E - the type of elements held in this dequeSerializable, Iterable<E>, Collection<E>, BlockingDeque<E>, BlockingQueue<E>, Deque<E>, Queue<E>, SequencedCollection<E>
public 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 | Description |
|---|---|
LinkedBlockingDeque() |
Creates a LinkedBlockingDeque with a capacity of Integer.MAX_VALUE. |
LinkedBlockingDeque |
Creates a LinkedBlockingDeque with the given (fixed) capacity. |
LinkedBlockingDeque |
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. |
| Modifier and Type | Method | Description |
|---|---|---|
boolean |
add |
Inserts the specified element at the end of this deque unless it would violate capacity restrictions. |
boolean |
addAll |
Appends all of the elements in the specified collection to the end of this deque, in the order that they are returned by the specified collection's iterator. |
void |
addFirst |
Inserts the specified element at the front of this deque if it is possible to do so immediately without violating capacity restrictions, throwing an IllegalStateException if no space is currently available. |
void |
addLast |
Inserts the specified element at the end of this deque if it is possible to do so immediately without violating capacity restrictions, throwing an IllegalStateException if no space is currently available. |
void |
clear() |
Atomically removes all of the elements from this deque. |
boolean |
contains |
Returns true if this deque contains the specified element. |
Iterator |
descendingIterator() |
Returns an iterator over the elements in this deque in reverse sequential order. |
int |
drainTo |
Removes all available elements from this queue and adds them to the given collection. |
int |
drainTo |
Removes at most the given number of available elements from this queue and adds them to the given collection. |
E |
element() |
Retrieves, but does not remove, the head of the queue represented by this deque. |
void |
forEach |
Performs the given action for each element of the Iterable until all elements have been processed or the action throws an exception. |
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. |
Iterator |
iterator() |
Returns an iterator over the elements in this deque in proper sequence. |
boolean |
offer |
Inserts the specified element into the queue represented by this deque (in other words, at the tail of this deque) if it is possible to do so immediately without violating capacity restrictions, returning true upon success and false if no space is currently available. |
boolean |
offer |
Inserts the specified element into the queue represented by this deque (in other words, at the tail of this deque), waiting up to the specified wait time if necessary for space to become available. |
boolean |
offerFirst |
Inserts the specified element at the front of this deque if it is possible to do so immediately without violating capacity restrictions, returning true upon success and false if no space is currently available. |
boolean |
offerFirst |
Inserts the specified element at the front of this deque, waiting up to the specified wait time if necessary for space to become available. |
boolean |
offerLast |
Inserts the specified element at the end of this deque if it is possible to do so immediately without violating capacity restrictions, returning true upon success and false if no space is currently available. |
boolean |
offerLast |
Inserts the specified element at the end of this deque, waiting up to the specified wait time if necessary for space to become available. |
E |
peek() |
Retrieves, but does not remove, 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 |
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 |
poll |
Retrieves and removes the head of the queue represented by this deque (in other words, the first element of this deque), waiting up to the specified wait time if necessary for an element to become available. |
E |
pollFirst() |
Retrieves and removes 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, waiting up to the specified wait time if necessary for an element to become available. |
E |
pollLast() |
Retrieves and removes the last element of this deque, or returns null if this deque is empty. |
E |
pollLast |
Retrieves and removes the last element of this deque, waiting up to the specified wait time if necessary for an element to become available. |
E |
pop() |
Pops an element from the stack represented by this deque. |
void |
push |
Pushes an element onto the stack represented by this deque (in other words, at the head of this deque) if it is possible to do so immediately without violating capacity restrictions, throwing an IllegalStateException if no space is currently available. |
void |
put |
Inserts the specified element into the queue represented by this deque (in other words, at the tail of this deque), waiting if necessary for space to become available. |
void |
putFirst |
Inserts the specified element at the front of this deque, waiting if necessary for space to become available. |
void |
putLast |
Inserts the specified element at the end of this deque, waiting if necessary for space to become available. |
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 |
Removes the first occurrence of the specified element from this deque. |
boolean |
removeAll |
Removes all of this collection's elements that are also contained in the specified collection (optional operation). |
E |
removeFirst() |
Retrieves and removes the first element of this deque. |
boolean |
removeFirstOccurrence |
Removes the first occurrence of the specified element from this deque. |
boolean |
removeIf |
Removes all of the elements of this collection that satisfy the given predicate. |
E |
removeLast() |
Retrieves and removes the last element of this deque. |
boolean |
removeLastOccurrence |
Removes the last occurrence of the specified element from this deque. |
boolean |
retainAll |
Retains only the elements in this collection that are contained in the specified collection (optional operation). |
int |
size() |
Returns the number of elements in this deque. |
Spliterator |
spliterator() |
Returns a Spliterator over the elements in this deque. |
E |
take() |
Retrieves and removes the head of the queue represented by this deque (in other words, the first element of this deque), waiting if necessary until an element becomes available. |
E |
takeFirst() |
Retrieves and removes the first element of this deque, waiting if necessary until an element becomes available. |
E |
takeLast() |
Retrieves and removes the last element of this deque, waiting if necessary until an element becomes available. |
Object[] |
toArray() |
Returns an array containing all of the elements in this deque, in proper sequence (from first to last element). |
<T> T[] |
toArray |
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. |
containsAll, isEmpty, toString
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
containsAll, equals, hashCode, isEmpty, parallelStream, stream, toArray
public LinkedBlockingDeque()
LinkedBlockingDeque with a capacity of Integer.MAX_VALUE.public LinkedBlockingDeque(int capacity)
LinkedBlockingDeque with the given (fixed) capacity.capacity - the capacity of this dequeIllegalArgumentException - 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)
BlockingDequeIllegalStateException if no space is currently available. When using a capacity-restricted deque, it is generally preferable to use offerFirst.addFirst in interface BlockingDeque<E>
addFirst in interface Deque<E>
addFirst in interface SequencedCollection<E>
e - the element to addIllegalStateException - if this deque is fullNullPointerException - if the specified element is nullpublic void addLast(E e)
BlockingDequeIllegalStateException if no space is currently available. When using a capacity-restricted deque, it is generally preferable to use offerLast.addLast in interface BlockingDeque<E>
addLast in interface Deque<E>
addLast in interface SequencedCollection<E>
e - the element to addIllegalStateException - if this deque is fullNullPointerException - if the specified element is nullpublic boolean offerFirst(E e)
BlockingDequetrue upon success and false if no space is currently available. When using a capacity-restricted deque, this method is generally preferable to the addFirst method, which can fail to insert an element only by throwing an exception.offerFirst in interface BlockingDeque<E>
offerFirst in interface Deque<E>
e - the element to addtrue if the element was added to this deque, else false
NullPointerException - if the specified element is nullpublic boolean offerLast(E e)
BlockingDequetrue upon success and false if no space is currently available. When using a capacity-restricted deque, this method is generally preferable to the addLast method, which can fail to insert an element only by throwing an exception.offerLast in interface BlockingDeque<E>
offerLast in interface Deque<E>
e - the element to addtrue if the element was added to this deque, else false
NullPointerException - if the specified element is nullpublic void putFirst(E e) throws InterruptedException
BlockingDequeputFirst in interface BlockingDeque<E>
e - the element to addNullPointerException - if the specified element is nullInterruptedException - if interrupted while waitingpublic void putLast(E e) throws InterruptedException
BlockingDequeputLast in interface BlockingDeque<E>
e - the element to addNullPointerException - if the specified element is nullInterruptedException - if interrupted while waitingpublic boolean offerFirst(E e, long timeout, TimeUnit unit) throws InterruptedException
BlockingDequeofferFirst in interface BlockingDeque<E>
e - the element to addtimeout - how long to wait before giving up, in units of unit
unit - a TimeUnit determining how to interpret the timeout parametertrue if successful, or false if the specified waiting time elapses before space is availableNullPointerException - if the specified element is nullInterruptedException - if interrupted while waitingpublic boolean offerLast(E e, long timeout, TimeUnit unit) throws InterruptedException
BlockingDequeofferLast in interface BlockingDeque<E>
e - the element to addtimeout - how long to wait before giving up, in units of unit
unit - a TimeUnit determining how to interpret the timeout parametertrue if successful, or false if the specified waiting time elapses before space is availableNullPointerException - if the specified element is nullInterruptedException - if interrupted while waitingpublic E removeFirst()
DequepollFirst only in that it throws an exception if this deque is empty.removeFirst in interface Deque<E>
removeFirst in interface SequencedCollection<E>
NoSuchElementException - if this deque is emptypublic E removeLast()
DequepollLast only in that it throws an exception if this deque is empty.removeLast in interface Deque<E>
removeLast in interface SequencedCollection<E>
NoSuchElementException - if this deque is emptypublic E pollFirst()
Dequenull if this deque is empty.public E pollLast()
Dequenull if this deque is empty.public E takeFirst() throws InterruptedException
BlockingDequetakeFirst in interface BlockingDeque<E>
InterruptedException - if interrupted while waitingpublic E takeLast() throws InterruptedException
BlockingDequetakeLast in interface BlockingDeque<E>
InterruptedException - if interrupted while waitingpublic E pollFirst(long timeout, TimeUnit unit) throws InterruptedException
BlockingDequepollFirst in interface BlockingDeque<E>
timeout - how long to wait before giving up, in units of unit
unit - a TimeUnit determining how to interpret the timeout parameternull if the specified waiting time elapses before an element is availableInterruptedException - if interrupted while waitingpublic E pollLast(long timeout, TimeUnit unit) throws InterruptedException
BlockingDequepollLast in interface BlockingDeque<E>
timeout - how long to wait before giving up, in units of unit
unit - a TimeUnit determining how to interpret the timeout parameternull if the specified waiting time elapses before an element is availableInterruptedException - if interrupted while waitingpublic E getFirst()
DequepeekFirst only in that it throws an exception if this deque is empty.getFirst in interface Deque<E>
getFirst in interface SequencedCollection<E>
NoSuchElementException - if this deque is emptypublic E getLast()
DequepeekLast only in that it throws an exception if this deque is empty.getLast in interface Deque<E>
getLast in interface SequencedCollection<E>
NoSuchElementException - if this deque is emptypublic E peekFirst()
Dequenull if this deque is empty.public E peekLast()
Dequenull if this deque is empty.public boolean removeFirstOccurrence(Object o)
BlockingDequee 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).removeFirstOccurrence in interface BlockingDeque<E>
removeFirstOccurrence in interface Deque<E>
o - element to be removed from this deque, if presenttrue if an element was removed as a result of this callpublic boolean removeLastOccurrence(Object o)
BlockingDequee 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).removeLastOccurrence in interface BlockingDeque<E>
removeLastOccurrence in interface Deque<E>
o - element to be removed from this deque, if presenttrue if an element was removed as a result of this callpublic boolean add(E e)
offer. This method is equivalent to addLast(E).
add in interface BlockingDeque<E>
add in interface BlockingQueue<E>
add in interface Collection<E>
add in interface Deque<E>
add in interface Queue<E>
add in class AbstractQueue<E>
e - the element to addtrue (as specified by Collection.add(E))IllegalStateException - if this deque is fullNullPointerException - if the specified element is nullpublic boolean offer(E e)
BlockingDequetrue upon success and false if no space is currently available. When using a capacity-restricted deque, this method is generally preferable to the BlockingDeque.add(E) method, which can fail to insert an element only by throwing an exception. This method is equivalent to offerLast.
offer in interface BlockingDeque<E>
offer in interface BlockingQueue<E>
offer in interface Deque<E>
offer in interface Queue<E>
e - the element to addtrue if the element was added to this queue, else false
NullPointerException - if the specified element is nullpublic void put(E e) throws InterruptedException
BlockingDequeThis method is equivalent to putLast.
put in interface BlockingDeque<E>
put in interface BlockingQueue<E>
e - the element to addNullPointerException - if the specified element is nullInterruptedException - if interrupted while waitingpublic boolean offer(E e, long timeout, TimeUnit unit) throws InterruptedException
BlockingDequeThis method is equivalent to offerLast.
offer in interface BlockingDeque<E>
offer in interface BlockingQueue<E>
e - the element to addtimeout - how long to wait before giving up, in units of unit
unit - a TimeUnit determining how to interpret the timeout parametertrue if the element was added to this deque, else false
NullPointerException - if the specified element is nullInterruptedException - if interrupted while waitingpublic 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()
BlockingDequenull if this deque is empty. This method is equivalent to Deque.pollFirst().
public E take() throws InterruptedException
BlockingDequeThis method is equivalent to takeFirst.
take in interface BlockingDeque<E>
take in interface BlockingQueue<E>
InterruptedException - if interrupted while waitingpublic E poll(long timeout, TimeUnit unit) throws InterruptedException
BlockingDequeThis method is equivalent to pollFirst.
poll in interface BlockingDeque<E>
poll in interface BlockingQueue<E>
timeout - how long to wait before giving up, in units of unit
unit - a TimeUnit determining how to interpret the timeout parameternull if the specified waiting time elapses before an element is availableInterruptedException - if interrupted while waitingpublic 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()
BlockingDequenull if this deque is empty. This method is equivalent to peekFirst.
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)
BlockingQueuec may result in elements being in neither, either or both collections when the associated exception is thrown. Attempts to drain a queue to itself result in IllegalArgumentException. Further, the behavior of this operation is undefined if the specified collection is modified while the operation is in progress.drainTo in interface BlockingQueue<E>
c - the collection to transfer elements intoUnsupportedOperationException - if addition of elements is not supported by the specified collectionClassCastException - if the class of an element of this queue prevents it from being added to the specified collectionNullPointerException - if the specified collection is nullIllegalArgumentException - if the specified collection is this queue, or some property of an element of this queue prevents it from being added to the specified collectionpublic int drainTo(Collection<? super E> c, int maxElements)
BlockingQueuec may result in elements being in neither, either or both collections when the associated exception is thrown. Attempts to drain a queue to itself result in IllegalArgumentException. Further, the behavior of this operation is undefined if the specified collection is modified while the operation is in progress.drainTo in interface BlockingQueue<E>
c - the collection to transfer elements intomaxElements - the maximum number of elements to transferUnsupportedOperationException - if addition of elements is not supported by the specified collectionClassCastException - if the class of an element of this queue prevents it from being added to the specified collectionNullPointerException - if the specified collection is nullIllegalArgumentException - if the specified collection is this queue, or some property of an element of this queue prevents it from being added to the specified collectionpublic void push(E e)
BlockingDequeIllegalStateException if no space is currently available. This method is equivalent to addFirst.
push in interface BlockingDeque<E>
push in interface Deque<E>
e - the element to pushIllegalStateException - if this deque is fullNullPointerException - if the specified element is nullpublic E pop()
DequeThis method is equivalent to Deque.removeFirst().
pop in interface Deque<E>
NoSuchElementException - if this deque is emptypublic 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 BlockingDeque<E>
remove in interface BlockingQueue<E>
remove in interface Collection<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 BlockingDeque<E>
size in interface Collection<E>
size in interface Deque<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 BlockingDeque<E>
contains in interface BlockingQueue<E>
contains in interface Collection<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 boolean addAll(Collection<? extends E> c)
addAll of a deque to itself result in IllegalArgumentException.addAll in interface Collection<E>
addAll in interface Deque<E>
addAll in class AbstractQueue<E>
c - the elements to be inserted into this dequetrue if this deque changed as a result of the callNullPointerException - if the specified collection or any of its elements are nullIllegalArgumentException - if the collection is this dequeIllegalStateException - if this deque is fullpublic 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>
T - the component type of the array to contain the collectiona - 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 void clear()
clear in interface Collection<E>
clear in class AbstractQueue<E>
public Iterator<E> iterator()
The returned iterator is weakly consistent.
iterator in interface BlockingDeque<E>
iterator in interface Collection<E>
iterator in interface Deque<E>
iterator in interface Iterable<E>
iterator in class AbstractCollection<E>
public Iterator<E> descendingIterator()
The returned iterator is weakly consistent.
descendingIterator in interface Deque<E>
public Spliterator<E> spliterator()
Spliterator over the elements in this deque. The returned spliterator is weakly consistent.
The Spliterator reports Spliterator.CONCURRENT, Spliterator.ORDERED, and Spliterator.NONNULL.
spliterator in interface Collection<E>
spliterator in interface Iterable<E>
Spliterator implements trySplit to permit limited parallelism.Spliterator over the elements in this dequepublic void forEach(Consumer<? super E> action)
IterableIterable until all elements have been processed or the action throws an exception. Actions are performed in the order of iteration, if that order is specified. Exceptions thrown by the action are relayed to the caller. The behavior of this method is unspecified if the action performs side-effects that modify the underlying source of elements, unless an overriding class has specified a concurrent modification policy.
forEach in interface Iterable<E>
action - The action to be performed for each elementNullPointerException - if the specified action is nullpublic boolean removeIf(Predicate<? super E> filter)
CollectionremoveIf in interface Collection<E>
filter - a predicate which returns true for elements to be removedtrue if any elements were removedNullPointerException - if the specified filter is nullpublic boolean removeAll(Collection<?> c)
AbstractCollectionremoveAll in interface Collection<E>
removeAll in class AbstractCollection<E>
c - collection containing elements to be removed from this collectiontrue if this collection changed as a result of the callNullPointerException - if this collection contains one or more null elements and the specified collection does not support null elements (optional) or if the specified collection is nullpublic boolean retainAll(Collection<?> c)
AbstractCollectionretainAll in interface Collection<E>
retainAll in class AbstractCollection<E>
c - collection containing elements to be retained in this collectiontrue if this collection changed as a result of the callNullPointerException - if this collection contains one or more null elements and the specified collection does not permit null elements (optional) or if the specified collection is null
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/util/concurrent/LinkedBlockingDeque.html