Java Queue class

java.util

Interface Queue<E>

Type Parameters:

E - the type of elements held in this collection

All Superinterfaces:

Collection<E>, Iterable<E>

All Known Subinterfaces:

BlockingQueue<E>

All Known Implementing Classes:

AbstractQueue, ArrayBlockingQueue, ConcurrentLinkedQueue, DelayQueue, LinkedBlockingQueue, LinkedList, PriorityBlockingQueue, PriorityQueue, SynchronousQueue

---

public interface Queue<E>

extends Collection<E>

A collection designed for holding elements prior to processing. Besides basic Collection operations, queues provide additional insertion, extraction, and inspection operations.

Queues typically, but do not necessarily, order elements in a FIFO (first-in-first-out) manner. Among the exceptions are priority queues, which order elements according to a supplied comparator, or the elements' natural ordering, and LIFO queues (or stacks) which order the elements LIFO (last-in-first-out). Whatever the ordering used, the head of the queue is that element which would be removed by a call to remove() or poll(). In a FIFO queue, all new elements are inserted at the tail of the queue. Other kinds of queues may use different placement rules. Every Queue implementation must specify its ordering properties

---

Method Summary
E	element()           Retrieves, but does not remove, the head of this queue.
boolean	offer(E o)           Inserts the specified element into this queue, if possible.
E	peek()           Retrieves, but does not remove, the head of this queue, returning null if this queue is empty.
E	poll()           Retrieves and removes the head of this queue, or null if this queue is empty.
E	remove()           Retrieves and removes the head of this queue.