E - the type of elements held in this collection
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. 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.
|
LinkedBlockingDeque(Collection
Creates a
LinkedBlockingDeque with a capacity of
Integer, 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.
|
| 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)
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(E e)
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(Object
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(Collection
Removes all available elements from this queue and adds them to the given collection.
|
int |
drainTo(Collection
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.
|
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(E e)
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(E e, long timeout, TimeUnit
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(E e)
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(E e, long timeout, TimeUnit
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(E e)
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(E e, long timeout, TimeUnit
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(long timeout, TimeUnit
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(long timeout, TimeUnit
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(long timeout, TimeUnit
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(E e)
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(E e)
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(E e)
Inserts the specified element at the front of this deque, waiting if necessary for space to become available.
|
void |
putLast(E e)
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(Object
Removes the first occurrence of the specified element from this deque.
|
E |
removeFirst()
Retrieves and removes the first element of this deque.
|
boolean |
removeFirstOccurrence(Object
Removes the first occurrence of the specified element from this deque.
|
E |
removeLast()
Retrieves and removes the last element of this deque.
|
boolean |
removeLastOccurrence(Object
Removes the last occurrence of the specified element from this deque.
|
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(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()
Returns a string representation of this collection.
|
addAllcontainsAll, isEmpty, removeAll, retainAllclone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, waitaddAll, containsAll, equals, hashCode, isEmpty, parallelStream, removeAll, removeIf, retainAll, streampublic LinkedBlockingDeque()
LinkedBlockingDeque with a capacity of
Integer.MAX_VALUE .
public LinkedBlockingDeque(int capacity)
LinkedBlockingDeque with the given (fixed) capacity.
capacity - the capacity of this deque
IllegalArgumentException - if
capacity is less than 1
public 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 contain
NullPointerException - if the specified collection or any of its elements are null
public void addFirst(E e)
BlockingDeque
IllegalStateException 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>
e - the element to add
IllegalStateException - if this deque is full
NullPointerException - if the specified element is null
public void addLast(E e)
BlockingDeque
IllegalStateException 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>
e - the element to add
IllegalStateException - if this deque is full
NullPointerException - if the specified element is null
public boolean offerFirst(E e)
BlockingDeque
true 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 add
true if the element was added to this deque, else
false
NullPointerException - if the specified element is null
public boolean offerLast(E e)
BlockingDeque
true 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 add
true if the element was added to this deque, else
false
NullPointerException - if the specified element is null
public void putFirst(E e) throws InterruptedException
BlockingDeque
putFirst in interface
BlockingDeque<E>
e - the element to add
NullPointerException - if the specified element is null
InterruptedException - if interrupted while waiting
public void putLast(E e) throws InterruptedException
BlockingDeque
putLast in interface
BlockingDeque<E>
e - the element to add
NullPointerException - if the specified element is null
InterruptedException - if interrupted while waiting
public boolean offerFirst(E e, long timeout, TimeUnitunit) throws InterruptedException
BlockingDeque
offerFirst in interface
BlockingDeque<E>
e - the element to add
timeout - how long to wait before giving up, in units of
unit
unit - a
TimeUnit determining how to interpret the
timeout parameter
true if successful, or
false if the specified waiting time elapses before space is available
NullPointerException - if the specified element is null
InterruptedException - if interrupted while waiting
public boolean offerLast(E e, long timeout, TimeUnitunit) throws InterruptedException
BlockingDeque
offerLast in interface
BlockingDeque<E>
e - the element to add
timeout - how long to wait before giving up, in units of
unit
unit - a
TimeUnit determining how to interpret the
timeout parameter
true if successful, or
false if the specified waiting time elapses before space is available
NullPointerException - if the specified element is null
InterruptedException - if interrupted while waiting
public E removeFirst()
Deque
pollFirst only in that it throws an exception if this deque is empty.
removeFirst in interface
Deque<E>
NoSuchElementException - if this deque is empty
public E removeLast()
Deque
pollLast only in that it throws an exception if this deque is empty.
removeLast in interface
Deque<E>
NoSuchElementException - if this deque is empty
public E pollFirst()
Deque
null if this deque is empty.
public E pollLast()
Deque
null if this deque is empty.
public E takeFirst() throws InterruptedException
BlockingDeque
takeFirst in interface
BlockingDeque<E>
InterruptedException - if interrupted while waiting
public E takeLast() throws InterruptedException
BlockingDeque
takeLast in interface
BlockingDeque<E>
InterruptedException - if interrupted while waiting
public E pollFirst(long timeout, TimeUnitunit) throws InterruptedException
BlockingDeque
pollFirst 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 parameter
null if the specified waiting time elapses before an element is available
InterruptedException - if interrupted while waiting
public E pollLast(long timeout, TimeUnitunit) throws InterruptedException
BlockingDeque
pollLast 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 parameter
null if the specified waiting time elapses before an element is available
InterruptedException - if interrupted while waiting
public E getFirst()
Deque
peekFirst only in that it throws an exception if this deque is empty.
getFirst in interface
Deque<E>
NoSuchElementException - if this deque is empty
public E getLast()
Deque
peekLast only in that it throws an exception if this deque is empty.
getLast in interface
Deque<E>
NoSuchElementException - if this deque is empty
public E peekFirst()
Deque
null if this deque is empty.
public E peekLast()
Deque
null if this deque is empty.
public boolean removeFirstOccurrence(Objecto)
BlockingDeque
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).
removeFirstOccurrence in interface
BlockingDeque<E>
removeFirstOccurrence in interface
Deque<E>
o - element to be removed from this deque, if present
true if an element was removed as a result of this call
public boolean removeLastOccurrence(Objecto)
BlockingDeque
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).
removeLastOccurrence in interface
BlockingDeque<E>
removeLastOccurrence in interface
Deque<E>
o - element to be removed from this deque, if present
true if an element was removed as a result of this call
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>
e - the element to add
Collection.add(E) )
IllegalStateException - if this deque is full
NullPointerException - if the specified element is null
public boolean offer(E e)
BlockingDeque
true 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 add
true if the element was added to this queue, else
false
NullPointerException - if the specified element is null
public void put(E e) throws InterruptedException
BlockingDeque
This method is equivalent to putLast.
put in interface
BlockingDeque<E>
put in interface
BlockingQueue<E>
e - the element to add
NullPointerException - if the specified element is null
InterruptedException - if interrupted while waiting
public boolean offer(E e, long timeout, TimeUnitunit) throws InterruptedException
BlockingDeque
This method is equivalent to offerLast.
offer in interface
BlockingDeque<E>
offer in interface
BlockingQueue<E>
e - the element to add
timeout - how long to wait before giving up, in units of
unit
unit - a
TimeUnit determining how to interpret the
timeout parameter
true if the element was added to this deque, else
false
NullPointerException - if the specified element is null
InterruptedException - if interrupted while waiting
public 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 empty
public E poll()
BlockingDeque
null if this deque is empty.
This method is equivalent to Deque.
public E take() throws InterruptedException
BlockingDeque
This method is equivalent to takeFirst.
take in interface
BlockingDeque<E>
take in interface
BlockingQueue<E>
InterruptedException - if interrupted while waiting
public E poll(long timeout, TimeUnitunit) throws InterruptedException
BlockingDeque
This 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 parameter
null if the specified waiting time elapses before an element is available
InterruptedException - if interrupted while waiting
public 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 empty
public E peek()
BlockingDeque
null 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)
BlockingQueue
c 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 into
UnsupportedOperationException - if addition of elements is not supported by the specified collection
ClassCastException - if the class of an element of this queue prevents it from being added to the specified collection
NullPointerException - if the specified collection is null
IllegalArgumentException - if the specified collection is this queue, or some property of an element of this queue prevents it from being added to the specified collection
public int drainTo(Collection<? super E> c, int maxElements)
BlockingQueue
c 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 into
maxElements - the maximum number of elements to transfer
UnsupportedOperationException - if addition of elements is not supported by the specified collection
ClassCastException - if the class of an element of this queue prevents it from being added to the specified collection
NullPointerException - if the specified collection is null
IllegalArgumentException - if the specified collection is this queue, or some property of an element of this queue prevents it from being added to the specified collection
public void push(E e)
BlockingDeque
IllegalStateException 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 push
IllegalStateException - if this deque is full
NullPointerException - if the specified element is null
public E pop()
Deque
This method is equivalent to Deque.
pop in interface
Deque<E>
NoSuchElementException - if this deque is empty
public boolean remove(Objecto)
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 present
true if this deque changed as a result of the call
public 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(Objecto)
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 deque
true if this deque contains the specified element
public 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 runtime type of the array to contain the collection
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
ArrayStoreException - if the runtime type of the specified array is not a supertype of the runtime type of every element in this deque
NullPointerException - if the specified array is null
public StringtoString()
AbstractCollection
String.valueOf(Object) .
toString in class
AbstractCollection<E>
public void clear()
public Iterator<E> iterator()
The returned iterator is weakly consistent.
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 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, Spliterator, and Spliterator.
spliterator in interface
Iterable<E>
spliterator in interface
Collection<E>
Spliterator over the elements in this deque