[cvs] / jsr166 / src / main / java / util / Vector.java Repository:
ViewVC logotype

Annotation of /jsr166/src/main/java/util/Vector.java

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1.8 - (view) (download)

1 : dl 1.1 /*
2 :     * %W% %E%
3 :     *
4 : jsr166 1.7 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
5 : dl 1.1 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6 :     */
7 :    
8 :     package java.util;
9 :    
10 :     /**
11 :     * The <code>Vector</code> class implements a growable array of
12 :     * objects. Like an array, it contains components that can be
13 :     * accessed using an integer index. However, the size of a
14 :     * <code>Vector</code> can grow or shrink as needed to accommodate
15 :     * adding and removing items after the <code>Vector</code> has been created.<p>
16 :     *
17 :     * Each vector tries to optimize storage management by maintaining a
18 :     * <code>capacity</code> and a <code>capacityIncrement</code>. The
19 :     * <code>capacity</code> is always at least as large as the vector
20 :     * size; it is usually larger because as components are added to the
21 :     * vector, the vector's storage increases in chunks the size of
22 :     * <code>capacityIncrement</code>. An application can increase the
23 :     * capacity of a vector before inserting a large number of
24 :     * components; this reduces the amount of incremental reallocation. <p>
25 :     *
26 :     * As of the Java 2 platform v1.2, this class has been retrofitted to
27 :     * implement List, so that it becomes a part of Java's collection framework.
28 :     * Unlike the new collection implementations, Vector is synchronized.<p>
29 :     *
30 :     * The Iterators returned by Vector's iterator and listIterator
31 :     * methods are <em>fail-fast</em>: if the Vector is structurally modified
32 :     * at any time after the Iterator is created, in any way except through the
33 :     * Iterator's own remove or add methods, the Iterator will throw a
34 :     * ConcurrentModificationException. Thus, in the face of concurrent
35 :     * modification, the Iterator fails quickly and cleanly, rather than risking
36 :     * arbitrary, non-deterministic behavior at an undetermined time in the future.
37 :     * The Enumerations returned by Vector's elements method are <em>not</em>
38 :     * fail-fast.
39 :     *
40 :     * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed
41 :     * as it is, generally speaking, impossible to make any hard guarantees in the
42 :     * presence of unsynchronized concurrent modification. Fail-fast iterators
43 :     * throw <tt>ConcurrentModificationException</tt> on a best-effort basis.
44 :     * Therefore, it would be wrong to write a program that depended on this
45 :     * exception for its correctness: <i>the fail-fast behavior of iterators
46 :     * should be used only to detect bugs.</i><p>
47 :     *
48 :     * This class is a member of the
49 :     * <a href="{@docRoot}/../guide/collections/index.html">
50 :     * Java Collections Framework</a>.
51 :     *
52 :     * @author Lee Boynton
53 :     * @author Jonathan Payne
54 :     * @version %I%, %G%
55 :     * @see Collection
56 :     * @see List
57 :     * @see ArrayList
58 :     * @see LinkedList
59 :     * @since JDK1.0
60 :     */
61 :     public class Vector<E>
62 :     extends AbstractList<E>
63 :     implements List<E>, RandomAccess, Cloneable, java.io.Serializable
64 :     {
65 :     /**
66 :     * The array buffer into which the components of the vector are
67 :     * stored. The capacity of the vector is the length of this array buffer,
68 :     * and is at least large enough to contain all the vector's elements.<p>
69 :     *
70 :     * Any array elements following the last element in the Vector are null.
71 :     *
72 :     * @serial
73 :     */
74 :     protected Object[] elementData;
75 :    
76 :     /**
77 :     * The number of valid components in this <tt>Vector</tt> object.
78 :     * Components <tt>elementData[0]</tt> through
79 :     * <tt>elementData[elementCount-1]</tt> are the actual items.
80 :     *
81 :     * @serial
82 :     */
83 :     protected int elementCount;
84 :    
85 :     /**
86 :     * The amount by which the capacity of the vector is automatically
87 :     * incremented when its size becomes greater than its capacity. If
88 :     * the capacity increment is less than or equal to zero, the capacity
89 :     * of the vector is doubled each time it needs to grow.
90 :     *
91 :     * @serial
92 :     */
93 :     protected int capacityIncrement;
94 :    
95 :     /** use serialVersionUID from JDK 1.0.2 for interoperability */
96 :     private static final long serialVersionUID = -2767605614048989439L;
97 :    
98 :     /**
99 :     * Constructs an empty vector with the specified initial capacity and
100 :     * capacity increment.
101 :     *
102 :     * @param initialCapacity the initial capacity of the vector
103 :     * @param capacityIncrement the amount by which the capacity is
104 :     * increased when the vector overflows
105 :     * @exception IllegalArgumentException if the specified initial capacity
106 :     * is negative
107 :     */
108 :     public Vector(int initialCapacity, int capacityIncrement) {
109 :     super();
110 :     if (initialCapacity < 0)
111 :     throw new IllegalArgumentException("Illegal Capacity: "+
112 :     initialCapacity);
113 :     this.elementData = new Object[initialCapacity];
114 :     this.capacityIncrement = capacityIncrement;
115 :     }
116 :    
117 :     /**
118 :     * Constructs an empty vector with the specified initial capacity and
119 :     * with its capacity increment equal to zero.
120 :     *
121 :     * @param initialCapacity the initial capacity of the vector
122 :     * @exception IllegalArgumentException if the specified initial capacity
123 :     * is negative
124 :     */
125 :     public Vector(int initialCapacity) {
126 :     this(initialCapacity, 0);
127 :     }
128 :    
129 :     /**
130 :     * Constructs an empty vector so that its internal data array
131 :     * has size <tt>10</tt> and its standard capacity increment is
132 :     * zero.
133 :     */
134 :     public Vector() {
135 :     this(10);
136 :     }
137 :    
138 :     /**
139 :     * Constructs a vector containing the elements of the specified
140 :     * collection, in the order they are returned by the collection's
141 :     * iterator.
142 :     *
143 :     * @param c the collection whose elements are to be placed into this
144 :     * vector
145 :     * @throws NullPointerException if the specified collection is null
146 :     * @since 1.2
147 :     */
148 :     public Vector(Collection<? extends E> c) {
149 : jsr166 1.6 elementData = c.toArray();
150 :     elementCount = elementData.length;
151 :     // c.toArray might (incorrectly) not return Object[] (see 6260652)
152 :     if (elementData.getClass() != Object[].class)
153 :     elementData = Arrays.copyOf(elementData, elementCount, Object[].class);
154 : dl 1.1 }
155 :    
156 :     /**
157 :     * Copies the components of this vector into the specified array.
158 :     * The item at index <tt>k</tt> in this vector is copied into
159 :     * component <tt>k</tt> of <tt>anArray</tt>.
160 :     *
161 :     * @param anArray the array into which the components get copied
162 :     * @throws NullPointerException if the given array is null
163 :     * @throws IndexOutOfBoundsException if the specified array is not
164 :     * large enough to hold all the components of this vector
165 :     * @throws ArrayStoreException if a component of this vector is not of
166 :     * a runtime type that can be stored in the specified array
167 :     * @see #toArray(Object[])
168 :     */
169 :     public synchronized void copyInto(Object[] anArray) {
170 :     System.arraycopy(elementData, 0, anArray, 0, elementCount);
171 :     }
172 :    
173 :     /**
174 :     * Trims the capacity of this vector to be the vector's current
175 :     * size. If the capacity of this vector is larger than its current
176 :     * size, then the capacity is changed to equal the size by replacing
177 :     * its internal data array, kept in the field <tt>elementData</tt>,
178 :     * with a smaller one. An application can use this operation to
179 :     * minimize the storage of a vector.
180 :     */
181 :     public synchronized void trimToSize() {
182 :     modCount++;
183 :     int oldCapacity = elementData.length;
184 :     if (elementCount < oldCapacity) {
185 :     elementData = Arrays.copyOf(elementData, elementCount);
186 :     }
187 :     }
188 :    
189 :     /**
190 :     * Increases the capacity of this vector, if necessary, to ensure
191 :     * that it can hold at least the number of components specified by
192 :     * the minimum capacity argument.
193 :     *
194 :     * <p>If the current capacity of this vector is less than
195 :     * <tt>minCapacity</tt>, then its capacity is increased by replacing its
196 :     * internal data array, kept in the field <tt>elementData</tt>, with a
197 :     * larger one. The size of the new data array will be the old size plus
198 :     * <tt>capacityIncrement</tt>, unless the value of
199 :     * <tt>capacityIncrement</tt> is less than or equal to zero, in which case
200 :     * the new capacity will be twice the old capacity; but if this new size
201 :     * is still smaller than <tt>minCapacity</tt>, then the new capacity will
202 :     * be <tt>minCapacity</tt>.
203 :     *
204 :     * @param minCapacity the desired minimum capacity
205 :     */
206 :     public synchronized void ensureCapacity(int minCapacity) {
207 :     modCount++;
208 :     ensureCapacityHelper(minCapacity);
209 :     }
210 :    
211 :     /**
212 :     * This implements the unsynchronized semantics of ensureCapacity.
213 :     * Synchronized methods in this class can internally call this
214 :     * method for ensuring capacity without incurring the cost of an
215 :     * extra synchronization.
216 :     *
217 :     * @see java.util.Vector#ensureCapacity(int)
218 :     */
219 :     private void ensureCapacityHelper(int minCapacity) {
220 :     int oldCapacity = elementData.length;
221 :     if (minCapacity > oldCapacity) {
222 :     Object[] oldData = elementData;
223 :     int newCapacity = (capacityIncrement > 0) ?
224 :     (oldCapacity + capacityIncrement) : (oldCapacity * 2);
225 :     if (newCapacity < minCapacity) {
226 :     newCapacity = minCapacity;
227 :     }
228 :     elementData = Arrays.copyOf(elementData, newCapacity);
229 :     }
230 :     }
231 :    
232 :     /**
233 :     * Sets the size of this vector. If the new size is greater than the
234 :     * current size, new <code>null</code> items are added to the end of
235 :     * the vector. If the new size is less than the current size, all
236 :     * components at index <code>newSize</code> and greater are discarded.
237 :     *
238 :     * @param newSize the new size of this vector
239 :     * @throws ArrayIndexOutOfBoundsException if new size is negative
240 :     */
241 :     public synchronized void setSize(int newSize) {
242 :     modCount++;
243 :     if (newSize > elementCount) {
244 :     ensureCapacityHelper(newSize);
245 :     } else {
246 :     for (int i = newSize ; i < elementCount ; i++) {
247 :     elementData[i] = null;
248 :     }
249 :     }
250 :     elementCount = newSize;
251 :     }
252 :    
253 :     /**
254 :     * Returns the current capacity of this vector.
255 :     *
256 :     * @return the current capacity (the length of its internal
257 :     * data array, kept in the field <tt>elementData</tt>
258 :     * of this vector)
259 :     */
260 :     public synchronized int capacity() {
261 :     return elementData.length;
262 :     }
263 :    
264 :     /**
265 :     * Returns the number of components in this vector.
266 :     *
267 :     * @return the number of components in this vector
268 :     */
269 :     public synchronized int size() {
270 :     return elementCount;
271 :     }
272 :    
273 :     /**
274 :     * Tests if this vector has no components.
275 :     *
276 :     * @return <code>true</code> if and only if this vector has
277 :     * no components, that is, its size is zero;
278 :     * <code>false</code> otherwise.
279 :     */
280 :     public synchronized boolean isEmpty() {
281 :     return elementCount == 0;
282 :     }
283 :    
284 :     /**
285 :     * Returns an enumeration of the components of this vector. The
286 :     * returned <tt>Enumeration</tt> object will generate all items in
287 :     * this vector. The first item generated is the item at index <tt>0</tt>,
288 :     * then the item at index <tt>1</tt>, and so on.
289 :     *
290 :     * @return an enumeration of the components of this vector
291 :     * @see Enumeration
292 :     * @see Iterator
293 :     */
294 :     public Enumeration<E> elements() {
295 :     return new Enumeration<E>() {
296 :     int count = 0;
297 :    
298 :     public boolean hasMoreElements() {
299 :     return count < elementCount;
300 :     }
301 :    
302 :     public E nextElement() {
303 :     synchronized (Vector.this) {
304 :     if (count < elementCount) {
305 :     return (E)elementData[count++];
306 :     }
307 :     }
308 :     throw new NoSuchElementException("Vector Enumeration");
309 :     }
310 :     };
311 :     }
312 :    
313 :     /**
314 :     * Returns <tt>true</tt> if this vector contains the specified element.
315 :     * More formally, returns <tt>true</tt> if and only if this vector
316 :     * contains at least one element <tt>e</tt> such that
317 :     * <tt>(o==null&nbsp;?&nbsp;e==null&nbsp;:&nbsp;o.equals(e))</tt>.
318 :     *
319 :     * @param o element whose presence in this vector is to be tested
320 :     * @return <tt>true</tt> if this vector contains the specified element
321 :     */
322 :     public boolean contains(Object o) {
323 :     return indexOf(o, 0) >= 0;
324 :     }
325 :    
326 :     /**
327 :     * Returns the index of the first occurrence of the specified element
328 :     * in this vector, or -1 if this vector does not contain the element.
329 :     * More formally, returns the lowest index <tt>i</tt> such that
330 :     * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
331 :     * or -1 if there is no such index.
332 :     *
333 :     * @param o element to search for
334 :     * @return the index of the first occurrence of the specified element in
335 :     * this vector, or -1 if this vector does not contain the element
336 :     */
337 :     public int indexOf(Object o) {
338 :     return indexOf(o, 0);
339 :     }
340 :    
341 :     /**
342 :     * Returns the index of the first occurrence of the specified element in
343 :     * this vector, searching forwards from <tt>index</tt>, or returns -1 if
344 :     * the element is not found.
345 :     * More formally, returns the lowest index <tt>i</tt> such that
346 :     * <tt>(i&nbsp;&gt;=&nbsp;index&nbsp;&amp;&amp;&nbsp;(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i))))</tt>,
347 :     * or -1 if there is no such index.
348 :     *
349 :     * @param o element to search for
350 :     * @param index index to start searching from
351 :     * @return the index of the first occurrence of the element in
352 :     * this vector at position <tt>index</tt> or later in the vector;
353 :     * <tt>-1</tt> if the element is not found.
354 :     * @throws IndexOutOfBoundsException if the specified index is negative
355 :     * @see Object#equals(Object)
356 :     */
357 :     public synchronized int indexOf(Object o, int index) {
358 :     if (o == null) {
359 :     for (int i = index ; i < elementCount ; i++)
360 :     if (elementData[i]==null)
361 :     return i;
362 :     } else {
363 :     for (int i = index ; i < elementCount ; i++)
364 :     if (o.equals(elementData[i]))
365 :     return i;
366 :     }
367 :     return -1;
368 :     }
369 :    
370 :     /**
371 :     * Returns the index of the last occurrence of the specified element
372 :     * in this vector, or -1 if this vector does not contain the element.
373 :     * More formally, returns the highest index <tt>i</tt> such that
374 :     * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
375 :     * or -1 if there is no such index.
376 :     *
377 :     * @param o element to search for
378 :     * @return the index of the last occurrence of the specified element in
379 :     * this vector, or -1 if this vector does not contain the element
380 :     */
381 :     public synchronized int lastIndexOf(Object o) {
382 :     return lastIndexOf(o, elementCount-1);
383 :     }
384 :    
385 :     /**
386 :     * Returns the index of the last occurrence of the specified element in
387 :     * this vector, searching backwards from <tt>index</tt>, or returns -1 if
388 :     * the element is not found.
389 :     * More formally, returns the highest index <tt>i</tt> such that
390 :     * <tt>(i&nbsp;&lt;=&nbsp;index&nbsp;&amp;&amp;&nbsp;(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i))))</tt>,
391 :     * or -1 if there is no such index.
392 :     *
393 :     * @param o element to search for
394 :     * @param index index to start searching backwards from
395 :     * @return the index of the last occurrence of the element at position
396 :     * less than or equal to <tt>index</tt> in this vector;
397 :     * -1 if the element is not found.
398 :     * @throws IndexOutOfBoundsException if the specified index is greater
399 :     * than or equal to the current size of this vector
400 :     */
401 :     public synchronized int lastIndexOf(Object o, int index) {
402 :     if (index >= elementCount)
403 :     throw new IndexOutOfBoundsException(index + " >= "+ elementCount);
404 :    
405 :     if (o == null) {
406 :     for (int i = index; i >= 0; i--)
407 :     if (elementData[i]==null)
408 :     return i;
409 :     } else {
410 :     for (int i = index; i >= 0; i--)
411 :     if (o.equals(elementData[i]))
412 :     return i;
413 :     }
414 :     return -1;
415 :     }
416 :    
417 :     /**
418 :     * Returns the component at the specified index.<p>
419 :     *
420 :     * This method is identical in functionality to the get method
421 :     * (which is part of the List interface).
422 :     *
423 :     * @param index an index into this vector
424 :     * @return the component at the specified index
425 :     * @exception ArrayIndexOutOfBoundsException if the <tt>index</tt>
426 :     * is negative or not less than the current size of this
427 :     * <tt>Vector</tt> object.
428 :     * @see #get(int)
429 :     * @see List
430 :     */
431 :     public synchronized E elementAt(int index) {
432 :     if (index >= elementCount) {
433 :     throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount);
434 :     }
435 :    
436 :     return (E)elementData[index];
437 :     }
438 :    
439 :     /**
440 :     * Returns the first component (the item at index <tt>0</tt>) of
441 :     * this vector.
442 :     *
443 :     * @return the first component of this vector
444 :     * @exception NoSuchElementException if this vector has no components
445 :     */
446 :     public synchronized E firstElement() {
447 :     if (elementCount == 0) {
448 :     throw new NoSuchElementException();
449 :     }
450 :     return (E)elementData[0];
451 :     }
452 :    
453 :     /**
454 :     * Returns the last component of the vector.
455 :     *
456 :     * @return the last component of the vector, i.e., the component at index
457 :     * <code>size()&nbsp;-&nbsp;1</code>.
458 :     * @exception NoSuchElementException if this vector is empty
459 :     */
460 :     public synchronized E lastElement() {
461 :     if (elementCount == 0) {
462 :     throw new NoSuchElementException();
463 :     }
464 :     return (E)elementData[elementCount - 1];
465 :     }
466 :    
467 :     /**
468 :     * Sets the component at the specified <code>index</code> of this
469 :     * vector to be the specified object. The previous component at that
470 :     * position is discarded.<p>
471 :     *
472 :     * The index must be a value greater than or equal to <code>0</code>
473 :     * and less than the current size of the vector. <p>
474 :     *
475 :     * This method is identical in functionality to the set method
476 :     * (which is part of the List interface). Note that the set method reverses
477 :     * the order of the parameters, to more closely match array usage. Note
478 :     * also that the set method returns the old value that was stored at the
479 :     * specified position.
480 :     *
481 :     * @param obj what the component is to be set to
482 :     * @param index the specified index
483 :     * @exception ArrayIndexOutOfBoundsException if the index was invalid
484 :     * @see #size()
485 :     * @see List
486 :     * @see #set(int, java.lang.Object)
487 :     */
488 :     public synchronized void setElementAt(E obj, int index) {
489 :     if (index >= elementCount) {
490 :     throw new ArrayIndexOutOfBoundsException(index + " >= " +
491 :     elementCount);
492 :     }
493 :     elementData[index] = obj;
494 :     }
495 :    
496 :     /**
497 :     * Deletes the component at the specified index. Each component in
498 :     * this vector with an index greater or equal to the specified
499 :     * <code>index</code> is shifted downward to have an index one
500 :     * smaller than the value it had previously. The size of this vector
501 :     * is decreased by <tt>1</tt>.<p>
502 :     *
503 :     * The index must be a value greater than or equal to <code>0</code>
504 :     * and less than the current size of the vector. <p>
505 :     *
506 :     * This method is identical in functionality to the remove method
507 :     * (which is part of the List interface). Note that the remove method
508 :     * returns the old value that was stored at the specified position.
509 :     *
510 :     * @param index the index of the object to remove
511 :     * @exception ArrayIndexOutOfBoundsException if the index was invalid
512 :     * @see #size()
513 :     * @see #remove(int)
514 :     * @see List
515 :     */
516 :     public synchronized void removeElementAt(int index) {
517 :     modCount++;
518 :     if (index >= elementCount) {
519 :     throw new ArrayIndexOutOfBoundsException(index + " >= " +
520 :     elementCount);
521 :     }
522 :     else if (index < 0) {
523 :     throw new ArrayIndexOutOfBoundsException(index);
524 :     }
525 :     int j = elementCount - index - 1;
526 :     if (j > 0) {
527 :     System.arraycopy(elementData, index + 1, elementData, index, j);
528 :     }
529 :     elementCount--;
530 :     elementData[elementCount] = null; /* to let gc do its work */
531 :     }
532 :    
533 :     /**
534 :     * Inserts the specified object as a component in this vector at the
535 :     * specified <code>index</code>. Each component in this vector with
536 :     * an index greater or equal to the specified <code>index</code> is
537 :     * shifted upward to have an index one greater than the value it had
538 :     * previously. <p>
539 :     *
540 :     * The index must be a value greater than or equal to <code>0</code>
541 :     * and less than or equal to the current size of the vector. (If the
542 :     * index is equal to the current size of the vector, the new element
543 :     * is appended to the Vector.)<p>
544 :     *
545 :     * This method is identical in functionality to the add(Object, int) method
546 :     * (which is part of the List interface). Note that the add method reverses
547 :     * the order of the parameters, to more closely match array usage.
548 :     *
549 :     * @param obj the component to insert
550 :     * @param index where to insert the new component
551 :     * @exception ArrayIndexOutOfBoundsException if the index was invalid
552 :     * @see #size()
553 :     * @see #add(int, Object)
554 :     * @see List
555 :     */
556 :     public synchronized void insertElementAt(E obj, int index) {
557 :     modCount++;
558 :     if (index > elementCount) {
559 :     throw new ArrayIndexOutOfBoundsException(index
560 :     + " > " + elementCount);
561 :     }
562 :     ensureCapacityHelper(elementCount + 1);
563 :     System.arraycopy(elementData, index, elementData, index + 1, elementCount - index);
564 :     elementData[index] = obj;
565 :     elementCount++;
566 :     }
567 :    
568 :     /**
569 :     * Adds the specified component to the end of this vector,
570 :     * increasing its size by one. The capacity of this vector is
571 :     * increased if its size becomes greater than its capacity. <p>
572 :     *
573 :     * This method is identical in functionality to the add(Object) method
574 :     * (which is part of the List interface).
575 :     *
576 :     * @param obj the component to be added
577 :     * @see #add(Object)
578 :     * @see List
579 :     */
580 :     public synchronized void addElement(E obj) {
581 :     modCount++;
582 :     ensureCapacityHelper(elementCount + 1);
583 :     elementData[elementCount++] = obj;
584 :     }
585 :    
586 :     /**
587 :     * Removes the first (lowest-indexed) occurrence of the argument
588 :     * from this vector. If the object is found in this vector, each
589 :     * component in the vector with an index greater or equal to the
590 :     * object's index is shifted downward to have an index one smaller
591 :     * than the value it had previously.<p>
592 :     *
593 :     * This method is identical in functionality to the remove(Object)
594 :     * method (which is part of the List interface).
595 :     *
596 :     * @param obj the component to be removed
597 :     * @return <code>true</code> if the argument was a component of this
598 :     * vector; <code>false</code> otherwise.
599 :     * @see List#remove(Object)
600 :     * @see List
601 :     */
602 :     public synchronized boolean removeElement(Object obj) {
603 :     modCount++;
604 :     int i = indexOf(obj);
605 :     if (i >= 0) {
606 :     removeElementAt(i);
607 :     return true;
608 :     }
609 :     return false;
610 :     }
611 :    
612 :     /**
613 :     * Removes all components from this vector and sets its size to zero.<p>
614 :     *
615 :     * This method is identical in functionality to the clear method
616 :     * (which is part of the List interface).
617 :     *
618 :     * @see #clear
619 :     * @see List
620 :     */
621 :     public synchronized void removeAllElements() {
622 :     modCount++;
623 :     // Let gc do its work
624 :     for (int i = 0; i < elementCount; i++)
625 :     elementData[i] = null;
626 :    
627 :     elementCount = 0;
628 :     }
629 :    
630 :     /**
631 :     * Returns a clone of this vector. The copy will contain a
632 :     * reference to a clone of the internal data array, not a reference
633 :     * to the original internal data array of this <tt>Vector</tt> object.
634 :     *
635 :     * @return a clone of this vector
636 :     */
637 :     public synchronized Object clone() {
638 :     try {
639 :     Vector<E> v = (Vector<E>) super.clone();
640 :     v.elementData = Arrays.copyOf(elementData, elementCount);
641 :     v.modCount = 0;
642 :     return v;
643 :     } catch (CloneNotSupportedException e) {
644 :     // this shouldn't happen, since we are Cloneable
645 :     throw new InternalError();
646 :     }
647 :     }
648 :    
649 :     /**
650 :     * Returns an array containing all of the elements in this Vector
651 :     * in the correct order.
652 :     *
653 :     * @since 1.2
654 :     */
655 :     public synchronized Object[] toArray() {
656 :     return Arrays.copyOf(elementData, elementCount);
657 :     }
658 :    
659 :     /**
660 :     * Returns an array containing all of the elements in this Vector in the
661 :     * correct order; the runtime type of the returned array is that of the
662 :     * specified array. If the Vector fits in the specified array, it is
663 :     * returned therein. Otherwise, a new array is allocated with the runtime
664 :     * type of the specified array and the size of this Vector.<p>
665 :     *
666 :     * If the Vector fits in the specified array with room to spare
667 :     * (i.e., the array has more elements than the Vector),
668 :     * the element in the array immediately following the end of the
669 :     * Vector is set to null. (This is useful in determining the length
670 :     * of the Vector <em>only</em> if the caller knows that the Vector
671 :     * does not contain any null elements.)
672 :     *
673 :     * @param a the array into which the elements of the Vector are to
674 :     * be stored, if it is big enough; otherwise, a new array of the
675 :     * same runtime type is allocated for this purpose.
676 :     * @return an array containing the elements of the Vector
677 :     * @exception ArrayStoreException the runtime type of a is not a supertype
678 :     * of the runtime type of every element in this Vector
679 :     * @throws NullPointerException if the given array is null
680 :     * @since 1.2
681 :     */
682 :     public synchronized <T> T[] toArray(T[] a) {
683 :     if (a.length < elementCount)
684 :     return (T[]) Arrays.copyOf(elementData, elementCount, a.getClass());
685 :    
686 :     System.arraycopy(elementData, 0, a, 0, elementCount);
687 :    
688 :     if (a.length > elementCount)
689 :     a[elementCount] = null;
690 :    
691 :     return a;
692 :     }
693 :    
694 :     // Positional Access Operations
695 :    
696 :     /**
697 :     * Returns the element at the specified position in this Vector.
698 :     *
699 :     * @param index index of the element to return
700 :     * @return object at the specified index
701 :     * @exception ArrayIndexOutOfBoundsException index is out of range (index
702 :     * &lt; 0 || index &gt;= size())
703 :     * @since 1.2
704 :     */
705 :     public synchronized E get(int index) {
706 :     if (index >= elementCount)
707 :     throw new ArrayIndexOutOfBoundsException(index);
708 :    
709 :     return (E)elementData[index];
710 :     }
711 :    
712 :     /**
713 :     * Replaces the element at the specified position in this Vector with the
714 :     * specified element.
715 :     *
716 :     * @param index index of the element to replace
717 :     * @param element element to be stored at the specified position
718 :     * @return the element previously at the specified position
719 :     * @exception ArrayIndexOutOfBoundsException index out of range
720 :     * (index &lt; 0 || index &gt;= size())
721 :     * @since 1.2
722 :     */
723 :     public synchronized E set(int index, E element) {
724 :     if (index >= elementCount)
725 :     throw new ArrayIndexOutOfBoundsException(index);
726 :    
727 :     Object oldValue = elementData[index];
728 :     elementData[index] = element;
729 :     return (E)oldValue;
730 :     }
731 :    
732 :     /**
733 :     * Appends the specified element to the end of this Vector.
734 :     *
735 :     * @param e element to be appended to this Vector
736 :     * @return <tt>true</tt> (as specified by {@link Collection#add})
737 :     * @since 1.2
738 :     */
739 :     public synchronized boolean add(E e) {
740 :     modCount++;
741 :     ensureCapacityHelper(elementCount + 1);
742 :     elementData[elementCount++] = e;
743 :     return true;
744 :     }
745 :    
746 :     /**
747 :     * Removes the first occurrence of the specified element in this Vector
748 :     * If the Vector does not contain the element, it is unchanged. More
749 :     * formally, removes the element with the lowest index i such that
750 :     * <code>(o==null ? get(i)==null : o.equals(get(i)))</code> (if such
751 :     * an element exists).
752 :     *
753 :     * @param o element to be removed from this Vector, if present
754 :     * @return true if the Vector contained the specified element
755 :     * @since 1.2
756 :     */
757 :     public boolean remove(Object o) {
758 :     return removeElement(o);
759 :     }
760 :    
761 :     /**
762 :     * Inserts the specified element at the specified position in this Vector.
763 :     * Shifts the element currently at that position (if any) and any
764 :     * subsequent elements to the right (adds one to their indices).
765 :     *
766 :     * @param index index at which the specified element is to be inserted
767 :     * @param element element to be inserted
768 :     * @exception ArrayIndexOutOfBoundsException index is out of range
769 :     * (index &lt; 0 || index &gt; size())
770 :     * @since 1.2
771 :     */
772 :     public void add(int index, E element) {
773 :     insertElementAt(element, index);
774 :     }
775 :    
776 :     /**
777 :     * Removes the element at the specified position in this Vector.
778 :     * Shifts any subsequent elements to the left (subtracts one from their
779 :     * indices). Returns the element that was removed from the Vector.
780 :     *
781 :     * @exception ArrayIndexOutOfBoundsException index out of range (index
782 :     * &lt; 0 || index &gt;= size())
783 :     * @param index the index of the element to be removed
784 :     * @return element that was removed
785 :     * @since 1.2
786 :     */
787 :     public synchronized E remove(int index) {
788 :     modCount++;
789 :     if (index >= elementCount)
790 :     throw new ArrayIndexOutOfBoundsException(index);
791 :     Object oldValue = elementData[index];
792 :    
793 :     int numMoved = elementCount - index - 1;
794 :     if (numMoved > 0)
795 :     System.arraycopy(elementData, index+1, elementData, index,
796 :     numMoved);
797 :     elementData[--elementCount] = null; // Let gc do its work
798 :    
799 :     return (E)oldValue;
800 :     }
801 :    
802 :     /**
803 :     * Removes all of the elements from this Vector. The Vector will
804 :     * be empty after this call returns (unless it throws an exception).
805 :     *
806 :     * @since 1.2
807 :     */
808 :     public void clear() {
809 :     removeAllElements();
810 :     }
811 :    
812 :     // Bulk Operations
813 :    
814 :     /**
815 :     * Returns true if this Vector contains all of the elements in the
816 :     * specified Collection.
817 :     *
818 :     * @param c a collection whose elements will be tested for containment
819 :     * in this Vector
820 :     * @return true if this Vector contains all of the elements in the
821 :     * specified collection
822 :     * @throws NullPointerException if the specified collection is null
823 :     */
824 :     public synchronized boolean containsAll(Collection<?> c) {
825 :     return super.containsAll(c);
826 :     }
827 :    
828 :     /**
829 :     * Appends all of the elements in the specified Collection to the end of
830 :     * this Vector, in the order that they are returned by the specified
831 :     * Collection's Iterator. The behavior of this operation is undefined if
832 :     * the specified Collection is modified while the operation is in progress.
833 :     * (This implies that the behavior of this call is undefined if the
834 :     * specified Collection is this Vector, and this Vector is nonempty.)
835 :     *
836 :     * @param c elements to be inserted into this Vector
837 :     * @return <tt>true</tt> if this Vector changed as a result of the call
838 :     * @throws NullPointerException if the specified collection is null
839 :     * @since 1.2
840 :     */
841 :     public synchronized boolean addAll(Collection<? extends E> c) {
842 :     modCount++;
843 :     Object[] a = c.toArray();
844 :     int numNew = a.length;
845 :     ensureCapacityHelper(elementCount + numNew);
846 :     System.arraycopy(a, 0, elementData, elementCount, numNew);
847 :     elementCount += numNew;
848 :     return numNew != 0;
849 :     }
850 :    
851 :     /**
852 :     * Removes from this Vector all of its elements that are contained in the
853 :     * specified Collection.
854 :     *
855 :     * @param c a collection of elements to be removed from the Vector
856 :     * @return true if this Vector changed as a result of the call
857 :     * @throws ClassCastException if the types of one or more elements
858 :     * in this vector are incompatible with the specified
859 :     * collection (optional)
860 :     * @throws NullPointerException if this vector contains one or more null
861 :     * elements and the specified collection does not support null
862 :     * elements (optional), or if the specified collection is null
863 :     * @since 1.2
864 :     */
865 :     public synchronized boolean removeAll(Collection<?> c) {
866 :     return super.removeAll(c);
867 :     }
868 :    
869 :     /**
870 :     * Retains only the elements in this Vector that are contained in the
871 :     * specified Collection. In other words, removes from this Vector all
872 :     * of its elements that are not contained in the specified Collection.
873 :     *
874 :     * @param c a collection of elements to be retained in this Vector
875 :     * (all other elements are removed)
876 :     * @return true if this Vector changed as a result of the call
877 :     * @throws ClassCastException if the types of one or more elements
878 :     * in this vector are incompatible with the specified
879 :     * collection (optional)
880 :     * @throws NullPointerException if this vector contains one or more null
881 :     * elements and the specified collection does not support null
882 :     * elements (optional), or if the specified collection is null
883 :     * @since 1.2
884 :     */
885 :     public synchronized boolean retainAll(Collection<?> c) {
886 :     return super.retainAll(c);
887 :     }
888 :    
889 :     /**
890 :     * Inserts all of the elements in the specified Collection into this
891 :     * Vector at the specified position. Shifts the element currently at
892 :     * that position (if any) and any subsequent elements to the right
893 :     * (increases their indices). The new elements will appear in the Vector
894 :     * in the order that they are returned by the specified Collection's
895 :     * iterator.
896 :     *
897 :     * @param index index at which to insert the first element from the
898 :     * specified collection
899 :     * @param c elements to be inserted into this Vector
900 :     * @return <tt>true</tt> if this Vector changed as a result of the call
901 :     * @exception ArrayIndexOutOfBoundsException index out of range (index
902 :     * &lt; 0 || index &gt; size())
903 :     * @throws NullPointerException if the specified collection is null
904 :     * @since 1.2
905 :     */
906 :     public synchronized boolean addAll(int index, Collection<? extends E> c) {
907 :     modCount++;
908 :     if (index < 0 || index > elementCount)
909 :     throw new ArrayIndexOutOfBoundsException(index);
910 :    
911 :     Object[] a = c.toArray();
912 :     int numNew = a.length;
913 :     ensureCapacityHelper(elementCount + numNew);
914 :    
915 :     int numMoved = elementCount - index;
916 :     if (numMoved > 0)
917 :     System.arraycopy(elementData, index, elementData, index + numNew,
918 :     numMoved);
919 :    
920 :     System.arraycopy(a, 0, elementData, index, numNew);
921 :     elementCount += numNew;
922 :     return numNew != 0;
923 :     }
924 :    
925 :     /**
926 :     * Compares the specified Object with this Vector for equality. Returns
927 :     * true if and only if the specified Object is also a List, both Lists
928 :     * have the same size, and all corresponding pairs of elements in the two
929 :     * Lists are <em>equal</em>. (Two elements <code>e1</code> and
930 :     * <code>e2</code> are <em>equal</em> if <code>(e1==null ? e2==null :
931 :     * e1.equals(e2))</code>.) In other words, two Lists are defined to be
932 :     * equal if they contain the same elements in the same order.
933 :     *
934 :     * @param o the Object to be compared for equality with this Vector
935 :     * @return true if the specified Object is equal to this Vector
936 :     */
937 :     public synchronized boolean equals(Object o) {
938 :     return super.equals(o);
939 :     }
940 :    
941 :     /**
942 :     * Returns the hash code value for this Vector.
943 :     */
944 :     public synchronized int hashCode() {
945 :     return super.hashCode();
946 :     }
947 :    
948 :     /**
949 :     * Returns a string representation of this Vector, containing
950 :     * the String representation of each element.
951 :     */
952 :     public synchronized String toString() {
953 :     return super.toString();
954 :     }
955 :    
956 :     /**
957 :     * Returns a view of the portion of this List between fromIndex,
958 :     * inclusive, and toIndex, exclusive. (If fromIndex and toIndex are
959 :     * equal, the returned List is empty.) The returned List is backed by this
960 :     * List, so changes in the returned List are reflected in this List, and
961 :     * vice-versa. The returned List supports all of the optional List
962 :     * operations supported by this List.<p>
963 :     *
964 :     * This method eliminates the need for explicit range operations (of
965 :     * the sort that commonly exist for arrays). Any operation that expects
966 :     * a List can be used as a range operation by operating on a subList view
967 :     * instead of a whole List. For example, the following idiom
968 :     * removes a range of elements from a List:
969 :     * <pre>
970 :     * list.subList(from, to).clear();
971 :     * </pre>
972 :     * Similar idioms may be constructed for indexOf and lastIndexOf,
973 :     * and all of the algorithms in the Collections class can be applied to
974 :     * a subList.<p>
975 :     *
976 :     * The semantics of the List returned by this method become undefined if
977 :     * the backing list (i.e., this List) is <i>structurally modified</i> in
978 :     * any way other than via the returned List. (Structural modifications are
979 :     * those that change the size of the List, or otherwise perturb it in such
980 :     * a fashion that iterations in progress may yield incorrect results.)
981 :     *
982 :     * @param fromIndex low endpoint (inclusive) of the subList
983 :     * @param toIndex high endpoint (exclusive) of the subList
984 :     * @return a view of the specified range within this List
985 :     * @throws IndexOutOfBoundsException endpoint index value out of range
986 :     * <code>(fromIndex &lt; 0 || toIndex &gt; size)</code>
987 :     * @throws IllegalArgumentException endpoint indices out of order
988 :     * <code>(fromIndex &gt; toIndex)</code>
989 :     */
990 :     public synchronized List<E> subList(int fromIndex, int toIndex) {
991 :     return Collections.synchronizedList(super.subList(fromIndex, toIndex),
992 :     this);
993 :     }
994 :    
995 :     /**
996 :     * Removes from this List all of the elements whose index is between
997 :     * fromIndex, inclusive and toIndex, exclusive. Shifts any succeeding
998 :     * elements to the left (reduces their index).
999 :     * This call shortens the ArrayList by (toIndex - fromIndex) elements. (If
1000 :     * toIndex==fromIndex, this operation has no effect.)
1001 :     *
1002 :     * @param fromIndex index of first element to be removed
1003 :     * @param toIndex index after last element to be removed
1004 :     */
1005 :     protected synchronized void removeRange(int fromIndex, int toIndex) {
1006 :     modCount++;
1007 :     int numMoved = elementCount - toIndex;
1008 :     System.arraycopy(elementData, toIndex, elementData, fromIndex,
1009 :     numMoved);
1010 :    
1011 :     // Let gc do its work
1012 :     int newElementCount = elementCount - (toIndex-fromIndex);
1013 :     while (elementCount != newElementCount)
1014 :     elementData[--elementCount] = null;
1015 :     }
1016 :    
1017 :     /**
1018 :     * Save the state of the <tt>Vector</tt> instance to a stream (that
1019 :     * is, serialize it). This method is present merely for synchronization.
1020 :     * It just calls the default writeObject method.
1021 :     */
1022 :     private synchronized void writeObject(java.io.ObjectOutputStream s)
1023 :     throws java.io.IOException
1024 :     {
1025 :     s.defaultWriteObject();
1026 :     }
1027 :    
1028 :     /**
1029 :     * Returns a list-iterator of the elements in this list (in proper
1030 :     * sequence), starting at the specified position in the list.
1031 :     * Obeys the general contract of <tt>List.listIterator(int)</tt>.<p>
1032 :     *
1033 :     * The list-iterator is <i>fail-fast</i>: if the list is structurally
1034 :     * modified at any time after the Iterator is created, in any way except
1035 :     * through the list-iterator's own <tt>remove</tt> or <tt>add</tt>
1036 :     * methods, the list-iterator will throw a
1037 :     * <tt>ConcurrentModificationException</tt>. Thus, in the face of
1038 :     * concurrent modification, the iterator fails quickly and cleanly, rather
1039 :     * than risking arbitrary, non-deterministic behavior at an undetermined
1040 :     * time in the future.
1041 :     *
1042 :     * @param index index of the first element to be returned from the
1043 :     * list-iterator (by a call to <tt>next</tt>)
1044 :     * @return a ListIterator of the elements in this list (in proper
1045 :     * sequence), starting at the specified position in the list
1046 :     * @throws IndexOutOfBoundsException {@inheritDoc}
1047 :     * @see List#listIterator(int)
1048 :     */
1049 :     public synchronized ListIterator<E> listIterator(int index) {
1050 :     if (index < 0 || index > elementCount)
1051 :     throw new IndexOutOfBoundsException("Index: "+index);
1052 :     return new VectorIterator(index);
1053 :     }
1054 : jsr166 1.2
1055 : dl 1.1 /**
1056 : dl 1.3 * {@inheritDoc}
1057 :     */
1058 :     public synchronized ListIterator<E> listIterator() {
1059 :     return new VectorIterator(0);
1060 :     }
1061 :    
1062 :     /**
1063 : dl 1.1 * Returns an iterator over the elements in this list in proper sequence.
1064 :     *
1065 :     * @return an iterator over the elements in this list in proper sequence
1066 :     */
1067 :     public synchronized Iterator<E> iterator() {
1068 :     return new VectorIterator(0);
1069 :     }
1070 :    
1071 :     /**
1072 : dl 1.3 * A streamlined version of AbstractList.ListItr.
1073 : dl 1.1 */
1074 : dl 1.3 private final class VectorIterator implements ListIterator<E> {
1075 :     int cursor; // current position
1076 :     int lastRet; // index of last returned element
1077 :     int expectedModCount; // to check for CME
1078 : dl 1.1
1079 :     VectorIterator(int index) {
1080 :     cursor = index;
1081 : dl 1.3 expectedModCount = modCount;
1082 : dl 1.1 lastRet = -1;
1083 :     }
1084 :    
1085 :     public boolean hasNext() {
1086 : dl 1.3 // Racy but within spec, since modifications are checked
1087 :     // within or after synchronization in next/previous
1088 : dl 1.5 return cursor != elementCount;
1089 : dl 1.1 }
1090 :    
1091 :     public boolean hasPrevious() {
1092 : dl 1.5 return cursor != 0;
1093 : dl 1.1 }
1094 :    
1095 :     public int nextIndex() {
1096 :     return cursor;
1097 :     }
1098 :    
1099 :     public int previousIndex() {
1100 :     return cursor - 1;
1101 :     }
1102 :    
1103 :     public E next() {
1104 : dl 1.3 try {
1105 :     int i = cursor;
1106 :     E next = get(i);
1107 :     lastRet = i;
1108 :     cursor = i + 1;
1109 :     return next;
1110 :     } catch (IndexOutOfBoundsException ex) {
1111 :     throw new NoSuchElementException();
1112 :     } finally {
1113 :     if (expectedModCount != modCount)
1114 :     throw new ConcurrentModificationException();
1115 : dl 1.1 }
1116 :     }
1117 : jsr166 1.4
1118 :     public E previous() {
1119 : dl 1.3 try {
1120 :     int i = cursor - 1;
1121 :     E prev = get(i);
1122 :     lastRet = i;
1123 :     cursor = i;
1124 :     return prev;
1125 :     } catch (IndexOutOfBoundsException ex) {
1126 :     throw new NoSuchElementException();
1127 :     } finally {
1128 :     if (expectedModCount != modCount)
1129 :     throw new ConcurrentModificationException();
1130 : dl 1.1 }
1131 :     }
1132 :    
1133 :     public void remove() {
1134 : dl 1.3 if (lastRet == -1)
1135 : dl 1.1 throw new IllegalStateException();
1136 : dl 1.3 if (expectedModCount != modCount)
1137 :     throw new ConcurrentModificationException();
1138 :     try {
1139 :     Vector.this.remove(lastRet);
1140 :     if (lastRet < cursor)
1141 :     cursor--;
1142 :     lastRet = -1;
1143 :     expectedModCount = modCount;
1144 : jsr166 1.4 } catch (IndexOutOfBoundsException ex) {
1145 : dl 1.3 throw new ConcurrentModificationException();
1146 :     }
1147 : dl 1.1 }
1148 :    
1149 :     public void set(E e) {
1150 : dl 1.3 if (lastRet == -1)
1151 : dl 1.1 throw new IllegalStateException();
1152 : dl 1.3 if (expectedModCount != modCount)
1153 :     throw new ConcurrentModificationException();
1154 :     try {
1155 :     Vector.this.set(lastRet, e);
1156 :     expectedModCount = modCount;
1157 :     } catch (IndexOutOfBoundsException ex) {
1158 :     throw new ConcurrentModificationException();
1159 :     }
1160 : dl 1.1 }
1161 :    
1162 :     public void add(E e) {
1163 : dl 1.3 if (expectedModCount != modCount)
1164 :     throw new ConcurrentModificationException();
1165 :     try {
1166 :     int i = cursor;
1167 :     Vector.this.add(i, e);
1168 :     cursor = i + 1;
1169 :     lastRet = -1;
1170 :     expectedModCount = modCount;
1171 :     } catch (IndexOutOfBoundsException ex) {
1172 :     throw new ConcurrentModificationException();
1173 :     }
1174 : dl 1.1 }
1175 :     }
1176 :     }

Doug Lea
ViewVC Help
Powered by ViewVC 1.0.8