public class java.util.concurrent
LinkedBlockingDeque<E>


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Java SE 6
  
Extends: AbstractCollection > AbstractQueue
Implements: BlockingDeque, Serializable
Details
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 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.
since1.6
Ethe type of elements held in this collection


Constructors
public LinkedBlockingDeque()
Creates a LinkedBlockingDeque with a capacity of Integer#MAX_VALUE.
public LinkedBlockingDeque(int capacity) Details
Creates a LinkedBlockingDeque with the given (fixed) capacity.
capacitythe capacity of this deque
ThrowsIllegalArgumentException: if capacity is less than 1
public LinkedBlockingDeque(Collection c) Details
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.
cthe collection of elements to initially contain
ThrowsNullPointerException: if the specified collection or any of its elements are null

Methods
public boolean add(Object e) Details
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.
ThrowsIllegalStateException: if the element cannot be added at this time due to capacity restrictions
ThrowsNullPointerException: als het gespecifieerde element null is

public void addFirst(Object e) Details
ThrowsIllegalStateException: if the element cannot be added at this time due to capacity restrictions
ThrowsNullPointerException: als het gespecifieerde element null is
public void addLast(Object e) Details
ThrowsIllegalStateException: if the element cannot be added at this time due to capacity restrictions
ThrowsNullPointerException: als het gespecifieerde element null is
public void clear()
Atomically removes all of the elements from this deque. The deque will be empty after this call returns.
public boolean contains(Object o) Details
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).
oobject to be checked for containment in this deque
returntrue if this deque contains the specified element
public Iterator descendingIterator()
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.
public int drainTo(Collection c) Details
ThrowsUnsupportedOperationException: if addition of elements is not supported by the specified collection
ThrowsClassCastException: if the class of an element of this queue prevents it from being added to the specified collection
ThrowsNullPointerException: if the specified collection is null
ThrowsIllegalArgumentException: 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 c, int maxElements) Details
ThrowsUnsupportedOperationException: if addition of elements is not supported by the specified collection
ThrowsClassCastException: if the class of an element of this queue prevents it from being added to the specified collection
ThrowsNullPointerException: if the specified collection is null
ThrowsIllegalArgumentException: 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 Object element() Details
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.
returnthe head of the queue represented by this deque
ThrowsNoSuchElementException: if this deque is empty

public Iterator iterator() Details
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.
returnan iterator over the elements in this deque in proper sequence
public boolean offer(Object e) Details
ThrowsNullPointerException: als het gespecifieerde element null is
public boolean offer(Object e, long timeout, TimeUnit unit) throws InterruptedException Details
ThrowsNullPointerException: als het gespecifieerde element null is
ThrowsInterruptedException: if interrupted while waiting
public boolean offerFirst(Object e) Details
ThrowsNullPointerException: als het gespecifieerde element null is
public boolean offerFirst(Object e, long timeout, TimeUnit unit) throws InterruptedException Details
ThrowsNullPointerException: als het gespecifieerde element null is
ThrowsInterruptedException: if interrupted while waiting
public boolean offerLast(Object e) Details
ThrowsNullPointerException: als het gespecifieerde element null is
public boolean offerLast(Object e, long timeout, TimeUnit unit) throws InterruptedException Details
ThrowsNullPointerException: als het gespecifieerde element null is
ThrowsInterruptedException: if interrupted while waiting
public Object peek()
public Object peekFirst()
public Object peekLast()
public Object poll()
public Object poll(long timeout, TimeUnit unit) throws InterruptedException
public Object pollFirst()
public Object pollFirst(long timeout, TimeUnit unit) throws InterruptedException
public Object pollLast()
public Object pollLast(long timeout, TimeUnit unit) throws InterruptedException
public Object pop() Details
ThrowsNoSuchElementException: if this deque is empty
public void push(Object e) Details
ThrowsIllegalStateException: if the element cannot be added at this time due to capacity restrictions
ThrowsNullPointerException: als het gespecifieerde element null is
public void put(Object e) throws InterruptedException Details
ThrowsNullPointerException: als het gespecifieerde element null is
ThrowsInterruptedException: if interrupted while waiting
public void putFirst(Object e) throws InterruptedException Details
ThrowsNullPointerException: als het gespecifieerde element null is
ThrowsInterruptedException: if interrupted while waiting
public void putLast(Object e) throws InterruptedException Details
ThrowsNullPointerException: als het gespecifieerde element null is
ThrowsInterruptedException: if interrupted while waiting
public int remainingCapacity()
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.

public Object remove() Details
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.
returnthe head of the queue represented by this deque
ThrowsNoSuchElementException: if this deque is empty

public boolean remove(Object o) Details
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.
oelement to be removed from this deque, if present
returntrue if this deque changed as a result of the call

public Object removeFirst() Details
ThrowsNoSuchElementException: if this deque is empty
public boolean removeFirstOccurrence(Object o)
public Object removeLast() Details
ThrowsNoSuchElementException: if this deque is empty
public boolean removeLastOccurrence(Object o)
public int size() Details
Returns the number of elements in this deque.
returnthe number of elements in this deque
public Object take() throws InterruptedException
public Object takeFirst() throws InterruptedException
public Object takeLast() throws InterruptedException
public Object[] toArray() Details
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.
returnan array containing all of the elements in this deque

public Object[]<T> toArray(Object[] a) Details
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().
athe 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
returnan array containing all of the elements in this deque
ThrowsArrayStoreException: if the runtime type of the specified array is not a supertype of the runtime type of every element in this deque
ThrowsNullPointerException: if the specified array is null
public String toString()

Properties
public Object getFirst() Details
ThrowsNoSuchElementException: if this deque is empty
public Object getLast() Details
ThrowsNoSuchElementException: if this deque is empty
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Java SE 6
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