575 :     * (which is part of the List interface).
576 :     *
577 :     * @param obj the component to be added
578 :     * @see #add(Object)
579 :     * @see List
580 :     */
581 :     public synchronized void addElement(E obj) {
582 :     modCount++;
583 :     ensureCapacityHelper(elementCount + 1);
584 :     elementData[elementCount++] = obj;
585 :     }
586 :    
587 :     /**
588 :     * Removes the first (lowest-indexed) occurrence of the argument
589 :     * from this vector. If the object is found in this vector, each
590 :     * component in the vector with an index greater or equal to the
591 :     * object's index is shifted downward to have an index one smaller
592 :     * than the value it had previously.<p>
593 :     *
594 :     * This method is identical in functionality to the remove(Object)
595 :     * method (which is part of the List interface).
596 :     *
597 :     * @param obj the component to be removed
598 :     * @return <code>true</code> if the argument was a component of this
599 :     * vector; <code>false</code> otherwise.
600 :     * @see List#remove(Object)
601 :     * @see List
602 :     */
603 :     public synchronized boolean removeElement(Object obj) {
604 :     modCount++;
605 :     int i = indexOf(obj);
606 :     if (i >= 0) {
607 :     removeElementAt(i);
608 :     return true;
609 :     }
610 :     return false;
611 :     }
612 :    
613 :     /**
614 :     * Removes all components from this vector and sets its size to zero.<p>
615 :     *
616 :     * This method is identical in functionality to the clear method
617 :     * (which is part of the List interface).
618 :     *
619 :     * @see #clear
620 :     * @see List
621 :     */
622 :     public synchronized void removeAllElements() {
623 :     modCount++;
624 :     // Let gc do its work
625 :     for (int i = 0; i < elementCount; i++)
626 :     elementData[i] = null;
627 :    
628 :     elementCount = 0;
629 :     }
630 :    
631 :     /**
632 :     * Returns a clone of this vector. The copy will contain a
633 :     * reference to a clone of the internal data array, not a reference
634 :     * to the original internal data array of this <tt>Vector</tt> object.
635 :     *
636 :     * @return a clone of this vector
637 :     */
638 :     public synchronized Object clone() {
639 :     try {
640 :     Vector<E> v = (Vector<E>) super.clone();
641 :     v.elementData = Arrays.copyOf(elementData, elementCount);
642 :     v.modCount = 0;
643 :     return v;
644 :     } catch (CloneNotSupportedException e) {
645 :     // this shouldn't happen, since we are Cloneable
646 :     throw new InternalError();
647 :     }
648 :     }
649 :    
650 :     /**
651 :     * Returns an array containing all of the elements in this Vector
652 :     * in the correct order.
653 :     *
654 :     * @since 1.2
655 :     */
656 :     public synchronized Object[] toArray() {
657 :     return Arrays.copyOf(elementData, elementCount);
658 :     }
659 :    
660 :     /**
661 :     * Returns an array containing all of the elements in this Vector in the
662 :     * correct order; the runtime type of the returned array is that of the
663 :     * specified array. If the Vector fits in the specified array, it is
664 :     * returned therein. Otherwise, a new array is allocated with the runtime
665 :     * type of the specified array and the size of this Vector.<p>
666 :     *
667 :     * If the Vector fits in the specified array with room to spare
668 :     * (i.e., the array has more elements than the Vector),
669 :     * the element in the array immediately following the end of the
670 :     * Vector is set to null. (This is useful in determining the length
671 :     * of the Vector <em>only</em> if the caller knows that the Vector
672 :     * does not contain any null elements.)
673 :     *
674 :     * @param a the array into which the elements of the Vector are to
675 :     * be stored, if it is big enough; otherwise, a new array of the
676 :     * same runtime type is allocated for this purpose.
677 :     * @return an array containing the elements of the Vector
678 :     * @exception ArrayStoreException the runtime type of a is not a supertype
679 :     * of the runtime type of every element in this Vector
680 :     * @throws NullPointerException if the given array is null
681 :     * @since 1.2
682 :     */
683 :     public synchronized <T> T[] toArray(T[] a) {
684 :     if (a.length < elementCount)
685 :     return (T[]) Arrays.copyOf(elementData, elementCount, a.getClass());
686 :    
687 :     System.arraycopy(elementData, 0, a, 0, elementCount);
688 :    
689 :     if (a.length > elementCount)
690 :     a[elementCount] = null;
691 :    
692 :     return a;
693 :     }
694 :    
695 :     // Positional Access Operations
696 :    
697 :     /**
698 :     * Returns the element at the specified position in this Vector.
699 :     *
700 :     * @param index index of the element to return
701 :     * @return object at the specified index
702 :     * @exception ArrayIndexOutOfBoundsException index is out of range (index
703 :     * &lt; 0 || index &gt;= size())
704 :     * @since 1.2
705 :     */
706 :     public synchronized E get(int index) {
707 :     if (index >= elementCount)
708 :     throw new ArrayIndexOutOfBoundsException(index);
709 :    
710 :     return (E)elementData[index];
711 :     }
712 :    
713 :     /**
714 :     * Replaces the element at the specified position in this Vector with the
715 :     * specified element.
716 :     *
717 :     * @param index index of the element to replace
718 :     * @param element element to be stored at the specified position
719 :     * @return the element previously at the specified position
720 :     * @exception ArrayIndexOutOfBoundsException index out of range
721 :     * (index &lt; 0 || index &gt;= size())
722 :     * @since 1.2
723 :     */
724 :     public synchronized E set(int index, E element) {
725 :     if (index >= elementCount)
726 :     throw new ArrayIndexOutOfBoundsException(index);
727 :    
728 :     Object oldValue = elementData[index];
729 :     elementData[index] = element;
730 :     return (E)oldValue;
731 :     }
732 :    
733 :     /**
734 :     * Appends the specified element to the end of this Vector.
735 :     *
736 :     * @param e element to be appended to this Vector
737 :     * @return <tt>true</tt> (as specified by {@link Collection#add})
738 :     * @since 1.2
739 :     */
740 :     public synchronized boolean add(E e) {
741 :     modCount++;
742 :     ensureCapacityHelper(elementCount + 1);
743 :     elementData[elementCount++] = e;
744 :     return true;
745 :     }
746 :    
747 :     /**
748 :     * Removes the first occurrence of the specified element in this Vector
749 :     * If the Vector does not contain the element, it is unchanged. More
750 :     * formally, removes the element with the lowest index i such that
751 :     * <code>(o==null ? get(i)==null : o.equals(get(i)))</code> (if such
752 :     * an element exists).
753 :     *
754 :     * @param o element to be removed from this Vector, if present
755 :     * @return true if the Vector contained the specified element
756 :     * @since 1.2
757 :     */
758 :     public boolean remove(Object o) {
759 :     return removeElement(o);
760 :     }
761 :    
762 :     /**
763 :     * Inserts the specified element at the specified position in this Vector.
764 :     * Shifts the element currently at that position (if any) and any
765 :     * subsequent elements to the right (adds one to their indices).
766 :     *
767 :     * @param index index at which the specified element is to be inserted
768 :     * @param element element to be inserted
769 :     * @exception ArrayIndexOutOfBoundsException index is out of range
770 :     * (index &lt; 0 || index &gt; size())
771 :     * @since 1.2
772 :     */
773 :     public void add(int index, E element) {
774 :     insertElementAt(element, index);
775 :     }
776 :    
777 :     /**
778 :     * Removes the element at the specified position in this Vector.
779 :     * Shifts any subsequent elements to the left (subtracts one from their
780 :     * indices). Returns the element that was removed from the Vector.
781 :     *
782 :     * @exception ArrayIndexOutOfBoundsException index out of range (index
783 :     * &lt; 0 || index &gt;= size())
784 :     * @param index the index of the element to be removed
785 :     * @return element that was removed
786 :     * @since 1.2
787 :     */
788 :     public synchronized E remove(int index) {
789 :     modCount++;
790 :     if (index >= elementCount)
791 :     throw new ArrayIndexOutOfBoundsException(index);
792 :     Object oldValue = elementData[index];
793 :    
794 :     int numMoved = elementCount - index - 1;
795 :     if (numMoved > 0)
796 :     System.arraycopy(elementData, index+1, elementData, index,
797 :     numMoved);
798 :     elementData[--elementCount] = null; // Let gc do its work
799 :    
800 :     return (E)oldValue;
801 :     }
802 :    
803 :     /**
804 :     * Removes all of the elements from this Vector. The Vector will
805 :     * be empty after this call returns (unless it throws an exception).
806 :     *
807 :     * @since 1.2
808 :     */
809 :     public void clear() {
810 :     removeAllElements();
811 :     }
812 :    
813 :     // Bulk Operations
814 :    
815 :     /**
816 :     * Returns true if this Vector contains all of the elements in the
817 :     * specified Collection.
818 :     *
819 :     * @param c a collection whose elements will be tested for containment
820 :     * in this Vector
821 :     * @return true if this Vector contains all of the elements in the
822 :     * specified collection
823 :     * @throws NullPointerException if the specified collection is null
824 :     */
825 :     public synchronized boolean containsAll(Collection<?> c) {
826 :     return super.containsAll(c);
827 :     }
828 :    
829 :     /**
830 :     * Appends all of the elements in the specified Collection to the end of
831 :     * this Vector, in the order that they are returned by the specified
832 :     * Collection's Iterator. The behavior of this operation is undefined if
833 :     * the specified Collection is modified while the operation is in progress.
834 :     * (This implies that the behavior of this call is undefined if the
835 :     * specified Collection is this Vector, and this Vector is nonempty.)
836 :     *
837 :     * @param c elements to be inserted into this Vector
838 :     * @return <tt>true</tt> if this Vector changed as a result of the call
839 :     * @throws NullPointerException if the specified collection is null
840 :     * @since 1.2
841 :     */
842 :     public synchronized boolean addAll(Collection<? extends E> c) {
843 :     modCount++;
844 :     Object[] a = c.toArray();
845 :     int numNew = a.length;
846 :     ensureCapacityHelper(elementCount + numNew);
847 :     System.arraycopy(a, 0, elementData, elementCount, numNew);
848 :     elementCount += numNew;
849 :     return numNew != 0;
850 :     }
851 :    
852 :     /**
853 :     * Removes from this Vector all of its elements that are contained in the
854 :     * specified Collection.
855 :     *
856 :     * @param c a collection of elements to be removed from the Vector
857 :     * @return true if this Vector changed as a result of the call
858 :     * @throws ClassCastException if the types of one or more elements
859 :     * in this vector are incompatible with the specified
860 :     * collection (optional)
861 :     * @throws NullPointerException if this vector contains one or more null
862 :     * elements and the specified collection does not support null
863 :     * elements (optional), or if the specified collection is null
864 :     * @since 1.2
865 :     */
866 :     public synchronized boolean removeAll(Collection<?> c) {
867 :     return super.removeAll(c);
868 :     }
869 :    
870 :     /**
871 :     * Retains only the elements in this Vector that are contained in the
872 :     * specified Collection. In other words, removes from this Vector all
873 :     * of its elements that are not contained in the specified Collection.
874 :     *
875 :     * @param c a collection of elements to be retained in this Vector
876 :     * (all other elements are removed)
877 :     * @return true if this Vector changed as a result of the call
878 :     * @throws ClassCastException if the types of one or more elements
879 :     * in this vector are incompatible with the specified
880 :     * collection (optional)
881 :     * @throws NullPointerException if this vector contains one or more null
882 :     * elements and the specified collection does not support null
883 :     * elements (optional), or if the specified collection is null
884 :     * @since 1.2
885 :     */
886 :     public synchronized boolean retainAll(Collection<?> c) {
887 :     return super.retainAll(c);
888 :     }
889 :    
890 :     /**
891 :     * Inserts all of the elements in the specified Collection into this
892 :     * Vector at the specified position. Shifts the element currently at
893 :     * that position (if any) and any subsequent elements to the right
894 :     * (increases their indices). The new elements will appear in the Vector
895 :     * in the order that they are returned by the specified Collection's
896 :     * iterator.
897 :     *
898 :     * @param index index at which to insert the first element from the
899 :     * specified collection
900 :     * @param c elements to be inserted into this Vector
901 :     * @return <tt>true</tt> if this Vector changed as a result of the call
902 :     * @exception ArrayIndexOutOfBoundsException index out of range (index
903 :     * &lt; 0 || index &gt; size())
904 :     * @throws NullPointerException if the specified collection is null
905 :     * @since 1.2
906 :     */
907 :     public synchronized boolean addAll(int index, Collection<? extends E> c) {
908 :     modCount++;
909 :     if (index < 0 || index > elementCount)
910 :     throw new ArrayIndexOutOfBoundsException(index);
911 :    
912 :     Object[] a = c.toArray();
913 :     int numNew = a.length;
914 :     ensureCapacityHelper(elementCount + numNew);
915 :    
916 :     int numMoved = elementCount - index;
917 :     if (numMoved > 0)
918 :     System.arraycopy(elementData, index, elementData, index + numNew,
919 :     numMoved);
920 :    
921 :     System.arraycopy(a, 0, elementData, index, numNew);
922 :     elementCount += numNew;
923 :     return numNew != 0;
924 :     }
925 :    
926 :     /**
927 :     * Compares the specified Object with this Vector for equality. Returns
928 :     * true if and only if the specified Object is also a List, both Lists
929 :     * have the same size, and all corresponding pairs of elements in the two
930 :     * Lists are <em>equal</em>. (Two elements <code>e1</code> and
931 :     * <code>e2</code> are <em>equal</em> if <code>(e1==null ? e2==null :
932 :     * e1.equals(e2))</code>.) In other words, two Lists are defined to be
933 :     * equal if they contain the same elements in the same order.
934 :     *
935 :     * @param o the Object to be compared for equality with this Vector
936 :     * @return true if the specified Object is equal to this Vector
937 :     */
938 :     public synchronized boolean equals(Object o) {
939 :     return super.equals(o);
940 :     }
941 :    
942 :     /**
943 :     * Returns the hash code value for this Vector.
944 :     */
945 :     public synchronized int hashCode() {
946 :     return super.hashCode();
947 :     }
948 :    
949 :     /**
950 :     * Returns a string representation of this Vector, containing
951 :     * the String representation of each element.
952 :     */
953 :     public synchronized String toString() {
954 :     return super.toString();
955 :     }
956 :    
957 :     /**
958 :     * Returns a view of the portion of this List between fromIndex,
959 :     * inclusive, and toIndex, exclusive. (If fromIndex and toIndex are
960 :     * equal, the returned List is empty.) The returned List is backed by this
961 :     * List, so changes in the returned List are reflected in this List, and
962 :     * vice-versa. The returned List supports all of the optional List
963 :     * operations supported by this List.<p>
964 :     *
965 :     * This method eliminates the need for explicit range operations (of
966 :     * the sort that commonly exist for arrays). Any operation that expects
967 :     * a List can be used as a range operation by operating on a subList view
968 :     * instead of a whole List. For example, the following idiom
969 :     * removes a range of elements from a List:
970 :     * <pre>
971 :     * list.subList(from, to).clear();
972 :     * </pre>
973 :     * Similar idioms may be constructed for indexOf and lastIndexOf,
974 :     * and all of the algorithms in the Collections class can be applied to
975 :     * a subList.<p>
976 :     *
977 :     * The semantics of the List returned by this method become undefined if
978 :     * the backing list (i.e., this List) is <i>structurally modified</i> in
979 :     * any way other than via the returned List. (Structural modifications are
980 :     * those that change the size of the List, or otherwise perturb it in such
981 :     * a fashion that iterations in progress may yield incorrect results.)
982 :     *
983 :     * @param fromIndex low endpoint (inclusive) of the subList
984 :     * @param toIndex high endpoint (exclusive) of the subList
985 :     * @return a view of the specified range within this List
986 :     * @throws IndexOutOfBoundsException endpoint index value out of range
987 :     * <code>(fromIndex &lt; 0 || toIndex &gt; size)</code>
988 :     * @throws IllegalArgumentException endpoint indices out of order
989 :     * <code>(fromIndex &gt; toIndex)</code>
990 :     */
991 :     public synchronized List<E> subList(int fromIndex, int toIndex) {
992 :     return Collections.synchronizedList(super.subList(fromIndex, toIndex),
993 :     this);
994 :     }
995 :    
996 :     /**
997 :     * Removes from this List all of the elements whose index is between
998 :     * fromIndex, inclusive and toIndex, exclusive. Shifts any succeeding
999 :     * elements to the left (reduces their index).
1000 :     * This call shortens the ArrayList by (toIndex - fromIndex) elements. (If
1001 :     * toIndex==fromIndex, this operation has no effect.)
1002 :     *
1003 :     * @param fromIndex index of first element to be removed
1004 :     * @param toIndex index after last element to be removed
1005 :     */
1006 :     protected synchronized void removeRange(int fromIndex, int toIndex) {
1007 :     modCount++;
1008 :     int numMoved = elementCount - toIndex;
1009 :     System.arraycopy(elementData, toIndex, elementData, fromIndex,
1010 :     numMoved);
1011 :    
1012 :     // Let gc do its work
1013 :     int newElementCount = elementCount - (toIndex-fromIndex);
1014 :     while (elementCount != newElementCount)
1015 :     elementData[--elementCount] = null;
1016 :     }
1017 :    
1018 :     /**
1019 :     * Save the state of the <tt>Vector</tt> instance to a stream (that
1020 :     * is, serialize it). This method is present merely for synchronization.
1021 :     * It just calls the default writeObject method.
1022 :     */
1023 :     private synchronized void writeObject(java.io.ObjectOutputStream s)
1024 :     throws java.io.IOException
1025 :     {
1026 :     s.defaultWriteObject();
1027 :     }
1028 :    
1029 :     /**
1030 :     * Returns a list-iterator of the elements in this list (in proper
1031 :     * sequence), starting at the specified position in the list.
1032 :     * Obeys the general contract of <tt>List.listIterator(int)</tt>.<p>
1033 :     *
1034 :     * The list-iterator is <i>fail-fast</i>: if the list is structurally
1035 :     * modified at any time after the Iterator is created, in any way except
1036 :     * through the list-iterator's own <tt>remove</tt> or <tt>add</tt>
1037 :     * methods, the list-iterator will throw a
1038 :     * <tt>ConcurrentModificationException</tt>. Thus, in the face of
1039 :     * concurrent modification, the iterator fails quickly and cleanly, rather
1040 :     * than risking arbitrary, non-deterministic behavior at an undetermined
1041 :     * time in the future.
1042 :     *
1043 :     * @param index index of the first element to be returned from the
1044 :     * list-iterator (by a call to <tt>next</tt>)
1045 :     * @return a ListIterator of the elements in this list (in proper
1046 :     * sequence), starting at the specified position in the list
1047 :     * @throws IndexOutOfBoundsException {@inheritDoc}
1048 :     * @see List#listIterator(int)
1049 :     */
1050 :     public synchronized ListIterator<E> listIterator(int index) {
1051 :     if (index < 0 || index > elementCount)
1052 :     throw new IndexOutOfBoundsException("Index: "+index);
1053 :     return new VectorIterator(index);
1054 :     }
1055 : jsr166 1.2
1056 : dl 1.1 /**
1057 : dl 1.3 * {@inheritDoc}
1058 :     */
1059 :     public synchronized ListIterator<E> listIterator() {
1060 :     return new VectorIterator(0);
1061 :     }
1062 :    
1063 :     /**
1064 : dl 1.1 * Returns an iterator over the elements in this list in proper sequence.
1065 :     *
1066 :     * @return an iterator over the elements in this list in proper sequence
1067 :     */
1068 :     public synchronized Iterator<E> iterator() {
1069 :     return new VectorIterator(0);
1070 :     }
1071 :    
1072 :     /**
1073 : dl 1.3 * A streamlined version of AbstractList.ListItr.
1074 : dl 1.1 */
1075 : dl 1.3 private final class VectorIterator implements ListIterator<E> {
1076 :     int cursor; // current position
1077 :     int lastRet; // index of last returned element
1078 :     int expectedModCount; // to check for CME
1079 : dl 1.1
1080 :     VectorIterator(int index) {
1081 :     cursor = index;
1082 : dl 1.3 expectedModCount = modCount;
1083 : dl 1.1 lastRet = -1;
1084 :     }
1085 :    
1086 :     public boolean hasNext() {
1087 : dl 1.3 // Racy but within spec, since modifications are checked
1088 :     // within or after synchronization in next/previous
1089 : dl 1.5 return cursor != elementCount;
1090 : dl 1.1 }
1091 :    
1092 :     public boolean hasPrevious() {
1093 : dl 1.5 return cursor != 0;
1094 : dl 1.1 }
1095 :    
1096 :     public int nextIndex() {
1097 :     return cursor;
1098 :     }
1099 :    
1100 :     public int previousIndex() {
1101 :     return cursor - 1;
1102 :     }
1103 :    
1104 :     public E next() {
1105 : dl 1.3 try {
1106 :     int i = cursor;
1107 :     E next = get(i);
1108 :     lastRet = i;
1109 :     cursor = i + 1;
1110 :     return next;
1111 :     } catch (IndexOutOfBoundsException ex) {
1112 :     throw new NoSuchElementException();
1113 :     } finally {
1114 :     if (expectedModCount != modCount)
1115 :     throw new ConcurrentModificationException();
1116 : dl 1.1 }
1117 :     }
1118 : jsr166 1.4
1119 :     public E previous() {
1120 : dl 1.3 try {
1121 :     int i = cursor - 1;
1122 :     E prev = get(i);
1123 :     lastRet = i;
1124 :     cursor = i;
1125 :     return prev;
1126 :     } catch (IndexOutOfBoundsException ex) {
1127 :     throw new NoSuchElementException();
1128 :     } finally {
1129 :     if (expectedModCount != modCount)
1130 :     throw new ConcurrentModificationException();
1131 : dl 1.1 }
1132 :     }
1133 :    
1134 :     public void remove() {
1135 : dl 1.3 if (lastRet == -1)
1136 : dl 1.1 throw new IllegalStateException();
1137 : dl 1.3 if (expectedModCount != modCount)
1138 :     throw new ConcurrentModificationException();
1139 :     try {
1140 :     Vector.this.remove(lastRet);
1141 :     if (lastRet < cursor)
1142 :     cursor--;
1143 :     lastRet = -1;
1144 :     expectedModCount = modCount;
1145 : jsr166 1.4 } catch (IndexOutOfBoundsException ex) {
1146 : dl 1.3 throw new ConcurrentModificationException();
1147 :     }
1148 : dl 1.1 }
1149 :    
1150 :     public void set(E e) {
1151 : dl 1.3 if (lastRet == -1)
1152 : dl 1.1 throw new IllegalStateException();
1153 : dl 1.3 if (expectedModCount != modCount)
1154 :     throw new ConcurrentModificationException();
1155 :     try {
1156 :     Vector.this.set(lastRet, e);
1157 :     expectedModCount = modCount;
1158 :     } catch (IndexOutOfBoundsException ex) {
1159 :     throw new ConcurrentModificationException();
1160 :     }
1161 : dl 1.1 }
1162 :    
1163 :     public void add(E e) {
1164 : dl 1.3 if (expectedModCount != modCount)
1165 :     throw new ConcurrentModificationException();
1166 :     try {
1167 :     int i = cursor;
1168 :     Vector.this.add(i, e);
1169 :     cursor = i + 1;
1170 :     lastRet = -1;
1171 :     expectedModCount = modCount;
1172 :     } catch (IndexOutOfBoundsException ex) {
1173 :     throw new ConcurrentModificationException();
1174 :     }
1175 : dl 1.1 }
1176 :     }
1177 :     }

Doug Lea
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