| java.lang.Object | |||
| ↳ | java.util.AbstractCollection<E> | ||
| ↳ | java.util.AbstractQueue<E> | ||
| ↳ | java.util.concurrent.LinkedBlockingDeque<E> | ||
An optionally-bounded blocking deque based on linked nodes.
The optional capacity bound constructor argument serves as a
way to prevent excessive expansion. The capacity, if unspecified,
is equal to 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.
| Public Constructors | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Creates a
LinkedBlockingDeque with a capacity of
MAX_VALUE.
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Creates a
LinkedBlockingDeque with the given (fixed) capacity.
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Creates a
LinkedBlockingDeque with a capacity of
MAX_VALUE, initially containing the elements of
the given collection, added in traversal order of the
collection's iterator.
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| Public Methods | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Inserts the specified element at the end of this deque unless it would
violate capacity restrictions.
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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.
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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.
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Atomically removes all of the elements from this deque.
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Returns
true if this deque contains the specified element.
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Returns an iterator over the elements in this deque in reverse
sequential order.
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Removes all available elements from this queue and adds them
to the given collection.
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Removes at most the given number of available elements from
this queue and adds them to the given collection.
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Retrieves, but does not remove, the head of the queue represented by
this deque.
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Retrieves, but does not remove, the first element of this deque.
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Retrieves, but does not remove, the last element of this deque.
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Returns an iterator over the elements in this deque in proper sequence.
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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.
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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.
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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.
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Inserts the specified element at the front of this deque,
waiting up to the specified wait time if necessary for space to
become available.
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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.
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Inserts the specified element at the end of this deque,
waiting up to the specified wait time if necessary for space to
become available.
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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.
| |||||||||||
Retrieves, but does not remove, the first element of this deque,
or returns null if this deque is empty.
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Retrieves, but does not remove, the last element of this deque,
or returns null if this deque is empty.
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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.
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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.
| |||||||||||
Retrieves and removes the first element of this deque,
or returns null if this deque is empty.
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Retrieves and removes the first element of this deque, waiting
up to the specified wait time if necessary for an element to
become available.
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Retrieves and removes the last element of this deque,
or returns null if this deque is empty.
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Retrieves and removes the last element of this deque, waiting
up to the specified wait time if necessary for an element to
become available.
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Pops an element from the stack represented by this deque.
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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.
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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.
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Inserts the specified element at the front of this deque,
waiting if necessary for space to become available.
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Inserts the specified element at the end of this deque,
waiting if necessary for space to become available.
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Returns the number of additional elements that this deque can ideally
(in the absence of memory or resource constraints) accept without
blocking.
| |||||||||||
Retrieves and removes the head of the queue represented by this deque.
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Removes the first occurrence of the specified element from this deque.
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Retrieves and removes the first element of this deque.
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Removes the first occurrence of the specified element from this deque.
| |||||||||||
Retrieves and removes the last element of this deque.
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Removes the last occurrence of the specified element from this deque.
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Returns the number of elements in this deque.
| |||||||||||
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.
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Retrieves and removes the first element of this deque, waiting
if necessary until an element becomes available.
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Retrieves and removes the last element of this deque, waiting
if necessary until an element becomes available.
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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.
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Returns an array containing all of the elements in this deque, in
proper sequence (from first to last element).
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Returns the string representation of this
Collection.
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|
[Expand]
Inherited Methods | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
From class
java.util.AbstractQueue
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From class
java.util.AbstractCollection
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|
From class
java.lang.Object
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From interface
java.util.Queue
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From interface
java.util.Collection
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From interface
java.util.concurrent.BlockingDeque
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From interface
java.lang.Iterable
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From interface
java.util.concurrent.BlockingQueue
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From interface
java.util.Deque
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Creates a LinkedBlockingDeque with a capacity of
MAX_VALUE.
Creates a LinkedBlockingDeque with the given (fixed) capacity.
| capacity | the capacity of this deque |
|---|
| IllegalArgumentException | if capacity is less than 1
|
|---|
Creates a LinkedBlockingDeque with a capacity of
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 |
|---|
Inserts the specified element at the end of this deque unless it would
violate capacity restrictions. When using a capacity-restricted deque,
it is generally preferable to use method offer.
This method is equivalent to addLast(E).
| e | the element to add |
|---|
Developers
add(E))| IllegalStateException | if the element cannot be added at this time due to capacity restrictions |
|---|---|
| NullPointerException | if the specified element is null |
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.
| e | the element to add |
|---|
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.
| e | the element to add |
|---|
Atomically removes all of the elements from this deque. The deque will be empty after this call returns.
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).
| o | object to be checked for containment in this deque |
|---|
true if this deque contains the specified element
Returns an iterator over the elements in this deque in reverse sequential order. The elements will be returned in order from last (tail) to first (head).
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.
Removes all available elements from this queue and adds them
to the given collection. This operation may be more
efficient than repeatedly polling this queue. A failure
encountered while attempting to add elements to
collection 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.
| c | the collection to transfer elements into |
|---|
Removes at most the given number of available elements from
this queue and adds them to the given collection. A failure
encountered while attempting to add elements to
collection 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.
| c | the collection to transfer elements into |
|---|---|
| maxElements | the maximum number of elements to transfer |
Retrieves, but does not remove, the head of the queue represented by
this deque. This method differs from peek only in that
it throws an exception if this deque is empty.
This method is equivalent to getFirst.
| NoSuchElementException | if this deque is empty |
|---|
Retrieves, but does not remove, the first element of this deque.
This method differs from peekFirst only in that it
throws an exception if this deque is empty.
| NoSuchElementException |
|---|
Retrieves, but does not remove, the last element of this deque.
This method differs from peekLast only in that it
throws an exception if this deque is empty.
| NoSuchElementException |
|---|
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).
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.
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.
| e | the element to add |
|---|
| NullPointerException | if the specified element is null |
|---|
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.
| 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
falseInserts 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.
| e | the element to add |
|---|
| NullPointerException |
|---|
Inserts the specified element at the front of this deque, waiting up to the specified wait time if necessary for space to become available.
| 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 availableInserts 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.
| e | the element to add |
|---|
| NullPointerException |
|---|
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 | 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 availableRetrieves, 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.
null if this deque is empty
Retrieves, but does not remove, the first element of this deque, or returns null if this deque is empty.
Retrieves, but does not remove, the last element of this deque, or returns null if this deque is empty.
Retrieves and removes the head of the queue represented by this deque
(in other words, the first element of this deque), or returns
null if this deque is empty.
This method is equivalent to pollFirst().
null if this deque is empty
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.
| 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 |
|---|
Retrieves and removes the first element of this deque, or returns null if this deque is empty.
Retrieves and removes the first element of this deque, waiting up to the specified wait time if necessary for an element to become available.
| 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 |
|---|
Retrieves and removes the last element of this deque, or returns null if this deque is empty.
Retrieves and removes the last element of this deque, waiting up to the specified wait time if necessary for an element to become available.
| 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 |
|---|
Pops an element from the stack represented by this deque. In other words, removes and returns the first element of this deque.
This method is equivalent to removeFirst().
| NoSuchElementException |
|---|
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.
| e | the element to push |
|---|
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.
| e | the element to add |
|---|
Inserts the specified element at the front of this deque, waiting if necessary for space to become available.
| e | the element to add |
|---|
Inserts the specified element at the end of this deque, waiting if necessary for space to become available.
| e | the element to add |
|---|
Returns the number of additional elements that this deque can ideally
(in the absence of memory or resource constraints) accept without
blocking. This is always equal to the initial capacity of this deque
less the current 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.
Retrieves and removes the head of the queue represented by this deque.
This method differs from poll only in that it throws an
exception if this deque is empty.
This method is equivalent to removeFirst.
| NoSuchElementException | if this deque is empty |
|---|
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.
| o | element to be removed from this deque, if present |
|---|
true if this deque changed as a result of the call
Retrieves and removes the first element of this deque. This method
differs from pollFirst only in that it throws an
exception if this deque is empty.
| NoSuchElementException |
|---|
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).
| o | element to be removed from this deque, if present |
|---|
true if an element was removed as a result of this callRetrieves and removes the last element of this deque. This method
differs from pollLast only in that it throws an
exception if this deque is empty.
| NoSuchElementException |
|---|
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).
| o | element to be removed from this deque, if present |
|---|
true if an element was removed as a result of this callReturns the number of elements in this deque.
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.
| InterruptedException |
|---|
Retrieves and removes the first element of this deque, waiting if necessary until an element becomes available.
| InterruptedException |
|---|
Retrieves and removes the last element of this deque, waiting if necessary until an element becomes available.
| InterruptedException |
|---|
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. If the deque fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this deque.
If this deque fits in the specified array with room to spare
(i.e., the array has more elements than this deque), the element in
the array immediately following the end of the deque is set to
null.
Like the toArray() method, this method acts as bridge between
array-based and collection-based APIs. Further, this method allows
precise control over the runtime type of the output array, and may,
under certain circumstances, be used to save allocation costs.
Suppose x is a deque known to contain only strings.
The following code can be used to dump the deque into a newly
allocated array of String:
String[] y = x.toArray(new String[0]);
Note that toArray(new Object[0]) is identical in function to
toArray().| 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 |
Returns an array containing all of the elements in this deque, in proper sequence (from first to last element).
The returned array will be "safe" in that no references to it are maintained by this deque. (In other words, this method must allocate a new array). The caller is thus free to modify the returned array.
This method acts as bridge between array-based and collection-based APIs.
Returns the string representation of this Collection. The presentation
has a specific format. It is enclosed by square brackets ("[]"). Elements
are separated by ', ' (comma and space).
Collection.