E - the type of elements held in this collectionpublic class LinkedBlockingDeque<E> extends AbstractQueue<E> implements BlockingDeque<E>, Serializable
The optional capacity bound constructor argument serves as a
way to prevent excessive expansion. The capacity, if unspecified,
is equal to Integer.MAX_VALUE. Linked nodes are
dynamically created upon each insertion unless this would bring the
deque above capacity.
Most operations run in constant time (ignoring time spent
blocking). Exceptions include remove,
removeFirstOccurrence, removeLastOccurrence, contains, iterator.remove(), and the bulk
operations, all of which run in linear time.
This class and its iterator implement all of the
optional methods of the Collection and Iterator interfaces.
This class is a member of the Java Collections Framework.
| Constructor and Description |
|---|
LinkedBlockingDeque()
Creates a
LinkedBlockingDeque with a capacity of
Integer.MAX_VALUE. |
LinkedBlockingDeque(Collection<? extends E> c)
Creates a
LinkedBlockingDeque with a capacity of
Integer.MAX_VALUE, initially containing the elements of
the given collection, added in traversal order of the
collection's iterator. |
LinkedBlockingDeque(int capacity)
Creates a
LinkedBlockingDeque with the given (fixed) capacity. |
LinkedBlockingDeque(int capacity,
ReentrantLock lock)
Creates a
LinkedBlockingDeque with the given (fixed) capacity and
the caller's ReentrantLock object. |
LinkedBlockingDeque(ReentrantLock lock)
Creates a
LinkedBlockingDeque with a capacity of
Integer.MAX_VALUE using the caller's lock. |
| Modifier and Type | Method and Description |
|---|---|
boolean |
add(E e)
Inserts the specified element at the end of this deque unless it would
violate capacity restrictions.
|
void |
addFirst(E e) |
void |
addLast(E e) |
void |
clear()
Atomically removes all of the elements from this deque.
|
boolean |
contains(Object o)
Returns
true if this deque contains the specified element. |
Iterator<E> |
descendingIterator()
Returns an iterator over the elements in this deque in reverse
sequential order.
|
int |
drainTo(Collection<? super E> c) |
int |
drainTo(Collection<? super E> c,
int maxElements) |
E |
element()
Retrieves, but does not remove, the head of the queue represented by
this deque.
|
E |
getFirst() |
E |
getLast() |
Iterator<E> |
iterator()
Returns an iterator over the elements in this deque in proper sequence.
|
boolean |
offer(E e) |
boolean |
offer(E e,
long timeout,
TimeUnit unit) |
boolean |
offerFirst(E e) |
boolean |
offerFirst(E e,
long timeout,
TimeUnit unit) |
boolean |
offerLast(E e) |
boolean |
offerLast(E e,
long timeout,
TimeUnit unit) |
E |
peek() |
E |
peekFirst() |
E |
peekLast() |
E |
poll() |
E |
poll(long timeout,
TimeUnit unit) |
E |
pollFirst() |
E |
pollFirst(long timeout,
TimeUnit unit) |
E |
pollLast() |
E |
pollLast(long timeout,
TimeUnit unit) |
E |
pop() |
void |
push(E e) |
void |
put(E e) |
void |
putFirst(E e) |
void |
putLast(E e) |
int |
remainingCapacity()
Returns the number of additional elements that this deque can ideally
(in the absence of memory or resource constraints) accept without
blocking.
|
E |
remove()
Retrieves and removes the head of the queue represented by this deque.
|
boolean |
remove(Object o)
Removes the first occurrence of the specified element from this deque.
|
E |
removeFirst() |
boolean |
removeFirstOccurrence(Object o) |
E |
removeLast() |
boolean |
removeLastOccurrence(Object o) |
int |
size()
Returns the number of elements in this deque.
|
E |
take() |
E |
takeFirst() |
E |
takeLast() |
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; the runtime type of the returned array is that of
the specified array.
|
String |
toString() |
addAllcontainsAll, isEmpty, removeAll, retainAllclone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, waitaddAll, containsAll, equals, hashCode, isEmpty, removeAll, retainAllpublic LinkedBlockingDeque()
LinkedBlockingDeque with a capacity of
Integer.MAX_VALUE.public LinkedBlockingDeque(ReentrantLock lock)
LinkedBlockingDeque with a capacity of
Integer.MAX_VALUE using the caller's lock.public LinkedBlockingDeque(int capacity)
LinkedBlockingDeque with the given (fixed) capacity.capacity - the capacity of this dequeIllegalArgumentException - if capacity is less than 1public LinkedBlockingDeque(int capacity,
ReentrantLock lock)
LinkedBlockingDeque with the given (fixed) capacity and
the caller's ReentrantLock object.
Caution: By using the caller's lock, this constructor allows the caller to break the encapsulation of the synchronization and lock-based notification (signals). This can be used advantageously to create designs where an outer lock is shared by the collection which avoid deadlock arising from blocking operations on an inner lock while holding a distinct outer lock. However, the caller's decisions about its lock are no longer independent of the design decisions within this class since they share the same lock.
capacity - the capacity of this dequelock - the lock object.IllegalArgumentException - if capacity is less than 1public LinkedBlockingDeque(Collection<? extends E> c)
LinkedBlockingDeque with a capacity of
Integer.MAX_VALUE, initially containing the elements of
the given collection, added in traversal order of the
collection's iterator.c - the collection of elements to initially containNullPointerException - if the specified collection or any
of its elements are nullpublic void addFirst(E e)
addFirst in interface BlockingDeque<E>addFirst in interface Deque<E>IllegalStateExceptionNullPointerExceptionpublic void addLast(E e)
addLast in interface BlockingDeque<E>addLast in interface Deque<E>IllegalStateExceptionNullPointerExceptionpublic boolean offerFirst(E e)
offerFirst in interface BlockingDeque<E>offerFirst in interface Deque<E>NullPointerExceptionpublic boolean offerLast(E e)
offerLast in interface BlockingDeque<E>offerLast in interface Deque<E>NullPointerExceptionpublic void putFirst(E e) throws InterruptedException
putFirst in interface BlockingDeque<E>NullPointerExceptionInterruptedExceptionpublic void putLast(E e) throws InterruptedException
putLast in interface BlockingDeque<E>NullPointerExceptionInterruptedExceptionpublic boolean offerFirst(E e, long timeout, TimeUnit unit) throws InterruptedException
offerFirst in interface BlockingDeque<E>NullPointerExceptionInterruptedExceptionpublic boolean offerLast(E e, long timeout, TimeUnit unit) throws InterruptedException
offerLast in interface BlockingDeque<E>NullPointerExceptionInterruptedExceptionpublic E removeFirst()
removeFirst in interface Deque<E>NoSuchElementExceptionpublic E removeLast()
removeLast in interface Deque<E>NoSuchElementExceptionpublic E takeFirst() throws InterruptedException
takeFirst in interface BlockingDeque<E>InterruptedExceptionpublic E takeLast() throws InterruptedException
takeLast in interface BlockingDeque<E>InterruptedExceptionpublic E pollFirst(long timeout, TimeUnit unit) throws InterruptedException
pollFirst in interface BlockingDeque<E>InterruptedExceptionpublic E pollLast(long timeout, TimeUnit unit) throws InterruptedException
pollLast in interface BlockingDeque<E>InterruptedExceptionpublic E getFirst()
getFirst in interface Deque<E>NoSuchElementExceptionpublic E getLast()
getLast in interface Deque<E>NoSuchElementExceptionpublic boolean removeFirstOccurrence(Object o)
removeFirstOccurrence in interface BlockingDeque<E>removeFirstOccurrence in interface Deque<E>public boolean removeLastOccurrence(Object o)
removeLastOccurrence in interface BlockingDeque<E>removeLastOccurrence in interface Deque<E>public boolean add(E e)
offer.
This method is equivalent to addLast(E).
add in interface Collection<E>add in interface BlockingDeque<E>add in interface BlockingQueue<E>add in interface Deque<E>add in interface Queue<E>add in class AbstractQueue<E>IllegalStateException - if the element cannot be added at this
time due to capacity restrictionsNullPointerException - if the specified element is nullpublic boolean offer(E e)
offer in interface BlockingDeque<E>offer in interface BlockingQueue<E>offer in interface Deque<E>offer in interface Queue<E>NullPointerException - if the specified element is nullpublic void put(E e) throws InterruptedException
put in interface BlockingDeque<E>put in interface BlockingQueue<E>NullPointerExceptionInterruptedExceptionpublic boolean offer(E e, long timeout, TimeUnit unit) throws InterruptedException
offer in interface BlockingDeque<E>offer in interface BlockingQueue<E>NullPointerExceptionInterruptedExceptionpublic E remove()
poll only in that it throws an
exception if this deque is empty.
This method is equivalent to removeFirst.
remove in interface BlockingDeque<E>remove in interface Deque<E>remove in interface Queue<E>remove in class AbstractQueue<E>NoSuchElementException - if this deque is emptypublic E poll()
public E take() throws InterruptedException
take in interface BlockingDeque<E>take in interface BlockingQueue<E>InterruptedExceptionpublic E poll(long timeout, TimeUnit unit) throws InterruptedException
poll in interface BlockingDeque<E>poll in interface BlockingQueue<E>InterruptedExceptionpublic E element()
peek only in that
it throws an exception if this deque is empty.
This method is equivalent to getFirst.
element in interface BlockingDeque<E>element in interface Deque<E>element in interface Queue<E>element in class AbstractQueue<E>NoSuchElementException - if this deque is emptypublic E peek()
public int remainingCapacity()
size of this deque.
Note that you cannot always tell if an attempt to insert
an element will succeed by inspecting remainingCapacity
because it may be the case that another thread is about to
insert or remove an element.
remainingCapacity in interface BlockingQueue<E>public int drainTo(Collection<? super E> c)
drainTo in interface BlockingQueue<E>UnsupportedOperationExceptionClassCastExceptionNullPointerExceptionIllegalArgumentExceptionpublic int drainTo(Collection<? super E> c, int maxElements)
drainTo in interface BlockingQueue<E>UnsupportedOperationExceptionClassCastExceptionNullPointerExceptionIllegalArgumentExceptionpublic void push(E e)
push in interface BlockingDeque<E>push in interface Deque<E>IllegalStateExceptionNullPointerExceptionpublic E pop()
pop in interface Deque<E>NoSuchElementExceptionpublic boolean remove(Object o)
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.
remove in interface Collection<E>remove in interface BlockingDeque<E>remove in interface BlockingQueue<E>remove in interface Deque<E>remove in class AbstractCollection<E>o - element to be removed from this deque, if presenttrue if this deque changed as a result of the callpublic int size()
size in interface Collection<E>size in interface BlockingDeque<E>size in interface Deque<E>size in class AbstractCollection<E>public boolean contains(Object o)
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).contains in interface Collection<E>contains in interface BlockingDeque<E>contains in interface BlockingQueue<E>contains in interface Deque<E>contains in class AbstractCollection<E>o - object to be checked for containment in this dequetrue if this deque contains the specified elementpublic Object[] toArray()
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.
toArray in interface Collection<E>toArray in class AbstractCollection<E>public <T> T[] toArray(T[] a)
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().toArray in interface Collection<E>toArray in class AbstractCollection<E>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 purposeArrayStoreException - if the runtime type of the specified array
is not a supertype of the runtime type of every element in
this dequeNullPointerException - if the specified array is nullpublic String toString()
toString in class AbstractCollection<E>public void clear()
clear in interface Collection<E>clear in class AbstractQueue<E>public Iterator<E> iterator()
The returned iterator is a "weakly consistent" iterator that
will never throw ConcurrentModificationException, and guarantees to traverse
elements as they existed upon construction of the iterator, and
may (but is not guaranteed to) reflect any modifications
subsequent to construction.
iterator in interface Iterable<E>iterator in interface Collection<E>iterator in interface BlockingDeque<E>iterator in interface Deque<E>iterator in class AbstractCollection<E>public Iterator<E> descendingIterator()
The returned iterator is a "weakly consistent" iterator that
will never throw ConcurrentModificationException, and guarantees to traverse
elements as they existed upon construction of the iterator, and
may (but is not guaranteed to) reflect any modifications
subsequent to construction.
descendingIterator in interface Deque<E>Copyright © 2006–2019 SYSTAP, LLC DBA Blazegraph. All rights reserved.