Type Parameters:

E - the type of elements held in this collection

All Superinterfaces:

BlockingQueue<E>, Collection<E>, Deque<E>, Iterable<E>, Queue<E>

All Known Implementing Classes:

LinkedBlockingDeque

public interface BlockingDeque<E>
extends BlockingQueue<E>, Deque<E>

Since:

1.6

• Method Summary

  All Methods

  Modifier and Type	Method	Description
  boolean	add (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 throwing an IllegalStateException if no space is currently available.
  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.
  boolean	contains (Object o)	Returns true if this deque contains the specified element.
  E	element ()	Retrieves, but does not remove, the head of the queue represented by this deque (in other words, the first element of this deque).
  Iterator<E>	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 unit)	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 unit)	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 unit)	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	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 unit)	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 (long timeout, TimeUnit unit)	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 (long timeout, TimeUnit unit)	Retrieves and removes the last element of this deque, waiting up to the specified wait time if necessary for an element to become available.
  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.
  E	remove ()	Retrieves and removes the head of the queue represented by this deque (in other words, the first element of this deque).
  boolean	remove (Object o)	Removes the first occurrence of the specified element from this deque.
  boolean	removeFirstOccurrence (Object o)	Removes the first occurrence of the specified element from this deque.
  boolean	removeLastOccurrence (Object o)	Removes the last occurrence of the specified element from this deque.
  int	size ()	Returns the number of 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.

  • Methods inherited from interface java.util.concurrent.BlockingQueue

    drainTo, drainTo, remainingCapacity

  • Methods inherited from interface java.util.Deque

    descendingIterator, getFirst, getLast, peekFirst, peekLast, pollFirst, pollLast, pop, removeFirst, removeLast

  • Methods inherited from interface java.util.Collection

    addAll, clear, containsAll, equals, hashCode, isEmpty, parallelStream, removeAll, removeIf, retainAll, spliterator, stream, toArray, toArray

  • Methods inherited from interface java.lang.Iterable

    forEach

• Method Detail

  • addFirst

    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. When using a capacity-restricted deque, it is generally preferable to use offerFirst.

    Specified by:

    addFirst in interface Deque<E>

    Parameters:

    e - the element to add

    Throws:

    IllegalStateException - if the element cannot be added at this time due to capacity restrictions

    ClassCastException - if the class of the specified element prevents it from being added to this deque

    NullPointerException - if the specified element is null

    IllegalArgumentException - if some property of the specified element prevents it from being added to this deque

  • addLast

    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. When using a capacity-restricted deque, it is generally preferable to use offerLast.

    Specified by:

    addLast in interface Deque<E>

    Parameters:

    e - the element to add

    Throws:

    IllegalStateException - if the element cannot be added at this time due to capacity restrictions

    ClassCastException - if the class of the specified element prevents it from being added to this deque

    NullPointerException - if the specified element is null

    IllegalArgumentException - if some property of the specified element prevents it from being added to this deque

  • offerFirst

    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. 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.

    Specified by:

    offerFirst in interface Deque<E>

    Parameters:

    e - the element to add

    Returns:

    true if the element was added to this deque, else false

    Throws:

    ClassCastException - if the class of the specified element prevents it from being added to this deque

    NullPointerException - if the specified element is null

    IllegalArgumentException - if some property of the specified element prevents it from being added to this deque

  • offerLast

    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. 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.

    Specified by:

    offerLast in interface Deque<E>

    Parameters:

    e - the element to add

    Returns:

    true if the element was added to this deque, else false

    Throws:

    ClassCastException - if the class of the specified element prevents it from being added to this deque

    NullPointerException - if the specified element is null

    IllegalArgumentException - if some property of the specified element prevents it from being added to this deque

  • putFirst

    void putFirst(E e)
     throws InterruptedException 

    Inserts the specified element at the front of this deque, waiting if necessary for space to become available.

    Parameters:

    e - the element to add

    Throws:

    InterruptedException - if interrupted while waiting

    ClassCastException - if the class of the specified element prevents it from being added to this deque

    NullPointerException - if the specified element is null

    IllegalArgumentException - if some property of the specified element prevents it from being added to this deque

  • putLast

    void putLast(E e)
     throws InterruptedException 

    Inserts the specified element at the end of this deque, waiting if necessary for space to become available.

    Parameters:

    e - the element to add

    Throws:

    InterruptedException - if interrupted while waiting

    ClassCastException - if the class of the specified element prevents it from being added to this deque

    NullPointerException - if the specified element is null

    IllegalArgumentException - if some property of the specified element prevents it from being added to this deque

  • offerFirst

    boolean offerFirst(E e,
     long timeout,
     TimeUnit unit)
     throws InterruptedException 

    Inserts the specified element at the front of this deque, waiting up to the specified wait time if necessary for space to become available.

    Parameters:

    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

    Returns:

    true if successful, or false if the specified waiting time elapses before space is available

    Throws:

    InterruptedException - if interrupted while waiting

    ClassCastException - if the class of the specified element prevents it from being added to this deque

    NullPointerException - if the specified element is null

    IllegalArgumentException - if some property of the specified element prevents it from being added to this deque

  • offerLast

    boolean offerLast(E e,
     long timeout,
     TimeUnit unit)
     throws InterruptedException 

    Inserts the specified element at the end of this deque, waiting up to the specified wait time if necessary for space to become available.

    Parameters:

    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

    Returns:

    true if successful, or false if the specified waiting time elapses before space is available

    Throws:

    InterruptedException - if interrupted while waiting

    ClassCastException - if the class of the specified element prevents it from being added to this deque

    NullPointerException - if the specified element is null

    IllegalArgumentException - if some property of the specified element prevents it from being added to this deque

  • takeFirst

    E takeFirst()
     throws InterruptedException 

    Retrieves and removes the first element of this deque, waiting if necessary until an element becomes available.

    Returns:

    the head of this deque

    Throws:

    InterruptedException - if interrupted while waiting

  • takeLast

    E takeLast()
     throws InterruptedException 

    Retrieves and removes the last element of this deque, waiting if necessary until an element becomes available.

    Returns:

    the tail of this deque

    Throws:

    InterruptedException - if interrupted while waiting

  • pollFirst

    E pollFirst(long timeout,
     TimeUnit unit)
     throws InterruptedException 

    Retrieves and removes the first element of this deque, waiting up to the specified wait time if necessary for an element to become available.

    Parameters:

    timeout - how long to wait before giving up, in units of unit

    unit - a TimeUnit determining how to interpret the timeout parameter

    Returns:

    the head of this deque, or null if the specified waiting time elapses before an element is available

    Throws:

    InterruptedException - if interrupted while waiting

  • pollLast

    E pollLast(long timeout,
     TimeUnit unit)
     throws InterruptedException 

    Retrieves and removes the last element of this deque, waiting up to the specified wait time if necessary for an element to become available.

    Parameters:

    timeout - how long to wait before giving up, in units of unit

    unit - a TimeUnit determining how to interpret the timeout parameter

    Returns:

    the tail of this deque, or null if the specified waiting time elapses before an element is available

    Throws:

    InterruptedException - if interrupted while waiting

  • removeFirstOccurrence

    boolean removeFirstOccurrence(Object o)

    Removes the first occurrence 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).

    Specified by:

    removeFirstOccurrence in interface Deque<E>

    Parameters:

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

    Returns:

    true if an element was removed as a result of this call

    Throws:

    ClassCastException - if the class of the specified element is incompatible with this deque (optional)

    NullPointerException - if the specified element is null (optional)

  • removeLastOccurrence

    boolean removeLastOccurrence(Object o)

    Removes the last occurrence of the specified element from this deque. 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).

    Specified by:

    removeLastOccurrence in interface Deque<E>

    Parameters:

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

    Returns:

    true if an element was removed as a result of this call

    Throws:

    ClassCastException - if the class of the specified element is incompatible with this deque (optional)

    NullPointerException - if the specified element is null (optional)

  • add

    boolean add(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 throwing an IllegalStateException if no space is currently available. When using a capacity-restricted deque, it is generally preferable to use offer.

    This method is equivalent to addLast.

    Specified by:

    add in interface BlockingQueue<E>

    Specified by:

    add in interface Collection<E>

    Specified by:

    add in interface Deque<E>

    Specified by:

    add in interface Queue<E>

    Parameters:

    e - the element to add

    Returns:

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

    Throws:

    IllegalStateException - if the element cannot be added at this time due to capacity restrictions

    ClassCastException - if the class of the specified element prevents it from being added to this deque

    NullPointerException - if the specified element is null

    IllegalArgumentException - if some property of the specified element prevents it from being added to this deque

  • offer

    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. When using a capacity-restricted deque, this method is generally preferable to the add(E) method, which can fail to insert an element only by throwing an exception.

    This method is equivalent to offerLast.

    Specified by:

    offer in interface BlockingQueue<E>

    Specified by:

    offer in interface Deque<E>

    Specified by:

    offer in interface Queue<E>

    Parameters:

    e - the element to add

    Returns:

    true if the element was added to this queue, else false

    Throws:

    ClassCastException - if the class of the specified element prevents it from being added to this deque

    NullPointerException - if the specified element is null

    IllegalArgumentException - if some property of the specified element prevents it from being added to this deque

  • put

    void put(E e)
     throws InterruptedException 

    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.

    This method is equivalent to putLast.

    Specified by:

    put in interface BlockingQueue<E>

    Parameters:

    e - the element to add

    Throws:

    InterruptedException - if interrupted while waiting

    ClassCastException - if the class of the specified element prevents it from being added to this deque

    NullPointerException - if the specified element is null

    IllegalArgumentException - if some property of the specified element prevents it from being added to this deque

  • offer

    boolean offer(E e,
     long timeout,
     TimeUnit unit)
     throws InterruptedException 

    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.

    This method is equivalent to offerLast.

    Specified by:

    offer in interface BlockingQueue<E>

    Parameters:

    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

    Returns:

    true if the element was added to this deque, else false

    Throws:

    InterruptedException - if interrupted while waiting

    ClassCastException - if the class of the specified element prevents it from being added to this deque

    NullPointerException - if the specified element is null

    IllegalArgumentException - if some property of the specified element prevents it from being added to this deque

  • remove

    E remove()

    Retrieves and removes the head of the queue represented by this deque (in other words, the first element of 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.

    Specified by:

    remove in interface Deque<E>

    Specified by:

    remove in interface Queue<E>

    Returns:

    the head of the queue represented by this deque

    Throws:

    NoSuchElementException - if this deque is empty

  • poll

    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 Deque.pollFirst().

    Specified by:

    poll in interface Deque<E>

    Specified by:

    poll in interface Queue<E>

    Returns:

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

  • take

    E take()
    throws InterruptedException 

    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.

    This method is equivalent to takeFirst.

    Specified by:

    take in interface BlockingQueue<E>

    Returns:

    the head of this deque

    Throws:

    InterruptedException - if interrupted while waiting

  • poll

    E poll(long timeout,
     TimeUnit unit)
    throws InterruptedException 

    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.

    This method is equivalent to pollFirst.

    Specified by:

    poll in interface BlockingQueue<E>

    Parameters:

    timeout - how long to wait before giving up, in units of unit

    unit - a TimeUnit determining how to interpret the timeout parameter

    Returns:

    the head of this deque, or null if the specified waiting time elapses before an element is available

    Throws:

    InterruptedException - if interrupted while waiting

  • element

    E element()

    Retrieves, but does not remove, the head of the queue represented by this deque (in other words, the first element of 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.

    Specified by:

    element in interface Deque<E>

    Specified by:

    element in interface Queue<E>

    Returns:

    the head of this deque

    Throws:

    NoSuchElementException - if this deque is empty

  • peek

    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.

    This method is equivalent to peekFirst.

    Specified by:

    peek in interface Deque<E>

    Specified by:

    peek in interface Queue<E>

    Returns:

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

  • remove

    boolean remove(Object o)

    Removes the first occurrence 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.

    Specified by:

    remove in interface BlockingQueue<E>

    Specified by:

    remove in interface Collection<E>

    Specified by:

    remove in interface Deque<E>

    Parameters:

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

    Returns:

    true if this deque changed as a result of the call

    Throws:

    ClassCastException - if the class of the specified element is incompatible with this deque (optional)

    NullPointerException - if the specified element is null (optional)

  • contains

    boolean contains(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).

    Specified by:

    contains in interface BlockingQueue<E>

    Specified by:

    contains in interface Collection<E>

    Specified by:

    contains in interface Deque<E>

    Parameters:

    o - object to be checked for containment in this deque

    Returns:

    true if this deque contains the specified element

    Throws:

    ClassCastException - if the class of the specified element is incompatible with this deque (optional)

    NullPointerException - if the specified element is null (optional)

  • size

    int size()

    Returns the number of elements in this deque.

    Specified by:

    size in interface Collection<E>

    Specified by:

    size in interface Deque<E>

    Returns:

    the number of elements in this deque

  • iterator

    Iterator<E> iterator()

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

    Specified by:

    iterator in interface Collection<E>

    Specified by:

    iterator in interface Deque<E>

    Specified by:

    iterator in interface Iterable<E>

    Returns:

    an iterator over the elements in this deque in proper sequence

  • push

    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.

    This method is equivalent to addFirst.

    Specified by:

    push in interface Deque<E>

    Parameters:

    e - the element to push

    Throws:

    IllegalStateException - if the element cannot be added at this time due to capacity restrictions

    ClassCastException - if the class of the specified element prevents it from being added to this deque

    NullPointerException - if the specified element is null

    IllegalArgumentException - if some property of the specified element prevents it from being added to this deque