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| 1 | /* | ||
| 2 | * Copyright (c) 1994, 2011, Oracle and/or its affiliates. All rights reserved. | ||
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | ||
| 4 | * | ||
| 5 | * This code is free software; you can redistribute it and/or modify it | ||
| 6 | * under the terms of the GNU General Public License version 2 only, as | ||
| 7 | * published by the Free Software Foundation. Oracle designates this | ||
| 8 | * particular file as subject to the "Classpath" exception as provided | ||
| 9 | * by Oracle in the LICENSE file that accompanied this code. | ||
| 10 | * | ||
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT | ||
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | ||
| 14 | * version 2 for more details (a copy is included in the LICENSE file that | ||
| 15 | * accompanied this code). | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU General Public License version | ||
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, | ||
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | ||
| 20 | * | ||
| 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | |||
| 26 | package java.util; | ||
| 27 | |||
| 28 | /** | ||
| 29 | * The {@code Vector} class implements a growable array of | ||
| 30 | * objects. Like an array, it contains components that can be | ||
| 31 | * accessed using an integer index. However, the size of a | ||
| 32 | * {@code Vector} can grow or shrink as needed to accommodate | ||
| 33 | * adding and removing items after the {@code Vector} has been created. | ||
| 34 | * | ||
| 35 | * <p>Each vector tries to optimize storage management by maintaining a | ||
| 36 | * {@code capacity} and a {@code capacityIncrement}. The | ||
| 37 | * {@code capacity} is always at least as large as the vector | ||
| 38 | * size; it is usually larger because as components are added to the | ||
| 39 | * vector, the vector's storage increases in chunks the size of | ||
| 40 | * {@code capacityIncrement}. An application can increase the | ||
| 41 | * capacity of a vector before inserting a large number of | ||
| 42 | * components; this reduces the amount of incremental reallocation. | ||
| 43 | * | ||
| 44 | * <p><a name="fail-fast"/> | ||
| 45 | * The iterators returned by this class's {@link #iterator() iterator} and | ||
| 46 | * {@link #listIterator(int) listIterator} methods are <em>fail-fast</em>: | ||
| 47 | * if the vector is structurally modified at any time after the iterator is | ||
| 48 | * created, in any way except through the iterator's own | ||
| 49 | * {@link ListIterator#remove() remove} or | ||
| 50 | * {@link ListIterator#add(Object) add} methods, the iterator will throw a | ||
| 51 | * {@link ConcurrentModificationException}. Thus, in the face of | ||
| 52 | * concurrent modification, the iterator fails quickly and cleanly, rather | ||
| 53 | * than risking arbitrary, non-deterministic behavior at an undetermined | ||
| 54 | * time in the future. The {@link Enumeration Enumerations} returned by | ||
| 55 | * the {@link #elements() elements} method are <em>not</em> fail-fast. | ||
| 56 | * | ||
| 57 | * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed | ||
| 58 | * as it is, generally speaking, impossible to make any hard guarantees in the | ||
| 59 | * presence of unsynchronized concurrent modification. Fail-fast iterators | ||
| 60 | * throw {@code ConcurrentModificationException} on a best-effort basis. | ||
| 61 | * Therefore, it would be wrong to write a program that depended on this | ||
| 62 | * exception for its correctness: <i>the fail-fast behavior of iterators | ||
| 63 | * should be used only to detect bugs.</i> | ||
| 64 | * | ||
| 65 | * <p>As of the Java 2 platform v1.2, this class was retrofitted to | ||
| 66 | * implement the {@link List} interface, making it a member of the | ||
| 67 | * <a href="{@docRoot}/../technotes/guides/collections/index.html"> | ||
| 68 | * Java Collections Framework</a>. Unlike the new collection | ||
| 69 | * implementations, {@code Vector} is synchronized. If a thread-safe | ||
| 70 | * implementation is not needed, it is recommended to use {@link | ||
| 71 | * ArrayList} in place of {@code Vector}. | ||
| 72 | * | ||
| 73 | * @author Lee Boynton | ||
| 74 | * @author Jonathan Payne | ||
| 75 | * @see Collection | ||
| 76 | * @see LinkedList | ||
| 77 | * @since JDK1.0 | ||
| 78 | */ | ||
| 79 | public class Vector<E> | ||
| 80 | extends AbstractList<E> | ||
| 81 | implements List<E>, RandomAccess, Cloneable, java.io.Serializable | ||
| 82 | { | ||
| 83 | /** | ||
| 84 | * The array buffer into which the components of the vector are | ||
| 85 | * stored. The capacity of the vector is the length of this array buffer, | ||
| 86 | * and is at least large enough to contain all the vector's elements. | ||
| 87 | * | ||
| 88 | * <p>Any array elements following the last element in the Vector are null. | ||
| 89 | * | ||
| 90 | * @serial | ||
| 91 | */ | ||
| 92 | protected Object[] elementData; | ||
| 93 | |||
| 94 | /** | ||
| 95 | * The number of valid components in this {@code Vector} object. | ||
| 96 | * Components {@code elementData[0]} through | ||
| 97 | * {@code elementData[elementCount-1]} are the actual items. | ||
| 98 | * | ||
| 99 | * @serial | ||
| 100 | */ | ||
| 101 | protected int elementCount; | ||
| 102 | |||
| 103 | /** | ||
| 104 | * The amount by which the capacity of the vector is automatically | ||
| 105 | * incremented when its size becomes greater than its capacity. If | ||
| 106 | * the capacity increment is less than or equal to zero, the capacity | ||
| 107 | * of the vector is doubled each time it needs to grow. | ||
| 108 | * | ||
| 109 | * @serial | ||
| 110 | */ | ||
| 111 | protected int capacityIncrement; | ||
| 112 | |||
| 113 | /** use serialVersionUID from JDK 1.0.2 for interoperability */ | ||
| 114 | private static final long serialVersionUID = -2767605614048989439L; | ||
| 115 | |||
| 116 | /** | ||
| 117 | * Constructs an empty vector with the specified initial capacity and | ||
| 118 | * capacity increment. | ||
| 119 | * | ||
| 120 | * @param initialCapacity the initial capacity of the vector | ||
| 121 | * @param capacityIncrement the amount by which the capacity is | ||
| 122 | * increased when the vector overflows | ||
| 123 | * @throws IllegalArgumentException if the specified initial capacity | ||
| 124 | * is negative | ||
| 125 | */ | ||
| 126 | public Vector(int initialCapacity, int capacityIncrement) { | ||
| 127 | super(); | ||
| 128 | if (initialCapacity < 0) | ||
| 129 | throw new IllegalArgumentException("Illegal Capacity: "+ | ||
| 130 | initialCapacity); | ||
| 131 | this.elementData = new Object[initialCapacity]; | ||
| 132 | this.capacityIncrement = capacityIncrement; | ||
| 133 | } | ||
| 134 | |||
| 135 | /** | ||
| 136 | * Constructs an empty vector with the specified initial capacity and | ||
| 137 | * with its capacity increment equal to zero. | ||
| 138 | * | ||
| 139 | * @param initialCapacity the initial capacity of the vector | ||
| 140 | * @throws IllegalArgumentException if the specified initial capacity | ||
| 141 | * is negative | ||
| 142 | */ | ||
| 143 | public Vector(int initialCapacity) { | ||
| 144 | this(initialCapacity, 0); | ||
| 145 | } | ||
| 146 | |||
| 147 | /** | ||
| 148 | * Constructs an empty vector so that its internal data array | ||
| 149 | * has size {@code 10} and its standard capacity increment is | ||
| 150 | * zero. | ||
| 151 | */ | ||
| 152 | public Vector() { | ||
| 153 | this(10); | ||
| 154 | } | ||
| 155 | |||
| 156 | /** | ||
| 157 | * Constructs a vector containing the elements of the specified | ||
| 158 | * collection, in the order they are returned by the collection's | ||
| 159 | * iterator. | ||
| 160 | * | ||
| 161 | * @param c the collection whose elements are to be placed into this | ||
| 162 | * vector | ||
| 163 | * @throws NullPointerException if the specified collection is null | ||
| 164 | * @since 1.2 | ||
| 165 | */ | ||
| 166 | public Vector(Collection<? extends E> c) { | ||
| 167 | elementData = c.toArray(); | ||
| 168 | elementCount = elementData.length; | ||
| 169 | // c.toArray might (incorrectly) not return Object[] (see 6260652) | ||
| 170 | if (elementData.getClass() != Object[].class) | ||
| 171 | elementData = Arrays.copyOf(elementData, elementCount, Object[].class); | ||
| 172 | } | ||
| 173 | |||
| 174 | /** | ||
| 175 | * Copies the components of this vector into the specified array. | ||
| 176 | * The item at index {@code k} in this vector is copied into | ||
| 177 | * component {@code k} of {@code anArray}. | ||
| 178 | * | ||
| 179 | * @param anArray the array into which the components get copied | ||
| 180 | * @throws NullPointerException if the given array is null | ||
| 181 | * @throws IndexOutOfBoundsException if the specified array is not | ||
| 182 | * large enough to hold all the components of this vector | ||
| 183 | * @throws ArrayStoreException if a component of this vector is not of | ||
| 184 | * a runtime type that can be stored in the specified array | ||
| 185 | * @see #toArray(Object[]) | ||
| 186 | */ | ||
| 187 | public synchronized void copyInto(Object[] anArray) { | ||
| 188 | System.arraycopy(elementData, 0, anArray, 0, elementCount); | ||
| 189 | } | ||
| 190 | |||
| 191 | /** | ||
| 192 | * Trims the capacity of this vector to be the vector's current | ||
| 193 | * size. If the capacity of this vector is larger than its current | ||
| 194 | * size, then the capacity is changed to equal the size by replacing | ||
| 195 | * its internal data array, kept in the field {@code elementData}, | ||
| 196 | * with a smaller one. An application can use this operation to | ||
| 197 | * minimize the storage of a vector. | ||
| 198 | */ | ||
| 199 | public synchronized void trimToSize() { | ||
| 200 | modCount++; | ||
| 201 | int oldCapacity = elementData.length; | ||
| 202 | if (elementCount < oldCapacity) { | ||
| 203 | elementData = Arrays.copyOf(elementData, elementCount); | ||
| 204 | } | ||
| 205 | } | ||
| 206 | |||
| 207 | /** | ||
| 208 | * Increases the capacity of this vector, if necessary, to ensure | ||
| 209 | * that it can hold at least the number of components specified by | ||
| 210 | * the minimum capacity argument. | ||
| 211 | * | ||
| 212 | * <p>If the current capacity of this vector is less than | ||
| 213 | * {@code minCapacity}, then its capacity is increased by replacing its | ||
| 214 | * internal data array, kept in the field {@code elementData}, with a | ||
| 215 | * larger one. The size of the new data array will be the old size plus | ||
| 216 | * {@code capacityIncrement}, unless the value of | ||
| 217 | * {@code capacityIncrement} is less than or equal to zero, in which case | ||
| 218 | * the new capacity will be twice the old capacity; but if this new size | ||
| 219 | * is still smaller than {@code minCapacity}, then the new capacity will | ||
| 220 | * be {@code minCapacity}. | ||
| 221 | * | ||
| 222 | * @param minCapacity the desired minimum capacity | ||
| 223 | */ | ||
| 224 | public synchronized void ensureCapacity(int minCapacity) { | ||
| 225 | if (minCapacity > 0) { | ||
| 226 | modCount++; | ||
| 227 | ensureCapacityHelper(minCapacity); | ||
| 228 | } | ||
| 229 | } | ||
| 230 | |||
| 231 | /** | ||
| 232 | * This implements the unsynchronized semantics of ensureCapacity. | ||
| 233 | * Synchronized methods in this class can internally call this | ||
| 234 | * method for ensuring capacity without incurring the cost of an | ||
| 235 | * extra synchronization. | ||
| 236 | * | ||
| 237 | * @see #ensureCapacity(int) | ||
| 238 | */ | ||
| 239 | private void ensureCapacityHelper(int minCapacity) { | ||
| 240 | // overflow-conscious code | ||
| 241 | if (minCapacity - elementData.length > 0) | ||
| 242 | grow(minCapacity); | ||
| 243 | } | ||
| 244 | |||
| 245 | /** | ||
| 246 | * The maximum size of array to allocate. | ||
| 247 | * Some VMs reserve some header words in an array. | ||
| 248 | * Attempts to allocate larger arrays may result in | ||
| 249 | * OutOfMemoryError: Requested array size exceeds VM limit | ||
| 250 | */ | ||
| 251 | private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; | ||
| 252 | |||
| 253 | private void grow(int minCapacity) { | ||
| 254 | // overflow-conscious code | ||
| 255 | int oldCapacity = elementData.length; | ||
| 256 | int newCapacity = oldCapacity + ((capacityIncrement > 0) ? | ||
| 257 | capacityIncrement : oldCapacity); | ||
| 258 | if (newCapacity - minCapacity < 0) | ||
| 259 | newCapacity = minCapacity; | ||
| 260 | if (newCapacity - MAX_ARRAY_SIZE > 0) | ||
| 261 | newCapacity = hugeCapacity(minCapacity); | ||
| 262 | elementData = Arrays.copyOf(elementData, newCapacity); | ||
| 263 | } | ||
| 264 | |||
| 265 | private static int hugeCapacity(int minCapacity) { | ||
| 266 | if (minCapacity < 0) // overflow | ||
| 267 | throw new OutOfMemoryError(); | ||
| 268 | return (minCapacity > MAX_ARRAY_SIZE) ? | ||
| 269 | Integer.MAX_VALUE : | ||
| 270 | MAX_ARRAY_SIZE; | ||
| 271 | } | ||
| 272 | |||
| 273 | /** | ||
| 274 | * Sets the size of this vector. If the new size is greater than the | ||
| 275 | * current size, new {@code null} items are added to the end of | ||
| 276 | * the vector. If the new size is less than the current size, all | ||
| 277 | * components at index {@code newSize} and greater are discarded. | ||
| 278 | * | ||
| 279 | * @param newSize the new size of this vector | ||
| 280 | * @throws ArrayIndexOutOfBoundsException if the new size is negative | ||
| 281 | */ | ||
| 282 | public synchronized void setSize(int newSize) { | ||
| 283 | modCount++; | ||
| 284 | if (newSize > elementCount) { | ||
| 285 | ensureCapacityHelper(newSize); | ||
| 286 | } else { | ||
| 287 | for (int i = newSize ; i < elementCount ; i++) { | ||
| 288 | elementData[i] = null; | ||
| 289 | } | ||
| 290 | } | ||
| 291 | elementCount = newSize; | ||
| 292 | } | ||
| 293 | |||
| 294 | /** | ||
| 295 | * Returns the current capacity of this vector. | ||
| 296 | * | ||
| 297 | * @return the current capacity (the length of its internal | ||
| 298 | * data array, kept in the field {@code elementData} | ||
| 299 | * of this vector) | ||
| 300 | */ | ||
| 301 | public synchronized int capacity() { | ||
| 302 | return elementData.length; | ||
| 303 | } | ||
| 304 | |||
| 305 | /** | ||
| 306 | * Returns the number of components in this vector. | ||
| 307 | * | ||
| 308 | * @return the number of components in this vector | ||
| 309 | */ | ||
| 310 | public synchronized int size() { | ||
| 311 | return elementCount; | ||
| 312 | } | ||
| 313 | |||
| 314 | /** | ||
| 315 | * Tests if this vector has no components. | ||
| 316 | * | ||
| 317 | * @return {@code true} if and only if this vector has | ||
| 318 | * no components, that is, its size is zero; | ||
| 319 | * {@code false} otherwise. | ||
| 320 | */ | ||
| 321 | public synchronized boolean isEmpty() { | ||
| 322 | return elementCount == 0; | ||
| 323 | } | ||
| 324 | |||
| 325 | /** | ||
| 326 | * Returns an enumeration of the components of this vector. The | ||
| 327 | * returned {@code Enumeration} object will generate all items in | ||
| 328 | * this vector. The first item generated is the item at index {@code 0}, | ||
| 329 | * then the item at index {@code 1}, and so on. | ||
| 330 | * | ||
| 331 | * @return an enumeration of the components of this vector | ||
| 332 | * @see Iterator | ||
| 333 | */ | ||
| 334 | public Enumeration<E> elements() { | ||
| 335 | return new Enumeration<E>() { | ||
| 336 | int count = 0; | ||
| 337 | |||
| 338 | public boolean hasMoreElements() { | ||
| 339 | return count < elementCount; | ||
| 340 | } | ||
| 341 | |||
| 342 | public E nextElement() { | ||
| 343 | synchronized (Vector.this) { | ||
| 344 | if (count < elementCount) { | ||
| 345 | return elementData(count++); | ||
| 346 | } | ||
| 347 | } | ||
| 348 | throw new NoSuchElementException("Vector Enumeration"); | ||
| 349 | } | ||
| 350 | }; | ||
| 351 | } | ||
| 352 | |||
| 353 | /** | ||
| 354 | * Returns {@code true} if this vector contains the specified element. | ||
| 355 | * More formally, returns {@code true} if and only if this vector | ||
| 356 | * contains at least one element {@code e} such that | ||
| 357 | * <tt>(o==null ? e==null : o.equals(e))</tt>. | ||
| 358 | * | ||
| 359 | * @param o element whose presence in this vector is to be tested | ||
| 360 | * @return {@code true} if this vector contains the specified element | ||
| 361 | */ | ||
| 362 | public boolean contains(Object o) { | ||
| 363 | return indexOf(o, 0) >= 0; | ||
| 364 | } | ||
| 365 | |||
| 366 | /** | ||
| 367 | * Returns the index of the first occurrence of the specified element | ||
| 368 | * in this vector, or -1 if this vector does not contain the element. | ||
| 369 | * More formally, returns the lowest index {@code i} such that | ||
| 370 | * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>, | ||
| 371 | * or -1 if there is no such index. | ||
| 372 | * | ||
| 373 | * @param o element to search for | ||
| 374 | * @return the index of the first occurrence of the specified element in | ||
| 375 | * this vector, or -1 if this vector does not contain the element | ||
| 376 | */ | ||
| 377 | public int indexOf(Object o) { | ||
| 378 | return indexOf(o, 0); | ||
| 379 | } | ||
| 380 | |||
| 381 | /** | ||
| 382 | * Returns the index of the first occurrence of the specified element in | ||
| 383 | * this vector, searching forwards from {@code index}, or returns -1 if | ||
| 384 | * the element is not found. | ||
| 385 | * More formally, returns the lowest index {@code i} such that | ||
| 386 | * <tt>(i >= index && (o==null ? get(i)==null : o.equals(get(i))))</tt>, | ||
| 387 | * or -1 if there is no such index. | ||
| 388 | * | ||
| 389 | * @param o element to search for | ||
| 390 | * @param index index to start searching from | ||
| 391 | * @return the index of the first occurrence of the element in | ||
| 392 | * this vector at position {@code index} or later in the vector; | ||
| 393 | * {@code -1} if the element is not found. | ||
| 394 | * @throws IndexOutOfBoundsException if the specified index is negative | ||
| 395 | * @see Object#equals(Object) | ||
| 396 | */ | ||
| 397 | public synchronized int indexOf(Object o, int index) { | ||
| 398 | if (o == null) { | ||
| 399 | for (int i = index ; i < elementCount ; i++) | ||
| 400 | if (elementData[i]==null) | ||
| 401 | return i; | ||
| 402 | } else { | ||
| 403 | for (int i = index ; i < elementCount ; i++) | ||
| 404 | if (o.equals(elementData[i])) | ||
| 405 | return i; | ||
| 406 | } | ||
| 407 | return -1; | ||
| 408 | } | ||
| 409 | |||
| 410 | /** | ||
| 411 | * Returns the index of the last occurrence of the specified element | ||
| 412 | * in this vector, or -1 if this vector does not contain the element. | ||
| 413 | * More formally, returns the highest index {@code i} such that | ||
| 414 | * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>, | ||
| 415 | * or -1 if there is no such index. | ||
| 416 | * | ||
| 417 | * @param o element to search for | ||
| 418 | * @return the index of the last occurrence of the specified element in | ||
| 419 | * this vector, or -1 if this vector does not contain the element | ||
| 420 | */ | ||
| 421 | public synchronized int lastIndexOf(Object o) { | ||
| 422 | return lastIndexOf(o, elementCount-1); | ||
| 423 | } | ||
| 424 | |||
| 425 | /** | ||
| 426 | * Returns the index of the last occurrence of the specified element in | ||
| 427 | * this vector, searching backwards from {@code index}, or returns -1 if | ||
| 428 | * the element is not found. | ||
| 429 | * More formally, returns the highest index {@code i} such that | ||
| 430 | * <tt>(i <= index && (o==null ? get(i)==null : o.equals(get(i))))</tt>, | ||
| 431 | * or -1 if there is no such index. | ||
| 432 | * | ||
| 433 | * @param o element to search for | ||
| 434 | * @param index index to start searching backwards from | ||
| 435 | * @return the index of the last occurrence of the element at position | ||
| 436 | * less than or equal to {@code index} in this vector; | ||
| 437 | * -1 if the element is not found. | ||
| 438 | * @throws IndexOutOfBoundsException if the specified index is greater | ||
| 439 | * than or equal to the current size of this vector | ||
| 440 | */ | ||
| 441 | public synchronized int lastIndexOf(Object o, int index) { | ||
| 442 | if (index >= elementCount) | ||
| 443 | throw new IndexOutOfBoundsException(index + " >= "+ elementCount); | ||
| 444 | |||
| 445 | if (o == null) { | ||
| 446 | for (int i = index; i >= 0; i--) | ||
| 447 | if (elementData[i]==null) | ||
| 448 | return i; | ||
| 449 | } else { | ||
| 450 | for (int i = index; i >= 0; i--) | ||
| 451 | if (o.equals(elementData[i])) | ||
| 452 | return i; | ||
| 453 | } | ||
| 454 | return -1; | ||
| 455 | } | ||
| 456 | |||
| 457 | /** | ||
| 458 | * Returns the component at the specified index. | ||
| 459 | * | ||
| 460 | * <p>This method is identical in functionality to the {@link #get(int)} | ||
| 461 | * method (which is part of the {@link List} interface). | ||
| 462 | * | ||
| 463 | * @param index an index into this vector | ||
| 464 | * @return the component at the specified index | ||
| 465 | * @throws ArrayIndexOutOfBoundsException if the index is out of range | ||
| 466 | * ({@code index < 0 || index >= size()}) | ||
| 467 | */ | ||
| 468 | public synchronized E elementAt(int index) { | ||
| 469 | if (index >= elementCount) { | ||
| 470 | throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount); | ||
| 471 | } | ||
| 472 | |||
| 473 | return elementData(index); | ||
| 474 | } | ||
| 475 | |||
| 476 | /** | ||
| 477 | * Returns the first component (the item at index {@code 0}) of | ||
| 478 | * this vector. | ||
| 479 | * | ||
| 480 | * @return the first component of this vector | ||
| 481 | * @throws NoSuchElementException if this vector has no components | ||
| 482 | */ | ||
| 483 | public synchronized E firstElement() { | ||
| 484 | if (elementCount == 0) { | ||
| 485 | throw new NoSuchElementException(); | ||
| 486 | } | ||
| 487 | return elementData(0); | ||
| 488 | } | ||
| 489 | |||
| 490 | /** | ||
| 491 | * Returns the last component of the vector. | ||
| 492 | * | ||
| 493 | * @return the last component of the vector, i.e., the component at index | ||
| 494 | * <code>size() - 1</code>. | ||
| 495 | * @throws NoSuchElementException if this vector is empty | ||
| 496 | */ | ||
| 497 | public synchronized E lastElement() { | ||
| 498 | if (elementCount == 0) { | ||
| 499 | throw new NoSuchElementException(); | ||
| 500 | } | ||
| 501 | return elementData(elementCount - 1); | ||
| 502 | } | ||
| 503 | |||
| 504 | /** | ||
| 505 | * Sets the component at the specified {@code index} of this | ||
| 506 | * vector to be the specified object. The previous component at that | ||
| 507 | * position is discarded. | ||
| 508 | * | ||
| 509 | * <p>The index must be a value greater than or equal to {@code 0} | ||
| 510 | * and less than the current size of the vector. | ||
| 511 | * | ||
| 512 | * <p>This method is identical in functionality to the | ||
| 513 | * {@link #set(int, Object) set(int, E)} | ||
| 514 | * method (which is part of the {@link List} interface). Note that the | ||
| 515 | * {@code set} method reverses the order of the parameters, to more closely | ||
| 516 | * match array usage. Note also that the {@code set} method returns the | ||
| 517 | * old value that was stored at the specified position. | ||
| 518 | * | ||
| 519 | * @param obj what the component is to be set to | ||
| 520 | * @param index the specified index | ||
| 521 | * @throws ArrayIndexOutOfBoundsException if the index is out of range | ||
| 522 | * ({@code index < 0 || index >= size()}) | ||
| 523 | */ | ||
| 524 | public synchronized void setElementAt(E obj, int index) { | ||
| 525 | if (index >= elementCount) { | ||
| 526 | throw new ArrayIndexOutOfBoundsException(index + " >= " + | ||
| 527 | elementCount); | ||
| 528 | } | ||
| 529 | elementData[index] = obj; | ||
| 530 | } | ||
| 531 | |||
| 532 | /** | ||
| 533 | * Deletes the component at the specified index. Each component in | ||
| 534 | * this vector with an index greater or equal to the specified | ||
| 535 | * {@code index} is shifted downward to have an index one | ||
| 536 | * smaller than the value it had previously. The size of this vector | ||
| 537 | * is decreased by {@code 1}. | ||
| 538 | * | ||
| 539 | * <p>The index must be a value greater than or equal to {@code 0} | ||
| 540 | * and less than the current size of the vector. | ||
| 541 | * | ||
| 542 | * <p>This method is identical in functionality to the {@link #remove(int)} | ||
| 543 | * method (which is part of the {@link List} interface). Note that the | ||
| 544 | * {@code remove} method returns the old value that was stored at the | ||
| 545 | * specified position. | ||
| 546 | * | ||
| 547 | * @param index the index of the object to remove | ||
| 548 | * @throws ArrayIndexOutOfBoundsException if the index is out of range | ||
| 549 | * ({@code index < 0 || index >= size()}) | ||
| 550 | */ | ||
| 551 | public synchronized void removeElementAt(int index) { | ||
| 552 | modCount++; | ||
| 553 | if (index >= elementCount) { | ||
| 554 | throw new ArrayIndexOutOfBoundsException(index + " >= " + | ||
| 555 | elementCount); | ||
| 556 | } | ||
| 557 | else if (index < 0) { | ||
| 558 | throw new ArrayIndexOutOfBoundsException(index); | ||
| 559 | } | ||
| 560 | int j = elementCount - index - 1; | ||
| 561 | if (j > 0) { | ||
| 562 | System.arraycopy(elementData, index + 1, elementData, index, j); | ||
| 563 | } | ||
| 564 | elementCount--; | ||
| 565 | elementData[elementCount] = null; /* to let gc do its work */ | ||
| 566 | } | ||
| 567 | |||
| 568 | /** | ||
| 569 | * Inserts the specified object as a component in this vector at the | ||
| 570 | * specified {@code index}. Each component in this vector with | ||
| 571 | * an index greater or equal to the specified {@code index} is | ||
| 572 | * shifted upward to have an index one greater than the value it had | ||
| 573 | * previously. | ||
| 574 | * | ||
| 575 | * <p>The index must be a value greater than or equal to {@code 0} | ||
| 576 | * and less than or equal to the current size of the vector. (If the | ||
| 577 | * index is equal to the current size of the vector, the new element | ||
| 578 | * is appended to the Vector.) | ||
| 579 | * | ||
| 580 | * <p>This method is identical in functionality to the | ||
| 581 | * {@link #add(int, Object) add(int, E)} | ||
| 582 | * method (which is part of the {@link List} interface). Note that the | ||
| 583 | * {@code add} method reverses the order of the parameters, to more closely | ||
| 584 | * match array usage. | ||
| 585 | * | ||
| 586 | * @param obj the component to insert | ||
| 587 | * @param index where to insert the new component | ||
| 588 | * @throws ArrayIndexOutOfBoundsException if the index is out of range | ||
| 589 | * ({@code index < 0 || index > size()}) | ||
| 590 | */ | ||
| 591 | public synchronized void insertElementAt(E obj, int index) { | ||
| 592 | modCount++; | ||
| 593 | if (index > elementCount) { | ||
| 594 | throw new ArrayIndexOutOfBoundsException(index | ||
| 595 | + " > " + elementCount); | ||
| 596 | } | ||
| 597 | ensureCapacityHelper(elementCount + 1); | ||
| 598 | System.arraycopy(elementData, index, elementData, index + 1, elementCount - index); | ||
| 599 | elementData[index] = obj; | ||
| 600 | elementCount++; | ||
| 601 | } | ||
| 602 | |||
| 603 | /** | ||
| 604 | * Adds the specified component to the end of this vector, | ||
| 605 | * increasing its size by one. The capacity of this vector is | ||
| 606 | * increased if its size becomes greater than its capacity. | ||
| 607 | * | ||
| 608 | * <p>This method is identical in functionality to the | ||
| 609 | * {@link #add(Object) add(E)} | ||
| 610 | * method (which is part of the {@link List} interface). | ||
| 611 | * | ||
| 612 | * @param obj the component to be added | ||
| 613 | */ | ||
| 614 | public synchronized void addElement(E obj) { | ||
| 615 | modCount++; | ||
| 616 | ensureCapacityHelper(elementCount + 1); | ||
| 617 | elementData[elementCount++] = obj; | ||
| 618 | } | ||
| 619 | |||
| 620 | /** | ||
| 621 | * Removes the first (lowest-indexed) occurrence of the argument | ||
| 622 | * from this vector. If the object is found in this vector, each | ||
| 623 | * component in the vector with an index greater or equal to the | ||
| 624 | * object's index is shifted downward to have an index one smaller | ||
| 625 | * than the value it had previously. | ||
| 626 | * | ||
| 627 | * <p>This method is identical in functionality to the | ||
| 628 | * {@link #remove(Object)} method (which is part of the | ||
| 629 | * {@link List} interface). | ||
| 630 | * | ||
| 631 | * @param obj the component to be removed | ||
| 632 | * @return {@code true} if the argument was a component of this | ||
| 633 | * vector; {@code false} otherwise. | ||
| 634 | */ | ||
| 635 | public synchronized boolean removeElement(Object obj) { | ||
| 636 | modCount++; | ||
| 637 | int i = indexOf(obj); | ||
| 638 | if (i >= 0) { | ||
| 639 | removeElementAt(i); | ||
| 640 | return true; | ||
| 641 | } | ||
| 642 | return false; | ||
| 643 | } | ||
| 644 | |||
| 645 | /** | ||
| 646 | * Removes all components from this vector and sets its size to zero. | ||
| 647 | * | ||
| 648 | * <p>This method is identical in functionality to the {@link #clear} | ||
| 649 | * method (which is part of the {@link List} interface). | ||
| 650 | */ | ||
| 651 | public synchronized void removeAllElements() { | ||
| 652 | modCount++; | ||
| 653 | // Let gc do its work | ||
| 654 | for (int i = 0; i < elementCount; i++) | ||
| 655 | elementData[i] = null; | ||
| 656 | |||
| 657 | elementCount = 0; | ||
| 658 | } | ||
| 659 | |||
| 660 | /** | ||
| 661 | * Returns a clone of this vector. The copy will contain a | ||
| 662 | * reference to a clone of the internal data array, not a reference | ||
| 663 | * to the original internal data array of this {@code Vector} object. | ||
| 664 | * | ||
| 665 | * @return a clone of this vector | ||
| 666 | */ | ||
| 667 | public synchronized Object clone() { | ||
| 668 | try { | ||
| 669 | @SuppressWarnings("unchecked") | ||
| 670 | Vector<E> v = (Vector<E>) super.clone(); | ||
| 671 | v.elementData = Arrays.copyOf(elementData, elementCount); | ||
| 672 | v.modCount = 0; | ||
| 673 | return v; | ||
| 674 | } catch (CloneNotSupportedException e) { | ||
| 675 | // this shouldn't happen, since we are Cloneable | ||
| 676 | throw new InternalError(); | ||
| 677 | } | ||
| 678 | } | ||
| 679 | |||
| 680 | /** | ||
| 681 | * Returns an array containing all of the elements in this Vector | ||
| 682 | * in the correct order. | ||
| 683 | * | ||
| 684 | * @since 1.2 | ||
| 685 | */ | ||
| 686 | public synchronized Object[] toArray() { | ||
| 687 | return Arrays.copyOf(elementData, elementCount); | ||
| 688 | } | ||
| 689 | |||
| 690 | /** | ||
| 691 | * Returns an array containing all of the elements in this Vector in the | ||
| 692 | * correct order; the runtime type of the returned array is that of the | ||
| 693 | * specified array. If the Vector fits in the specified array, it is | ||
| 694 | * returned therein. Otherwise, a new array is allocated with the runtime | ||
| 695 | * type of the specified array and the size of this Vector. | ||
| 696 | * | ||
| 697 | * <p>If the Vector fits in the specified array with room to spare | ||
| 698 | * (i.e., the array has more elements than the Vector), | ||
| 699 | * the element in the array immediately following the end of the | ||
| 700 | * Vector is set to null. (This is useful in determining the length | ||
| 701 | * of the Vector <em>only</em> if the caller knows that the Vector | ||
| 702 | * does not contain any null elements.) | ||
| 703 | * | ||
| 704 | * @param a the array into which the elements of the Vector are to | ||
| 705 | * be stored, if it is big enough; otherwise, a new array of the | ||
| 706 | * same runtime type is allocated for this purpose. | ||
| 707 | * @return an array containing the elements of the Vector | ||
| 708 | * @throws ArrayStoreException if the runtime type of a is not a supertype | ||
| 709 | * of the runtime type of every element in this Vector | ||
| 710 | * @throws NullPointerException if the given array is null | ||
| 711 | * @since 1.2 | ||
| 712 | */ | ||
| 713 | @SuppressWarnings("unchecked") | ||
| 714 | public synchronized <T> T[] toArray(T[] a) { | ||
| 715 | if (a.length < elementCount) | ||
| 716 | return (T[]) Arrays.copyOf(elementData, elementCount, a.getClass()); | ||
| 717 | |||
| 718 | System.arraycopy(elementData, 0, a, 0, elementCount); | ||
| 719 | |||
| 720 | if (a.length > elementCount) | ||
| 721 | a[elementCount] = null; | ||
| 722 | |||
| 723 | return a; | ||
| 724 | } | ||
| 725 | |||
| 726 | // Positional Access Operations | ||
| 727 | |||
| 728 | @SuppressWarnings("unchecked") | ||
| 729 | E elementData(int index) { | ||
| 730 | return (E) elementData[index]; | ||
| 731 | } | ||
| 732 | |||
| 733 | /** | ||
| 734 | * Returns the element at the specified position in this Vector. | ||
| 735 | * | ||
| 736 | * @param index index of the element to return | ||
| 737 | * @return object at the specified index | ||
| 738 | * @throws ArrayIndexOutOfBoundsException if the index is out of range | ||
| 739 | * ({@code index < 0 || index >= size()}) | ||
| 740 | * @since 1.2 | ||
| 741 | */ | ||
| 742 | public synchronized E get(int index) { | ||
| 743 | if (index >= elementCount) | ||
| 744 | throw new ArrayIndexOutOfBoundsException(index); | ||
| 745 | |||
| 746 | return elementData(index); | ||
| 747 | } | ||
| 748 | |||
| 749 | /** | ||
| 750 | * Replaces the element at the specified position in this Vector with the | ||
| 751 | * specified element. | ||
| 752 | * | ||
| 753 | * @param index index of the element to replace | ||
| 754 | * @param element element to be stored at the specified position | ||
| 755 | * @return the element previously at the specified position | ||
| 756 | * @throws ArrayIndexOutOfBoundsException if the index is out of range | ||
| 757 | * ({@code index < 0 || index >= size()}) | ||
| 758 | * @since 1.2 | ||
| 759 | */ | ||
| 760 | public synchronized E set(int index, E element) { | ||
| 761 | if (index >= elementCount) | ||
| 762 | throw new ArrayIndexOutOfBoundsException(index); | ||
| 763 | |||
| 764 | E oldValue = elementData(index); | ||
| 765 | elementData[index] = element; | ||
| 766 | return oldValue; | ||
| 767 | } | ||
| 768 | |||
| 769 | /** | ||
| 770 | * Appends the specified element to the end of this Vector. | ||
| 771 | * | ||
| 772 | * @param e element to be appended to this Vector | ||
| 773 | * @return {@code true} (as specified by {@link Collection#add}) | ||
| 774 | * @since 1.2 | ||
| 775 | */ | ||
| 776 | public synchronized boolean add(E e) { | ||
| 777 | modCount++; | ||
| 778 | ensureCapacityHelper(elementCount + 1); | ||
| 779 | elementData[elementCount++] = e; | ||
| 780 | return true; | ||
| 781 | } | ||
| 782 | |||
| 783 | /** | ||
| 784 | * Removes the first occurrence of the specified element in this Vector | ||
| 785 | * If the Vector does not contain the element, it is unchanged. More | ||
| 786 | * formally, removes the element with the lowest index i such that | ||
| 787 | * {@code (o==null ? get(i)==null : o.equals(get(i)))} (if such | ||
| 788 | * an element exists). | ||
| 789 | * | ||
| 790 | * @param o element to be removed from this Vector, if present | ||
| 791 | * @return true if the Vector contained the specified element | ||
| 792 | * @since 1.2 | ||
| 793 | */ | ||
| 794 | public boolean remove(Object o) { | ||
| 795 | return removeElement(o); | ||
| 796 | } | ||
| 797 | |||
| 798 | /** | ||
| 799 | * Inserts the specified element at the specified position in this Vector. | ||
| 800 | * Shifts the element currently at that position (if any) and any | ||
| 801 | * subsequent elements to the right (adds one to their indices). | ||
| 802 | * | ||
| 803 | * @param index index at which the specified element is to be inserted | ||
| 804 | * @param element element to be inserted | ||
| 805 | * @throws ArrayIndexOutOfBoundsException if the index is out of range | ||
| 806 | * ({@code index < 0 || index > size()}) | ||
| 807 | * @since 1.2 | ||
| 808 | */ | ||
| 809 | public void add(int index, E element) { | ||
| 810 | insertElementAt(element, index); | ||
| 811 | } | ||
| 812 | |||
| 813 | /** | ||
| 814 | * Removes the element at the specified position in this Vector. | ||
| 815 | * Shifts any subsequent elements to the left (subtracts one from their | ||
| 816 | * indices). Returns the element that was removed from the Vector. | ||
| 817 | * | ||
| 818 | * @throws ArrayIndexOutOfBoundsException if the index is out of range | ||
| 819 | * ({@code index < 0 || index >= size()}) | ||
| 820 | * @param index the index of the element to be removed | ||
| 821 | * @return element that was removed | ||
| 822 | * @since 1.2 | ||
| 823 | */ | ||
| 824 | public synchronized E remove(int index) { | ||
| 825 | modCount++; | ||
| 826 | if (index >= elementCount) | ||
| 827 | throw new ArrayIndexOutOfBoundsException(index); | ||
| 828 | E oldValue = elementData(index); | ||
| 829 | |||
| 830 | int numMoved = elementCount - index - 1; | ||
| 831 | if (numMoved > 0) | ||
| 832 | System.arraycopy(elementData, index+1, elementData, index, | ||
| 833 | numMoved); | ||
| 834 | elementData[--elementCount] = null; // Let gc do its work | ||
| 835 | |||
| 836 | return oldValue; | ||
| 837 | } | ||
| 838 | |||
| 839 | /** | ||
| 840 | * Removes all of the elements from this Vector. The Vector will | ||
| 841 | * be empty after this call returns (unless it throws an exception). | ||
| 842 | * | ||
| 843 | * @since 1.2 | ||
| 844 | */ | ||
| 845 | public void clear() { | ||
| 846 | removeAllElements(); | ||
| 847 | } | ||
| 848 | |||
| 849 | // Bulk Operations | ||
| 850 | |||
| 851 | /** | ||
| 852 | * Returns true if this Vector contains all of the elements in the | ||
| 853 | * specified Collection. | ||
| 854 | * | ||
| 855 | * @param c a collection whose elements will be tested for containment | ||
| 856 | * in this Vector | ||
| 857 | * @return true if this Vector contains all of the elements in the | ||
| 858 | * specified collection | ||
| 859 | * @throws NullPointerException if the specified collection is null | ||
| 860 | */ | ||
| 861 | public synchronized boolean containsAll(Collection<?> c) { | ||
| 862 | return super.containsAll(c); | ||
| 863 | } | ||
| 864 | |||
| 865 | /** | ||
| 866 | * Appends all of the elements in the specified Collection to the end of | ||
| 867 | * this Vector, in the order that they are returned by the specified | ||
| 868 | * Collection's Iterator. The behavior of this operation is undefined if | ||
| 869 | * the specified Collection is modified while the operation is in progress. | ||
| 870 | * (This implies that the behavior of this call is undefined if the | ||
| 871 | * specified Collection is this Vector, and this Vector is nonempty.) | ||
| 872 | * | ||
| 873 | * @param c elements to be inserted into this Vector | ||
| 874 | * @return {@code true} if this Vector changed as a result of the call | ||
| 875 | * @throws NullPointerException if the specified collection is null | ||
| 876 | * @since 1.2 | ||
| 877 | */ | ||
| 878 | public synchronized boolean addAll(Collection<? extends E> c) { | ||
| 879 | modCount++; | ||
| 880 | Object[] a = c.toArray(); | ||
| 881 | int numNew = a.length; | ||
| 882 | ensureCapacityHelper(elementCount + numNew); | ||
| 883 | System.arraycopy(a, 0, elementData, elementCount, numNew); | ||
| 884 | elementCount += numNew; | ||
| 885 | return numNew != 0; | ||
| 886 | } | ||
| 887 | |||
| 888 | /** | ||
| 889 | * Removes from this Vector all of its elements that are contained in the | ||
| 890 | * specified Collection. | ||
| 891 | * | ||
| 892 | * @param c a collection of elements to be removed from the Vector | ||
| 893 | * @return true if this Vector changed as a result of the call | ||
| 894 | * @throws ClassCastException if the types of one or more elements | ||
| 895 | * in this vector are incompatible with the specified | ||
| 896 | * collection | ||
| 897 | * (<a href="Collection.html#optional-restrictions">optional</a>) | ||
| 898 | * @throws NullPointerException if this vector contains one or more null | ||
| 899 | * elements and the specified collection does not support null | ||
| 900 | * elements | ||
| 901 | * (<a href="Collection.html#optional-restrictions">optional</a>), | ||
| 902 | * or if the specified collection is null | ||
| 903 | * @since 1.2 | ||
| 904 | */ | ||
| 905 | public synchronized boolean removeAll(Collection<?> c) { | ||
| 906 | return super.removeAll(c); | ||
| 907 | } | ||
| 908 | |||
| 909 | /** | ||
| 910 | * Retains only the elements in this Vector that are contained in the | ||
| 911 | * specified Collection. In other words, removes from this Vector all | ||
| 912 | * of its elements that are not contained in the specified Collection. | ||
| 913 | * | ||
| 914 | * @param c a collection of elements to be retained in this Vector | ||
| 915 | * (all other elements are removed) | ||
| 916 | * @return true if this Vector changed as a result of the call | ||
| 917 | * @throws ClassCastException if the types of one or more elements | ||
| 918 | * in this vector are incompatible with the specified | ||
| 919 | * collection | ||
| 920 | * (<a href="Collection.html#optional-restrictions">optional</a>) | ||
| 921 | * @throws NullPointerException if this vector contains one or more null | ||
| 922 | * elements and the specified collection does not support null | ||
| 923 | * elements | ||
| 924 | * (<a href="Collection.html#optional-restrictions">optional</a>), | ||
| 925 | * or if the specified collection is null | ||
| 926 | * @since 1.2 | ||
| 927 | */ | ||
| 928 | public synchronized boolean retainAll(Collection<?> c) { | ||
| 929 | return super.retainAll(c); | ||
| 930 | } | ||
| 931 | |||
| 932 | /** | ||
| 933 | * Inserts all of the elements in the specified Collection into this | ||
| 934 | * Vector at the specified position. Shifts the element currently at | ||
| 935 | * that position (if any) and any subsequent elements to the right | ||
| 936 | * (increases their indices). The new elements will appear in the Vector | ||
| 937 | * in the order that they are returned by the specified Collection's | ||
| 938 | * iterator. | ||
| 939 | * | ||
| 940 | * @param index index at which to insert the first element from the | ||
| 941 | * specified collection | ||
| 942 | * @param c elements to be inserted into this Vector | ||
| 943 | * @return {@code true} if this Vector changed as a result of the call | ||
| 944 | * @throws ArrayIndexOutOfBoundsException if the index is out of range | ||
| 945 | * ({@code index < 0 || index > size()}) | ||
| 946 | * @throws NullPointerException if the specified collection is null | ||
| 947 | * @since 1.2 | ||
| 948 | */ | ||
| 949 | public synchronized boolean addAll(int index, Collection<? extends E> c) { | ||
| 950 | modCount++; | ||
| 951 | if (index < 0 || index > elementCount) | ||
| 952 | throw new ArrayIndexOutOfBoundsException(index); | ||
| 953 | |||
| 954 | Object[] a = c.toArray(); | ||
| 955 | int numNew = a.length; | ||
| 956 | ensureCapacityHelper(elementCount + numNew); | ||
| 957 | |||
| 958 | int numMoved = elementCount - index; | ||
| 959 | if (numMoved > 0) | ||
| 960 | System.arraycopy(elementData, index, elementData, index + numNew, | ||
| 961 | numMoved); | ||
| 962 | |||
| 963 | System.arraycopy(a, 0, elementData, index, numNew); | ||
| 964 | elementCount += numNew; | ||
| 965 | return numNew != 0; | ||
| 966 | } | ||
| 967 | |||
| 968 | /** | ||
| 969 | * Compares the specified Object with this Vector for equality. Returns | ||
| 970 | * true if and only if the specified Object is also a List, both Lists | ||
| 971 | * have the same size, and all corresponding pairs of elements in the two | ||
| 972 | * Lists are <em>equal</em>. (Two elements {@code e1} and | ||
| 973 | * {@code e2} are <em>equal</em> if {@code (e1==null ? e2==null : | ||
| 974 | * e1.equals(e2))}.) In other words, two Lists are defined to be | ||
| 975 | * equal if they contain the same elements in the same order. | ||
| 976 | * | ||
| 977 | * @param o the Object to be compared for equality with this Vector | ||
| 978 | * @return true if the specified Object is equal to this Vector | ||
| 979 | */ | ||
| 980 | public synchronized boolean equals(Object o) { | ||
| 981 | return super.equals(o); | ||
| 982 | } | ||
| 983 | |||
| 984 | /** | ||
| 985 | * Returns the hash code value for this Vector. | ||
| 986 | */ | ||
| 987 | public synchronized int hashCode() { | ||
| 988 | return super.hashCode(); | ||
| 989 | } | ||
| 990 | |||
| 991 | /** | ||
| 992 | * Returns a string representation of this Vector, containing | ||
| 993 | * the String representation of each element. | ||
| 994 | */ | ||
| 995 | public synchronized String toString() { | ||
| 996 | return super.toString(); | ||
| 997 | } | ||
| 998 | |||
| 999 | /** | ||
| 1000 | * Returns a view of the portion of this List between fromIndex, | ||
| 1001 | * inclusive, and toIndex, exclusive. (If fromIndex and toIndex are | ||
| 1002 | * equal, the returned List is empty.) The returned List is backed by this | ||
| 1003 | * List, so changes in the returned List are reflected in this List, and | ||
| 1004 | * vice-versa. The returned List supports all of the optional List | ||
| 1005 | * operations supported by this List. | ||
| 1006 | * | ||
| 1007 | * <p>This method eliminates the need for explicit range operations (of | ||
| 1008 | * the sort that commonly exist for arrays). Any operation that expects | ||
| 1009 | * a List can be used as a range operation by operating on a subList view | ||
| 1010 | * instead of a whole List. For example, the following idiom | ||
| 1011 | * removes a range of elements from a List: | ||
| 1012 | * <pre> | ||
| 1013 | * list.subList(from, to).clear(); | ||
| 1014 | * </pre> | ||
| 1015 | * Similar idioms may be constructed for indexOf and lastIndexOf, | ||
| 1016 | * and all of the algorithms in the Collections class can be applied to | ||
| 1017 | * a subList. | ||
| 1018 | * | ||
| 1019 | * <p>The semantics of the List returned by this method become undefined if | ||
| 1020 | * the backing list (i.e., this List) is <i>structurally modified</i> in | ||
| 1021 | * any way other than via the returned List. (Structural modifications are | ||
| 1022 | * those that change the size of the List, or otherwise perturb it in such | ||
| 1023 | * a fashion that iterations in progress may yield incorrect results.) | ||
| 1024 | * | ||
| 1025 | * @param fromIndex low endpoint (inclusive) of the subList | ||
| 1026 | * @param toIndex high endpoint (exclusive) of the subList | ||
| 1027 | * @return a view of the specified range within this List | ||
| 1028 | * @throws IndexOutOfBoundsException if an endpoint index value is out of range | ||
| 1029 | * {@code (fromIndex < 0 || toIndex > size)} | ||
| 1030 | * @throws IllegalArgumentException if the endpoint indices are out of order | ||
| 1031 | * {@code (fromIndex > toIndex)} | ||
| 1032 | */ | ||
| 1033 | public synchronized List<E> subList(int fromIndex, int toIndex) { | ||
| 1034 | return Collections.synchronizedList(super.subList(fromIndex, toIndex), | ||
| 1035 | this); | ||
| 1036 | } | ||
| 1037 | |||
| 1038 | /** | ||
| 1039 | * Removes from this list all of the elements whose index is between | ||
| 1040 | * {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. | ||
| 1041 | * Shifts any succeeding elements to the left (reduces their index). | ||
| 1042 | * This call shortens the list by {@code (toIndex - fromIndex)} elements. | ||
| 1043 | * (If {@code toIndex==fromIndex}, this operation has no effect.) | ||
| 1044 | */ | ||
| 1045 | protected synchronized void removeRange(int fromIndex, int toIndex) { | ||
| 1046 | modCount++; | ||
| 1047 | int numMoved = elementCount - toIndex; | ||
| 1048 | System.arraycopy(elementData, toIndex, elementData, fromIndex, | ||
| 1049 | numMoved); | ||
| 1050 | |||
| 1051 | // Let gc do its work | ||
| 1052 | int newElementCount = elementCount - (toIndex-fromIndex); | ||
| 1053 | while (elementCount != newElementCount) | ||
| 1054 | elementData[--elementCount] = null; | ||
| 1055 | } | ||
| 1056 | |||
| 1057 | /** | ||
| 1058 | * Save the state of the {@code Vector} instance to a stream (that | ||
| 1059 | * is, serialize it). | ||
| 1060 | * This method performs synchronization to ensure the consistency | ||
| 1061 | * of the serialized data. | ||
| 1062 | */ | ||
| 1063 | private void writeObject(java.io.ObjectOutputStream s) | ||
| 1064 | throws java.io.IOException { | ||
| 1065 | final java.io.ObjectOutputStream.PutField fields = s.putFields(); | ||
| 1066 | final Object[] data; | ||
| 1067 | synchronized (this) { | ||
| 1068 | fields.put("capacityIncrement", capacityIncrement); | ||
| 1069 | fields.put("elementCount", elementCount); | ||
| 1070 | data = elementData.clone(); | ||
| 1071 | } | ||
| 1072 | fields.put("elementData", data); | ||
| 1073 | s.writeFields(); | ||
| 1074 | } | ||
| 1075 | |||
| 1076 | /** | ||
| 1077 | * Returns a list iterator over the elements in this list (in proper | ||
| 1078 | * sequence), starting at the specified position in the list. | ||
| 1079 | * The specified index indicates the first element that would be | ||
| 1080 | * returned by an initial call to {@link ListIterator#next next}. | ||
| 1081 | * An initial call to {@link ListIterator#previous previous} would | ||
| 1082 | * return the element with the specified index minus one. | ||
| 1083 | * | ||
| 1084 | * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. | ||
| 1085 | * | ||
| 1086 | * @throws IndexOutOfBoundsException {@inheritDoc} | ||
| 1087 | */ | ||
| 1088 | public synchronized ListIterator<E> listIterator(int index) { | ||
| 1089 | if (index < 0 || index > elementCount) | ||
| 1090 | throw new IndexOutOfBoundsException("Index: "+index); | ||
| 1091 | return new ListItr(index); | ||
| 1092 | } | ||
| 1093 | |||
| 1094 | /** | ||
| 1095 | * Returns a list iterator over the elements in this list (in proper | ||
| 1096 | * sequence). | ||
| 1097 | * | ||
| 1098 | * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. | ||
| 1099 | * | ||
| 1100 | * @see #listIterator(int) | ||
| 1101 | */ | ||
| 1102 | public synchronized ListIterator<E> listIterator() { | ||
| 1103 | return new ListItr(0); | ||
| 1104 | } | ||
| 1105 | |||
| 1106 | /** | ||
| 1107 | * Returns an iterator over the elements in this list in proper sequence. | ||
| 1108 | * | ||
| 1109 | * <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>. | ||
| 1110 | * | ||
| 1111 | * @return an iterator over the elements in this list in proper sequence | ||
| 1112 | */ | ||
| 1113 | public synchronized Iterator<E> iterator() { | ||
| 1114 | return new Itr(); | ||
| 1115 | } | ||
| 1116 | |||
| 1117 | /** | ||
| 1118 | * An optimized version of AbstractList.Itr | ||
| 1119 | */ | ||
| 1120 | private class Itr implements Iterator<E> { | ||
| 1121 | int cursor; // index of next element to return | ||
| 1122 | int lastRet = -1; // index of last element returned; -1 if no such | ||
| 1123 | int expectedModCount = modCount; | ||
| 1124 | |||
| 1125 | public boolean hasNext() { | ||
| 1126 | // Racy but within spec, since modifications are checked | ||
| 1127 | // within or after synchronization in next/previous | ||
| 1128 | return cursor != elementCount; | ||
| 1129 | } | ||
| 1130 | |||
| 1131 | public E next() { | ||
| 1132 | synchronized (Vector.this) { | ||
| 1133 | checkForComodification(); | ||
| 1134 | int i = cursor; | ||
| 1135 | if (i >= elementCount) | ||
| 1136 | throw new NoSuchElementException(); | ||
| 1137 | cursor = i + 1; | ||
| 1138 | return elementData(lastRet = i); | ||
| 1139 | } | ||
| 1140 | } | ||
| 1141 | |||
| 1142 | public void remove() { | ||
| 1143 | if (lastRet == -1) | ||
| 1144 | throw new IllegalStateException(); | ||
| 1145 | synchronized (Vector.this) { | ||
| 1146 | checkForComodification(); | ||
| 1147 | Vector.this.remove(lastRet); | ||
| 1148 | expectedModCount = modCount; | ||
| 1149 | } | ||
| 1150 | cursor = lastRet; | ||
| 1151 | lastRet = -1; | ||
| 1152 | } | ||
| 1153 | |||
| 1154 | final void checkForComodification() { | ||
| 1155 | if (modCount != expectedModCount) | ||
| 1156 | throw new ConcurrentModificationException(); | ||
| 1157 | } | ||
| 1158 | } | ||
| 1159 | |||
| 1160 | /** | ||
| 1161 | * An optimized version of AbstractList.ListItr | ||
| 1162 | */ | ||
| 1163 | final class ListItr extends Itr implements ListIterator<E> { | ||
| 1164 | ListItr(int index) { | ||
| 1165 | super(); | ||
| 1166 | cursor = index; | ||
| 1167 | } | ||
| 1168 | |||
| 1169 | public boolean hasPrevious() { | ||
| 1170 | return cursor != 0; | ||
| 1171 | } | ||
| 1172 | |||
| 1173 | public int nextIndex() { | ||
| 1174 | return cursor; | ||
| 1175 | } | ||
| 1176 | |||
| 1177 | public int previousIndex() { | ||
| 1178 | return cursor - 1; | ||
| 1179 | } | ||
| 1180 | |||
| 1181 | public E previous() { | ||
| 1182 | synchronized (Vector.this) { | ||
| 1183 | checkForComodification(); | ||
| 1184 | int i = cursor - 1; | ||
| 1185 | if (i < 0) | ||
| 1186 | throw new NoSuchElementException(); | ||
| 1187 | cursor = i; | ||
| 1188 | return elementData(lastRet = i); | ||
| 1189 | } | ||
| 1190 | } | ||
| 1191 | |||
| 1192 | public void set(E e) { | ||
| 1193 | if (lastRet == -1) | ||
| 1194 | throw new IllegalStateException(); | ||
| 1195 | synchronized (Vector.this) { | ||
| 1196 | checkForComodification(); | ||
| 1197 | Vector.this.set(lastRet, e); | ||
| 1198 | } | ||
| 1199 | } | ||
| 1200 | |||
| 1201 | public void add(E e) { | ||
| 1202 | int i = cursor; | ||
| 1203 | synchronized (Vector.this) { | ||
| 1204 | checkForComodification(); | ||
| 1205 | Vector.this.add(i, e); | ||
| 1206 | expectedModCount = modCount; | ||
| 1207 | } | ||
| 1208 | cursor = i + 1; | ||
| 1209 | lastRet = -1; | ||
| 1210 | } | ||
| 1211 | } | ||
| 1212 | } | ||