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Préférences
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JavaTM 2 Platform Std. Ed. v1.6.0
java.util.concurrent
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Constructor Summary | |
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PriorityBlockingQueue()
Creates a PriorityBlockingQueue with the default initial capacity (11) that orders its elements according to their natural ordering. |
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PriorityBlockingQueue(Collection<? extends E> c)
Creates a PriorityBlockingQueue containing the elements in the specified collection. |
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PriorityBlockingQueue(int initialCapacity)
Creates a PriorityBlockingQueue with the specified initial capacity that orders its elements according to their natural ordering. |
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PriorityBlockingQueue(int initialCapacity,
Comparator<? super E> comparator)
Creates a PriorityBlockingQueue with the specified initial capacity that orders its elements according to the specified comparator. |
Method Summary | ||
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boolean |
add(E e)
Inserts the specified element into this priority queue. |
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void |
clear()
Atomically removes all of the elements from this queue. |
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Comparator<? super E> |
comparator()
Returns the comparator used to order the elements in this queue, or null if this queue uses the natural ordering of its elements. |
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boolean |
contains(Object o)
Returns true if this queue contains the specified element. |
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int |
drainTo(Collection<? super E> c)
Removes all available elements from this queue and adds them to 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 to the given collection. |
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Iterator<E> |
iterator()
Returns an iterator over the elements in this queue. |
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boolean |
offer(E e)
Inserts the specified element into this priority queue. |
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boolean |
offer(E e,
long timeout,
TimeUnit unit)
Inserts the specified element into this priority queue. |
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E |
peek()
Retrieves, but does not remove, the head of this queue, or returns null if this queue is empty. |
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E |
poll()
Retrieves and removes the head of this queue, or returns null if this queue is empty. |
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E |
poll(long timeout,
TimeUnit unit)
Retrieves and removes the head of this queue, waiting up to the specified wait time if necessary for an element to become available. |
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void |
put(E e)
Inserts the specified element into this priority queue. |
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int |
remainingCapacity()
Always returns Integer.MAX_VALUE because a PriorityBlockingQueue is not capacity constrained. |
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boolean |
remove(Object o)
Removes a single instance of the specified element from this queue, if it is present. |
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int |
size()
Returns the number of elements in this collection. |
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E |
take()
Retrieves and removes the head of this queue, waiting if necessary until an element becomes available. |
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Object[] |
toArray()
Returns an array containing all of the elements in this queue. |
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toArray(T[] a)
Returns an array containing all of the elements in this queue; the runtime type of the returned array is that of the specified array. |
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String |
toString()
Returns a string representation of this collection. |
Methods inherited from class java.util.AbstractQueue |
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addAll, element, remove |
Methods inherited from class java.util.AbstractCollection |
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containsAll, isEmpty, removeAll, retainAll |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Methods inherited from interface java.util.Queue |
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element, remove |
Methods inherited from interface java.util.Collection |
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addAll, containsAll, equals, hashCode, isEmpty, removeAll, retainAll |
Constructor Detail |
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public PriorityBlockingQueue()
public PriorityBlockingQueue(int initialCapacity)
initialCapacity
- the initial capacity for this priority queue
IllegalArgumentException
- if initialCapacity is less
than 1public PriorityBlockingQueue(int initialCapacity, Comparator<? super E> comparator)
initialCapacity
- the initial capacity for this priority queuecomparator
- the comparator that will be used to order this
priority queue. If null
, the natural ordering of the elements will be used.
IllegalArgumentException
- if initialCapacity is less
than 1public PriorityBlockingQueue(Collection<? extends E> c)
SortedSet
or a PriorityQueue
, this
priority queue will be ordered according to the same ordering.
Otherwise, this priority queue will be ordered according to the
natural ordering of its elements.
c
- the collection whose elements are to be placed
into this priority queue
ClassCastException
- if elements of the specified collection
cannot be compared to one another according to the priority
queue's ordering
NullPointerException
- if the specified collection or any
of its elements are nullMethod Detail |
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public boolean add(E e)
add
in interface Collection<E>
add
in interface BlockingQueue<E>
add
in interface Queue<E>
add
in class AbstractQueue<E>
e
- the element to add
Collection.add(E)
)
ClassCastException
- if the specified element cannot be compared
with elements currently in the priority queue according to the
priority queue's ordering
NullPointerException
- if the specified element is nullpublic boolean offer(E e)
e
- the element to add
Queue.offer(E)
)
ClassCastException
- if the specified element cannot be compared
with elements currently in the priority queue according to the
priority queue's ordering
NullPointerException
- if the specified element is nullpublic void put(E e)
put
in interface BlockingQueue<E>
e
- the element to add
ClassCastException
- if the specified element cannot be compared
with elements currently in the priority queue according to the
priority queue's ordering
NullPointerException
- if the specified element is nullpublic boolean offer(E e, long timeout, TimeUnit unit)
offer
in interface BlockingQueue<E>
e
- the element to addtimeout
- This parameter is ignored as the method never blocksunit
- This parameter is ignored as the method never blocks
ClassCastException
- if the specified element cannot be compared
with elements currently in the priority queue according to the
priority queue's ordering
NullPointerException
- if the specified element is nullpublic E poll()
Queue
public E take() throws InterruptedException
BlockingQueue
take
in interface BlockingQueue<E>
InterruptedException
- if interrupted while waitingpublic E poll(long timeout, TimeUnit unit) throws InterruptedException
BlockingQueue
poll
in interface BlockingQueue<E>
timeout
- how long to wait before giving up, in units of
unitunit
- a TimeUnit determining how to interpret the
timeout parameter
InterruptedException
- if interrupted while waitingpublic E peek()
Queue
public Comparator<? super E> comparator()
public int size()
Collection
size
in interface Collection<E>
size
in class AbstractCollection<E>
public int remainingCapacity()
remainingCapacity
in interface BlockingQueue<E>
public boolean remove(Object o)
e
such
that o.equals(e)
, if this queue contains one or more such
elements. Returns true
if and only if this queue contained
the specified element (or equivalently, if this queue changed as a
result of the call).
remove
in interface Collection<E>
remove
in interface BlockingQueue<E>
remove
in class AbstractCollection<E>
o
- element to be removed from this queue, if present
public boolean contains(Object o)
true
if this queue contains the specified element.
More formally, returns true
if and only if this queue contains
at least one element e
such that o.equals(e)
.
contains
in interface Collection<E>
contains
in interface BlockingQueue<E>
contains
in class AbstractCollection<E>
o
- object to be checked for containment in this queue
public Object[] toArray()
The returned array will be "safe" in that no references to it are maintained by this queue. (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 String toString()
AbstractCollection
String.valueOf(Object)
.
toString
in class AbstractCollection<E>
public int drainTo(Collection<? super E> c)
BlockingQueue
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 collectionpublic int drainTo(Collection<? super E> c, int maxElements)
BlockingQueue
drainTo
in interface BlockingQueue<E>
c
- the collection to transfer elements intomaxElements
- 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 collectionpublic void clear()
clear
in interface Collection<E>
clear
in class AbstractQueue<E>
public <T> T[] toArray(T[] a)
If this queue fits in the specified array with room to spare (i.e., the array has more elements than this queue), the element in the array immediately following the end of the queue 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 queue known to contain only strings. The following code can be used to dump the queue 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>
a
- the array into which the elements of the queue 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 queue
NullPointerException
- if the specified array is nullpublic Iterator<E> iterator()
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.
iterator
in interface Iterable<E>
iterator
in interface Collection<E>
iterator
in class AbstractCollection<E>