Summary: Protected Ctors | Methods | Inherited Methods | [Expand All]

public abstract class

AbstractQueue

extends AbstractCollection<E>
implements Queue<E>

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

Known Direct Subclasses

ArrayBlockingQueue<E>, ConcurrentLinkedQueue<E>, DelayQueue<E extends Delayed>, LinkedBlockingDeque<E>, LinkedBlockingQueue<E>, PriorityBlockingQueue<E>, PriorityQueue<E>, SynchronousQueue<E>

Class Overview

AbstractQueue is an abstract class which implements some of the methods in Queue. The provided implementations of add, remove and element are based on offer, poll, and peek except that they throw exceptions to indicate some error instead of returning true or false.

Summary

Protected Constructors
	AbstractQueue() Constructor to be used by subclasses.

Public Methods
boolean	add(E o) Adds an element to the queue.
boolean	addAll(Collection<? extends E> c) Adds all the elements of a collection to the queue.
void	clear() Removes all elements of the queue, leaving it empty.
E	element() Returns but does not remove the element at the head of the queue.
E	remove() Removes the element at the head of the queue and returns it.

[Expand]

Inherited Methods

From class java.util.AbstractCollection

boolean	add(E object) Attempts to add `object` to the contents of this `Collection` (optional).
boolean	addAll(Collection<? extends E> collection) Attempts to add all of the objects contained in `collection` to the contents of this `Collection` (optional).
void	clear() Removes all elements from this `Collection`, leaving it empty (optional).
boolean	contains(Object object) Tests whether this `Collection` contains the specified object.
boolean	containsAll(Collection<?> collection) Tests whether this `Collection` contains all objects contained in the specified `Collection`.
boolean	isEmpty() Returns if this `Collection` contains no elements.
abstract Iterator<E>	iterator() Returns an instance of `Iterator` that may be used to access the objects contained by this `Collection`.
boolean	remove(Object object) Removes one instance of the specified object from this `Collection` if one is contained (optional).
boolean	removeAll(Collection<?> collection) Removes all occurrences in this `Collection` of each object in the specified `Collection` (optional).
boolean	retainAll(Collection<?> collection) Removes all objects from this `Collection` that are not also found in the `Collection` passed (optional).
abstract int	size() Returns a count of how many objects this `Collection` contains.
<T> T[]	toArray(T[] contents) Returns an array containing all elements contained in this `Collection`.
Object[]	toArray() Returns a new array containing all elements contained in this `Collection`.
String	toString() Returns the string representation of this `Collection`.

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Called before the object's memory is reclaimed by the VM.
final Class<? extends Object>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

From interface java.lang.Iterable

From interface java.util.Collection

abstract boolean	add(E object) Attempts to add `object` to the contents of this `Collection` (optional).
abstract boolean	addAll(Collection<? extends E> collection) Attempts to add all of the objects contained in `Collection` to the contents of this `Collection` (optional).
abstract void	clear() Removes all elements from this `Collection`, leaving it empty (optional).
abstract boolean	contains(Object object) Tests whether this `Collection` contains the specified object.
abstract boolean	containsAll(Collection<?> collection) Tests whether this `Collection` contains all objects contained in the specified `Collection`.
abstract boolean	equals(Object object) Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison.
abstract int	hashCode() Returns an integer hash code for the receiver.
abstract boolean	isEmpty() Returns if this `Collection` contains no elements.
abstract Iterator<E>	iterator() Returns an instance of `Iterator` that may be used to access the objects contained by this `Collection`.
abstract boolean	remove(Object object) Removes one instance of the specified object from this `Collection` if one is contained (optional).
abstract boolean	removeAll(Collection<?> collection) Removes all occurrences in this `Collection` of each object in the specified `Collection` (optional).
abstract boolean	retainAll(Collection<?> collection) Removes all objects from this `Collection` that are not also found in the `Collection` passed (optional).
abstract int	size() Returns a count of how many objects this `Collection` contains.
abstract <T> T[]	toArray(T[] array) Returns an array containing all elements contained in this `Collection`.
abstract Object[]	toArray() Returns a new array containing all elements contained in this `Collection`.

From interface java.util.Queue

Protected Constructors

protected AbstractQueue ()

Since: API Level 1

Constructor to be used by subclasses.

Public Methods

public boolean add (E o)

Since: API Level 1

Adds an element to the queue.

Parameters

o	the element to be added to the queue.

Returns

true if the operation succeeds, otherwise false.

Throws

IllegalStateException	if the element is not allowed to be added to the queue.

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

Since: API Level 1

Adds all the elements of a collection to the queue. If the collection is the queue itself, then an IllegalArgumentException will be thrown. If during the process, some runtime exception is thrown, then those elements in the collection which have already successfully been added will remain in the queue. The result of the method is undefined if the collection is modified during the process of the method.

Parameters

c	the collection to be added to the queue.

Returns

true if the operation succeeds, otherwise false.

Throws

NullPointerException	if the collection or any element of it is null.
IllegalArgumentException	If the collection to be added to the queue is the queue itself.

public void clear ()

Since: API Level 1

Removes all elements of the queue, leaving it empty.

public E element ()

Since: API Level 1

Returns but does not remove the element at the head of the queue.

Returns

the element at the head of the queue.

Throws

NoSuchElementException	if the queue is empty.

public E remove ()

Since: API Level 1

Removes the element at the head of the queue and returns it.

Returns

the element at the head of the queue.

Throws

NoSuchElementException	if the queue is empty.

Interfaces

Classes

Enums

Exceptions

Errors

AbstractQueue

Class Overview

Summary

Protected Constructors

protected AbstractQueue ()

Public Methods

public boolean add (E o)

Parameters

Returns

Throws

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

Parameters

Returns

Throws

public void clear ()

public E element ()

Returns

Throws

public E remove ()

Returns

Throws