| 12 |
|
* additional insertion, extraction, and inspection operations. |
| 13 |
|
* |
| 14 |
|
* <p>Queues typically, but do not necessarily, order elements in a |
| 15 |
< |
* FIFO (first-in-first-out) manner. Among the exceptions are priority |
| 16 |
< |
* queues, which order elements according to a supplied comparators, or |
| 17 |
< |
* the elements natural ordering. Every Queue implementation must specify |
| 18 |
< |
* its ordering guarantees. |
| 15 |
> |
* FIFO (first-in-first-out) manner. Among the exceptions are |
| 16 |
> |
* priority queues, which order elements according to a supplied |
| 17 |
> |
* comparator, or the elements' natural ordering. Every Queue |
| 18 |
> |
* implementation must specify its ordering guarantees. |
| 19 |
|
* |
| 20 |
|
* <p>The {@link #offer(E)} method adds an element if possible, otherwise |
| 21 |
|
* returning <tt>false</tt>. This differs from the {@link |
| 23 |
|
* failure. It is designed for use in collections in which failure to |
| 24 |
|
* add is a normal, rather than exceptional occurrence, for example, |
| 25 |
|
* in fixed-capacity (or “bounded”) queues. |
| 26 |
+ |
|
| 27 |
|
* |
| 28 |
|
* <p>The {@link #remove()} and {@link #poll()} methods remove and return an |
| 29 |
< |
* element in accord with the implementation's ordering policy. For example, |
| 30 |
< |
* in FIFO queues, they remove and return the oldest element in the queue. |
| 29 |
> |
* element in accord with the implementation's ordering policy. |
| 30 |
> |
* Exactly which element is removed from the queue is a function |
| 31 |
> |
* of the queue's ordering policy, which differs from implementation |
| 32 |
> |
* to implementation. Possible orderings include (but are not limited |
| 33 |
> |
* to) first-in-first-out (FIFO), element priority, and arbitrary. |
| 34 |
|
* The <tt>remove()</tt> and <tt>poll()</tt> methods differ only in their |
| 35 |
|
* behavior when the queue is empty: the <tt>remove()</tt> method throws an |
| 36 |
|
* exception, while the <tt>poll()</tt> method returns <tt>null</tt>. |
| 75 |
|
|
| 76 |
|
/** |
| 77 |
|
* Remove and return an element from the queue if one is available. |
| 74 |
– |
* Exactly which element is removed from the queue is a function |
| 75 |
– |
* of the queue's ordering policy, which differs from implementation |
| 76 |
– |
* to implementation. Possible orderings include (but are not limited |
| 77 |
– |
* to) first-in-first-out (FIFO), element priority, and arbitrary. |
| 78 |
|
* |
| 79 |
|
* @return an element previously on the queue, or <tt>null</tt> if the |
| 80 |
|
* queue is empty. |
