java.util.concurrent
类 LinkedBlockingQueue<E>
java.lang.Object
java.util.AbstractCollection<E>
java.util.AbstractQueue<E>
java.util.concurrent.LinkedBlockingQueue<E>
- 类型参数:
E
- the type of elements held in this collection
- 所有已实现的接口:
- Serializable, Iterable<E>, Collection<E>, BlockingQueue<E>, Queue<E>
public class LinkedBlockingQueue<E>extends AbstractQueue<E>implements BlockingQueue<E>, Serializable
An optionally-bounded blocking queue based on linked nodes. This queue orders elements FIFO (first-in-first-out). The head of the queue is that element that has been on the queue the longest time. The tail of the queue is that element that has been on the queue the shortest time. New elements are inserted at the tail of the queue, and the queue retrieval operations obtain elements at the head of the queue. Linked queues typically have higher throughput than array-based queues but less predictable performance in most concurrent applications.
The optional capacity bound constructor argument serves as a way to prevent excessive queue expansion. The capacity, if unspecified, is equal to Integer.MAX_VALUE. Linked nodes are dynamically created upon each insertion unless this would bring the queue above capacity.
This class implements all of the optional methods of the Collection and Iterator interfaces.
- 从以下版本开始:
- 1.5
- 作者:
- Doug Lea
- 另请参见:
- 序列化表格
构造方法摘要 | |
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LinkedBlockingQueue() Creates a LinkedBlockingQueue with a capacity of Integer.MAX_VALUE. |
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LinkedBlockingQueue(Collection<? extends E> c) Creates a LinkedBlockingQueue with a capacity of Integer.MAX_VALUE, initially containing the elements of the given collection, added in traversal order of the collection's iterator. |
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LinkedBlockingQueue(int capacity) Creates a LinkedBlockingQueue with the given (fixed) capacity. |
方法摘要 | ||
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void |
clear() Removes all elements of the queue, leaving it empty. |
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int |
drainTo(Collection<? super E> c) Removes all available elements from this queue and adds them into the given collection. |
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int |
drainTo(Collection<? super E> c, int maxElements) Removes at most the given number of available elements from this queue and adds them into the given collection. |
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Iterator<E> |
iterator() Returns an iterator over the elements in this queue in proper sequence. |
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boolean |
offer(E o) Inserts the specified element at the tail of this queue if possible, returning immediately if this queue is full. |
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boolean |
offer(E o, long timeout, TimeUnit unit) Inserts the specified element at the tail of this queue, waiting if necessary up to the specified wait time for space to become available. |
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E |
peek() Gets but does not remove the element at the head of the queue. |
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E |
poll() Gets and removes the element at the head of the queue, or returns null if there is no element in the queue. |
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E |
poll(long timeout, TimeUnit unit) Retrieves and removes the head of this queue, waiting if necessary up to the specified wait time if no elements are present on this queue. |
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void |
put(E o) Adds the specified element to the tail of this queue, waiting if necessary for space to become available. |
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int |
remainingCapacity() Returns the number of elements that this queue can ideally (in the absence of memory or resource constraints) accept without blocking. |
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boolean |
remove(Object o) Removes one instance of the specified object from this Collection if one is contained (optional). |
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int |
size() Returns the number of elements in this queue. |
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E |
take() Retrieves and removes the head of this queue, waiting if no elements are present on this queue. |
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Object[] |
toArray() Returns a new array containing all elements contained in this Collection . |
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toArray(T[] a) Returns an array containing all elements contained in this Collection . |
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String |
toString() Returns the string representation of this Collection . |
从类 java.util.AbstractQueue 继承的方法 |
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add, addAll, element, remove |
从类 java.util.AbstractCollection 继承的方法 |
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contains, containsAll, isEmpty, removeAll, retainAll |
从类 java.lang.Object 继承的方法 |
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equals, getClass, hashCode, notify, notifyAll, wait, wait, wait |
从接口 java.util.concurrent.BlockingQueue 继承的方法 |
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add |
从接口 java.util.Queue 继承的方法 |
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element, remove |
从接口 java.util.Collection 继承的方法 |
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addAll, contains, containsAll, equals, hashCode, isEmpty, removeAll, retainAll |
构造方法详细信息 |
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LinkedBlockingQueue
public LinkedBlockingQueue()
- Creates a LinkedBlockingQueue with a capacity of Integer.MAX_VALUE.
LinkedBlockingQueue
public LinkedBlockingQueue(int capacity)
- Creates a LinkedBlockingQueue with the given (fixed) capacity.
- 参数:
capacity
- the capacity of this queue.- 抛出:
IllegalArgumentException
- if capacity is not greater than zero.
LinkedBlockingQueue
public LinkedBlockingQueue(Collection<? extends E> c)
- Creates a LinkedBlockingQueue with a capacity of Integer.MAX_VALUE, initially containing the elements of the given collection, added in traversal order of the collection's iterator.
- 参数:
c
- the collection of elements to initially contain- 抛出:
NullPointerException
- if c or any element within it is null
方法详细信息 |
---|
size
public int size()
- Returns the number of elements in this queue.
- 指定者:
- 接口
Collection<E>
中的size
- 指定者:
- 类
AbstractCollection<E>
中的size
- 返回:
- the number of elements in this queue.
remainingCapacity
public int remainingCapacity()
- Returns the number of elements that this queue can ideally (in the absence of memory or resource constraints) accept without blocking. This is always equal to the initial capacity of this queue less the current size of this queue.
Note that you cannot always tell if an attempt to add an element will succeed by inspecting remainingCapacity because it may be the case that a waiting consumer is ready to take an element out of an otherwise full queue.
- 指定者:
- 接口
BlockingQueue<E>
中的remainingCapacity
- 返回:
- the remaining capacity
put
public void put(E o) throws InterruptedException
- Adds the specified element to the tail of this queue, waiting if necessary for space to become available.
- 指定者:
- 接口
BlockingQueue<E>
中的put
- 参数:
o
- the element to add- 抛出:
InterruptedException
- if interrupted while waiting.NullPointerException
- if the specified element is null.
offer
public boolean offer(E o, long timeout, TimeUnit unit) throws InterruptedException
- Inserts the specified element at the tail of this queue, waiting if necessary up to the specified wait time for space to become available.
- 指定者:
- 接口
BlockingQueue<E>
中的offer
- 参数:
o
- the element to addtimeout
- how long to wait before giving up, in units of unitunit
- a TimeUnit determining how to interpret the timeout parameter- 返回:
- true if successful, or false if the specified waiting time elapses before space is available.
- 抛出:
InterruptedException
- if interrupted while waiting.NullPointerException
- if the specified element is null.
offer
public boolean offer(E o)
- Inserts the specified element at the tail of this queue if possible, returning immediately if this queue is full.
- 指定者:
- 接口
BlockingQueue<E>
中的offer
- 指定者:
- 接口
Queue<E>
中的offer
- 参数:
o
- the element to add.- 返回:
- true if it was possible to add the element to this queue, else false
- 抛出:
NullPointerException
- if the specified element is null
take
public E take() throws InterruptedException
- 从接口
BlockingQueue
复制的描述 - Retrieves and removes the head of this queue, waiting if no elements are present on this queue.
- 指定者:
- 接口
BlockingQueue<E>
中的take
- 返回:
- the head of this queue
- 抛出:
InterruptedException
- if interrupted while waiting.
poll
public E poll(long timeout, TimeUnit unit) throws InterruptedException
- 从接口
BlockingQueue
复制的描述 - Retrieves and removes the head of this queue, waiting if necessary up to the specified wait time if no elements are present on this queue.
- 指定者:
- 接口
BlockingQueue<E>
中的poll
- 参数:
timeout
- how long to wait before giving up, in units of unitunit
- a TimeUnit determining how to interpret the timeout parameter- 返回:
- the head of this queue, or null if the specified waiting time elapses before an element is present.
- 抛出:
InterruptedException
- if interrupted while waiting.
poll
public E poll()
- 从接口
Queue
复制的描述 - Gets and removes the element at the head of the queue, or returns
null
if there is no element in the queue. - 指定者:
- 接口
Queue<E>
中的poll
- 返回:
- the element at the head of the queue or
null
if there is no element in the queue.
peek
public E peek()
- 从接口
Queue
复制的描述 - Gets but does not remove the element at the head of the queue.
- 指定者:
- 接口
Queue<E>
中的peek
- 返回:
- the element at the head of the queue or
null
if there is no element in the queue.
remove
public boolean remove(Object o)
- 从类
AbstractCollection
复制的描述 - Removes one instance of the specified object from this
Collection
if one is contained (optional). This implementation iterates over thisCollection
and tests for each elemente
returned by the iterator, whethere
is equal to the given object. Ifobject != null
then this test is performed usingobject.equals(e)
, otherwise usingobject == null
. If an element equal to the given object is found, then theremove
method is called on the iterator andtrue
is returned,false
otherwise. If the iterator does not support removing elements, anUnsupportedOperationException
is thrown. - 指定者:
- 接口
Collection<E>
中的remove
- 覆盖:
- 类
AbstractCollection<E>
中的remove
- 参数:
o
- the object to remove.- 返回:
true
if thisCollection
is modified,false
otherwise.
toArray
public Object[] toArray()
- 从接口
Collection
复制的描述 - Returns a new array containing all elements contained in this
Collection
. If the implementation has ordered elements it will return the element array in the same order as an iterator would return them. The array returned does not reflect any changes of theCollection
. A new array is created even if the underlying data structure is already an array. - 指定者:
- 接口
Collection<E>
中的toArray
- 覆盖:
- 类
AbstractCollection<E>
中的toArray
- 返回:
- an array of the elements from this
Collection
.
toArray
public <T> T[] toArray(T[] a)
- 从接口
Collection
复制的描述 - Returns an array containing all elements contained in this
Collection
. If the specified array is large enough to hold the elements, the specified array is used, otherwise an array of the same type is created. If the specified array is used and is larger than thisCollection
, the array element following theCollection
elements is set to null. If the implementation has ordered elements it will return the element array in the same order as an iterator would return them.toArray(new Object[0])
behaves exactly the same way astoArray()
does. - 指定者:
- 接口
Collection<E>
中的toArray
- 覆盖:
- 类
AbstractCollection<E>
中的toArray
- 参数:
a
- the array.- 返回:
- an array of the elements from this
Collection
.
toString
public String toString()
- 从类
AbstractCollection
复制的描述 - 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). - 覆盖:
- 类
AbstractCollection<E>
中的toString
- 返回:
- the string representation of this
Collection
.
clear
public void clear()
- 从类
AbstractQueue
复制的描述 - Removes all elements of the queue, leaving it empty.
- 指定者:
- 接口
Collection<E>
中的clear
- 覆盖:
- 类
AbstractQueue<E>
中的clear
- 另请参见:
- AbstractCollection.iterator(), AbstractCollection.isEmpty(), AbstractCollection.size()
drainTo
public int drainTo(Collection<? super E> c)
- 从接口
BlockingQueue
复制的描述 - Removes all available elements from this queue and adds them into 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.
- 指定者:
- 接口
BlockingQueue<E>
中的drainTo
- 参数:
c
- the collection to transfer elements into- 返回:
- the number of elements transferred.
drainTo
public int drainTo(Collection<? super E> c, int maxElements)
- 从接口
BlockingQueue
复制的描述 - Removes at most the given number of available elements from this queue and adds them into 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 inIllegalArgumentException. Further, the behavior of this operation is undefined if the specified collection is modified while the operation is in progress.
- 指定者:
- 接口
BlockingQueue<E>
中的drainTo
- 参数:
c
- the collection to transfer elements intomaxElements
- the maximum number of elements to transfer- 返回:
- the number of elements transferred.
iterator
public Iterator<E> iterator()
- Returns an iterator over the elements in this queue in proper sequence.The returned Iterator is a "weakly consistent" iterator thatwill never throw ConcurrentModificationException,and guarantees to traverse elements as they existed uponconstruction of the iterator, and may (but is not guaranteed to)reflect any modifications subsequent to construction.
- 指定者:
- 接口
Iterable<E>
中的iterator
- 指定者:
- 接口
Collection<E>
中的iterator
- 指定者:
- 类
AbstractCollection<E>
中的iterator
- 返回:
- an iterator over the elements in this queue in proper sequence.
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