Source for java.util.Vector

   1: /* Vector.java -- Class that provides growable arrays.
   2:    Copyright (C) 1998, 1999, 2000, 2001, 2004, 2005, 2006,  
   3:    Free Software Foundation, Inc.
   4: 
   5: This file is part of GNU Classpath.
   6: 
   7: GNU Classpath is free software; you can redistribute it and/or modify
   8: it under the terms of the GNU General Public License as published by
   9: the Free Software Foundation; either version 2, or (at your option)
  10: any later version.
  11: 
  12: GNU Classpath is distributed in the hope that it will be useful, but
  13: WITHOUT ANY WARRANTY; without even the implied warranty of
  14: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15: General Public License for more details.
  16: 
  17: You should have received a copy of the GNU General Public License
  18: along with GNU Classpath; see the file COPYING.  If not, write to the
  19: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20: 02110-1301 USA.
  21: 
  22: Linking this library statically or dynamically with other modules is
  23: making a combined work based on this library.  Thus, the terms and
  24: conditions of the GNU General Public License cover the whole
  25: combination.
  26: 
  27: As a special exception, the copyright holders of this library give you
  28: permission to link this library with independent modules to produce an
  29: executable, regardless of the license terms of these independent
  30: modules, and to copy and distribute the resulting executable under
  31: terms of your choice, provided that you also meet, for each linked
  32: independent module, the terms and conditions of the license of that
  33: module.  An independent module is a module which is not derived from
  34: or based on this library.  If you modify this library, you may extend
  35: this exception to your version of the library, but you are not
  36: obligated to do so.  If you do not wish to do so, delete this
  37: exception statement from your version. */
  38: 
  39: 
  40: package java.util;
  41: 
  42: import java.io.IOException;
  43: import java.io.ObjectOutputStream;
  44: import java.io.Serializable;
  45: import java.lang.reflect.Array;
  46: 
  47: /**
  48:  * The <code>Vector</code> classes implements growable arrays of Objects.
  49:  * You can access elements in a Vector with an index, just as you
  50:  * can in a built in array, but Vectors can grow and shrink to accommodate
  51:  * more or fewer objects.<p>
  52:  *
  53:  * Vectors try to mantain efficiency in growing by having a
  54:  * <code>capacityIncrement</code> that can be specified at instantiation.
  55:  * When a Vector can no longer hold a new Object, it grows by the amount
  56:  * in <code>capacityIncrement</code>. If this value is 0, the vector doubles in
  57:  * size.<p>
  58:  *
  59:  * Vector implements the JDK 1.2 List interface, and is therefore a fully
  60:  * compliant Collection object. The iterators are fail-fast - if external
  61:  * code structurally modifies the vector, any operation on the iterator will
  62:  * then throw a {@link ConcurrentModificationException}. The Vector class is
  63:  * fully synchronized, but the iterators are not. So, when iterating over a
  64:  * vector, be sure to synchronize on the vector itself.  If you don't want the
  65:  * expense of synchronization, use ArrayList instead. On the other hand, the
  66:  * Enumeration of elements() is not thread-safe, nor is it fail-fast; so it
  67:  * can lead to undefined behavior even in a single thread if you modify the
  68:  * vector during iteration.<p>
  69:  *
  70:  * Note: Some methods, especially those specified by List, specify throwing
  71:  * {@link IndexOutOfBoundsException}, but it is easier to implement by
  72:  * throwing the subclass {@link ArrayIndexOutOfBoundsException}. Others
  73:  * directly specify this subclass.
  74:  *
  75:  * @author Scott G. Miller
  76:  * @author Bryce McKinlay
  77:  * @author Eric Blake (ebb9@email.byu.edu)
  78:  * @see Collection
  79:  * @see List
  80:  * @see ArrayList
  81:  * @see LinkedList
  82:  * @since 1.0
  83:  * @status updated to 1.4
  84:  */
  85: public class Vector<T> extends AbstractList<T>
  86:   implements List<T>, RandomAccess, Cloneable, Serializable
  87: {
  88:   /**
  89:    * Compatible with JDK 1.0+.
  90:    */
  91:   private static final long serialVersionUID = -2767605614048989439L;
  92: 
  93:   /**
  94:    * The internal array used to hold members of a Vector. The elements are
  95:    * in positions 0 through elementCount - 1, and all remaining slots are null.
  96:    * @serial the elements
  97:    */
  98:   protected T[] elementData;
  99: 
 100:   /**
 101:    * The number of elements currently in the vector, also returned by
 102:    * {@link #size}.
 103:    * @serial the size
 104:    */
 105:   protected int elementCount;
 106: 
 107:   /**
 108:    * The amount the Vector's internal array should be increased in size when
 109:    * a new element is added that exceeds the current size of the array,
 110:    * or when {@link #ensureCapacity} is called. If &lt;= 0, the vector just
 111:    * doubles in size.
 112:    * @serial the amount to grow the vector by
 113:    */
 114:   protected int capacityIncrement;
 115: 
 116:   /**
 117:    * Constructs an empty vector with an initial size of 10, and
 118:    * a capacity increment of 0
 119:    */
 120:   public Vector()
 121:   {
 122:     this(10, 0);
 123:   }
 124: 
 125:   /**
 126:    * Constructs a vector containing the contents of Collection, in the
 127:    * order given by the collection.
 128:    *
 129:    * @param c collection of elements to add to the new vector
 130:    * @throws NullPointerException if c is null
 131:    * @since 1.2
 132:    */
 133:   public Vector(Collection<? extends T> c)
 134:   {
 135:     elementCount = c.size();
 136:     elementData = c.toArray((T[]) new Object[elementCount]);
 137:   }
 138: 
 139:   /**
 140:    * Constructs a Vector with the initial capacity and capacity
 141:    * increment specified.
 142:    *
 143:    * @param initialCapacity the initial size of the Vector's internal array
 144:    * @param capacityIncrement the amount the internal array should be
 145:    *        increased by when necessary, 0 to double the size
 146:    * @throws IllegalArgumentException if initialCapacity &lt; 0
 147:    */
 148:   public Vector(int initialCapacity, int capacityIncrement)
 149:   {
 150:     if (initialCapacity < 0)
 151:       throw new IllegalArgumentException();
 152:     elementData = (T[]) new Object[initialCapacity];
 153:     this.capacityIncrement = capacityIncrement;
 154:   }
 155: 
 156:   /**
 157:    * Constructs a Vector with the initial capacity specified, and a capacity
 158:    * increment of 0 (double in size).
 159:    *
 160:    * @param initialCapacity the initial size of the Vector's internal array
 161:    * @throws IllegalArgumentException if initialCapacity &lt; 0
 162:    */
 163:   public Vector(int initialCapacity)
 164:   {
 165:     this(initialCapacity, 0);
 166:   }
 167: 
 168:   /**
 169:    * Copies the contents of the Vector into the provided array.  If the
 170:    * array is too small to fit all the elements in the Vector, an 
 171:    * {@link IndexOutOfBoundsException} is thrown without modifying the array.  
 172:    * Old elements in the array are overwritten by the new elements.
 173:    *
 174:    * @param a target array for the copy
 175:    * @throws IndexOutOfBoundsException the array is not large enough
 176:    * @throws NullPointerException the array is null
 177:    * @see #toArray(Object[])
 178:    */
 179:   public synchronized void copyInto(Object[] a)
 180:   {
 181:     System.arraycopy(elementData, 0, a, 0, elementCount);
 182:   }
 183: 
 184:   /**
 185:    * Trims the Vector down to size.  If the internal data array is larger
 186:    * than the number of Objects its holding, a new array is constructed
 187:    * that precisely holds the elements. Otherwise this does nothing.
 188:    */
 189:   public synchronized void trimToSize()
 190:   {
 191:     // Don't bother checking for the case where size() == the capacity of the
 192:     // vector since that is a much less likely case; it's more efficient to
 193:     // not do the check and lose a bit of performance in that infrequent case
 194: 
 195:     T[] newArray = (T[]) new Object[elementCount];
 196:     System.arraycopy(elementData, 0, newArray, 0, elementCount);
 197:     elementData = newArray;
 198:   }
 199: 
 200:   /**
 201:    * Ensures that <code>minCapacity</code> elements can fit within this Vector.
 202:    * If <code>elementData</code> is too small, it is expanded as follows:
 203:    * If the <code>elementCount + capacityIncrement</code> is adequate, that
 204:    * is the new size. If <code>capacityIncrement</code> is non-zero, the
 205:    * candidate size is double the current. If that is not enough, the new
 206:    * size is <code>minCapacity</code>.
 207:    *
 208:    * @param minCapacity the desired minimum capacity, negative values ignored
 209:    */
 210:   public synchronized void ensureCapacity(int minCapacity)
 211:   {
 212:     if (elementData.length >= minCapacity)
 213:       return;
 214: 
 215:     int newCapacity;
 216:     if (capacityIncrement <= 0)
 217:       newCapacity = elementData.length * 2;
 218:     else
 219:       newCapacity = elementData.length + capacityIncrement;
 220: 
 221:     T[] newArray = (T[]) new Object[Math.max(newCapacity, minCapacity)];
 222: 
 223:     System.arraycopy(elementData, 0, newArray, 0, elementCount);
 224:     elementData = newArray;
 225:   }
 226: 
 227:   /**
 228:    * Explicitly sets the size of the vector (but not necessarily the size of
 229:    * the internal data array). If the new size is smaller than the old one,
 230:    * old values that don't fit are lost. If the new size is larger than the
 231:    * old one, the vector is padded with null entries.
 232:    *
 233:    * @param newSize The new size of the internal array
 234:    * @throws ArrayIndexOutOfBoundsException if the new size is negative
 235:    */
 236:   public synchronized void setSize(int newSize)
 237:   {
 238:     // Don't bother checking for the case where size() == the capacity of the
 239:     // vector since that is a much less likely case; it's more efficient to
 240:     // not do the check and lose a bit of performance in that infrequent case
 241:     modCount++;
 242:     ensureCapacity(newSize);
 243:     if (newSize < elementCount)
 244:       Arrays.fill(elementData, newSize, elementCount, null);
 245:     elementCount = newSize;
 246:   }
 247: 
 248:   /**
 249:    * Returns the size of the internal data array (not the amount of elements
 250:    * contained in the Vector).
 251:    *
 252:    * @return capacity of the internal data array
 253:    */
 254:   public synchronized int capacity()
 255:   {
 256:     return elementData.length;
 257:   }
 258: 
 259:   /**
 260:    * Returns the number of elements stored in this Vector.
 261:    *
 262:    * @return the number of elements in this Vector
 263:    */
 264:   public synchronized int size()
 265:   {
 266:     return elementCount;
 267:   }
 268: 
 269:   /**
 270:    * Returns true if this Vector is empty, false otherwise
 271:    *
 272:    * @return true if the Vector is empty, false otherwise
 273:    */
 274:   public synchronized boolean isEmpty()
 275:   {
 276:     return elementCount == 0;
 277:   }
 278: 
 279:   /**
 280:    * Returns an Enumeration of the elements of this Vector. The enumeration
 281:    * visits the elements in increasing index order, but is NOT thread-safe.
 282:    *
 283:    * @return an Enumeration
 284:    * @see #iterator()
 285:    */
 286:   // No need to synchronize as the Enumeration is not thread-safe!
 287:   public Enumeration<T> elements()
 288:   {
 289:     return new Enumeration<T>()
 290:     {
 291:       private int i = 0;
 292: 
 293:       public boolean hasMoreElements()
 294:       {
 295:         return i < elementCount;
 296:       }
 297: 
 298:       public T nextElement()
 299:       {
 300:         if (i >= elementCount)
 301:           throw new NoSuchElementException();
 302:         return elementData[i++];
 303:       }
 304:     };
 305:   }
 306: 
 307:   /**
 308:    * Returns true when <code>elem</code> is contained in this Vector.
 309:    *
 310:    * @param elem the element to check
 311:    * @return true if the object is contained in this Vector, false otherwise
 312:    */
 313:   public boolean contains(Object elem)
 314:   {
 315:     return indexOf(elem, 0) >= 0;
 316:   }
 317: 
 318:   /**
 319:    * Returns the first occurrence of <code>elem</code> in the Vector, or -1 if
 320:    * <code>elem</code> is not found.
 321:    *
 322:    * @param elem the object to search for
 323:    * @return the index of the first occurrence, or -1 if not found
 324:    */
 325:   public int indexOf(Object elem)
 326:   {
 327:     return indexOf(elem, 0);
 328:   }
 329: 
 330:   /**
 331:    * Searches the vector starting at <code>index</code> for object
 332:    * <code>elem</code> and returns the index of the first occurrence of this
 333:    * Object.  If the object is not found, or index is larger than the size
 334:    * of the vector, -1 is returned.
 335:    *
 336:    * @param e the Object to search for
 337:    * @param index start searching at this index
 338:    * @return the index of the next occurrence, or -1 if it is not found
 339:    * @throws IndexOutOfBoundsException if index &lt; 0
 340:    */
 341:   public synchronized int indexOf(Object e, int index)
 342:   {
 343:     for (int i = index; i < elementCount; i++)
 344:       if (equals(e, elementData[i]))
 345:         return i;
 346:     return -1;
 347:   }
 348: 
 349:   /**
 350:    * Returns the last index of <code>elem</code> within this Vector, or -1
 351:    * if the object is not within the Vector.
 352:    *
 353:    * @param elem the object to search for
 354:    * @return the last index of the object, or -1 if not found
 355:    */
 356:   public int lastIndexOf(Object elem)
 357:   {
 358:     return lastIndexOf(elem, elementCount - 1);
 359:   }
 360: 
 361:   /**
 362:    * Returns the index of the first occurrence of <code>elem</code>, when
 363:    * searching backwards from <code>index</code>.  If the object does not
 364:    * occur in this Vector, or index is less than 0, -1 is returned.
 365:    *
 366:    * @param e the object to search for
 367:    * @param index the index to start searching in reverse from
 368:    * @return the index of the Object if found, -1 otherwise
 369:    * @throws IndexOutOfBoundsException if index &gt;= size()
 370:    */
 371:   public synchronized int lastIndexOf(Object e, int index)
 372:   {
 373:     checkBoundExclusive(index);
 374:     for (int i = index; i >= 0; i--)
 375:       if (equals(e, elementData[i]))
 376:         return i;
 377:     return -1;
 378:   }
 379: 
 380:   /**
 381:    * Returns the Object stored at <code>index</code>.
 382:    *
 383:    * @param index the index of the Object to retrieve
 384:    * @return the object at <code>index</code>
 385:    * @throws ArrayIndexOutOfBoundsException index &lt; 0 || index &gt;= size()
 386:    * @see #get(int)
 387:    */
 388:   public synchronized T elementAt(int index)
 389:   {
 390:     checkBoundExclusive(index);
 391:     return elementData[index];
 392:   }
 393: 
 394:   /**
 395:    * Returns the first element (index 0) in the Vector.
 396:    *
 397:    * @return the first Object in the Vector
 398:    * @throws NoSuchElementException the Vector is empty
 399:    */
 400:   public synchronized T firstElement()
 401:   {
 402:     if (elementCount == 0)
 403:       throw new NoSuchElementException();
 404: 
 405:     return elementData[0];
 406:   }
 407: 
 408:   /**
 409:    * Returns the last element in the Vector.
 410:    *
 411:    * @return the last Object in the Vector
 412:    * @throws NoSuchElementException the Vector is empty
 413:    */
 414:   public synchronized T lastElement()
 415:   {
 416:     if (elementCount == 0)
 417:       throw new NoSuchElementException();
 418: 
 419:     return elementData[elementCount - 1];
 420:   }
 421: 
 422:   /**
 423:    * Changes the element at <code>index</code> to be <code>obj</code>
 424:    *
 425:    * @param obj the object to store
 426:    * @param index the position in the Vector to store the object
 427:    * @throws ArrayIndexOutOfBoundsException the index is out of range
 428:    * @see #set(int, Object)
 429:    */
 430:   public void setElementAt(T obj, int index)
 431:   {
 432:     set(index, obj);
 433:   }
 434: 
 435:   /**
 436:    * Removes the element at <code>index</code>, and shifts all elements at
 437:    * positions greater than index to their index - 1.
 438:    *
 439:    * @param index the index of the element to remove
 440:    * @throws ArrayIndexOutOfBoundsException index &lt; 0 || index &gt;= size();
 441:    * @see #remove(int)
 442:    */
 443:   public void removeElementAt(int index)
 444:   {
 445:     remove(index);
 446:   }
 447: 
 448:   /**
 449:    * Inserts a new element into the Vector at <code>index</code>.  Any elements
 450:    * at or greater than index are shifted up one position.
 451:    *
 452:    * @param obj the object to insert
 453:    * @param index the index at which the object is inserted
 454:    * @throws ArrayIndexOutOfBoundsException index &lt; 0 || index &gt; size()
 455:    * @see #add(int, Object)
 456:    */
 457:   public synchronized void insertElementAt(T obj, int index)
 458:   {
 459:     checkBoundInclusive(index);
 460:     if (elementCount == elementData.length)
 461:       ensureCapacity(elementCount + 1);
 462:     modCount++;
 463:     System.arraycopy(elementData, index, elementData, index + 1,
 464:                      elementCount - index);
 465:     elementCount++;
 466:     elementData[index] = obj;
 467:   }
 468: 
 469:   /**
 470:    * Adds an element to the Vector at the end of the Vector.  The vector
 471:    * is increased by ensureCapacity(size() + 1) if needed.
 472:    *
 473:    * @param obj the object to add to the Vector
 474:    */
 475:   public synchronized void addElement(T obj)
 476:   {
 477:     if (elementCount == elementData.length)
 478:       ensureCapacity(elementCount + 1);
 479:     modCount++;
 480:     elementData[elementCount++] = obj;
 481:   }
 482: 
 483:   /**
 484:    * Removes the first (the lowest index) occurrence of the given object from
 485:    * the Vector. If such a remove was performed (the object was found), true
 486:    * is returned. If there was no such object, false is returned.
 487:    *
 488:    * @param obj the object to remove from the Vector
 489:    * @return true if the Object was in the Vector, false otherwise
 490:    * @see #remove(Object)
 491:    */
 492:   public synchronized boolean removeElement(Object obj)
 493:   {
 494:     int idx = indexOf(obj, 0);
 495:     if (idx >= 0)
 496:       {
 497:         remove(idx);
 498:         return true;
 499:       }
 500:     return false;
 501:   }
 502: 
 503:   /**
 504:    * Removes all elements from the Vector.  Note that this does not
 505:    * resize the internal data array.
 506:    *
 507:    * @see #clear()
 508:    */
 509:   public synchronized void removeAllElements()
 510:   {
 511:     if (elementCount == 0)
 512:       return;
 513: 
 514:     modCount++;
 515:     Arrays.fill(elementData, 0, elementCount, null);
 516:     elementCount = 0;
 517:   }
 518: 
 519:   /**
 520:    * Creates a new Vector with the same contents as this one. The clone is
 521:    * shallow; elements are not cloned.
 522:    *
 523:    * @return the clone of this vector
 524:    */
 525:   public synchronized Object clone()
 526:   {
 527:     try
 528:       {
 529:         Vector clone = (Vector) super.clone();
 530:         clone.elementData = (Object[]) elementData.clone();
 531:         return clone;
 532:       }
 533:     catch (CloneNotSupportedException ex)
 534:       {
 535:         // Impossible to get here.
 536:         throw new InternalError(ex.toString());
 537:       }
 538:   }
 539: 
 540:   /**
 541:    * Returns an Object array with the contents of this Vector, in the order
 542:    * they are stored within this Vector.  Note that the Object array returned
 543:    * is not the internal data array, and that it holds only the elements
 544:    * within the Vector.  This is similar to creating a new Object[] with the
 545:    * size of this Vector, then calling Vector.copyInto(yourArray).
 546:    *
 547:    * @return an Object[] containing the contents of this Vector in order
 548:    * @since 1.2
 549:    */
 550:   public synchronized Object[] toArray()
 551:   {
 552:     Object[] newArray = new Object[elementCount];
 553:     copyInto(newArray);
 554:     return newArray;
 555:   }
 556: 
 557:   /**
 558:    * Returns an array containing the contents of this Vector.
 559:    * If the provided array is large enough, the contents are copied
 560:    * into that array, and a null is placed in the position size().
 561:    * In this manner, you can obtain the size of a Vector by the position
 562:    * of the null element, if you know the vector does not itself contain
 563:    * null entries.  If the array is not large enough, reflection is used
 564:    * to create a bigger one of the same runtime type.
 565:    *
 566:    * @param a an array to copy the Vector into if large enough
 567:    * @return an array with the contents of this Vector in order
 568:    * @throws ArrayStoreException the runtime type of the provided array
 569:    *         cannot hold the elements of the Vector
 570:    * @throws NullPointerException if <code>a</code> is null
 571:    * @since 1.2
 572:    */
 573:   public synchronized <S> S[] toArray(S[] a)
 574:   {
 575:     if (a.length < elementCount)
 576:       a = (S[]) Array.newInstance(a.getClass().getComponentType(),
 577:                   elementCount);
 578:     else if (a.length > elementCount)
 579:       a[elementCount] = null;
 580:     System.arraycopy(elementData, 0, a, 0, elementCount);
 581:     return a;
 582:   }
 583: 
 584:   /**
 585:    * Returns the element at position <code>index</code>.
 586:    *
 587:    * @param index the position from which an element will be retrieved
 588:    * @return the element at that position
 589:    * @throws ArrayIndexOutOfBoundsException index &lt; 0 || index &gt;= size()
 590:    * @since 1.2
 591:    */
 592:   public T get(int index)
 593:   {
 594:     return elementAt(index);
 595:   }
 596: 
 597:   /**
 598:    * Puts <code>element</code> into the Vector at position <code>index</code>
 599:    * and returns the Object that previously occupied that position.
 600:    *
 601:    * @param index the index within the Vector to place the Object
 602:    * @param element the Object to store in the Vector
 603:    * @return the previous object at the specified index
 604:    * @throws ArrayIndexOutOfBoundsException index &lt; 0 || index &gt;= size()
 605:    * @since 1.2
 606:    */
 607:   public synchronized T set(int index, T element)
 608:   {
 609:     checkBoundExclusive(index);
 610:     T temp = elementData[index];
 611:     elementData[index] = element;
 612:     return temp;
 613:   }
 614: 
 615:   /**
 616:    * Adds an object to the Vector.
 617:    *
 618:    * @param o the element to add to the Vector
 619:    * @return true, as specified by List
 620:    * @since 1.2
 621:    */
 622:   public boolean add(T o)
 623:   {
 624:     addElement(o);
 625:     return true;
 626:   }
 627: 
 628:   /**
 629:    * Removes the given Object from the Vector.  If it exists, true
 630:    * is returned, if not, false is returned.
 631:    *
 632:    * @param o the object to remove from the Vector
 633:    * @return true if the Object existed in the Vector, false otherwise
 634:    * @since 1.2
 635:    */
 636:   public boolean remove(Object o)
 637:   {
 638:     return removeElement(o);
 639:   }
 640: 
 641:   /**
 642:    * Adds an object at the specified index.  Elements at or above
 643:    * index are shifted up one position.
 644:    *
 645:    * @param index the index at which to add the element
 646:    * @param element the element to add to the Vector
 647:    * @throws ArrayIndexOutOfBoundsException index &lt; 0 || index &gt; size()
 648:    * @since 1.2
 649:    */
 650:   public void add(int index, T element)
 651:   {
 652:     insertElementAt(element, index);
 653:   }
 654: 
 655:   /**
 656:    * Removes the element at the specified index, and returns it.
 657:    *
 658:    * @param index the position from which to remove the element
 659:    * @return the object removed
 660:    * @throws ArrayIndexOutOfBoundsException index &lt; 0 || index &gt;= size()
 661:    * @since 1.2
 662:    */
 663:   public synchronized T remove(int index)
 664:   {
 665:     checkBoundExclusive(index);
 666:     T temp = elementData[index];
 667:     modCount++;
 668:     elementCount--;
 669:     if (index < elementCount)
 670:       System.arraycopy(elementData, index + 1, elementData, index,
 671:                        elementCount - index);
 672:     elementData[elementCount] = null;
 673:     return temp;
 674:   }
 675: 
 676:   /**
 677:    * Clears all elements in the Vector and sets its size to 0.
 678:    */
 679:   public void clear()
 680:   {
 681:     removeAllElements();
 682:   }
 683: 
 684:   /**
 685:    * Returns true if this Vector contains all the elements in c.
 686:    *
 687:    * @param c the collection to compare to
 688:    * @return true if this vector contains all elements of c
 689:    * @throws NullPointerException if c is null
 690:    * @since 1.2
 691:    */
 692:   public synchronized boolean containsAll(Collection<?> c)
 693:   {
 694:     // Here just for the sychronization.
 695:     return super.containsAll(c);
 696:   }
 697: 
 698:   /**
 699:    * Appends all elements of the given collection to the end of this Vector.
 700:    * Behavior is undefined if the collection is modified during this operation
 701:    * (for example, if this == c).
 702:    *
 703:    * @param c the collection to append
 704:    * @return true if this vector changed, in other words c was not empty
 705:    * @throws NullPointerException if c is null
 706:    * @since 1.2
 707:    */
 708:   public synchronized boolean addAll(Collection<? extends T> c)
 709:   {
 710:     return addAll(elementCount, c);
 711:   }
 712: 
 713:   /**
 714:    * Remove from this vector all elements contained in the given collection.
 715:    *
 716:    * @param c the collection to filter out
 717:    * @return true if this vector changed
 718:    * @throws NullPointerException if c is null
 719:    * @since 1.2
 720:    */
 721:   public synchronized boolean removeAll(Collection<?> c)
 722:   {
 723:     // The NullPointerException is thrown implicitly when the Vector
 724:     // is not empty and c is null. The RI allows null arguments when
 725:     // the vector is empty. See Mauve test:
 726:     // gnu/testlet/java/util/Vector/removeAll.java
 727: 
 728:     int i;
 729:     int j;
 730:     for (i = 0; i < elementCount; i++)
 731:       if (c.contains(elementData[i]))
 732:         break;
 733:     if (i == elementCount)
 734:       return false;
 735: 
 736:     modCount++;
 737:     for (j = i++; i < elementCount; i++)
 738:       if (! c.contains(elementData[i]))
 739:         elementData[j++] = elementData[i];
 740:     elementCount -= i - j;
 741:     return true;
 742:   }
 743: 
 744:   /**
 745:    * Retain in this vector only the elements contained in the given collection.
 746:    *
 747:    * @param c the collection to filter by
 748:    * @return true if this vector changed
 749:    * @throws NullPointerException if c is null
 750:    * @since 1.2
 751:    */
 752:   public synchronized boolean retainAll(Collection<?> c)
 753:   {
 754:     // The NullPointerException is thrown implicitly when the Vector
 755:     // is not empty and c is null. The RI allows null arguments when
 756:     // the vector is empty. See Mauve test:
 757:     // gnu/testlet/java/util/Vector/retainAll.java
 758: 
 759:     int i;
 760:     int j;
 761:     for (i = 0; i < elementCount; i++)
 762:       if (! c.contains(elementData[i]))
 763:         break;
 764:     if (i == elementCount)
 765:       return false;
 766: 
 767:     modCount++;
 768:     for (j = i++; i < elementCount; i++)
 769:       if (c.contains(elementData[i]))
 770:         elementData[j++] = elementData[i];
 771:     elementCount -= i - j;
 772:     return true;
 773:   }
 774: 
 775:   /**
 776:    * Inserts all elements of the given collection at the given index of
 777:    * this Vector. Behavior is undefined if the collection is modified during
 778:    * this operation (for example, if this == c).
 779:    *
 780:    * @param c the collection to append
 781:    * @return true if this vector changed, in other words c was not empty
 782:    * @throws NullPointerException if c is null
 783:    * @throws ArrayIndexOutOfBoundsException index &lt; 0 || index &gt; size()
 784:    * @since 1.2
 785:    */
 786:   public synchronized boolean addAll(int index, Collection<? extends T> c)
 787:   {
 788:     checkBoundInclusive(index);
 789:     Iterator<? extends T> itr = c.iterator();
 790:     int csize = c.size();
 791: 
 792:     modCount++;
 793:     ensureCapacity(elementCount + csize);
 794:     int end = index + csize;
 795:     if (elementCount > 0 && index != elementCount)
 796:       System.arraycopy(elementData, index,
 797:                elementData, end, elementCount - index);
 798:     elementCount += csize;
 799:     for ( ; index < end; index++)
 800:       elementData[index] = itr.next();
 801:     return (csize > 0);
 802:   }
 803: 
 804:   /**
 805:    * Compares this to the given object.
 806:    *
 807:    * @param o the object to compare to
 808:    * @return true if the two are equal
 809:    * @since 1.2
 810:    */
 811:   public synchronized boolean equals(Object o)
 812:   {
 813:     // Here just for the sychronization.
 814:     return super.equals(o);
 815:   }
 816: 
 817:   /**
 818:    * Computes the hashcode of this object.
 819:    *
 820:    * @return the hashcode
 821:    * @since 1.2
 822:    */
 823:   public synchronized int hashCode()
 824:   {
 825:     // Here just for the sychronization.
 826:     return super.hashCode();
 827:   }
 828: 
 829:   /**
 830:    * Returns a string representation of this Vector in the form
 831:    * "[element0, element1, ... elementN]".
 832:    *
 833:    * @return the String representation of this Vector
 834:    */
 835:   public synchronized String toString()
 836:   {
 837:     // Here just for the sychronization.
 838:     return super.toString();
 839:   }
 840: 
 841:   /**
 842:    * Obtain a List view of a subsection of this list, from fromIndex
 843:    * (inclusive) to toIndex (exclusive). If the two indices are equal, the
 844:    * sublist is empty. The returned list is modifiable, and changes in one
 845:    * reflect in the other. If this list is structurally modified in
 846:    * any way other than through the returned list, the result of any subsequent
 847:    * operations on the returned list is undefined.
 848:    * <p>
 849:    *
 850:    * @param fromIndex the index that the returned list should start from
 851:    *        (inclusive)
 852:    * @param toIndex the index that the returned list should go to (exclusive)
 853:    * @return a List backed by a subsection of this vector
 854:    * @throws IndexOutOfBoundsException if fromIndex &lt; 0
 855:    *         || toIndex &gt; size()
 856:    * @throws IllegalArgumentException if fromIndex &gt; toIndex
 857:    * @see ConcurrentModificationException
 858:    * @since 1.2
 859:    */
 860:   public synchronized List<T> subList(int fromIndex, int toIndex)
 861:   {
 862:     List<T> sub = super.subList(fromIndex, toIndex);
 863:     // We must specify the correct object to synchronize upon, hence the
 864:     // use of a non-public API
 865:     return new Collections.SynchronizedList<T>(this, sub);
 866:   }
 867: 
 868:   /**
 869:    * Removes a range of elements from this list.
 870:    * Does nothing when toIndex is equal to fromIndex.
 871:    *
 872:    * @param fromIndex the index to start deleting from (inclusive)
 873:    * @param toIndex the index to delete up to (exclusive)
 874:    * @throws IndexOutOfBoundsException if fromIndex &gt; toIndex
 875:    */
 876:   // This does not need to be synchronized, because it is only called through
 877:   // clear() of a sublist, and clear() had already synchronized.
 878:   protected void removeRange(int fromIndex, int toIndex)
 879:   {
 880:     int change = toIndex - fromIndex;
 881:     if (change > 0)
 882:       {
 883:         modCount++;
 884:         System.arraycopy(elementData, toIndex, elementData, fromIndex,
 885:                          elementCount - toIndex);
 886:         int save = elementCount;
 887:         elementCount -= change;
 888:         Arrays.fill(elementData, elementCount, save, null);
 889:       }
 890:     else if (change < 0)
 891:       throw new IndexOutOfBoundsException();
 892:   }
 893: 
 894:   /**
 895:    * Checks that the index is in the range of possible elements (inclusive).
 896:    *
 897:    * @param index the index to check
 898:    * @throws ArrayIndexOutOfBoundsException if index &gt; size
 899:    */
 900:   private void checkBoundInclusive(int index)
 901:   {
 902:     // Implementation note: we do not check for negative ranges here, since
 903:     // use of a negative index will cause an ArrayIndexOutOfBoundsException
 904:     // with no effort on our part.
 905:     if (index > elementCount)
 906:       throw new ArrayIndexOutOfBoundsException(index + " > " + elementCount);
 907:   }
 908: 
 909:   /**
 910:    * Checks that the index is in the range of existing elements (exclusive).
 911:    *
 912:    * @param index the index to check
 913:    * @throws ArrayIndexOutOfBoundsException if index &gt;= size
 914:    */
 915:   private void checkBoundExclusive(int index)
 916:   {
 917:     // Implementation note: we do not check for negative ranges here, since
 918:     // use of a negative index will cause an ArrayIndexOutOfBoundsException
 919:     // with no effort on our part.
 920:     if (index >= elementCount)
 921:       throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount);
 922:   }
 923: 
 924:   /**
 925:    * Serializes this object to the given stream.
 926:    *
 927:    * @param s the stream to write to
 928:    * @throws IOException if the underlying stream fails
 929:    * @serialData just calls default write function
 930:    */
 931:   private synchronized void writeObject(ObjectOutputStream s)
 932:     throws IOException
 933:   {
 934:     s.defaultWriteObject();
 935:   }
 936: 
 937: }