java.util
Class AbstractQueue<E>

java.lang.Object
  java.util.AbstractCollection<E>
      java.util.AbstractQueue<E>

Type Parameters:

E - the types of objects this queue can hold

All Implemented Interfaces:

Iterable<E>, Collection<E>, Queue<E>

Direct Known Subclasses:

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

public abstract class AbstractQueue<E>
extends AbstractCollection<E>
implements Queue<E>

Abstract superclass for Queue implementations.

Since:

1.5

Constructor Summary

protected

AbstractQueue() Default constructor.

Method Summary

boolean	add(E object) Adds the given object to the queue.
boolean	addAll(Collection<? extends E> collection) Adds the objects from the given collection to the queue.
void	clear() Removes all objects from this queue.
E	element() Returns the head object of the queue.
E	remove() Removes the head object from the queue.

Methods inherited from class java.util.AbstractCollection

contains, containsAll, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Queue

offer, peek, poll

Methods inherited from interface java.util.Collection

contains, containsAll, equals, hashCode, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray

Constructor Detail

AbstractQueue

protected AbstractQueue()

Default constructor.

Method Detail

add

public boolean add(E object)

Adds the given object to the queue.

Specified by:

add in interface Collection<E>

Overrides:

add in class AbstractCollection<E>

Parameters:

object - the object to add

Returns:

true

Throws:

NullPointerException - if the object is null

IllegalStateException - if the object cannot be added

addAll

public boolean addAll(Collection<? extends E> collection)

Adds the objects from the given collection to the queue.

Specified by:

addAll in interface Collection<E>

Overrides:

addAll in class AbstractCollection<E>

Parameters:

collection - the Collection of objects

Returns:

true if the queue changed

Throws:

NullPointerException - if the collection or any of it's objects are null

IllegalArgumentException - if the collection is this queue

clear

public void clear()

Removes all objects from this queue.

Specified by:

clear in interface Collection<E>

Overrides:

clear in class AbstractCollection<E>

See Also:

AbstractCollection.isEmpty(), AbstractCollection.size()

element

public E element()

Returns the head object of the queue. Does not remove the object from the queue.

Specified by:

element in interface Queue<E>

Returns:

the head object

Throws:

NoSuchElementException - if the queue is empty

remove

public E remove()

Removes the head object from the queue.

Specified by:

remove in interface Queue<E>

Returns:

the head object

Throws:

NoSuchElementException - if the queue is empty