net.tsz.afinal.core
类 ArrayDeque<E>

java.lang.Object
  net.tsz.afinal.core.AbstractCollection<E>
      net.tsz.afinal.core.ArrayDeque<E>

类型参数：

E - the type of elements held in this collection

所有已实现的接口：

java.io.Serializable, java.lang.Cloneable, java.lang.Iterable<E>, java.util.Collection<E>, Deque<E>, Queue<E>

public class ArrayDeque<E>
extends AbstractCollection<E>
implements Deque<E>, java.lang.Cloneable, java.io.Serializable

Resizable-array implementation of the Deque interface. Array deques have no capacity restrictions; they grow as necessary to support usage. They are not thread-safe; in the absence of external synchronization, they do not support concurrent access by multiple threads. Null elements are prohibited. This class is likely to be faster than Stack when used as a stack, and faster than LinkedList when used as a queue.

Most ArrayDeque operations run in amortized constant time. Exceptions include remove, removeFirstOccurrence, removeLastOccurrence, contains, iterator.remove(), and the bulk operations, all of which run in linear time.

The iterators returned by this class's iterator method are fail-fast: If the deque is modified at any time after the iterator is created, in any way except through the iterator's own remove method, the iterator will generally throw a ConcurrentModificationException. Thus, in the face of concurrent modification, the iterator fails quickly and cleanly, rather than risking arbitrary, non-deterministic behavior at an undetermined time in the future.

Note that the fail-fast behavior of an iterator cannot be guaranteed as it is, generally speaking, impossible to make any hard guarantees in the presence of unsynchronized concurrent modification. Fail-fast iterators throw ConcurrentModificationException on a best-effort basis. Therefore, it would be wrong to write a program that depended on this exception for its correctness: the fail-fast behavior of iterators should be used only to detect bugs.

This class and its iterator implement all of the optional methods of the Collection and Iterator interfaces.

从以下版本开始：

1.6

作者：

Josh Bloch and Doug Lea

另请参见：

序列化表格

构造方法摘要

ArrayDeque()
Constructs an empty array deque with an initial capacity sufficient to hold 16 elements.

ArrayDeque(java.util.Collection<? extends E> c)
Constructs a deque containing the elements of the specified collection, in the order they are returned by the collection's iterator.

ArrayDeque(int numElements)
Constructs an empty array deque with an initial capacity sufficient to hold the specified number of elements.

方法摘要

boolean	add(E e) Inserts the specified element at the end of this deque.
void	addFirst(E e) Inserts the specified element at the front of this deque.
void	addLast(E e) Inserts the specified element at the end of this deque.
void	clear() Removes all of the elements from this deque.
ArrayDeque<E>	clone() Returns a copy of this deque.
boolean	contains(java.lang.Object o) Returns true if this deque contains the specified element.
java.util.Iterator<E>	descendingIterator() Returns an iterator over the elements in this deque in reverse sequential order.
E	element() Retrieves, but does not remove, the head of the queue represented by this deque.
E	getFirst() Retrieves, but does not remove, the first element of this deque.
E	getLast() Retrieves, but does not remove, the last element of this deque.
boolean	isEmpty() Returns true if this deque contains no elements.
java.util.Iterator<E>	iterator() Returns an iterator over the elements in this deque.
boolean	offer(E e) Inserts the specified element at the end of this deque.
boolean	offerFirst(E e) Inserts the specified element at the front of this deque.
boolean	offerLast(E e) Inserts the specified element at the end of this deque.
E	peek() Retrieves, but does not remove, the head of the queue represented by this deque, or returns null if this deque is empty.
E	peekFirst() Retrieves, but does not remove, the first element of this deque, or returns null if this deque is empty.
E	peekLast() Retrieves, but does not remove, the last element of this deque, or returns null if this deque is empty.
E	poll() Retrieves and removes the head of the queue represented by this deque (in other words, the first element of this deque), or returns null if this deque is empty.
E	pollFirst() Retrieves and removes the first element of this deque, or returns null if this deque is empty.
E	pollLast() Retrieves and removes the last element of this deque, or returns null if this deque is empty.
E	pop() Pops an element from the stack represented by this deque.
void	push(E e) Pushes an element onto the stack represented by this deque.
E	remove() Retrieves and removes the head of the queue represented by this deque.
boolean	remove(java.lang.Object o) Removes a single instance of the specified element from this deque.
E	removeFirst() Retrieves and removes the first element of this deque.
boolean	removeFirstOccurrence(java.lang.Object o) Removes the first occurrence of the specified element in this deque (when traversing the deque from head to tail).
E	removeLast() Retrieves and removes the last element of this deque.
boolean	removeLastOccurrence(java.lang.Object o) Removes the last occurrence of the specified element in this deque (when traversing the deque from head to tail).
int	size() Returns the number of elements in this deque.
java.lang.Object[]	toArray() Returns an array containing all of the elements in this deque in proper sequence (from first to last element).
<T> T[]	toArray(T[] a) Returns an array containing all of the elements in this deque in proper sequence (from first to last element); the runtime type of the returned array is that of the specified array.

从类 net.tsz.afinal.core.AbstractCollection 继承的方法

addAll, containsAll, removeAll, retainAll, toString

从类 java.lang.Object 继承的方法

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

从接口 java.util.Collection 继承的方法

addAll, containsAll, equals, hashCode, removeAll, retainAll

构造方法详细信息

ArrayDeque

public ArrayDeque()

Constructs an empty array deque with an initial capacity sufficient to hold 16 elements.

ArrayDeque

public ArrayDeque(int numElements)

Constructs an empty array deque with an initial capacity sufficient to hold the specified number of elements.

参数：

numElements - lower bound on initial capacity of the deque

ArrayDeque

public ArrayDeque(java.util.Collection<? extends E> c)

Constructs a deque containing the elements of the specified collection, in the order they are returned by the collection's iterator. (The first element returned by the collection's iterator becomes the first element, or front of the deque.)

参数：

c - the collection whose elements are to be placed into the deque

抛出：

java.lang.NullPointerException - if the specified collection is null

方法详细信息

addFirst

public void addFirst(E e)

Inserts the specified element at the front of this deque.

指定者：

接口 Deque<E> 中的 addFirst

参数：

e - the element to add

抛出：

java.lang.NullPointerException - if the specified element is null

addLast

public void addLast(E e)

Inserts the specified element at the end of this deque.

This method is equivalent to add(E).

指定者：

接口 Deque<E> 中的 addLast

参数：

e - the element to add

抛出：

java.lang.NullPointerException - if the specified element is null

offerFirst

public boolean offerFirst(E e)

Inserts the specified element at the front of this deque.

指定者：

接口 Deque<E> 中的 offerFirst

参数：

e - the element to add

返回：

true (as specified by Deque.offerFirst(E))

抛出：

java.lang.NullPointerException - if the specified element is null

offerLast

public boolean offerLast(E e)

Inserts the specified element at the end of this deque.

指定者：

接口 Deque<E> 中的 offerLast

参数：

e - the element to add

返回：

true (as specified by Deque.offerLast(E))

抛出：

java.lang.NullPointerException - if the specified element is null

removeFirst

public E removeFirst()

从接口 Deque 复制的描述

Retrieves and removes the first element of this deque. This method differs from pollFirst only in that it throws an exception if this deque is empty.

指定者：

接口 Deque<E> 中的 removeFirst

返回：

the head of this deque

抛出：

java.util.NoSuchElementException

removeLast

public E removeLast()

从接口 Deque 复制的描述

Retrieves and removes the last element of this deque. This method differs from pollLast only in that it throws an exception if this deque is empty.

指定者：

接口 Deque<E> 中的 removeLast

返回：

the tail of this deque

抛出：

java.util.NoSuchElementException

pollFirst

public E pollFirst()

从接口 Deque 复制的描述

Retrieves and removes the first element of this deque, or returns null if this deque is empty.

指定者：

接口 Deque<E> 中的 pollFirst

返回：

the head of this deque, or null if this deque is empty

pollLast

public E pollLast()

从接口 Deque 复制的描述

Retrieves and removes the last element of this deque, or returns null if this deque is empty.

指定者：

接口 Deque<E> 中的 pollLast

返回：

the tail of this deque, or null if this deque is empty

getFirst

public E getFirst()

从接口 Deque 复制的描述

Retrieves, but does not remove, the first element of this deque. This method differs from peekFirst only in that it throws an exception if this deque is empty.

指定者：

接口 Deque<E> 中的 getFirst

返回：

the head of this deque

抛出：

java.util.NoSuchElementException

getLast

public E getLast()

从接口 Deque 复制的描述

Retrieves, but does not remove, the last element of this deque. This method differs from peekLast only in that it throws an exception if this deque is empty.

指定者：

接口 Deque<E> 中的 getLast

返回：

the tail of this deque

抛出：

java.util.NoSuchElementException

peekFirst

public E peekFirst()

从接口 Deque 复制的描述

Retrieves, but does not remove, the first element of this deque, or returns null if this deque is empty.

指定者：

接口 Deque<E> 中的 peekFirst

返回：

the head of this deque, or null if this deque is empty

peekLast

public E peekLast()

从接口 Deque 复制的描述

Retrieves, but does not remove, the last element of this deque, or returns null if this deque is empty.

指定者：

接口 Deque<E> 中的 peekLast

返回：

the tail of this deque, or null if this deque is empty

removeFirstOccurrence

public boolean removeFirstOccurrence(java.lang.Object o)

Removes the first occurrence of the specified element in this deque (when traversing the deque from head to tail). If the deque does not contain the element, it is unchanged. More formally, removes the first element e such that o.equals(e) (if such an element exists). Returns true if this deque contained the specified element (or equivalently, if this deque changed as a result of the call).

指定者：

接口 Deque<E> 中的 removeFirstOccurrence

参数：

o - element to be removed from this deque, if present

返回：

true if the deque contained the specified element

removeLastOccurrence

public boolean removeLastOccurrence(java.lang.Object o)

Removes the last occurrence of the specified element in this deque (when traversing the deque from head to tail). If the deque does not contain the element, it is unchanged. More formally, removes the last element e such that o.equals(e) (if such an element exists). Returns true if this deque contained the specified element (or equivalently, if this deque changed as a result of the call).

指定者：

接口 Deque<E> 中的 removeLastOccurrence

参数：

o - element to be removed from this deque, if present

返回：

true if the deque contained the specified element

add

public boolean add(E e)

Inserts the specified element at the end of this deque.

This method is equivalent to addLast(E).

指定者：

接口 java.util.Collection<E> 中的 add

指定者：

接口 Deque<E> 中的 add

指定者：

接口 Queue<E> 中的 add

覆盖：

类 AbstractCollection<E> 中的 add

参数：

e - the element to add

返回：

true (as specified by Collection.add(E))

抛出：

java.lang.NullPointerException - if the specified element is null

offer

public boolean offer(E e)

Inserts the specified element at the end of this deque.

This method is equivalent to offerLast(E).

指定者：

接口 Deque<E> 中的 offer

指定者：

接口 Queue<E> 中的 offer

参数：

e - the element to add

返回：

true (as specified by Queue.offer(E))

抛出：

java.lang.NullPointerException - if the specified element is null

remove

public E remove()

Retrieves and removes the head of the queue represented by this deque. This method differs from poll only in that it throws an exception if this deque is empty.

This method is equivalent to removeFirst().

指定者：

接口 Deque<E> 中的 remove

指定者：

接口 Queue<E> 中的 remove

返回：

the head of the queue represented by this deque

抛出：

java.util.NoSuchElementException

poll

public E poll()

Retrieves and removes the head of the queue represented by this deque (in other words, the first element of this deque), or returns null if this deque is empty.

This method is equivalent to pollFirst().

指定者：

接口 Deque<E> 中的 poll

指定者：

接口 Queue<E> 中的 poll

返回：

the head of the queue represented by this deque, or null if this deque is empty

element

public E element()

Retrieves, but does not remove, the head of the queue represented by this deque. This method differs from peek only in that it throws an exception if this deque is empty.

This method is equivalent to getFirst().

指定者：

接口 Deque<E> 中的 element

指定者：

接口 Queue<E> 中的 element

返回：

the head of the queue represented by this deque

抛出：

java.util.NoSuchElementException

peek

public E peek()

Retrieves, but does not remove, the head of the queue represented by this deque, or returns null if this deque is empty.

This method is equivalent to peekFirst().

指定者：

接口 Deque<E> 中的 peek

指定者：

接口 Queue<E> 中的 peek

返回：

the head of the queue represented by this deque, or null if this deque is empty

push

public void push(E e)

Pushes an element onto the stack represented by this deque. In other words, inserts the element at the front of this deque.

This method is equivalent to addFirst(E).

指定者：

接口 Deque<E> 中的 push

参数：

e - the element to push

抛出：

java.lang.NullPointerException - if the specified element is null

pop

public E pop()

Pops an element from the stack represented by this deque. In other words, removes and returns the first element of this deque.

This method is equivalent to removeFirst().

指定者：

接口 Deque<E> 中的 pop

返回：

the element at the front of this deque (which is the top of the stack represented by this deque)

抛出：

java.util.NoSuchElementException

size

public int size()

Returns the number of elements in this deque.

指定者：

接口 java.util.Collection<E> 中的 size

指定者：

接口 Deque<E> 中的 size

指定者：

类 AbstractCollection<E> 中的 size

返回：

the number of elements in this deque

isEmpty

public boolean isEmpty()

Returns true if this deque contains no elements.

指定者：

接口 java.util.Collection<E> 中的 isEmpty

覆盖：

类 AbstractCollection<E> 中的 isEmpty

返回：

true if this deque contains no elements

另请参见：

AbstractCollection.size()

iterator

public java.util.Iterator<E> iterator()

Returns an iterator over the elements in this deque. The elements will be ordered from first (head) to last (tail). This is the same order that elements would be dequeued (via successive calls to remove() or popped (via successive calls to pop()).

指定者：

接口 java.lang.Iterable<E> 中的 iterator

指定者：

接口 java.util.Collection<E> 中的 iterator

指定者：

接口 Deque<E> 中的 iterator

指定者：

类 AbstractCollection<E> 中的 iterator

返回：

an iterator over the elements in this deque

descendingIterator

public java.util.Iterator<E> descendingIterator()

从接口 Deque 复制的描述

Returns an iterator over the elements in this deque in reverse sequential order. The elements will be returned in order from last (tail) to first (head).

指定者：

接口 Deque<E> 中的 descendingIterator

返回：

an iterator over the elements in this deque in reverse sequence

contains

public boolean contains(java.lang.Object o)

Returns true if this deque contains the specified element. More formally, returns true if and only if this deque contains at least one element e such that o.equals(e).

指定者：

接口 java.util.Collection<E> 中的 contains

指定者：

接口 Deque<E> 中的 contains

覆盖：

类 AbstractCollection<E> 中的 contains

参数：

o - object to be checked for containment in this deque

返回：

true if this deque contains the specified element

remove

public boolean remove(java.lang.Object o)

Removes a single instance of the specified element from this deque. If the deque does not contain the element, it is unchanged. More formally, removes the first element e such that o.equals(e) (if such an element exists). Returns true if this deque contained the specified element (or equivalently, if this deque changed as a result of the call).

This method is equivalent to removeFirstOccurrence(java.lang.Object).

指定者：

接口 java.util.Collection<E> 中的 remove

指定者：

接口 Deque<E> 中的 remove

覆盖：

类 AbstractCollection<E> 中的 remove

参数：

o - element to be removed from this deque, if present

返回：

true if this deque contained the specified element

clear

public void clear()

Removes all of the elements from this deque. The deque will be empty after this call returns.

指定者：

接口 java.util.Collection<E> 中的 clear

覆盖：

类 AbstractCollection<E> 中的 clear

另请参见：

AbstractCollection.iterator(), AbstractCollection.isEmpty(), AbstractCollection.size()

toArray

public java.lang.Object[] toArray()

Returns an array containing all of the elements in this deque in proper sequence (from first to last element).

The returned array will be "safe" in that no references to it are maintained by this deque. (In other words, this method must allocate a new array). The caller is thus free to modify the returned array.

This method acts as bridge between array-based and collection-based APIs.

指定者：

接口 java.util.Collection<E> 中的 toArray

覆盖：

类 AbstractCollection<E> 中的 toArray

返回：

an array containing all of the elements in this deque

toArray

public <T> T[] toArray(T[] a)

Returns an array containing all of the elements in this deque in proper sequence (from first to last element); the runtime type of the returned array is that of the specified array. If the deque fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this deque.

If this deque fits in the specified array with room to spare (i.e., the array has more elements than this deque), the element in the array immediately following the end of the deque is set to null.

Like the toArray() method, this method acts as bridge between array-based and collection-based APIs. Further, this method allows precise control over the runtime type of the output array, and may, under certain circumstances, be used to save allocation costs.

Suppose x is a deque known to contain only strings. The following code can be used to dump the deque into a newly allocated array of String:

     String[] y = x.toArray(new String[0]);

Note that toArray(new Object[0]) is identical in function to toArray().

指定者：

接口 java.util.Collection<E> 中的 toArray

覆盖：

类 AbstractCollection<E> 中的 toArray

参数：

a - the array into which the elements of the deque are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose

返回：

an array containing all of the elements in this deque

抛出：

java.lang.ArrayStoreException - if the runtime type of the specified array is not a supertype of the runtime type of every element in this deque

java.lang.NullPointerException - if the specified array is null

clone

public ArrayDeque<E> clone()

Returns a copy of this deque.

覆盖：

类 java.lang.Object 中的 clone

返回：

a copy of this deque