1/* 2 * Copyright (c) 1994, 2013, 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 26package java.util; 27 28import java.util.function.Consumer; 29import java.util.function.Predicate; 30import java.util.function.UnaryOperator; 31 32/** 33 * The {@code Vector} class implements a growable array of 34 * objects. Like an array, it contains components that can be 35 * accessed using an integer index. However, the size of a 36 * {@code Vector} can grow or shrink as needed to accommodate 37 * adding and removing items after the {@code Vector} has been created. 38 * 39 * <p>Each vector tries to optimize storage management by maintaining a 40 * {@code capacity} and a {@code capacityIncrement}. The 41 * {@code capacity} is always at least as large as the vector 42 * size; it is usually larger because as components are added to the 43 * vector, the vector's storage increases in chunks the size of 44 * {@code capacityIncrement}. An application can increase the 45 * capacity of a vector before inserting a large number of 46 * components; this reduces the amount of incremental reallocation. 47 * 48 * <p id="fail-fast"> 49 * The iterators returned by this class's {@link #iterator() iterator} and 50 * {@link #listIterator(int) listIterator} methods are <em>fail-fast</em>: 51 * if the vector is structurally modified at any time after the iterator is 52 * created, in any way except through the iterator's own 53 * {@link ListIterator#remove() remove} or 54 * {@link ListIterator#add(Object) add} methods, the iterator will throw a 55 * {@link ConcurrentModificationException}. Thus, in the face of 56 * concurrent modification, the iterator fails quickly and cleanly, rather 57 * than risking arbitrary, non-deterministic behavior at an undetermined 58 * time in the future. The {@link Enumeration Enumerations} returned by 59 * the {@link #elements() elements} method are <em>not</em> fail-fast; if the 60 * Vector is structurally modified at any time after the enumeration is 61 * created then the results of enumerating are undefined. 62 * 63 * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed 64 * as it is, generally speaking, impossible to make any hard guarantees in the 65 * presence of unsynchronized concurrent modification. Fail-fast iterators 66 * throw {@code ConcurrentModificationException} on a best-effort basis. 67 * Therefore, it would be wrong to write a program that depended on this 68 * exception for its correctness: <i>the fail-fast behavior of iterators 69 * should be used only to detect bugs.</i> 70 * 71 * <p>As of the Java 2 platform v1.2, this class was retrofitted to 72 * implement the {@link List} interface, making it a member of the 73 * <a href="{@docRoot}/java/util/package-summary.html#CollectionsFramework"> 74 * Java Collections Framework</a>. Unlike the new collection 75 * implementations, {@code Vector} is synchronized. If a thread-safe 76 * implementation is not needed, it is recommended to use {@link 77 * ArrayList} in place of {@code Vector}. 78 * 79 * @param <E> Type of component elements 80 * 81 * @author Lee Boynton 82 * @author Jonathan Payne 83 * @see Collection 84 * @see LinkedList 85 * @since 1.0 86 */ 87public class Vector<E> 88 extends AbstractList<E> 89 implements List<E>, RandomAccess, Cloneable, java.io.Serializable 90{ 91 /** 92 * The array buffer into which the components of the vector are 93 * stored. The capacity of the vector is the length of this array buffer, 94 * and is at least large enough to contain all the vector's elements. 95 * 96 * <p>Any array elements following the last element in the Vector are null. 97 * 98 * @serial 99 */ 100 protected Object[] elementData; 101 102 /** 103 * The number of valid components in this {@code Vector} object. 104 * Components {@code elementData[0]} through 105 * {@code elementData[elementCount-1]} are the actual items. 106 * 107 * @serial 108 */ 109 protected int elementCount; 110 111 /** 112 * The amount by which the capacity of the vector is automatically 113 * incremented when its size becomes greater than its capacity. If 114 * the capacity increment is less than or equal to zero, the capacity 115 * of the vector is doubled each time it needs to grow. 116 * 117 * @serial 118 */ 119 protected int capacityIncrement; 120 121 /** use serialVersionUID from JDK 1.0.2 for interoperability */ 122 private static final long serialVersionUID = -2767605614048989439L; 123 124 /** 125 * Constructs an empty vector with the specified initial capacity and 126 * capacity increment. 127 * 128 * @param initialCapacity the initial capacity of the vector 129 * @param capacityIncrement the amount by which the capacity is 130 * increased when the vector overflows 131 * @throws IllegalArgumentException if the specified initial capacity 132 * is negative 133 */ 134 public Vector(int initialCapacity, int capacityIncrement) { 135 super(); 136 if (initialCapacity < 0) 137 throw new IllegalArgumentException("Illegal Capacity: "+ 138 initialCapacity); 139 this.elementData = new Object[initialCapacity]; 140 this.capacityIncrement = capacityIncrement; 141 } 142 143 /** 144 * Constructs an empty vector with the specified initial capacity and 145 * with its capacity increment equal to zero. 146 * 147 * @param initialCapacity the initial capacity of the vector 148 * @throws IllegalArgumentException if the specified initial capacity 149 * is negative 150 */ 151 public Vector(int initialCapacity) { 152 this(initialCapacity, 0); 153 } 154 155 /** 156 * Constructs an empty vector so that its internal data array 157 * has size {@code 10} and its standard capacity increment is 158 * zero. 159 */ 160 public Vector() { 161 this(10); 162 } 163 164 /** 165 * Constructs a vector containing the elements of the specified 166 * collection, in the order they are returned by the collection's 167 * iterator. 168 * 169 * @param c the collection whose elements are to be placed into this 170 * vector 171 * @throws NullPointerException if the specified collection is null 172 * @since 1.2 173 */ 174 public Vector(Collection<? extends E> c) { 175 elementData = c.toArray(); 176 elementCount = elementData.length; 177 // defend against c.toArray (incorrectly) not returning Object[] 178 // (see e.g. https://bugs.openjdk.java.net/browse/JDK-6260652) 179 if (elementData.getClass() != Object[].class) 180 elementData = Arrays.copyOf(elementData, elementCount, Object[].class); 181 } 182 183 /** 184 * Copies the components of this vector into the specified array. 185 * The item at index {@code k} in this vector is copied into 186 * component {@code k} of {@code anArray}. 187 * 188 * @param anArray the array into which the components get copied 189 * @throws NullPointerException if the given array is null 190 * @throws IndexOutOfBoundsException if the specified array is not 191 * large enough to hold all the components of this vector 192 * @throws ArrayStoreException if a component of this vector is not of 193 * a runtime type that can be stored in the specified array 194 * @see #toArray(Object[]) 195 */ 196 public synchronized void copyInto(Object[] anArray) { 197 System.arraycopy(elementData, 0, anArray, 0, elementCount); 198 } 199 200 /** 201 * Trims the capacity of this vector to be the vector's current 202 * size. If the capacity of this vector is larger than its current 203 * size, then the capacity is changed to equal the size by replacing 204 * its internal data array, kept in the field {@code elementData}, 205 * with a smaller one. An application can use this operation to 206 * minimize the storage of a vector. 207 */ 208 public synchronized void trimToSize() { 209 modCount++; 210 int oldCapacity = elementData.length; 211 if (elementCount < oldCapacity) { 212 elementData = Arrays.copyOf(elementData, elementCount); 213 } 214 } 215 216 /** 217 * Increases the capacity of this vector, if necessary, to ensure 218 * that it can hold at least the number of components specified by 219 * the minimum capacity argument. 220 * 221 * <p>If the current capacity of this vector is less than 222 * {@code minCapacity}, then its capacity is increased by replacing its 223 * internal data array, kept in the field {@code elementData}, with a 224 * larger one. The size of the new data array will be the old size plus 225 * {@code capacityIncrement}, unless the value of 226 * {@code capacityIncrement} is less than or equal to zero, in which case 227 * the new capacity will be twice the old capacity; but if this new size 228 * is still smaller than {@code minCapacity}, then the new capacity will 229 * be {@code minCapacity}. 230 * 231 * @param minCapacity the desired minimum capacity 232 */ 233 public synchronized void ensureCapacity(int minCapacity) { 234 if (minCapacity > 0) { 235 modCount++; 236 if (minCapacity > elementData.length) 237 grow(minCapacity); 238 } 239 } 240 241 /** 242 * The maximum size of array to allocate (unless necessary). 243 * Some VMs reserve some header words in an array. 244 * Attempts to allocate larger arrays may result in 245 * OutOfMemoryError: Requested array size exceeds VM limit 246 */ 247 private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; 248 249 /** 250 * Increases the capacity to ensure that it can hold at least the 251 * number of elements specified by the minimum capacity argument. 252 * 253 * @param minCapacity the desired minimum capacity 254 * @throws OutOfMemoryError if minCapacity is less than zero 255 */ 256 private Object[] grow(int minCapacity) { 257 return elementData = Arrays.copyOf(elementData, 258 newCapacity(minCapacity)); 259 } 260 261 private Object[] grow() { 262 return grow(elementCount + 1); 263 } 264 265 /** 266 * Returns a capacity at least as large as the given minimum capacity. 267 * Will not return a capacity greater than MAX_ARRAY_SIZE unless 268 * the given minimum capacity is greater than MAX_ARRAY_SIZE. 269 * 270 * @param minCapacity the desired minimum capacity 271 * @throws OutOfMemoryError if minCapacity is less than zero 272 */ 273 private int newCapacity(int minCapacity) { 274 // overflow-conscious code 275 int oldCapacity = elementData.length; 276 int newCapacity = oldCapacity + ((capacityIncrement > 0) ? 277 capacityIncrement : oldCapacity); 278 if (newCapacity - minCapacity <= 0) { 279 if (minCapacity < 0) // overflow 280 throw new OutOfMemoryError(); 281 return minCapacity; 282 } 283 return (newCapacity - MAX_ARRAY_SIZE <= 0) 284 ? newCapacity 285 : hugeCapacity(minCapacity); 286 } 287 288 private static int hugeCapacity(int minCapacity) { 289 if (minCapacity < 0) // overflow 290 throw new OutOfMemoryError(); 291 return (minCapacity > MAX_ARRAY_SIZE) ? 292 Integer.MAX_VALUE : 293 MAX_ARRAY_SIZE; 294 } 295 296 /** 297 * Sets the size of this vector. If the new size is greater than the 298 * current size, new {@code null} items are added to the end of 299 * the vector. If the new size is less than the current size, all 300 * components at index {@code newSize} and greater are discarded. 301 * 302 * @param newSize the new size of this vector 303 * @throws ArrayIndexOutOfBoundsException if the new size is negative 304 */ 305 public synchronized void setSize(int newSize) { 306 modCount++; 307 if (newSize > elementData.length) 308 grow(newSize); 309 final Object[] es = elementData; 310 for (int to = elementCount, i = newSize; i < to; i++) 311 es[i] = null; 312 elementCount = newSize; 313 } 314 315 /** 316 * Returns the current capacity of this vector. 317 * 318 * @return the current capacity (the length of its internal 319 * data array, kept in the field {@code elementData} 320 * of this vector) 321 */ 322 public synchronized int capacity() { 323 return elementData.length; 324 } 325 326 /** 327 * Returns the number of components in this vector. 328 * 329 * @return the number of components in this vector 330 */ 331 public synchronized int size() { 332 return elementCount; 333 } 334 335 /** 336 * Tests if this vector has no components. 337 * 338 * @return {@code true} if and only if this vector has 339 * no components, that is, its size is zero; 340 * {@code false} otherwise. 341 */ 342 public synchronized boolean isEmpty() { 343 return elementCount == 0; 344 } 345 346 /** 347 * Returns an enumeration of the components of this vector. The 348 * returned {@code Enumeration} object will generate all items in 349 * this vector. The first item generated is the item at index {@code 0}, 350 * then the item at index {@code 1}, and so on. If the vector is 351 * structurally modified while enumerating over the elements then the 352 * results of enumerating are undefined. 353 * 354 * @return an enumeration of the components of this vector 355 * @see Iterator 356 */ 357 public Enumeration<E> elements() { 358 return new Enumeration<E>() { 359 int count = 0; 360 361 public boolean hasMoreElements() { 362 return count < elementCount; 363 } 364 365 public E nextElement() { 366 synchronized (Vector.this) { 367 if (count < elementCount) { 368 return elementData(count++); 369 } 370 } 371 throw new NoSuchElementException("Vector Enumeration"); 372 } 373 }; 374 } 375 376 /** 377 * Returns {@code true} if this vector contains the specified element. 378 * More formally, returns {@code true} if and only if this vector 379 * contains at least one element {@code e} such that 380 * {@code Objects.equals(o, e)}. 381 * 382 * @param o element whose presence in this vector is to be tested 383 * @return {@code true} if this vector contains the specified element 384 */ 385 public boolean contains(Object o) { 386 return indexOf(o, 0) >= 0; 387 } 388 389 /** 390 * Returns the index of the first occurrence of the specified element 391 * in this vector, or -1 if this vector does not contain the element. 392 * More formally, returns the lowest index {@code i} such that 393 * {@code Objects.equals(o, get(i))}, 394 * or -1 if there is no such index. 395 * 396 * @param o element to search for 397 * @return the index of the first occurrence of the specified element in 398 * this vector, or -1 if this vector does not contain the element 399 */ 400 public int indexOf(Object o) { 401 return indexOf(o, 0); 402 } 403 404 /** 405 * Returns the index of the first occurrence of the specified element in 406 * this vector, searching forwards from {@code index}, or returns -1 if 407 * the element is not found. 408 * More formally, returns the lowest index {@code i} such that 409 * {@code (i >= index && Objects.equals(o, get(i)))}, 410 * or -1 if there is no such index. 411 * 412 * @param o element to search for 413 * @param index index to start searching from 414 * @return the index of the first occurrence of the element in 415 * this vector at position {@code index} or later in the vector; 416 * {@code -1} if the element is not found. 417 * @throws IndexOutOfBoundsException if the specified index is negative 418 * @see Object#equals(Object) 419 */ 420 public synchronized int indexOf(Object o, int index) { 421 if (o == null) { 422 for (int i = index ; i < elementCount ; i++) 423 if (elementData[i]==null) 424 return i; 425 } else { 426 for (int i = index ; i < elementCount ; i++) 427 if (o.equals(elementData[i])) 428 return i; 429 } 430 return -1; 431 } 432 433 /** 434 * Returns the index of the last occurrence of the specified element 435 * in this vector, or -1 if this vector does not contain the element. 436 * More formally, returns the highest index {@code i} such that 437 * {@code Objects.equals(o, get(i))}, 438 * or -1 if there is no such index. 439 * 440 * @param o element to search for 441 * @return the index of the last occurrence of the specified element in 442 * this vector, or -1 if this vector does not contain the element 443 */ 444 public synchronized int lastIndexOf(Object o) { 445 return lastIndexOf(o, elementCount-1); 446 } 447 448 /** 449 * Returns the index of the last occurrence of the specified element in 450 * this vector, searching backwards from {@code index}, or returns -1 if 451 * the element is not found. 452 * More formally, returns the highest index {@code i} such that 453 * {@code (i <= index && Objects.equals(o, get(i)))}, 454 * or -1 if there is no such index. 455 * 456 * @param o element to search for 457 * @param index index to start searching backwards from 458 * @return the index of the last occurrence of the element at position 459 * less than or equal to {@code index} in this vector; 460 * -1 if the element is not found. 461 * @throws IndexOutOfBoundsException if the specified index is greater 462 * than or equal to the current size of this vector 463 */ 464 public synchronized int lastIndexOf(Object o, int index) { 465 if (index >= elementCount) 466 throw new IndexOutOfBoundsException(index + " >= "+ elementCount); 467 468 if (o == null) { 469 for (int i = index; i >= 0; i--) 470 if (elementData[i]==null) 471 return i; 472 } else { 473 for (int i = index; i >= 0; i--) 474 if (o.equals(elementData[i])) 475 return i; 476 } 477 return -1; 478 } 479 480 /** 481 * Returns the component at the specified index. 482 * 483 * <p>This method is identical in functionality to the {@link #get(int)} 484 * method (which is part of the {@link List} interface). 485 * 486 * @param index an index into this vector 487 * @return the component at the specified index 488 * @throws ArrayIndexOutOfBoundsException if the index is out of range 489 * ({@code index < 0 || index >= size()}) 490 */ 491 public synchronized E elementAt(int index) { 492 if (index >= elementCount) { 493 throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount); 494 } 495 496 return elementData(index); 497 } 498 499 /** 500 * Returns the first component (the item at index {@code 0}) of 501 * this vector. 502 * 503 * @return the first component of this vector 504 * @throws NoSuchElementException if this vector has no components 505 */ 506 public synchronized E firstElement() { 507 if (elementCount == 0) { 508 throw new NoSuchElementException(); 509 } 510 return elementData(0); 511 } 512 513 /** 514 * Returns the last component of the vector. 515 * 516 * @return the last component of the vector, i.e., the component at index 517 * {@code size() - 1} 518 * @throws NoSuchElementException if this vector is empty 519 */ 520 public synchronized E lastElement() { 521 if (elementCount == 0) { 522 throw new NoSuchElementException(); 523 } 524 return elementData(elementCount - 1); 525 } 526 527 /** 528 * Sets the component at the specified {@code index} of this 529 * vector to be the specified object. The previous component at that 530 * position is discarded. 531 * 532 * <p>The index must be a value greater than or equal to {@code 0} 533 * and less than the current size of the vector. 534 * 535 * <p>This method is identical in functionality to the 536 * {@link #set(int, Object) set(int, E)} 537 * method (which is part of the {@link List} interface). Note that the 538 * {@code set} method reverses the order of the parameters, to more closely 539 * match array usage. Note also that the {@code set} method returns the 540 * old value that was stored at the specified position. 541 * 542 * @param obj what the component is to be set to 543 * @param index the specified index 544 * @throws ArrayIndexOutOfBoundsException if the index is out of range 545 * ({@code index < 0 || index >= size()}) 546 */ 547 public synchronized void setElementAt(E obj, int index) { 548 if (index >= elementCount) { 549 throw new ArrayIndexOutOfBoundsException(index + " >= " + 550 elementCount); 551 } 552 elementData[index] = obj; 553 } 554 555 /** 556 * Deletes the component at the specified index. Each component in 557 * this vector with an index greater or equal to the specified 558 * {@code index} is shifted downward to have an index one 559 * smaller than the value it had previously. The size of this vector 560 * is decreased by {@code 1}. 561 * 562 * <p>The index must be a value greater than or equal to {@code 0} 563 * and less than the current size of the vector. 564 * 565 * <p>This method is identical in functionality to the {@link #remove(int)} 566 * method (which is part of the {@link List} interface). Note that the 567 * {@code remove} method returns the old value that was stored at the 568 * specified position. 569 * 570 * @param index the index of the object to remove 571 * @throws ArrayIndexOutOfBoundsException if the index is out of range 572 * ({@code index < 0 || index >= size()}) 573 */ 574 public synchronized void removeElementAt(int index) { 575 if (index >= elementCount) { 576 throw new ArrayIndexOutOfBoundsException(index + " >= " + 577 elementCount); 578 } 579 else if (index < 0) { 580 throw new ArrayIndexOutOfBoundsException(index); 581 } 582 int j = elementCount - index - 1; 583 if (j > 0) { 584 System.arraycopy(elementData, index + 1, elementData, index, j); 585 } 586 modCount++; 587 elementCount--; 588 elementData[elementCount] = null; /* to let gc do its work */ 589 } 590 591 /** 592 * Inserts the specified object as a component in this vector at the 593 * specified {@code index}. Each component in this vector with 594 * an index greater or equal to the specified {@code index} is 595 * shifted upward to have an index one greater than the value it had 596 * previously. 597 * 598 * <p>The index must be a value greater than or equal to {@code 0} 599 * and less than or equal to the current size of the vector. (If the 600 * index is equal to the current size of the vector, the new element 601 * is appended to the Vector.) 602 * 603 * <p>This method is identical in functionality to the 604 * {@link #add(int, Object) add(int, E)} 605 * method (which is part of the {@link List} interface). Note that the 606 * {@code add} method reverses the order of the parameters, to more closely 607 * match array usage. 608 * 609 * @param obj the component to insert 610 * @param index where to insert the new component 611 * @throws ArrayIndexOutOfBoundsException if the index is out of range 612 * ({@code index < 0 || index > size()}) 613 */ 614 public synchronized void insertElementAt(E obj, int index) { 615 if (index > elementCount) { 616 throw new ArrayIndexOutOfBoundsException(index 617 + " > " + elementCount); 618 } 619 modCount++; 620 final int s = elementCount; 621 Object[] elementData = this.elementData; 622 if (s == elementData.length) 623 elementData = grow(); 624 System.arraycopy(elementData, index, 625 elementData, index + 1, 626 s - index); 627 elementData[index] = obj; 628 elementCount = s + 1; 629 } 630 631 /** 632 * Adds the specified component to the end of this vector, 633 * increasing its size by one. The capacity of this vector is 634 * increased if its size becomes greater than its capacity. 635 * 636 * <p>This method is identical in functionality to the 637 * {@link #add(Object) add(E)} 638 * method (which is part of the {@link List} interface). 639 * 640 * @param obj the component to be added 641 */ 642 public synchronized void addElement(E obj) { 643 modCount++; 644 add(obj, elementData, elementCount); 645 } 646 647 /** 648 * Removes the first (lowest-indexed) occurrence of the argument 649 * from this vector. If the object is found in this vector, each 650 * component in the vector with an index greater or equal to the 651 * object's index is shifted downward to have an index one smaller 652 * than the value it had previously. 653 * 654 * <p>This method is identical in functionality to the 655 * {@link #remove(Object)} method (which is part of the 656 * {@link List} interface). 657 * 658 * @param obj the component to be removed 659 * @return {@code true} if the argument was a component of this 660 * vector; {@code false} otherwise. 661 */ 662 public synchronized boolean removeElement(Object obj) { 663 modCount++; 664 int i = indexOf(obj); 665 if (i >= 0) { 666 removeElementAt(i); 667 return true; 668 } 669 return false; 670 } 671 672 /** 673 * Removes all components from this vector and sets its size to zero. 674 * 675 * <p>This method is identical in functionality to the {@link #clear} 676 * method (which is part of the {@link List} interface). 677 */ 678 public synchronized void removeAllElements() { 679 final Object[] es = elementData; 680 for (int to = elementCount, i = elementCount = 0; i < to; i++) 681 es[i] = null; 682 modCount++; 683 } 684 685 /** 686 * Returns a clone of this vector. The copy will contain a 687 * reference to a clone of the internal data array, not a reference 688 * to the original internal data array of this {@code Vector} object. 689 * 690 * @return a clone of this vector 691 */ 692 public synchronized Object clone() { 693 try { 694 @SuppressWarnings("unchecked") 695 Vector<E> v = (Vector<E>) super.clone(); 696 v.elementData = Arrays.copyOf(elementData, elementCount); 697 v.modCount = 0; 698 return v; 699 } catch (CloneNotSupportedException e) { 700 // this shouldn't happen, since we are Cloneable 701 throw new InternalError(e); 702 } 703 } 704 705 /** 706 * Returns an array containing all of the elements in this Vector 707 * in the correct order. 708 * 709 * @since 1.2 710 */ 711 public synchronized Object[] toArray() { 712 return Arrays.copyOf(elementData, elementCount); 713 } 714 715 /** 716 * Returns an array containing all of the elements in this Vector in the 717 * correct order; the runtime type of the returned array is that of the 718 * specified array. If the Vector fits in the specified array, it is 719 * returned therein. Otherwise, a new array is allocated with the runtime 720 * type of the specified array and the size of this Vector. 721 * 722 * <p>If the Vector fits in the specified array with room to spare 723 * (i.e., the array has more elements than the Vector), 724 * the element in the array immediately following the end of the 725 * Vector is set to null. (This is useful in determining the length 726 * of the Vector <em>only</em> if the caller knows that the Vector 727 * does not contain any null elements.) 728 * 729 * @param <T> type of array elements. The same type as {@code <E>} or a 730 * supertype of {@code <E>}. 731 * @param a the array into which the elements of the Vector are to 732 * be stored, if it is big enough; otherwise, a new array of the 733 * same runtime type is allocated for this purpose. 734 * @return an array containing the elements of the Vector 735 * @throws ArrayStoreException if the runtime type of a, {@code <T>}, is not 736 * a supertype of the runtime type, {@code <E>}, of every element in this 737 * Vector 738 * @throws NullPointerException if the given array is null 739 * @since 1.2 740 */ 741 @SuppressWarnings("unchecked") 742 public synchronized <T> T[] toArray(T[] a) { 743 if (a.length < elementCount) 744 return (T[]) Arrays.copyOf(elementData, elementCount, a.getClass()); 745 746 System.arraycopy(elementData, 0, a, 0, elementCount); 747 748 if (a.length > elementCount) 749 a[elementCount] = null; 750 751 return a; 752 } 753 754 // Positional Access Operations 755 756 @SuppressWarnings("unchecked") 757 E elementData(int index) { 758 return (E) elementData[index]; 759 } 760 761 @SuppressWarnings("unchecked") 762 static <E> E elementAt(Object[] es, int index) { 763 return (E) es[index]; 764 } 765 766 /** 767 * Returns the element at the specified position in this Vector. 768 * 769 * @param index index of the element to return 770 * @return object at the specified index 771 * @throws ArrayIndexOutOfBoundsException if the index is out of range 772 * ({@code index < 0 || index >= size()}) 773 * @since 1.2 774 */ 775 public synchronized E get(int index) { 776 if (index >= elementCount) 777 throw new ArrayIndexOutOfBoundsException(index); 778 779 return elementData(index); 780 } 781 782 /** 783 * Replaces the element at the specified position in this Vector with the 784 * specified element. 785 * 786 * @param index index of the element to replace 787 * @param element element to be stored at the specified position 788 * @return the element previously at the specified position 789 * @throws ArrayIndexOutOfBoundsException if the index is out of range 790 * ({@code index < 0 || index >= size()}) 791 * @since 1.2 792 */ 793 public synchronized E set(int index, E element) { 794 if (index >= elementCount) 795 throw new ArrayIndexOutOfBoundsException(index); 796 797 E oldValue = elementData(index); 798 elementData[index] = element; 799 return oldValue; 800 } 801 802 /** 803 * This helper method split out from add(E) to keep method 804 * bytecode size under 35 (the -XX:MaxInlineSize default value), 805 * which helps when add(E) is called in a C1-compiled loop. 806 */ 807 private void add(E e, Object[] elementData, int s) { 808 if (s == elementData.length) 809 elementData = grow(); 810 elementData[s] = e; 811 elementCount = s + 1; 812 } 813 814 /** 815 * Appends the specified element to the end of this Vector. 816 * 817 * @param e element to be appended to this Vector 818 * @return {@code true} (as specified by {@link Collection#add}) 819 * @since 1.2 820 */ 821 public synchronized boolean add(E e) { 822 modCount++; 823 add(e, elementData, elementCount); 824 return true; 825 } 826 827 /** 828 * Removes the first occurrence of the specified element in this Vector 829 * If the Vector does not contain the element, it is unchanged. More 830 * formally, removes the element with the lowest index i such that 831 * {@code Objects.equals(o, get(i))} (if such 832 * an element exists). 833 * 834 * @param o element to be removed from this Vector, if present 835 * @return true if the Vector contained the specified element 836 * @since 1.2 837 */ 838 public boolean remove(Object o) { 839 return removeElement(o); 840 } 841 842 /** 843 * Inserts the specified element at the specified position in this Vector. 844 * Shifts the element currently at that position (if any) and any 845 * subsequent elements to the right (adds one to their indices). 846 * 847 * @param index index at which the specified element is to be inserted 848 * @param element element to be inserted 849 * @throws ArrayIndexOutOfBoundsException if the index is out of range 850 * ({@code index < 0 || index > size()}) 851 * @since 1.2 852 */ 853 public void add(int index, E element) { 854 insertElementAt(element, index); 855 } 856 857 /** 858 * Removes the element at the specified position in this Vector. 859 * Shifts any subsequent elements to the left (subtracts one from their 860 * indices). Returns the element that was removed from the Vector. 861 * 862 * @param index the index of the element to be removed 863 * @return element that was removed 864 * @throws ArrayIndexOutOfBoundsException if the index is out of range 865 * ({@code index < 0 || index >= size()}) 866 * @since 1.2 867 */ 868 public synchronized E remove(int index) { 869 modCount++; 870 if (index >= elementCount) 871 throw new ArrayIndexOutOfBoundsException(index); 872 E oldValue = elementData(index); 873 874 int numMoved = elementCount - index - 1; 875 if (numMoved > 0) 876 System.arraycopy(elementData, index+1, elementData, index, 877 numMoved); 878 elementData[--elementCount] = null; // Let gc do its work 879 880 return oldValue; 881 } 882 883 /** 884 * Removes all of the elements from this Vector. The Vector will 885 * be empty after this call returns (unless it throws an exception). 886 * 887 * @since 1.2 888 */ 889 public void clear() { 890 removeAllElements(); 891 } 892 893 // Bulk Operations 894 895 /** 896 * Returns true if this Vector contains all of the elements in the 897 * specified Collection. 898 * 899 * @param c a collection whose elements will be tested for containment 900 * in this Vector 901 * @return true if this Vector contains all of the elements in the 902 * specified collection 903 * @throws NullPointerException if the specified collection is null 904 */ 905 public synchronized boolean containsAll(Collection<?> c) { 906 return super.containsAll(c); 907 } 908 909 /** 910 * Appends all of the elements in the specified Collection to the end of 911 * this Vector, in the order that they are returned by the specified 912 * Collection's Iterator. The behavior of this operation is undefined if 913 * the specified Collection is modified while the operation is in progress. 914 * (This implies that the behavior of this call is undefined if the 915 * specified Collection is this Vector, and this Vector is nonempty.) 916 * 917 * @param c elements to be inserted into this Vector 918 * @return {@code true} if this Vector changed as a result of the call 919 * @throws NullPointerException if the specified collection is null 920 * @since 1.2 921 */ 922 public boolean addAll(Collection<? extends E> c) { 923 Object[] a = c.toArray(); 924 modCount++; 925 int numNew = a.length; 926 if (numNew == 0) 927 return false; 928 synchronized (this) { 929 Object[] elementData = this.elementData; 930 final int s = elementCount; 931 if (numNew > elementData.length - s) 932 elementData = grow(s + numNew); 933 System.arraycopy(a, 0, elementData, s, numNew); 934 elementCount = s + numNew; 935 return true; 936 } 937 } 938 939 /** 940 * Removes from this Vector all of its elements that are contained in the 941 * specified Collection. 942 * 943 * @param c a collection of elements to be removed from the Vector 944 * @return true if this Vector changed as a result of the call 945 * @throws ClassCastException if the types of one or more elements 946 * in this vector are incompatible with the specified 947 * collection 948 * (<a href="Collection.html#optional-restrictions">optional</a>) 949 * @throws NullPointerException if this vector contains one or more null 950 * elements and the specified collection does not support null 951 * elements 952 * (<a href="Collection.html#optional-restrictions">optional</a>), 953 * or if the specified collection is null 954 * @since 1.2 955 */ 956 public boolean removeAll(Collection<?> c) { 957 Objects.requireNonNull(c); 958 return bulkRemove(e -> c.contains(e)); 959 } 960 961 /** 962 * Retains only the elements in this Vector that are contained in the 963 * specified Collection. In other words, removes from this Vector all 964 * of its elements that are not contained in the specified Collection. 965 * 966 * @param c a collection of elements to be retained in this Vector 967 * (all other elements are removed) 968 * @return true if this Vector changed as a result of the call 969 * @throws ClassCastException if the types of one or more elements 970 * in this vector are incompatible with the specified 971 * collection 972 * (<a href="Collection.html#optional-restrictions">optional</a>) 973 * @throws NullPointerException if this vector contains one or more null 974 * elements and the specified collection does not support null 975 * elements 976 * (<a href="Collection.html#optional-restrictions">optional</a>), 977 * or if the specified collection is null 978 * @since 1.2 979 */ 980 public boolean retainAll(Collection<?> c) { 981 Objects.requireNonNull(c); 982 return bulkRemove(e -> !c.contains(e)); 983 } 984 985 /** 986 * @throws NullPointerException {@inheritDoc} 987 */ 988 @Override 989 public boolean removeIf(Predicate<? super E> filter) { 990 Objects.requireNonNull(filter); 991 return bulkRemove(filter); 992 } 993 994 // A tiny bit set implementation 995 996 private static long[] nBits(int n) { 997 return new long[((n - 1) >> 6) + 1]; 998 } 999 private static void setBit(long[] bits, int i) { 1000 bits[i >> 6] |= 1L << i; 1001 } 1002 private static boolean isClear(long[] bits, int i) { 1003 return (bits[i >> 6] & (1L << i)) == 0; 1004 } 1005 1006 private synchronized boolean bulkRemove(Predicate<? super E> filter) { 1007 int expectedModCount = modCount; 1008 final Object[] es = elementData; 1009 final int end = elementCount; 1010 int i; 1011 // Optimize for initial run of survivors 1012 for (i = 0; i < end && !filter.test(elementAt(es, i)); i++) 1013 ; 1014 // Tolerate predicates that reentrantly access the collection for 1015 // read (but writers still get CME), so traverse once to find 1016 // elements to delete, a second pass to physically expunge. 1017 if (i < end) { 1018 final int beg = i; 1019 final long[] deathRow = nBits(end - beg); 1020 deathRow[0] = 1L; // set bit 0 1021 for (i = beg + 1; i < end; i++) 1022 if (filter.test(elementAt(es, i))) 1023 setBit(deathRow, i - beg); 1024 if (modCount != expectedModCount) 1025 throw new ConcurrentModificationException(); 1026 expectedModCount++; 1027 modCount++; 1028 int w = beg; 1029 for (i = beg; i < end; i++) 1030 if (isClear(deathRow, i - beg)) 1031 es[w++] = es[i]; 1032 for (i = elementCount = w; i < end; i++) 1033 es[i] = null; 1034 return true; 1035 } else { 1036 if (modCount != expectedModCount) 1037 throw new ConcurrentModificationException(); 1038 return false; 1039 } 1040 } 1041 1042 /** 1043 * Inserts all of the elements in the specified Collection into this 1044 * Vector at the specified position. Shifts the element currently at 1045 * that position (if any) and any subsequent elements to the right 1046 * (increases their indices). The new elements will appear in the Vector 1047 * in the order that they are returned by the specified Collection's 1048 * iterator. 1049 * 1050 * @param index index at which to insert the first element from the 1051 * specified collection 1052 * @param c elements to be inserted into this Vector 1053 * @return {@code true} if this Vector changed as a result of the call 1054 * @throws ArrayIndexOutOfBoundsException if the index is out of range 1055 * ({@code index < 0 || index > size()}) 1056 * @throws NullPointerException if the specified collection is null 1057 * @since 1.2 1058 */ 1059 public synchronized boolean addAll(int index, Collection<? extends E> c) { 1060 if (index < 0 || index > elementCount) 1061 throw new ArrayIndexOutOfBoundsException(index); 1062 1063 Object[] a = c.toArray(); 1064 modCount++; 1065 int numNew = a.length; 1066 if (numNew == 0) 1067 return false; 1068 Object[] elementData = this.elementData; 1069 final int s = elementCount; 1070 if (numNew > elementData.length - s) 1071 elementData = grow(s + numNew); 1072 1073 int numMoved = s - index; 1074 if (numMoved > 0) 1075 System.arraycopy(elementData, index, 1076 elementData, index + numNew, 1077 numMoved); 1078 System.arraycopy(a, 0, elementData, index, numNew); 1079 elementCount = s + numNew; 1080 return true; 1081 } 1082 1083 /** 1084 * Compares the specified Object with this Vector for equality. Returns 1085 * true if and only if the specified Object is also a List, both Lists 1086 * have the same size, and all corresponding pairs of elements in the two 1087 * Lists are <em>equal</em>. (Two elements {@code e1} and 1088 * {@code e2} are <em>equal</em> if {@code Objects.equals(e1, e2)}.) 1089 * In other words, two Lists are defined to be 1090 * equal if they contain the same elements in the same order. 1091 * 1092 * @param o the Object to be compared for equality with this Vector 1093 * @return true if the specified Object is equal to this Vector 1094 */ 1095 public synchronized boolean equals(Object o) { 1096 return super.equals(o); 1097 } 1098 1099 /** 1100 * Returns the hash code value for this Vector. 1101 */ 1102 public synchronized int hashCode() { 1103 return super.hashCode(); 1104 } 1105 1106 /** 1107 * Returns a string representation of this Vector, containing 1108 * the String representation of each element. 1109 */ 1110 public synchronized String toString() { 1111 return super.toString(); 1112 } 1113 1114 /** 1115 * Returns a view of the portion of this List between fromIndex, 1116 * inclusive, and toIndex, exclusive. (If fromIndex and toIndex are 1117 * equal, the returned List is empty.) The returned List is backed by this 1118 * List, so changes in the returned List are reflected in this List, and 1119 * vice-versa. The returned List supports all of the optional List 1120 * operations supported by this List. 1121 * 1122 * <p>This method eliminates the need for explicit range operations (of 1123 * the sort that commonly exist for arrays). Any operation that expects 1124 * a List can be used as a range operation by operating on a subList view 1125 * instead of a whole List. For example, the following idiom 1126 * removes a range of elements from a List: 1127 * <pre> 1128 * list.subList(from, to).clear(); 1129 * </pre> 1130 * Similar idioms may be constructed for indexOf and lastIndexOf, 1131 * and all of the algorithms in the Collections class can be applied to 1132 * a subList. 1133 * 1134 * <p>The semantics of the List returned by this method become undefined if 1135 * the backing list (i.e., this List) is <i>structurally modified</i> in 1136 * any way other than via the returned List. (Structural modifications are 1137 * those that change the size of the List, or otherwise perturb it in such 1138 * a fashion that iterations in progress may yield incorrect results.) 1139 * 1140 * @param fromIndex low endpoint (inclusive) of the subList 1141 * @param toIndex high endpoint (exclusive) of the subList 1142 * @return a view of the specified range within this List 1143 * @throws IndexOutOfBoundsException if an endpoint index value is out of range 1144 * {@code (fromIndex < 0 || toIndex > size)} 1145 * @throws IllegalArgumentException if the endpoint indices are out of order 1146 * {@code (fromIndex > toIndex)} 1147 */ 1148 public synchronized List<E> subList(int fromIndex, int toIndex) { 1149 return Collections.synchronizedList(super.subList(fromIndex, toIndex), 1150 this); 1151 } 1152 1153 /** 1154 * Removes from this list all of the elements whose index is between 1155 * {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. 1156 * Shifts any succeeding elements to the left (reduces their index). 1157 * This call shortens the list by {@code (toIndex - fromIndex)} elements. 1158 * (If {@code toIndex==fromIndex}, this operation has no effect.) 1159 */ 1160 protected synchronized void removeRange(int fromIndex, int toIndex) { 1161 modCount++; 1162 shiftTailOverGap(elementData, fromIndex, toIndex); 1163 } 1164 1165 /** Erases the gap from lo to hi, by sliding down following elements. */ 1166 private void shiftTailOverGap(Object[] es, int lo, int hi) { 1167 System.arraycopy(es, hi, es, lo, elementCount - hi); 1168 for (int to = elementCount, i = (elementCount -= hi - lo); i < to; i++) 1169 es[i] = null; 1170 } 1171 1172 /** 1173 * Saves the state of the {@code Vector} instance to a stream 1174 * (that is, serializes it). 1175 * This method performs synchronization to ensure the consistency 1176 * of the serialized data. 1177 * 1178 * @param s the stream 1179 * @throws java.io.IOException if an I/O error occurs 1180 */ 1181 private void writeObject(java.io.ObjectOutputStream s) 1182 throws java.io.IOException { 1183 final java.io.ObjectOutputStream.PutField fields = s.putFields(); 1184 final Object[] data; 1185 synchronized (this) { 1186 fields.put("capacityIncrement", capacityIncrement); 1187 fields.put("elementCount", elementCount); 1188 data = elementData.clone(); 1189 } 1190 fields.put("elementData", data); 1191 s.writeFields(); 1192 } 1193 1194 /** 1195 * Returns a list iterator over the elements in this list (in proper 1196 * sequence), starting at the specified position in the list. 1197 * The specified index indicates the first element that would be 1198 * returned by an initial call to {@link ListIterator#next next}. 1199 * An initial call to {@link ListIterator#previous previous} would 1200 * return the element with the specified index minus one. 1201 * 1202 * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. 1203 * 1204 * @throws IndexOutOfBoundsException {@inheritDoc} 1205 */ 1206 public synchronized ListIterator<E> listIterator(int index) { 1207 if (index < 0 || index > elementCount) 1208 throw new IndexOutOfBoundsException("Index: "+index); 1209 return new ListItr(index); 1210 } 1211 1212 /** 1213 * Returns a list iterator over the elements in this list (in proper 1214 * sequence). 1215 * 1216 * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. 1217 * 1218 * @see #listIterator(int) 1219 */ 1220 public synchronized ListIterator<E> listIterator() { 1221 return new ListItr(0); 1222 } 1223 1224 /** 1225 * Returns an iterator over the elements in this list in proper sequence. 1226 * 1227 * <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>. 1228 * 1229 * @return an iterator over the elements in this list in proper sequence 1230 */ 1231 public synchronized Iterator<E> iterator() { 1232 return new Itr(); 1233 } 1234 1235 /** 1236 * An optimized version of AbstractList.Itr 1237 */ 1238 private class Itr implements Iterator<E> { 1239 int cursor; // index of next element to return 1240 int lastRet = -1; // index of last element returned; -1 if no such 1241 int expectedModCount = modCount; 1242 1243 public boolean hasNext() { 1244 // Racy but within spec, since modifications are checked 1245 // within or after synchronization in next/previous 1246 return cursor != elementCount; 1247 } 1248 1249 public E next() { 1250 synchronized (Vector.this) { 1251 checkForComodification(); 1252 int i = cursor; 1253 if (i >= elementCount) 1254 throw new NoSuchElementException(); 1255 cursor = i + 1; 1256 return elementData(lastRet = i); 1257 } 1258 } 1259 1260 public void remove() { 1261 if (lastRet == -1) 1262 throw new IllegalStateException(); 1263 synchronized (Vector.this) { 1264 checkForComodification(); 1265 Vector.this.remove(lastRet); 1266 expectedModCount = modCount; 1267 } 1268 cursor = lastRet; 1269 lastRet = -1; 1270 } 1271 1272 @Override 1273 public void forEachRemaining(Consumer<? super E> action) { 1274 Objects.requireNonNull(action); 1275 synchronized (Vector.this) { 1276 final int size = elementCount; 1277 int i = cursor; 1278 if (i >= size) { 1279 return; 1280 } 1281 final Object[] es = elementData; 1282 if (i >= es.length) 1283 throw new ConcurrentModificationException(); 1284 while (i < size && modCount == expectedModCount) 1285 action.accept(elementAt(es, i++)); 1286 // update once at end of iteration to reduce heap write traffic 1287 cursor = i; 1288 lastRet = i - 1; 1289 checkForComodification(); 1290 } 1291 } 1292 1293 final void checkForComodification() { 1294 if (modCount != expectedModCount) 1295 throw new ConcurrentModificationException(); 1296 } 1297 } 1298 1299 /** 1300 * An optimized version of AbstractList.ListItr 1301 */ 1302 final class ListItr extends Itr implements ListIterator<E> { 1303 ListItr(int index) { 1304 super(); 1305 cursor = index; 1306 } 1307 1308 public boolean hasPrevious() { 1309 return cursor != 0; 1310 } 1311 1312 public int nextIndex() { 1313 return cursor; 1314 } 1315 1316 public int previousIndex() { 1317 return cursor - 1; 1318 } 1319 1320 public E previous() { 1321 synchronized (Vector.this) { 1322 checkForComodification(); 1323 int i = cursor - 1; 1324 if (i < 0) 1325 throw new NoSuchElementException(); 1326 cursor = i; 1327 return elementData(lastRet = i); 1328 } 1329 } 1330 1331 public void set(E e) { 1332 if (lastRet == -1) 1333 throw new IllegalStateException(); 1334 synchronized (Vector.this) { 1335 checkForComodification(); 1336 Vector.this.set(lastRet, e); 1337 } 1338 } 1339 1340 public void add(E e) { 1341 int i = cursor; 1342 synchronized (Vector.this) { 1343 checkForComodification(); 1344 Vector.this.add(i, e); 1345 expectedModCount = modCount; 1346 } 1347 cursor = i + 1; 1348 lastRet = -1; 1349 } 1350 } 1351 1352 /** 1353 * @throws NullPointerException {@inheritDoc} 1354 */ 1355 @Override 1356 public synchronized void forEach(Consumer<? super E> action) { 1357 Objects.requireNonNull(action); 1358 final int expectedModCount = modCount; 1359 final Object[] es = elementData; 1360 final int size = elementCount; 1361 for (int i = 0; modCount == expectedModCount && i < size; i++) 1362 action.accept(elementAt(es, i)); 1363 if (modCount != expectedModCount) 1364 throw new ConcurrentModificationException(); 1365 } 1366 1367 /** 1368 * @throws NullPointerException {@inheritDoc} 1369 */ 1370 @Override 1371 public synchronized void replaceAll(UnaryOperator<E> operator) { 1372 Objects.requireNonNull(operator); 1373 final int expectedModCount = modCount; 1374 final Object[] es = elementData; 1375 final int size = elementCount; 1376 for (int i = 0; modCount == expectedModCount && i < size; i++) 1377 es[i] = operator.apply(elementAt(es, i)); 1378 if (modCount != expectedModCount) 1379 throw new ConcurrentModificationException(); 1380 modCount++; 1381 } 1382 1383 @SuppressWarnings("unchecked") 1384 @Override 1385 public synchronized void sort(Comparator<? super E> c) { 1386 final int expectedModCount = modCount; 1387 Arrays.sort((E[]) elementData, 0, elementCount, c); 1388 if (modCount != expectedModCount) 1389 throw new ConcurrentModificationException(); 1390 modCount++; 1391 } 1392 1393 /** 1394 * Creates a <em><a href="Spliterator.html#binding">late-binding</a></em> 1395 * and <em>fail-fast</em> {@link Spliterator} over the elements in this 1396 * list. 1397 * 1398 * <p>The {@code Spliterator} reports {@link Spliterator#SIZED}, 1399 * {@link Spliterator#SUBSIZED}, and {@link Spliterator#ORDERED}. 1400 * Overriding implementations should document the reporting of additional 1401 * characteristic values. 1402 * 1403 * @return a {@code Spliterator} over the elements in this list 1404 * @since 1.8 1405 */ 1406 @Override 1407 public Spliterator<E> spliterator() { 1408 return new VectorSpliterator(null, 0, -1, 0); 1409 } 1410 1411 /** Similar to ArrayList Spliterator */ 1412 final class VectorSpliterator implements Spliterator<E> { 1413 private Object[] array; 1414 private int index; // current index, modified on advance/split 1415 private int fence; // -1 until used; then one past last index 1416 private int expectedModCount; // initialized when fence set 1417 1418 /** Creates new spliterator covering the given range. */ 1419 VectorSpliterator(Object[] array, int origin, int fence, 1420 int expectedModCount) { 1421 this.array = array; 1422 this.index = origin; 1423 this.fence = fence; 1424 this.expectedModCount = expectedModCount; 1425 } 1426 1427 private int getFence() { // initialize on first use 1428 int hi; 1429 if ((hi = fence) < 0) { 1430 synchronized (Vector.this) { 1431 array = elementData; 1432 expectedModCount = modCount; 1433 hi = fence = elementCount; 1434 } 1435 } 1436 return hi; 1437 } 1438 1439 public Spliterator<E> trySplit() { 1440 int hi = getFence(), lo = index, mid = (lo + hi) >>> 1; 1441 return (lo >= mid) ? null : 1442 new VectorSpliterator(array, lo, index = mid, expectedModCount); 1443 } 1444 1445 @SuppressWarnings("unchecked") 1446 public boolean tryAdvance(Consumer<? super E> action) { 1447 Objects.requireNonNull(action); 1448 int i; 1449 if (getFence() > (i = index)) { 1450 index = i + 1; 1451 action.accept((E)array[i]); 1452 if (modCount != expectedModCount) 1453 throw new ConcurrentModificationException(); 1454 return true; 1455 } 1456 return false; 1457 } 1458 1459 @SuppressWarnings("unchecked") 1460 public void forEachRemaining(Consumer<? super E> action) { 1461 Objects.requireNonNull(action); 1462 final int hi = getFence(); 1463 final Object[] a = array; 1464 int i; 1465 for (i = index, index = hi; i < hi; i++) 1466 action.accept((E) a[i]); 1467 if (modCount != expectedModCount) 1468 throw new ConcurrentModificationException(); 1469 } 1470 1471 public long estimateSize() { 1472 return getFence() - index; 1473 } 1474 1475 public int characteristics() { 1476 return Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED; 1477 } 1478 } 1479 1480 void checkInvariants() { 1481 // assert elementCount >= 0; 1482 // assert elementCount == elementData.length || elementData[elementCount] == null; 1483 } 1484} 1485