1 /* 2 * Copyright (c) 1994, 2019, 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 import java.io.IOException; 29 import java.io.ObjectInputStream; 30 import java.io.StreamCorruptedException; 31 import java.util.function.Consumer; 32 import java.util.function.Predicate; 33 import java.util.function.UnaryOperator; 34 35 import jdk.internal.util.ArraysSupport; 36 37 /** 38 * The {@code Vector} class implements a growable array of 39 * objects. Like an array, it contains components that can be 40 * accessed using an integer index. However, the size of a 41 * {@code Vector} can grow or shrink as needed to accommodate 42 * adding and removing items after the {@code Vector} has been created. 43 * 44 * <p>Each vector tries to optimize storage management by maintaining a 45 * {@code capacity} and a {@code capacityIncrement}. The 46 * {@code capacity} is always at least as large as the vector 47 * size; it is usually larger because as components are added to the 48 * vector, the vector's storage increases in chunks the size of 49 * {@code capacityIncrement}. An application can increase the 50 * capacity of a vector before inserting a large number of 51 * components; this reduces the amount of incremental reallocation. 52 * 53 * <p id="fail-fast"> 54 * The iterators returned by this class's {@link #iterator() iterator} and 55 * {@link #listIterator(int) listIterator} methods are <em>fail-fast</em>: 56 * if the vector is structurally modified at any time after the iterator is 57 * created, in any way except through the iterator's own 58 * {@link ListIterator#remove() remove} or 59 * {@link ListIterator#add(Object) add} methods, the iterator will throw a 60 * {@link ConcurrentModificationException}. Thus, in the face of 61 * concurrent modification, the iterator fails quickly and cleanly, rather 62 * than risking arbitrary, non-deterministic behavior at an undetermined 63 * time in the future. The {@link Enumeration Enumerations} returned by 64 * the {@link #elements() elements} method are <em>not</em> fail-fast; if the 65 * Vector is structurally modified at any time after the enumeration is 66 * created then the results of enumerating are undefined. 67 * 68 * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed 69 * as it is, generally speaking, impossible to make any hard guarantees in the 70 * presence of unsynchronized concurrent modification. Fail-fast iterators 71 * throw {@code ConcurrentModificationException} on a best-effort basis. 72 * Therefore, it would be wrong to write a program that depended on this 73 * exception for its correctness: <i>the fail-fast behavior of iterators 74 * should be used only to detect bugs.</i> 75 * 76 * <p>As of the Java 2 platform v1.2, this class was retrofitted to 77 * implement the {@link List} interface, making it a member of the 78 * <a href="{@docRoot}/java.base/java/util/package-summary.html#CollectionsFramework"> 79 * Java Collections Framework</a>. Unlike the new collection 80 * implementations, {@code Vector} is synchronized. If a thread-safe 81 * implementation is not needed, it is recommended to use {@link 82 * ArrayList} in place of {@code Vector}. 83 * 84 * @param <E> Type of component elements 85 * 86 * @author Lee Boynton 87 * @author Jonathan Payne 88 * @see Collection 89 * @see LinkedList 90 * @since 1.0 91 */ 92 public class Vector<E> 93 extends AbstractList<E> 94 implements List<E>, RandomAccess, Cloneable, java.io.Serializable 95 { 96 /** 97 * The array buffer into which the components of the vector are 98 * stored. The capacity of the vector is the length of this array buffer, 99 * and is at least large enough to contain all the vector's elements. 100 * 101 * <p>Any array elements following the last element in the Vector are null. 102 * 103 * @serial 104 */ 105 @SuppressWarnings("serial") // Conditionally serializable 106 protected Object[] elementData; 107 108 /** 109 * The number of valid components in this {@code Vector} object. 110 * Components {@code elementData[0]} through 111 * {@code elementData[elementCount-1]} are the actual items. 112 * 113 * @serial 114 */ 115 protected int elementCount; 116 117 /** 118 * The amount by which the capacity of the vector is automatically 119 * incremented when its size becomes greater than its capacity. If 120 * the capacity increment is less than or equal to zero, the capacity 121 * of the vector is doubled each time it needs to grow. 122 * 123 * @serial 124 */ 125 protected int capacityIncrement; 126 127 /** use serialVersionUID from JDK 1.0.2 for interoperability */ 128 @java.io.Serial 129 private static final long serialVersionUID = -2767605614048989439L; 130 131 /** 132 * Constructs an empty vector with the specified initial capacity and 133 * capacity increment. 134 * 135 * @param initialCapacity the initial capacity of the vector 136 * @param capacityIncrement the amount by which the capacity is 137 * increased when the vector overflows 138 * @throws IllegalArgumentException if the specified initial capacity 139 * is negative 140 */ 141 public Vector(int initialCapacity, int capacityIncrement) { 142 super(); 143 if (initialCapacity < 0) 144 throw new IllegalArgumentException("Illegal Capacity: "+ 145 initialCapacity); 146 this.elementData = new Object[initialCapacity]; 147 this.capacityIncrement = capacityIncrement; 148 } 149 150 /** 151 * Constructs an empty vector with the specified initial capacity and 152 * with its capacity increment equal to zero. 153 * 154 * @param initialCapacity the initial capacity of the vector 155 * @throws IllegalArgumentException if the specified initial capacity 156 * is negative 157 */ 158 public Vector(int initialCapacity) { 159 this(initialCapacity, 0); 160 } 161 162 /** 163 * Constructs an empty vector so that its internal data array 164 * has size {@code 10} and its standard capacity increment is 165 * zero. 166 */ 167 public Vector() { 168 this(10); 169 } 170 171 /** 172 * Constructs a vector containing the elements of the specified 173 * collection, in the order they are returned by the collection's 174 * iterator. 175 * 176 * @param c the collection whose elements are to be placed into this 177 * vector 178 * @throws NullPointerException if the specified collection is null 179 * @since 1.2 180 */ 181 public Vector(Collection<? extends E> c) { 182 elementData = c.toArray(); 183 elementCount = elementData.length; 184 // defend against c.toArray (incorrectly) not returning Object[] 185 // (see e.g. https://bugs.openjdk.java.net/browse/JDK-6260652) 186 if (elementData.getClass() != Object[].class) 187 elementData = Arrays.copyOf(elementData, elementCount, Object[].class); 188 } 189 190 /** 191 * Copies the components of this vector into the specified array. 192 * The item at index {@code k} in this vector is copied into 193 * component {@code k} of {@code anArray}. 194 * 195 * @param anArray the array into which the components get copied 196 * @throws NullPointerException if the given array is null 197 * @throws IndexOutOfBoundsException if the specified array is not 198 * large enough to hold all the components of this vector 199 * @throws ArrayStoreException if a component of this vector is not of 200 * a runtime type that can be stored in the specified array 201 * @see #toArray(Object[]) 202 */ 203 public synchronized void copyInto(Object[] anArray) { 204 System.arraycopy(elementData, 0, anArray, 0, elementCount); 205 } 206 207 /** 208 * Trims the capacity of this vector to be the vector's current 209 * size. If the capacity of this vector is larger than its current 210 * size, then the capacity is changed to equal the size by replacing 211 * its internal data array, kept in the field {@code elementData}, 212 * with a smaller one. An application can use this operation to 213 * minimize the storage of a vector. 214 */ 215 public synchronized void trimToSize() { 216 modCount++; 217 int oldCapacity = elementData.length; 218 if (elementCount < oldCapacity) { 219 elementData = Arrays.copyOf(elementData, elementCount); 220 } 221 } 222 223 /** 224 * Increases the capacity of this vector, if necessary, to ensure 225 * that it can hold at least the number of components specified by 226 * the minimum capacity argument. 227 * 228 * <p>If the current capacity of this vector is less than 229 * {@code minCapacity}, then its capacity is increased by replacing its 230 * internal data array, kept in the field {@code elementData}, with a 231 * larger one. The size of the new data array will be the old size plus 232 * {@code capacityIncrement}, unless the value of 233 * {@code capacityIncrement} is less than or equal to zero, in which case 234 * the new capacity will be twice the old capacity; but if this new size 235 * is still smaller than {@code minCapacity}, then the new capacity will 236 * be {@code minCapacity}. 237 * 238 * @param minCapacity the desired minimum capacity 239 */ 240 public synchronized void ensureCapacity(int minCapacity) { 241 if (minCapacity > 0) { 242 modCount++; 243 if (minCapacity > elementData.length) 244 grow(minCapacity); 245 } 246 } 247 248 /** 249 * Increases the capacity to ensure that it can hold at least the 250 * number of elements specified by the minimum capacity argument. 251 * 252 * @param minCapacity the desired minimum capacity 253 * @throws OutOfMemoryError if minCapacity is less than zero 254 */ 255 private Object[] grow(int minCapacity) { 256 int oldCapacity = elementData.length; 257 int newCapacity = ArraysSupport.newLength(oldCapacity, 258 minCapacity - oldCapacity, /* minimum growth */ 259 capacityIncrement > 0 ? capacityIncrement : oldCapacity 260 /* preferred growth */); 261 return elementData = Arrays.copyOf(elementData, newCapacity); 262 } 263 264 private Object[] grow() { 265 return grow(elementCount + 1); 266 } 267 268 /** 269 * Sets the size of this vector. If the new size is greater than the 270 * current size, new {@code null} items are added to the end of 271 * the vector. If the new size is less than the current size, all 272 * components at index {@code newSize} and greater are discarded. 273 * 274 * @param newSize the new size of this vector 275 * @throws ArrayIndexOutOfBoundsException if the new size is negative 276 */ 277 public synchronized void setSize(int newSize) { 278 modCount++; 279 if (newSize > elementData.length) 280 grow(newSize); 281 final Object[] es = elementData; 282 for (int to = elementCount, i = newSize; i < to; i++) 283 es[i] = null; 284 elementCount = newSize; 285 } 286 287 /** 288 * Returns the current capacity of this vector. 289 * 290 * @return the current capacity (the length of its internal 291 * data array, kept in the field {@code elementData} 292 * of this vector) 293 */ 294 public synchronized int capacity() { 295 return elementData.length; 296 } 297 298 /** 299 * Returns the number of components in this vector. 300 * 301 * @return the number of components in this vector 302 */ 303 public synchronized int size() { 304 return elementCount; 305 } 306 307 /** 308 * Tests if this vector has no components. 309 * 310 * @return {@code true} if and only if this vector has 311 * no components, that is, its size is zero; 312 * {@code false} otherwise. 313 */ 314 public synchronized boolean isEmpty() { 315 return elementCount == 0; 316 } 317 318 /** 319 * Returns an enumeration of the components of this vector. The 320 * returned {@code Enumeration} object will generate all items in 321 * this vector. The first item generated is the item at index {@code 0}, 322 * then the item at index {@code 1}, and so on. If the vector is 323 * structurally modified while enumerating over the elements then the 324 * results of enumerating are undefined. 325 * 326 * @return an enumeration of the components of this vector 327 * @see Iterator 328 */ 329 public Enumeration<E> elements() { 330 return new Enumeration<E>() { 331 int count = 0; 332 333 public boolean hasMoreElements() { 334 return count < elementCount; 335 } 336 337 public E nextElement() { 338 synchronized (Vector.this) { 339 if (count < elementCount) { 340 return elementData(count++); 341 } 342 } 343 throw new NoSuchElementException("Vector Enumeration"); 344 } 345 }; 346 } 347 348 /** 349 * Returns {@code true} if this vector contains the specified element. 350 * More formally, returns {@code true} if and only if this vector 351 * contains at least one element {@code e} such that 352 * {@code Objects.equals(o, e)}. 353 * 354 * @param o element whose presence in this vector is to be tested 355 * @return {@code true} if this vector contains the specified element 356 */ 357 public boolean contains(Object o) { 358 return indexOf(o, 0) >= 0; 359 } 360 361 /** 362 * Returns the index of the first occurrence of the specified element 363 * in this vector, or -1 if this vector does not contain the element. 364 * More formally, returns the lowest index {@code i} such that 365 * {@code Objects.equals(o, get(i))}, 366 * or -1 if there is no such index. 367 * 368 * @param o element to search for 369 * @return the index of the first occurrence of the specified element in 370 * this vector, or -1 if this vector does not contain the element 371 */ 372 public int indexOf(Object o) { 373 return indexOf(o, 0); 374 } 375 376 /** 377 * Returns the index of the first occurrence of the specified element in 378 * this vector, searching forwards from {@code index}, or returns -1 if 379 * the element is not found. 380 * More formally, returns the lowest index {@code i} such that 381 * {@code (i >= index && Objects.equals(o, get(i)))}, 382 * or -1 if there is no such index. 383 * 384 * @param o element to search for 385 * @param index index to start searching from 386 * @return the index of the first occurrence of the element in 387 * this vector at position {@code index} or later in the vector; 388 * {@code -1} if the element is not found. 389 * @throws IndexOutOfBoundsException if the specified index is negative 390 * @see Object#equals(Object) 391 */ 392 public synchronized int indexOf(Object o, int index) { 393 if (o == null) { 394 for (int i = index ; i < elementCount ; i++) 395 if (elementData[i]==null) 396 return i; 397 } else { 398 for (int i = index ; i < elementCount ; i++) 399 if (o.equals(elementData[i])) 400 return i; 401 } 402 return -1; 403 } 404 405 /** 406 * Returns the index of the last occurrence of the specified element 407 * in this vector, or -1 if this vector does not contain the element. 408 * More formally, returns the highest index {@code i} such that 409 * {@code Objects.equals(o, get(i))}, 410 * or -1 if there is no such index. 411 * 412 * @param o element to search for 413 * @return the index of the last occurrence of the specified element in 414 * this vector, or -1 if this vector does not contain the element 415 */ 416 public synchronized int lastIndexOf(Object o) { 417 return lastIndexOf(o, elementCount-1); 418 } 419 420 /** 421 * Returns the index of the last occurrence of the specified element in 422 * this vector, searching backwards from {@code index}, or returns -1 if 423 * the element is not found. 424 * More formally, returns the highest index {@code i} such that 425 * {@code (i <= index && Objects.equals(o, get(i)))}, 426 * or -1 if there is no such index. 427 * 428 * @param o element to search for 429 * @param index index to start searching backwards from 430 * @return the index of the last occurrence of the element at position 431 * less than or equal to {@code index} in this vector; 432 * -1 if the element is not found. 433 * @throws IndexOutOfBoundsException if the specified index is greater 434 * than or equal to the current size of this vector 435 */ 436 public synchronized int lastIndexOf(Object o, int index) { 437 if (index >= elementCount) 438 throw new IndexOutOfBoundsException(index + " >= "+ elementCount); 439 440 if (o == null) { 441 for (int i = index; i >= 0; i--) 442 if (elementData[i]==null) 443 return i; 444 } else { 445 for (int i = index; i >= 0; i--) 446 if (o.equals(elementData[i])) 447 return i; 448 } 449 return -1; 450 } 451 452 /** 453 * Returns the component at the specified index. 454 * 455 * <p>This method is identical in functionality to the {@link #get(int)} 456 * method (which is part of the {@link List} interface). 457 * 458 * @param index an index into this vector 459 * @return the component at the specified index 460 * @throws ArrayIndexOutOfBoundsException if the index is out of range 461 * ({@code index < 0 || index >= size()}) 462 */ 463 public synchronized E elementAt(int index) { 464 if (index >= elementCount) { 465 throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount); 466 } 467 468 return elementData(index); 469 } 470 471 /** 472 * Returns the first component (the item at index {@code 0}) of 473 * this vector. 474 * 475 * @return the first component of this vector 476 * @throws NoSuchElementException if this vector has no components 477 */ 478 public synchronized E firstElement() { 479 if (elementCount == 0) { 480 throw new NoSuchElementException(); 481 } 482 return elementData(0); 483 } 484 485 /** 486 * Returns the last component of the vector. 487 * 488 * @return the last component of the vector, i.e., the component at index 489 * {@code size() - 1} 490 * @throws NoSuchElementException if this vector is empty 491 */ 492 public synchronized E lastElement() { 493 if (elementCount == 0) { 494 throw new NoSuchElementException(); 495 } 496 return elementData(elementCount - 1); 497 } 498 499 /** 500 * Sets the component at the specified {@code index} of this 501 * vector to be the specified object. The previous component at that 502 * position is discarded. 503 * 504 * <p>The index must be a value greater than or equal to {@code 0} 505 * and less than the current size of the vector. 506 * 507 * <p>This method is identical in functionality to the 508 * {@link #set(int, Object) set(int, E)} 509 * method (which is part of the {@link List} interface). Note that the 510 * {@code set} method reverses the order of the parameters, to more closely 511 * match array usage. Note also that the {@code set} method returns the 512 * old value that was stored at the specified position. 513 * 514 * @param obj what the component is to be set to 515 * @param index the specified index 516 * @throws ArrayIndexOutOfBoundsException if the index is out of range 517 * ({@code index < 0 || index >= size()}) 518 */ 519 public synchronized void setElementAt(E obj, int index) { 520 if (index >= elementCount) { 521 throw new ArrayIndexOutOfBoundsException(index + " >= " + 522 elementCount); 523 } 524 elementData[index] = obj; 525 } 526 527 /** 528 * Deletes the component at the specified index. Each component in 529 * this vector with an index greater or equal to the specified 530 * {@code index} is shifted downward to have an index one 531 * smaller than the value it had previously. The size of this vector 532 * is decreased by {@code 1}. 533 * 534 * <p>The index must be a value greater than or equal to {@code 0} 535 * and less than the current size of the vector. 536 * 537 * <p>This method is identical in functionality to the {@link #remove(int)} 538 * method (which is part of the {@link List} interface). Note that the 539 * {@code remove} method returns the old value that was stored at the 540 * specified position. 541 * 542 * @param index the index of the object to remove 543 * @throws ArrayIndexOutOfBoundsException if the index is out of range 544 * ({@code index < 0 || index >= size()}) 545 */ 546 public synchronized void removeElementAt(int index) { 547 if (index >= elementCount) { 548 throw new ArrayIndexOutOfBoundsException(index + " >= " + 549 elementCount); 550 } 551 else if (index < 0) { 552 throw new ArrayIndexOutOfBoundsException(index); 553 } 554 int j = elementCount - index - 1; 555 if (j > 0) { 556 System.arraycopy(elementData, index + 1, elementData, index, j); 557 } 558 modCount++; 559 elementCount--; 560 elementData[elementCount] = null; /* to let gc do its work */ 561 } 562 563 /** 564 * Inserts the specified object as a component in this vector at the 565 * specified {@code index}. Each component in this vector with 566 * an index greater or equal to the specified {@code index} is 567 * shifted upward to have an index one greater than the value it had 568 * previously. 569 * 570 * <p>The index must be a value greater than or equal to {@code 0} 571 * and less than or equal to the current size of the vector. (If the 572 * index is equal to the current size of the vector, the new element 573 * is appended to the Vector.) 574 * 575 * <p>This method is identical in functionality to the 576 * {@link #add(int, Object) add(int, E)} 577 * method (which is part of the {@link List} interface). Note that the 578 * {@code add} method reverses the order of the parameters, to more closely 579 * match array usage. 580 * 581 * @param obj the component to insert 582 * @param index where to insert the new component 583 * @throws ArrayIndexOutOfBoundsException if the index is out of range 584 * ({@code index < 0 || index > size()}) 585 */ 586 public synchronized void insertElementAt(E obj, int index) { 587 if (index > elementCount) { 588 throw new ArrayIndexOutOfBoundsException(index 589 + " > " + elementCount); 590 } 591 modCount++; 592 final int s = elementCount; 593 Object[] elementData = this.elementData; 594 if (s == elementData.length) 595 elementData = grow(); 596 System.arraycopy(elementData, index, 597 elementData, index + 1, 598 s - index); 599 elementData[index] = obj; 600 elementCount = s + 1; 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 add(obj, elementData, elementCount); 617 } 618 619 /** 620 * Removes the first (lowest-indexed) occurrence of the argument 621 * from this vector. If the object is found in this vector, each 622 * component in the vector with an index greater or equal to the 623 * object's index is shifted downward to have an index one smaller 624 * than the value it had previously. 625 * 626 * <p>This method is identical in functionality to the 627 * {@link #remove(Object)} method (which is part of the 628 * {@link List} interface). 629 * 630 * @param obj the component to be removed 631 * @return {@code true} if the argument was a component of this 632 * vector; {@code false} otherwise. 633 */ 634 public synchronized boolean removeElement(Object obj) { 635 modCount++; 636 int i = indexOf(obj); 637 if (i >= 0) { 638 removeElementAt(i); 639 return true; 640 } 641 return false; 642 } 643 644 /** 645 * Removes all components from this vector and sets its size to zero. 646 * 647 * <p>This method is identical in functionality to the {@link #clear} 648 * method (which is part of the {@link List} interface). 649 */ 650 public synchronized void removeAllElements() { 651 final Object[] es = elementData; 652 for (int to = elementCount, i = elementCount = 0; i < to; i++) 653 es[i] = null; 654 modCount++; 655 } 656 657 /** 658 * Returns a clone of this vector. The copy will contain a 659 * reference to a clone of the internal data array, not a reference 660 * to the original internal data array of this {@code Vector} object. 661 * 662 * @return a clone of this vector 663 */ 664 public synchronized Object clone() { 665 try { 666 @SuppressWarnings("unchecked") 667 Vector<E> v = (Vector<E>) super.clone(); 668 v.elementData = Arrays.copyOf(elementData, elementCount); 669 v.modCount = 0; 670 return v; 671 } catch (CloneNotSupportedException e) { 672 // this shouldn't happen, since we are Cloneable 673 throw new InternalError(e); 674 } 675 } 676 677 /** 678 * Returns an array containing all of the elements in this Vector 679 * in the correct order. 680 * 681 * @since 1.2 682 */ 683 public synchronized Object[] toArray() { 684 return Arrays.copyOf(elementData, elementCount); 685 } 686 687 /** 688 * Returns an array containing all of the elements in this Vector in the 689 * correct order; the runtime type of the returned array is that of the 690 * specified array. If the Vector fits in the specified array, it is 691 * returned therein. Otherwise, a new array is allocated with the runtime 692 * type of the specified array and the size of this Vector. 693 * 694 * <p>If the Vector fits in the specified array with room to spare 695 * (i.e., the array has more elements than the Vector), 696 * the element in the array immediately following the end of the 697 * Vector is set to null. (This is useful in determining the length 698 * of the Vector <em>only</em> if the caller knows that the Vector 699 * does not contain any null elements.) 700 * 701 * @param <T> type of array elements. The same type as {@code <E>} or a 702 * supertype of {@code <E>}. 703 * @param a the array into which the elements of the Vector are to 704 * be stored, if it is big enough; otherwise, a new array of the 705 * same runtime type is allocated for this purpose. 706 * @return an array containing the elements of the Vector 707 * @throws ArrayStoreException if the runtime type of a, {@code <T>}, is not 708 * a supertype of the runtime type, {@code <E>}, of every element in this 709 * 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 @SuppressWarnings("unchecked") 734 static <E> E elementAt(Object[] es, int index) { 735 return (E) es[index]; 736 } 737 738 /** 739 * Returns the element at the specified position in this Vector. 740 * 741 * @param index index of the element to return 742 * @return object at the specified index 743 * @throws ArrayIndexOutOfBoundsException if the index is out of range 744 * ({@code index < 0 || index >= size()}) 745 * @since 1.2 746 */ 747 public synchronized E get(int index) { 748 if (index >= elementCount) 749 throw new ArrayIndexOutOfBoundsException(index); 750 751 return elementData(index); 752 } 753 754 /** 755 * Replaces the element at the specified position in this Vector with the 756 * specified element. 757 * 758 * @param index index of the element to replace 759 * @param element element to be stored at the specified position 760 * @return the element previously at the specified position 761 * @throws ArrayIndexOutOfBoundsException if the index is out of range 762 * ({@code index < 0 || index >= size()}) 763 * @since 1.2 764 */ 765 public synchronized E set(int index, E element) { 766 if (index >= elementCount) 767 throw new ArrayIndexOutOfBoundsException(index); 768 769 E oldValue = elementData(index); 770 elementData[index] = element; 771 return oldValue; 772 } 773 774 /** 775 * This helper method split out from add(E) to keep method 776 * bytecode size under 35 (the -XX:MaxInlineSize default value), 777 * which helps when add(E) is called in a C1-compiled loop. 778 */ 779 private void add(E e, Object[] elementData, int s) { 780 if (s == elementData.length) 781 elementData = grow(); 782 elementData[s] = e; 783 elementCount = s + 1; 784 } 785 786 /** 787 * Appends the specified element to the end of this Vector. 788 * 789 * @param e element to be appended to this Vector 790 * @return {@code true} (as specified by {@link Collection#add}) 791 * @since 1.2 792 */ 793 public synchronized boolean add(E e) { 794 modCount++; 795 add(e, elementData, elementCount); 796 return true; 797 } 798 799 /** 800 * Removes the first occurrence of the specified element in this Vector 801 * If the Vector does not contain the element, it is unchanged. More 802 * formally, removes the element with the lowest index i such that 803 * {@code Objects.equals(o, get(i))} (if such 804 * an element exists). 805 * 806 * @param o element to be removed from this Vector, if present 807 * @return true if the Vector contained the specified element 808 * @since 1.2 809 */ 810 public boolean remove(Object o) { 811 return removeElement(o); 812 } 813 814 /** 815 * Inserts the specified element at the specified position in this Vector. 816 * Shifts the element currently at that position (if any) and any 817 * subsequent elements to the right (adds one to their indices). 818 * 819 * @param index index at which the specified element is to be inserted 820 * @param element element to be inserted 821 * @throws ArrayIndexOutOfBoundsException if the index is out of range 822 * ({@code index < 0 || index > size()}) 823 * @since 1.2 824 */ 825 public void add(int index, E element) { 826 insertElementAt(element, index); 827 } 828 829 /** 830 * Removes the element at the specified position in this Vector. 831 * Shifts any subsequent elements to the left (subtracts one from their 832 * indices). Returns the element that was removed from the Vector. 833 * 834 * @param index the index of the element to be removed 835 * @return element that was removed 836 * @throws ArrayIndexOutOfBoundsException if the index is out of range 837 * ({@code index < 0 || index >= size()}) 838 * @since 1.2 839 */ 840 public synchronized E remove(int index) { 841 modCount++; 842 if (index >= elementCount) 843 throw new ArrayIndexOutOfBoundsException(index); 844 E oldValue = elementData(index); 845 846 int numMoved = elementCount - index - 1; 847 if (numMoved > 0) 848 System.arraycopy(elementData, index+1, elementData, index, 849 numMoved); 850 elementData[--elementCount] = null; // Let gc do its work 851 852 return oldValue; 853 } 854 855 /** 856 * Removes all of the elements from this Vector. The Vector will 857 * be empty after this call returns (unless it throws an exception). 858 * 859 * @since 1.2 860 */ 861 public void clear() { 862 removeAllElements(); 863 } 864 865 // Bulk Operations 866 867 /** 868 * Returns true if this Vector contains all of the elements in the 869 * specified Collection. 870 * 871 * @param c a collection whose elements will be tested for containment 872 * in this Vector 873 * @return true if this Vector contains all of the elements in the 874 * specified collection 875 * @throws NullPointerException if the specified collection is null 876 */ 877 public synchronized boolean containsAll(Collection<?> c) { 878 return super.containsAll(c); 879 } 880 881 /** 882 * Appends all of the elements in the specified Collection to the end of 883 * this Vector, in the order that they are returned by the specified 884 * Collection's Iterator. The behavior of this operation is undefined if 885 * the specified Collection is modified while the operation is in progress. 886 * (This implies that the behavior of this call is undefined if the 887 * specified Collection is this Vector, and this Vector is nonempty.) 888 * 889 * @param c elements to be inserted into this Vector 890 * @return {@code true} if this Vector changed as a result of the call 891 * @throws NullPointerException if the specified collection is null 892 * @since 1.2 893 */ 894 public boolean addAll(Collection<? extends E> c) { 895 Object[] a = c.toArray(); 896 modCount++; 897 int numNew = a.length; 898 if (numNew == 0) 899 return false; 900 synchronized (this) { 901 Object[] elementData = this.elementData; 902 final int s = elementCount; 903 if (numNew > elementData.length - s) 904 elementData = grow(s + numNew); 905 System.arraycopy(a, 0, elementData, s, numNew); 906 elementCount = s + numNew; 907 return true; 908 } 909 } 910 911 /** 912 * Removes from this Vector all of its elements that are contained in the 913 * specified Collection. 914 * 915 * @param c a collection of elements to be removed from the Vector 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 boolean removeAll(Collection<?> c) { 929 Objects.requireNonNull(c); 930 return bulkRemove(e -> c.contains(e)); 931 } 932 933 /** 934 * Retains only the elements in this Vector that are contained in the 935 * specified Collection. In other words, removes from this Vector all 936 * of its elements that are not contained in the specified Collection. 937 * 938 * @param c a collection of elements to be retained in this Vector 939 * (all other elements are removed) 940 * @return true if this Vector changed as a result of the call 941 * @throws ClassCastException if the types of one or more elements 942 * in this vector are incompatible with the specified 943 * collection 944 * (<a href="Collection.html#optional-restrictions">optional</a>) 945 * @throws NullPointerException if this vector contains one or more null 946 * elements and the specified collection does not support null 947 * elements 948 * (<a href="Collection.html#optional-restrictions">optional</a>), 949 * or if the specified collection is null 950 * @since 1.2 951 */ 952 public boolean retainAll(Collection<?> c) { 953 Objects.requireNonNull(c); 954 return bulkRemove(e -> !c.contains(e)); 955 } 956 957 /** 958 * @throws NullPointerException {@inheritDoc} 959 */ 960 @Override 961 public boolean removeIf(Predicate<? super E> filter) { 962 Objects.requireNonNull(filter); 963 return bulkRemove(filter); 964 } 965 966 // A tiny bit set implementation 967 968 private static long[] nBits(int n) { 969 return new long[((n - 1) >> 6) + 1]; 970 } 971 private static void setBit(long[] bits, int i) { 972 bits[i >> 6] |= 1L << i; 973 } 974 private static boolean isClear(long[] bits, int i) { 975 return (bits[i >> 6] & (1L << i)) == 0; 976 } 977 978 private synchronized boolean bulkRemove(Predicate<? super E> filter) { 979 int expectedModCount = modCount; 980 final Object[] es = elementData; 981 final int end = elementCount; 982 int i; 983 // Optimize for initial run of survivors 984 for (i = 0; i < end && !filter.test(elementAt(es, i)); i++) 985 ; 986 // Tolerate predicates that reentrantly access the collection for 987 // read (but writers still get CME), so traverse once to find 988 // elements to delete, a second pass to physically expunge. 989 if (i < end) { 990 final int beg = i; 991 final long[] deathRow = nBits(end - beg); 992 deathRow[0] = 1L; // set bit 0 993 for (i = beg + 1; i < end; i++) 994 if (filter.test(elementAt(es, i))) 995 setBit(deathRow, i - beg); 996 if (modCount != expectedModCount) 997 throw new ConcurrentModificationException(); 998 modCount++; 999 int w = beg; 1000 for (i = beg; i < end; i++) 1001 if (isClear(deathRow, i - beg)) 1002 es[w++] = es[i]; 1003 for (i = elementCount = w; i < end; i++) 1004 es[i] = null; 1005 return true; 1006 } else { 1007 if (modCount != expectedModCount) 1008 throw new ConcurrentModificationException(); 1009 return false; 1010 } 1011 } 1012 1013 /** 1014 * Inserts all of the elements in the specified Collection into this 1015 * Vector at the specified position. Shifts the element currently at 1016 * that position (if any) and any subsequent elements to the right 1017 * (increases their indices). The new elements will appear in the Vector 1018 * in the order that they are returned by the specified Collection's 1019 * iterator. 1020 * 1021 * @param index index at which to insert the first element from the 1022 * specified collection 1023 * @param c elements to be inserted into this Vector 1024 * @return {@code true} if this Vector changed as a result of the call 1025 * @throws ArrayIndexOutOfBoundsException if the index is out of range 1026 * ({@code index < 0 || index > size()}) 1027 * @throws NullPointerException if the specified collection is null 1028 * @since 1.2 1029 */ 1030 public synchronized boolean addAll(int index, Collection<? extends E> c) { 1031 if (index < 0 || index > elementCount) 1032 throw new ArrayIndexOutOfBoundsException(index); 1033 1034 Object[] a = c.toArray(); 1035 modCount++; 1036 int numNew = a.length; 1037 if (numNew == 0) 1038 return false; 1039 Object[] elementData = this.elementData; 1040 final int s = elementCount; 1041 if (numNew > elementData.length - s) 1042 elementData = grow(s + numNew); 1043 1044 int numMoved = s - index; 1045 if (numMoved > 0) 1046 System.arraycopy(elementData, index, 1047 elementData, index + numNew, 1048 numMoved); 1049 System.arraycopy(a, 0, elementData, index, numNew); 1050 elementCount = s + numNew; 1051 return true; 1052 } 1053 1054 /** 1055 * Compares the specified Object with this Vector for equality. Returns 1056 * true if and only if the specified Object is also a List, both Lists 1057 * have the same size, and all corresponding pairs of elements in the two 1058 * Lists are <em>equal</em>. (Two elements {@code e1} and 1059 * {@code e2} are <em>equal</em> if {@code Objects.equals(e1, e2)}.) 1060 * In other words, two Lists are defined to be 1061 * equal if they contain the same elements in the same order. 1062 * 1063 * @param o the Object to be compared for equality with this Vector 1064 * @return true if the specified Object is equal to this Vector 1065 */ 1066 public synchronized boolean equals(Object o) { 1067 return super.equals(o); 1068 } 1069 1070 /** 1071 * Returns the hash code value for this Vector. 1072 */ 1073 public synchronized int hashCode() { 1074 return super.hashCode(); 1075 } 1076 1077 /** 1078 * Returns a string representation of this Vector, containing 1079 * the String representation of each element. 1080 */ 1081 public synchronized String toString() { 1082 return super.toString(); 1083 } 1084 1085 /** 1086 * Returns a view of the portion of this List between fromIndex, 1087 * inclusive, and toIndex, exclusive. (If fromIndex and toIndex are 1088 * equal, the returned List is empty.) The returned List is backed by this 1089 * List, so changes in the returned List are reflected in this List, and 1090 * vice-versa. The returned List supports all of the optional List 1091 * operations supported by this List. 1092 * 1093 * <p>This method eliminates the need for explicit range operations (of 1094 * the sort that commonly exist for arrays). Any operation that expects 1095 * a List can be used as a range operation by operating on a subList view 1096 * instead of a whole List. For example, the following idiom 1097 * removes a range of elements from a List: 1098 * <pre> 1099 * list.subList(from, to).clear(); 1100 * </pre> 1101 * Similar idioms may be constructed for indexOf and lastIndexOf, 1102 * and all of the algorithms in the Collections class can be applied to 1103 * a subList. 1104 * 1105 * <p>The semantics of the List returned by this method become undefined if 1106 * the backing list (i.e., this List) is <i>structurally modified</i> in 1107 * any way other than via the returned List. (Structural modifications are 1108 * those that change the size of the List, or otherwise perturb it in such 1109 * a fashion that iterations in progress may yield incorrect results.) 1110 * 1111 * @param fromIndex low endpoint (inclusive) of the subList 1112 * @param toIndex high endpoint (exclusive) of the subList 1113 * @return a view of the specified range within this List 1114 * @throws IndexOutOfBoundsException if an endpoint index value is out of range 1115 * {@code (fromIndex < 0 || toIndex > size)} 1116 * @throws IllegalArgumentException if the endpoint indices are out of order 1117 * {@code (fromIndex > toIndex)} 1118 */ 1119 public synchronized List<E> subList(int fromIndex, int toIndex) { 1120 return Collections.synchronizedList(super.subList(fromIndex, toIndex), 1121 this); 1122 } 1123 1124 /** 1125 * Removes from this list all of the elements whose index is between 1126 * {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. 1127 * Shifts any succeeding elements to the left (reduces their index). 1128 * This call shortens the list by {@code (toIndex - fromIndex)} elements. 1129 * (If {@code toIndex==fromIndex}, this operation has no effect.) 1130 */ 1131 protected synchronized void removeRange(int fromIndex, int toIndex) { 1132 modCount++; 1133 shiftTailOverGap(elementData, fromIndex, toIndex); 1134 } 1135 1136 /** Erases the gap from lo to hi, by sliding down following elements. */ 1137 private void shiftTailOverGap(Object[] es, int lo, int hi) { 1138 System.arraycopy(es, hi, es, lo, elementCount - hi); 1139 for (int to = elementCount, i = (elementCount -= hi - lo); i < to; i++) 1140 es[i] = null; 1141 } 1142 1143 /** 1144 * Loads a {@code Vector} instance from a stream 1145 * (that is, deserializes it). 1146 * This method performs checks to ensure the consistency 1147 * of the fields. 1148 * 1149 * @param in the stream 1150 * @throws java.io.IOException if an I/O error occurs 1151 * @throws ClassNotFoundException if the stream contains data 1152 * of a non-existing class 1153 */ 1154 @java.io.Serial 1155 private void readObject(ObjectInputStream in) 1156 throws IOException, ClassNotFoundException { 1157 ObjectInputStream.GetField gfields = in.readFields(); 1158 int count = gfields.get("elementCount", 0); 1159 Object[] data = (Object[])gfields.get("elementData", null); 1160 if (count < 0 || data == null || count > data.length) { 1161 throw new StreamCorruptedException("Inconsistent vector internals"); 1162 } 1163 elementCount = count; 1164 elementData = data.clone(); 1165 } 1166 1167 /** 1168 * Saves the state of the {@code Vector} instance to a stream 1169 * (that is, serializes it). 1170 * This method performs synchronization to ensure the consistency 1171 * of the serialized data. 1172 * 1173 * @param s the stream 1174 * @throws java.io.IOException if an I/O error occurs 1175 */ 1176 @java.io.Serial 1177 private void writeObject(java.io.ObjectOutputStream s) 1178 throws java.io.IOException { 1179 final java.io.ObjectOutputStream.PutField fields = s.putFields(); 1180 final Object[] data; 1181 synchronized (this) { 1182 fields.put("capacityIncrement", capacityIncrement); 1183 fields.put("elementCount", elementCount); 1184 data = elementData.clone(); 1185 } 1186 fields.put("elementData", data); 1187 s.writeFields(); 1188 } 1189 1190 /** 1191 * Returns a list iterator over the elements in this list (in proper 1192 * sequence), starting at the specified position in the list. 1193 * The specified index indicates the first element that would be 1194 * returned by an initial call to {@link ListIterator#next next}. 1195 * An initial call to {@link ListIterator#previous previous} would 1196 * return the element with the specified index minus one. 1197 * 1198 * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. 1199 * 1200 * @throws IndexOutOfBoundsException {@inheritDoc} 1201 */ 1202 public synchronized ListIterator<E> listIterator(int index) { 1203 if (index < 0 || index > elementCount) 1204 throw new IndexOutOfBoundsException("Index: "+index); 1205 return new ListItr(index); 1206 } 1207 1208 /** 1209 * Returns a list iterator over the elements in this list (in proper 1210 * sequence). 1211 * 1212 * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. 1213 * 1214 * @see #listIterator(int) 1215 */ 1216 public synchronized ListIterator<E> listIterator() { 1217 return new ListItr(0); 1218 } 1219 1220 /** 1221 * Returns an iterator over the elements in this list in proper sequence. 1222 * 1223 * <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>. 1224 * 1225 * @return an iterator over the elements in this list in proper sequence 1226 */ 1227 public synchronized Iterator<E> iterator() { 1228 return new Itr(); 1229 } 1230 1231 /** 1232 * An optimized version of AbstractList.Itr 1233 */ 1234 private class Itr implements Iterator<E> { 1235 int cursor; // index of next element to return 1236 int lastRet = -1; // index of last element returned; -1 if no such 1237 int expectedModCount = modCount; 1238 1239 public boolean hasNext() { 1240 // Racy but within spec, since modifications are checked 1241 // within or after synchronization in next/previous 1242 return cursor != elementCount; 1243 } 1244 1245 public E next() { 1246 synchronized (Vector.this) { 1247 checkForComodification(); 1248 int i = cursor; 1249 if (i >= elementCount) 1250 throw new NoSuchElementException(); 1251 cursor = i + 1; 1252 return elementData(lastRet = i); 1253 } 1254 } 1255 1256 public void remove() { 1257 if (lastRet == -1) 1258 throw new IllegalStateException(); 1259 synchronized (Vector.this) { 1260 checkForComodification(); 1261 Vector.this.remove(lastRet); 1262 expectedModCount = modCount; 1263 } 1264 cursor = lastRet; 1265 lastRet = -1; 1266 } 1267 1268 @Override 1269 public void forEachRemaining(Consumer<? super E> action) { 1270 Objects.requireNonNull(action); 1271 synchronized (Vector.this) { 1272 final int size = elementCount; 1273 int i = cursor; 1274 if (i >= size) { 1275 return; 1276 } 1277 final Object[] es = elementData; 1278 if (i >= es.length) 1279 throw new ConcurrentModificationException(); 1280 while (i < size && modCount == expectedModCount) 1281 action.accept(elementAt(es, i++)); 1282 // update once at end of iteration to reduce heap write traffic 1283 cursor = i; 1284 lastRet = i - 1; 1285 checkForComodification(); 1286 } 1287 } 1288 1289 final void checkForComodification() { 1290 if (modCount != expectedModCount) 1291 throw new ConcurrentModificationException(); 1292 } 1293 } 1294 1295 /** 1296 * An optimized version of AbstractList.ListItr 1297 */ 1298 final class ListItr extends Itr implements ListIterator<E> { 1299 ListItr(int index) { 1300 super(); 1301 cursor = index; 1302 } 1303 1304 public boolean hasPrevious() { 1305 return cursor != 0; 1306 } 1307 1308 public int nextIndex() { 1309 return cursor; 1310 } 1311 1312 public int previousIndex() { 1313 return cursor - 1; 1314 } 1315 1316 public E previous() { 1317 synchronized (Vector.this) { 1318 checkForComodification(); 1319 int i = cursor - 1; 1320 if (i < 0) 1321 throw new NoSuchElementException(); 1322 cursor = i; 1323 return elementData(lastRet = i); 1324 } 1325 } 1326 1327 public void set(E e) { 1328 if (lastRet == -1) 1329 throw new IllegalStateException(); 1330 synchronized (Vector.this) { 1331 checkForComodification(); 1332 Vector.this.set(lastRet, e); 1333 } 1334 } 1335 1336 public void add(E e) { 1337 int i = cursor; 1338 synchronized (Vector.this) { 1339 checkForComodification(); 1340 Vector.this.add(i, e); 1341 expectedModCount = modCount; 1342 } 1343 cursor = i + 1; 1344 lastRet = -1; 1345 } 1346 } 1347 1348 /** 1349 * @throws NullPointerException {@inheritDoc} 1350 */ 1351 @Override 1352 public synchronized void forEach(Consumer<? super E> action) { 1353 Objects.requireNonNull(action); 1354 final int expectedModCount = modCount; 1355 final Object[] es = elementData; 1356 final int size = elementCount; 1357 for (int i = 0; modCount == expectedModCount && i < size; i++) 1358 action.accept(elementAt(es, i)); 1359 if (modCount != expectedModCount) 1360 throw new ConcurrentModificationException(); 1361 } 1362 1363 /** 1364 * @throws NullPointerException {@inheritDoc} 1365 */ 1366 @Override 1367 public synchronized void replaceAll(UnaryOperator<E> operator) { 1368 Objects.requireNonNull(operator); 1369 final int expectedModCount = modCount; 1370 final Object[] es = elementData; 1371 final int size = elementCount; 1372 for (int i = 0; modCount == expectedModCount && i < size; i++) 1373 es[i] = operator.apply(elementAt(es, i)); 1374 if (modCount != expectedModCount) 1375 throw new ConcurrentModificationException(); 1376 // TODO(8203662): remove increment of modCount from ... 1377 modCount++; 1378 } 1379 1380 @SuppressWarnings("unchecked") 1381 @Override 1382 public synchronized void sort(Comparator<? super E> c) { 1383 final int expectedModCount = modCount; 1384 Arrays.sort((E[]) elementData, 0, elementCount, c); 1385 if (modCount != expectedModCount) 1386 throw new ConcurrentModificationException(); 1387 modCount++; 1388 } 1389 1390 /** 1391 * Creates a <em><a href="Spliterator.html#binding">late-binding</a></em> 1392 * and <em>fail-fast</em> {@link Spliterator} over the elements in this 1393 * list. 1394 * 1395 * <p>The {@code Spliterator} reports {@link Spliterator#SIZED}, 1396 * {@link Spliterator#SUBSIZED}, and {@link Spliterator#ORDERED}. 1397 * Overriding implementations should document the reporting of additional 1398 * characteristic values. 1399 * 1400 * @return a {@code Spliterator} over the elements in this list 1401 * @since 1.8 1402 */ 1403 @Override 1404 public Spliterator<E> spliterator() { 1405 return new VectorSpliterator(null, 0, -1, 0); 1406 } 1407 1408 /** Similar to ArrayList Spliterator */ 1409 final class VectorSpliterator implements Spliterator<E> { 1410 private Object[] array; 1411 private int index; // current index, modified on advance/split 1412 private int fence; // -1 until used; then one past last index 1413 private int expectedModCount; // initialized when fence set 1414 1415 /** Creates new spliterator covering the given range. */ 1416 VectorSpliterator(Object[] array, int origin, int fence, 1417 int expectedModCount) { 1418 this.array = array; 1419 this.index = origin; 1420 this.fence = fence; 1421 this.expectedModCount = expectedModCount; 1422 } 1423 1424 private int getFence() { // initialize on first use 1425 int hi; 1426 if ((hi = fence) < 0) { 1427 synchronized (Vector.this) { 1428 array = elementData; 1429 expectedModCount = modCount; 1430 hi = fence = elementCount; 1431 } 1432 } 1433 return hi; 1434 } 1435 1436 public Spliterator<E> trySplit() { 1437 int hi = getFence(), lo = index, mid = (lo + hi) >>> 1; 1438 return (lo >= mid) ? null : 1439 new VectorSpliterator(array, lo, index = mid, expectedModCount); 1440 } 1441 1442 @SuppressWarnings("unchecked") 1443 public boolean tryAdvance(Consumer<? super E> action) { 1444 Objects.requireNonNull(action); 1445 int i; 1446 if (getFence() > (i = index)) { 1447 index = i + 1; 1448 action.accept((E)array[i]); 1449 if (modCount != expectedModCount) 1450 throw new ConcurrentModificationException(); 1451 return true; 1452 } 1453 return false; 1454 } 1455 1456 @SuppressWarnings("unchecked") 1457 public void forEachRemaining(Consumer<? super E> action) { 1458 Objects.requireNonNull(action); 1459 final int hi = getFence(); 1460 final Object[] a = array; 1461 int i; 1462 for (i = index, index = hi; i < hi; i++) 1463 action.accept((E) a[i]); 1464 if (modCount != expectedModCount) 1465 throw new ConcurrentModificationException(); 1466 } 1467 1468 public long estimateSize() { 1469 return getFence() - index; 1470 } 1471 1472 public int characteristics() { 1473 return Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED; 1474 } 1475 } 1476 1477 void checkInvariants() { 1478 // assert elementCount >= 0; 1479 // assert elementCount == elementData.length || elementData[elementCount] == null; 1480 } 1481 }