| 14 |
|
* {@link Stack} when used as a stack, and faster than {@link LinkedList} |
| 15 |
|
* when used as a queue. |
| 16 |
|
* |
| 17 |
< |
* <p>Most <tt>ArrayDeque</tt> operations run in amortized constant time. |
| 18 |
< |
* Exceptions include {@link #remove(Object) remove}, {@link |
| 19 |
< |
* #removeFirstOccurrence removeFirstOccurrence}, {@link #removeLastOccurrence |
| 20 |
< |
* removeLastOccurrence}, {@link #contains contains}, {@link #iterator |
| 21 |
< |
* iterator.remove()}, and the bulk operations, all of which run in linear |
| 22 |
< |
* time. |
| 17 |
> |
* <p>Most {@code ArrayDeque} operations run in amortized constant time. |
| 18 |
> |
* Exceptions include |
| 19 |
> |
* {@link #remove(Object) remove}, |
| 20 |
> |
* {@link #removeFirstOccurrence removeFirstOccurrence}, |
| 21 |
> |
* {@link #removeLastOccurrence removeLastOccurrence}, |
| 22 |
> |
* {@link #contains contains}, |
| 23 |
> |
* {@link #iterator iterator.remove()}, |
| 24 |
> |
* and the bulk operations, all of which run in linear time. |
| 25 |
|
* |
| 26 |
< |
* <p>The iterators returned by this class's <tt>iterator</tt> method are |
| 27 |
< |
* <i>fail-fast</i>: If the deque is modified at any time after the iterator |
| 28 |
< |
* is created, in any way except through the iterator's own <tt>remove</tt> |
| 29 |
< |
* method, the iterator will generally throw a {@link |
| 26 |
> |
* <p>The iterators returned by this class's {@link #iterator() iterator} |
| 27 |
> |
* method are <em>fail-fast</em>: If the deque is modified at any time after |
| 28 |
> |
* the iterator is created, in any way except through the iterator's own |
| 29 |
> |
* {@code remove} method, the iterator will generally throw a {@link |
| 30 |
|
* ConcurrentModificationException}. Thus, in the face of concurrent |
| 31 |
|
* modification, the iterator fails quickly and cleanly, rather than risking |
| 32 |
|
* arbitrary, non-deterministic behavior at an undetermined time in the |
| 35 |
|
* <p>Note that the fail-fast behavior of an iterator cannot be guaranteed |
| 36 |
|
* as it is, generally speaking, impossible to make any hard guarantees in the |
| 37 |
|
* presence of unsynchronized concurrent modification. Fail-fast iterators |
| 38 |
< |
* throw <tt>ConcurrentModificationException</tt> on a best-effort basis. |
| 38 |
> |
* throw {@code ConcurrentModificationException} on a best-effort basis. |
| 39 |
|
* Therefore, it would be wrong to write a program that depended on this |
| 40 |
|
* exception for its correctness: <i>the fail-fast behavior of iterators |
| 41 |
|
* should be used only to detect bugs.</i> |
| 221 |
|
* Inserts the specified element at the front of this deque. |
| 222 |
|
* |
| 223 |
|
* @param e the element to add |
| 224 |
< |
* @return <tt>true</tt> (as specified by {@link Deque#offerFirst}) |
| 224 |
> |
* @return {@code true} (as specified by {@link Deque#offerFirst}) |
| 225 |
|
* @throws NullPointerException if the specified element is null |
| 226 |
|
*/ |
| 227 |
|
public boolean offerFirst(E e) { |
| 233 |
|
* Inserts the specified element at the end of this deque. |
| 234 |
|
* |
| 235 |
|
* @param e the element to add |
| 236 |
< |
* @return <tt>true</tt> (as specified by {@link Deque#offerLast}) |
| 236 |
> |
* @return {@code true} (as specified by {@link Deque#offerLast}) |
| 237 |
|
* @throws NullPointerException if the specified element is null |
| 238 |
|
*/ |
| 239 |
|
public boolean offerLast(E e) { |
| 321 |
|
* Removes the first occurrence of the specified element in this |
| 322 |
|
* deque (when traversing the deque from head to tail). |
| 323 |
|
* If the deque does not contain the element, it is unchanged. |
| 324 |
< |
* More formally, removes the first element <tt>e</tt> such that |
| 325 |
< |
* <tt>o.equals(e)</tt> (if such an element exists). |
| 326 |
< |
* Returns <tt>true</tt> if this deque contained the specified element |
| 324 |
> |
* More formally, removes the first element {@code e} such that |
| 325 |
> |
* {@code o.equals(e)} (if such an element exists). |
| 326 |
> |
* Returns {@code true} if this deque contained the specified element |
| 327 |
|
* (or equivalently, if this deque changed as a result of the call). |
| 328 |
|
* |
| 329 |
|
* @param o element to be removed from this deque, if present |
| 330 |
< |
* @return <tt>true</tt> if the deque contained the specified element |
| 330 |
> |
* @return {@code true} if the deque contained the specified element |
| 331 |
|
*/ |
| 332 |
|
public boolean removeFirstOccurrence(Object o) { |
| 333 |
|
if (o == null) |
| 349 |
|
* Removes the last occurrence of the specified element in this |
| 350 |
|
* deque (when traversing the deque from head to tail). |
| 351 |
|
* If the deque does not contain the element, it is unchanged. |
| 352 |
< |
* More formally, removes the last element <tt>e</tt> such that |
| 353 |
< |
* <tt>o.equals(e)</tt> (if such an element exists). |
| 354 |
< |
* Returns <tt>true</tt> if this deque contained the specified element |
| 352 |
> |
* More formally, removes the last element {@code e} such that |
| 353 |
> |
* {@code o.equals(e)} (if such an element exists). |
| 354 |
> |
* Returns {@code true} if this deque contained the specified element |
| 355 |
|
* (or equivalently, if this deque changed as a result of the call). |
| 356 |
|
* |
| 357 |
|
* @param o element to be removed from this deque, if present |
| 358 |
< |
* @return <tt>true</tt> if the deque contained the specified element |
| 358 |
> |
* @return {@code true} if the deque contained the specified element |
| 359 |
|
*/ |
| 360 |
|
public boolean removeLastOccurrence(Object o) { |
| 361 |
|
if (o == null) |
| 381 |
|
* <p>This method is equivalent to {@link #addLast}. |
| 382 |
|
* |
| 383 |
|
* @param e the element to add |
| 384 |
< |
* @return <tt>true</tt> (as specified by {@link Collection#add}) |
| 384 |
> |
* @return {@code true} (as specified by {@link Collection#add}) |
| 385 |
|
* @throws NullPointerException if the specified element is null |
| 386 |
|
*/ |
| 387 |
|
public boolean add(E e) { |
| 395 |
|
* <p>This method is equivalent to {@link #offerLast}. |
| 396 |
|
* |
| 397 |
|
* @param e the element to add |
| 398 |
< |
* @return <tt>true</tt> (as specified by {@link Queue#offer}) |
| 398 |
> |
* @return {@code true} (as specified by {@link Queue#offer}) |
| 399 |
|
* @throws NullPointerException if the specified element is null |
| 400 |
|
*/ |
| 401 |
|
public boolean offer(E e) { |
| 420 |
|
/** |
| 421 |
|
* Retrieves and removes the head of the queue represented by this deque |
| 422 |
|
* (in other words, the first element of this deque), or returns |
| 423 |
< |
* <tt>null</tt> if this deque is empty. |
| 423 |
> |
* {@code null} if this deque is empty. |
| 424 |
|
* |
| 425 |
|
* <p>This method is equivalent to {@link #pollFirst}. |
| 426 |
|
* |
| 427 |
|
* @return the head of the queue represented by this deque, or |
| 428 |
< |
* <tt>null</tt> if this deque is empty |
| 428 |
> |
* {@code null} if this deque is empty |
| 429 |
|
*/ |
| 430 |
|
public E poll() { |
| 431 |
|
return pollFirst(); |
| 447 |
|
|
| 448 |
|
/** |
| 449 |
|
* Retrieves, but does not remove, the head of the queue represented by |
| 450 |
< |
* this deque, or returns <tt>null</tt> if this deque is empty. |
| 450 |
> |
* this deque, or returns {@code null} if this deque is empty. |
| 451 |
|
* |
| 452 |
|
* <p>This method is equivalent to {@link #peekFirst}. |
| 453 |
|
* |
| 454 |
|
* @return the head of the queue represented by this deque, or |
| 455 |
< |
* <tt>null</tt> if this deque is empty |
| 455 |
> |
* {@code null} if this deque is empty |
| 456 |
|
*/ |
| 457 |
|
public E peek() { |
| 458 |
|
return peekFirst(); |
| 556 |
|
} |
| 557 |
|
|
| 558 |
|
/** |
| 559 |
< |
* Returns <tt>true</tt> if this deque contains no elements. |
| 559 |
> |
* Returns {@code true} if this deque contains no elements. |
| 560 |
|
* |
| 561 |
< |
* @return <tt>true</tt> if this deque contains no elements |
| 561 |
> |
* @return {@code true} if this deque contains no elements |
| 562 |
|
*/ |
| 563 |
|
public boolean isEmpty() { |
| 564 |
|
return head == tail; |
| 665 |
|
} |
| 666 |
|
|
| 667 |
|
/** |
| 668 |
< |
* Returns <tt>true</tt> if this deque contains the specified element. |
| 669 |
< |
* More formally, returns <tt>true</tt> if and only if this deque contains |
| 670 |
< |
* at least one element <tt>e</tt> such that <tt>o.equals(e)</tt>. |
| 668 |
> |
* Returns {@code true} if this deque contains the specified element. |
| 669 |
> |
* More formally, returns {@code true} if and only if this deque contains |
| 670 |
> |
* at least one element {@code e} such that {@code o.equals(e)}. |
| 671 |
|
* |
| 672 |
|
* @param o object to be checked for containment in this deque |
| 673 |
< |
* @return <tt>true</tt> if this deque contains the specified element |
| 673 |
> |
* @return {@code true} if this deque contains the specified element |
| 674 |
|
*/ |
| 675 |
|
public boolean contains(Object o) { |
| 676 |
|
if (o == null) |
| 689 |
|
/** |
| 690 |
|
* Removes a single instance of the specified element from this deque. |
| 691 |
|
* If the deque does not contain the element, it is unchanged. |
| 692 |
< |
* More formally, removes the first element <tt>e</tt> such that |
| 693 |
< |
* <tt>o.equals(e)</tt> (if such an element exists). |
| 694 |
< |
* Returns <tt>true</tt> if this deque contained the specified element |
| 692 |
> |
* More formally, removes the first element {@code e} such that |
| 693 |
> |
* {@code o.equals(e)} (if such an element exists). |
| 694 |
> |
* Returns {@code true} if this deque contained the specified element |
| 695 |
|
* (or equivalently, if this deque changed as a result of the call). |
| 696 |
|
* |
| 697 |
|
* <p>This method is equivalent to {@link #removeFirstOccurrence}. |
| 698 |
|
* |
| 699 |
|
* @param o element to be removed from this deque, if present |
| 700 |
< |
* @return <tt>true</tt> if this deque contained the specified element |
| 700 |
> |
* @return {@code true} if this deque contained the specified element |
| 701 |
|
*/ |
| 702 |
|
public boolean remove(Object o) { |
| 703 |
|
return removeFirstOccurrence(o); |
| 749 |
|
* <p>If this deque fits in the specified array with room to spare |
| 750 |
|
* (i.e., the array has more elements than this deque), the element in |
| 751 |
|
* the array immediately following the end of the deque is set to |
| 752 |
< |
* <tt>null</tt>. |
| 752 |
> |
* {@code null}. |
| 753 |
|
* |
| 754 |
|
* <p>Like the {@link #toArray()} method, this method acts as bridge between |
| 755 |
|
* array-based and collection-based APIs. Further, this method allows |
| 756 |
|
* precise control over the runtime type of the output array, and may, |
| 757 |
|
* under certain circumstances, be used to save allocation costs. |
| 758 |
|
* |
| 759 |
< |
* <p>Suppose <tt>x</tt> is a deque known to contain only strings. |
| 759 |
> |
* <p>Suppose {@code x} is a deque known to contain only strings. |
| 760 |
|
* The following code can be used to dump the deque into a newly |
| 761 |
< |
* allocated array of <tt>String</tt>: |
| 761 |
> |
* allocated array of {@code String}: |
| 762 |
|
* |
| 763 |
|
* <pre> {@code String[] y = x.toArray(new String[0]);}</pre> |
| 764 |
|
* |
| 765 |
< |
* Note that <tt>toArray(new Object[0])</tt> is identical in function to |
| 766 |
< |
* <tt>toArray()</tt>. |
| 765 |
> |
* Note that {@code toArray(new Object[0])} is identical in function to |
| 766 |
> |
* {@code toArray()}. |
| 767 |
|
* |
| 768 |
|
* @param a the array into which the elements of the deque are to |
| 769 |
|
* be stored, if it is big enough; otherwise, a new array of the |
| 809 |
|
/** |
| 810 |
|
* Saves this deque to a stream (that is, serializes it). |
| 811 |
|
* |
| 812 |
< |
* @serialData The current size (<tt>int</tt>) of the deque, |
| 812 |
> |
* @serialData The current size ({@code int}) of the deque, |
| 813 |
|
* followed by all of its elements (each an object reference) in |
| 814 |
|
* first-to-last order. |
| 815 |
|
*/ |
