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

public class

ArrayDeque

extends AbstractCollection<E>
implements Deque<E>

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

Class Overview

An implementation of Deque, backed by an array. ArrayDeques have no size limit, can not contain null element, and they are not thread-safe. All optional operations are supported, and the elements can be any objects.

Summary

Public Constructors
	ArrayDeque() Constructs a new empty instance of ArrayDeque big enough for 16 elements.
	ArrayDeque(int minSize) Constructs a new empty instance of ArrayDeque big enough for specified number of elements.
	ArrayDeque(Collection<? extends E> c) Constructs a new instance of ArrayDeque containing the elements of the specified collection, with the order returned by the collection's iterator.

Public Methods
boolean	add(Object e) Inserts the element to the tail of the deque.
void	addFirst(Object e)
void	addLast(Object e)
void	clear() Empty the deque.
boolean	contains(Object obj) Returns true if the specified element is in the deque.
Iterator<E>	descendingIterator() Returns the iterator in reverse order, from tail to head.
E	element() Gets but does not remove the head element of this deque.
E	getFirst() Gets but not removes the head element of this deque.
E	getLast() Gets but not removes the tail element of this deque.
boolean	isEmpty() Returns true if the deque has no elements.
Iterator<E>	iterator() Returns the iterator of the deque.
boolean	offer(Object e) Inserts the element at the tail of the deque.
boolean	offerFirst(Object e)
boolean	offerLast(Object e)
E	peek() Gets but not removes the head element of this deque.
E	peekFirst() Gets but not removes the head element of this deque.
E	peekLast() Gets but not removes the tail element of this deque.
E	poll() Gets and removes the head element of this deque.
E	pollFirst() Gets and removes the head element of this deque.
E	pollLast() Gets and removes the tail element of this deque.
E	pop() Pops the head element of the deque, just same as removeFirst().
void	push(Object e)
E	remove() Gets and removes the head element of this deque.
boolean	remove(Object obj) Removes the first equivalent element of the specified object.
E	removeFirst() Gets and removes the head element of this deque.
boolean	removeFirstOccurrence(Object obj) Removes the first equivalent element of the specified object.
E	removeLast() Gets and removes the tail element of this deque.
boolean	removeLastOccurrence(Object obj) Removes the last equivalent element of the specified object.
int	size() Returns the size of the deque.

[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.
Object[]	toArray() Returns a new array containing all elements contained in this `ArrayList`.
String	toString() Returns the string representation of this `Collection`.

From class java.lang.Object

boolean	equals(Object obj) Indicates whether some other object is "equal to" this one.
final Class<?>	getClass() Returns the runtime class of an object.
int	hashCode() Returns a hash code value for the object.
final void	notify() Wakes up a single thread that is waiting on this object's monitor.
final void	notifyAll() Wakes up all threads that are waiting on this object's monitor.
String	toString() Returns a string representation of the object.
final void	wait(long timeout, int nanos) Causes current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.
final void	wait(long timeout) Causes current thread to wait until either another thread invokes the `notify()` method or the `notifyAll()` method for this object, or a specified amount of time has elapsed.
final void	wait() Causes current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object.

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[] a) Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.
abstract Object[]	toArray() Returns an array containing all of the elements in this collection.

From interface java.util.Deque

abstract void	addFirst(E e) Inserts an element at the head of this deque if it dose not violate size limit immediately.
abstract void	addLast(E e) Inserts an element at the tail of this deque if it dose not violate size limit immediately.
abstract Iterator<E>	descendingIterator() Returns the iterator in reverse order, from tail to head.
abstract E	getFirst() Gets but not removes the head element of this deque.
abstract E	getLast() Gets but not removes the tail element of this deque.
abstract boolean	offerFirst(E e) Inserts an element at the head of this deque unless it would violate size limit.
abstract boolean	offerLast(E e) Inserts an element at the tail of this deque unless it would violate size limit.
abstract E	peekFirst() Gets but not removes the head element of this deque.
abstract E	peekLast() Gets but not removes the tail element of this deque.
abstract E	pollFirst() Gets and removes the head element of this deque.
abstract E	pollLast() Gets and removes the tail element of this deque.
abstract E	pop() Pops the head element of the deque, just same as removeFirst().
abstract void	push(E e) Pushes the element to the deque(at the head of the deque), just same as addFirst(E).
abstract E	removeFirst() Gets and removes the head element of this deque.
abstract boolean	removeFirstOccurrence(Object o) Removes the first equivalent element of the specified object.
abstract E	removeLast() Gets and removes the tail element of this deque.
abstract boolean	removeLastOccurrence(Object o) Removes the last equivalent element of the specified object.

From interface java.util.Queue

Public Constructors

public ArrayDeque ()

Constructs a new empty instance of ArrayDeque big enough for 16 elements.

public ArrayDeque (int minSize)

Constructs a new empty instance of ArrayDeque big enough for specified number of elements.

Parameters

minSize	the smallest size of the ArrayDeque

public ArrayDeque (Collection<? extends E> c)

Constructs a new instance of ArrayDeque containing the elements of the specified collection, with the order returned by the collection's iterator.

Parameters

c	the source of the elements

Throws

NullPointerException	if the collection is null

Public Methods

public boolean add (Object e)

Inserts the element to the tail of the deque.

Parameters

e	the element

Returns

true

public void addFirst (Object e)

Parameters

e	the element

Throws

NullPointerException	if the element is null

public void addLast (Object e)

Parameters

e	the element

Throws

NullPointerException	if the element is null

public void clear ()

Empty the deque.

public boolean contains (Object obj)

Returns true if the specified element is in the deque.

Parameters

obj	the element

Returns

true if the element is in the deque, false otherwise

public Iterator<E> descendingIterator ()

Returns the iterator in reverse order, from tail to head.

Returns

the reverse order Iterator

public E element ()

Gets but does not remove the head element of this deque. It throws an exception if the deque is empty.

Returns

the head element

Throws

NoSuchElementException	if the deque is empty

public E getFirst ()

Gets but not removes the head element of this deque. This method throws an exception if the deque is empty.

Returns

the head element

Throws

NoSuchElementException	if the deque is empty

public E getLast ()

Gets but not removes the tail element of this deque. This method throws an exception if the deque is empty.

Returns

the tail element

Throws

NoSuchElementException	if the deque is empty

public boolean isEmpty ()

Returns true if the deque has no elements.

Returns

true if the deque has no elements, false otherwise

public Iterator<E> iterator ()

Returns the iterator of the deque. The elements will be ordered from head to tail.

Returns

the iterator

public boolean offer (Object e)

Inserts the element at the tail of the deque.

Parameters

e	the element

Returns

true if the operation succeeds or false if it fails.

Throws

NullPointerException	if the element is null

public boolean offerFirst (Object e)

Parameters

e	the element

Returns

true

Throws

NullPointerException	if the element is null

public boolean offerLast (Object e)

Parameters

e	the element

Returns

true if the operation succeeds or false if it fails

Throws

NullPointerException	if the element is null

public E peek ()

Gets but not removes the head element of this deque. This method returns null if the deque is empty.

Returns

the head element or null if the deque is empty

public E peekFirst ()

Gets but not removes the head element of this deque. This method returns null if the deque is empty.

Returns

the head element or null if the deque is empty

public E peekLast ()

Gets but not removes the tail element of this deque. This method returns null if the deque is empty.

Returns

the tail element or null if the deque is empty

public E poll ()

Gets and removes the head element of this deque. This method returns null if the deque is empty.

Returns

the head element or null if the deque is empty

public E pollFirst ()

Gets and removes the head element of this deque. This method returns null if the deque is empty.

Returns

the head element or null if the deque is empty

public E pollLast ()

Gets and removes the tail element of this deque. This method returns null if the deque is empty.

Returns

the tail element or null if the deque is empty

public E pop ()

Pops the head element of the deque, just same as removeFirst().

Returns

the head element

Throws

NoSuchElementException	if the deque is empty

public void push (Object e)

Parameters

e	the element to push

Throws

NullPointerException	if the element is null

public E remove ()

Gets and removes the head element of this deque. This method throws an exception if the deque is empty.

Returns

the head element

Throws

NoSuchElementException	if the deque is empty

public boolean remove (Object obj)

Removes the first equivalent element of the specified object. If the deque does not contain the element, it is unchanged and returns false.

Parameters

obj	the element to be removed

Returns

true if the operation succeeds or false if the deque does not contain the element

public E removeFirst ()

Gets and removes the head element of this deque. This method throws an exception if the deque is empty.

Returns

the head element

Throws

NoSuchElementException	if the deque is empty

public boolean removeFirstOccurrence (Object obj)

Removes the first equivalent element of the specified object. If the deque does not contain the element, it is unchanged and returns false.

Parameters

obj	the element to be removed

Returns

true if the operation succeeds or false if the deque does not contain the element

public E removeLast ()

Gets and removes the tail element of this deque. This method throws an exception if the deque is empty.

Returns

the tail element

Throws

NoSuchElementException	if the deque is empty

public boolean removeLastOccurrence (Object obj)

Removes the last equivalent element of the specified object. If the deque does not contain the element, it is unchanged and returns false.

Parameters

obj	the element to be removed

Returns

true if the operation succeeds or false if the deque does not contain the element.

public int size ()

Returns the size of the deque.

Returns

the size of the deque

Interfaces

Classes

Exceptions

ArrayDeque

Class Overview

Summary

Public Constructors

public ArrayDeque ()

public ArrayDeque (int minSize)

Parameters

public ArrayDeque (Collection<? extends E> c)

Parameters

Throws

Public Methods

public boolean add (Object e)

Parameters

Returns

See Also

public void addFirst (Object e)

Parameters

Throws

See Also

public void addLast (Object e)

Parameters

Throws

See Also

public void clear ()

See Also

public boolean contains (Object obj)

Parameters

Returns

See Also

public Iterator<E> descendingIterator ()

Returns

See Also

public E element ()

Returns

Throws

See Also

public E getFirst ()

Returns

Throws

See Also

public E getLast ()

Returns

Throws

See Also

public boolean isEmpty ()

Returns

See Also

public Iterator<E> iterator ()

Returns

See Also

public boolean offer (Object e)

Parameters

Returns

Throws

See Also

public boolean offerFirst (Object e)

Parameters

Returns

Throws

See Also

public boolean offerLast (Object e)

Parameters

Returns

Throws

See Also

public E peek ()

Returns

See Also

public E peekFirst ()

Returns

See Also

public E peekLast ()

Returns

See Also

public E poll ()

Returns

See Also