| java.lang.Object | |||
| ↳ | java.util.AbstractCollection<E> | ||
| ↳ | java.util.AbstractQueue<E> | ||
| ↳ | java.util.concurrent.PriorityBlockingQueue<E> | ||
An unbounded blocking queue that uses the same ordering rules as class PriorityQueue and supplies blocking retrieval operations. While this queue is logically unbounded, attempted additions may fail due to resource exhaustion (causing OutOfMemoryError). This class does not permit null elements. A priority queue relying on natural ordering also does not permit insertion of non-comparable objects (doing so results in ClassCastException).
This class implements all of the optional methods of the Collection and Iterator interfaces.
The Iterator provided in method iterator() is not guaranteed to traverse the elements of the PriorityBlockingQueue in any particular order. If you need ordered traversal, consider using Arrays.sort(pq.toArray()).
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Creates a PriorityBlockingQueue with the default initial
capacity
(11) that orders its elements according to their natural
ordering (using Comparable).
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Creates a PriorityBlockingQueue with the specified initial
capacity
that orders its elements according to their natural ordering
(using Comparable).
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Creates a PriorityBlockingQueue with the specified initial
capacity
that orders its elements according to the specified comparator.
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Creates a PriorityBlockingQueue containing the elements
in the specified collection.
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| Public Methods | |||||||||||
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Adds the specified element to this queue.
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Atomically removes all of the elements from this delay queue.
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Returns the comparator used to order this collection, or null
if this collection is sorted according to its elements natural ordering
(using Comparable).
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Searches this Collection for the specified object.
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Removes at most the given number of available elements from
this queue and adds them into the given collection.
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Removes all available elements from this queue and adds them
into the given collection.
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Returns an iterator over the elements in this queue.
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Inserts the specified element into this priority queue.
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Inserts the specified element into this priority queue.
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Gets but not removes the element in the head of the queue, or throws
exception if there is no element in the queue.
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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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Gets and removes the element in the head of the queue, or returns null if
there is no element in the queue.
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Adds the specified element to this priority queue.
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Always returns Integer.MAX_VALUE because
a PriorityBlockingQueue is not capacity constrained.
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Removes the first occurrence of the specified object from this
Collection.
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Returns the number of elements in this Collection.
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Retrieves and removes the head of this queue, waiting
if no elements are present on this queue.
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Returns an array containing all elements contained in this Collection.
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Returns a new array containing all elements contained in this Collection.
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Returns the string representation of this Collection.
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[Expand]
Inherited Methods | |||||||||||
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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.lang.Iterable
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From interface java.util.Collection
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From interface java.util.Queue
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From interface java.util.concurrent.BlockingQueue
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Creates a PriorityBlockingQueue with the default initial capacity (11) that orders its elements according to their natural ordering (using Comparable).
Creates a PriorityBlockingQueue with the specified initial capacity that orders its elements according to their natural ordering (using Comparable).
| initialCapacity | the initial capacity for this priority queue. |
|---|
| IllegalArgumentException | if initialCapacity is less than 1 |
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Creates a PriorityBlockingQueue with the specified initial capacity that orders its elements according to the specified comparator.
| initialCapacity | the initial capacity for this priority queue. |
|---|---|
| comparator | the comparator used to order this priority queue. If null then the order depends on the elements' natural ordering. |
| IllegalArgumentException | if initialCapacity is less than 1 |
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Creates a PriorityBlockingQueue containing the elements in the specified collection. The priority queue has an initial capacity of 110% of the size of the specified collection. If the specified collection is a SortedSet or a PriorityQueue, this priority queue will be sorted according to the same comparator, or according to its elements' natural order if the collection is sorted according to its elements' natural order. Otherwise, this priority queue is ordered according to its elements' natural order.
| c | the collection whose elements are to be placed into this priority queue. |
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| ClassCastException | if elements of the specified collection cannot be compared to one another according to the priority queue's ordering. |
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| NullPointerException | if c or any element within it is null |
Adds the specified element to this queue.
| o | the element to add |
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| NullPointerException | if the specified element is null. |
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| ClassCastException | if the specified element cannot be compared with elements currently in the priority queue according to the priority queue's ordering. |
Atomically removes all of the elements from this delay queue. The queue will be empty after this call returns.
Returns the comparator used to order this collection, or null if this collection is sorted according to its elements natural ordering (using Comparable).
Searches this Collection for the specified object.
| o | the object to search for |
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object is an element of this Collection,
false otherwise
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 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 |
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| maxElements | the maximum number of elements to transfer |
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.
| c | the collection to transfer elements into |
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Returns an iterator over the elements in this queue. The iterator does not return the elements in any particular order. The returned iterator is a thread-safe "fast-fail" iterator that will throw ConcurrentModificationException upon detected interference.
Inserts the specified element into this priority queue. As the queue is unbounded this method will never block.
| o | the element to add |
|---|---|
| timeout | This parameter is ignored as the method never blocks |
| unit | This parameter is ignored as the method never blocks |
| ClassCastException | if the element cannot be compared with elements currently in the priority queue according to the priority queue's ordering. |
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| NullPointerException | if the specified element is null. |
Inserts the specified element into this priority queue.
| o | the element to add |
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| ClassCastException | if the specified element cannot be compared with elements currently in the priority queue according to the priority queue's ordering. |
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| NullPointerException | if the specified element is null. |
Gets but not removes the element in the head of the queue, or throws exception if there is no element in the queue.
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.
| timeout | how long to wait before giving up, in units of unit |
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| unit | a TimeUnit determining how to interpret the timeout parameter |
| InterruptedException |
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Gets and removes the element in the head of the queue, or returns null if there is no element in the queue.
Adds the specified element to this priority queue. As the queue is unbounded this method will never block.
| o | the element to add |
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| ClassCastException | if the element cannot be compared with elements currently in the priority queue according to the priority queue's ordering. |
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| NullPointerException | if the specified element is null. |
Always returns Integer.MAX_VALUE because a PriorityBlockingQueue is not capacity constrained.
Removes the first occurrence of the specified object from this Collection. This operation traverses over the collection, looking for the specified object. Once the object is found, the object will be removed from the collection using the iterator's remove method. This collection will throw an UnsupportedOperationException if the iterator returned does not implement remove method, and the specified object is in this collection.
| o | the object to remove |
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Returns the number of elements in this Collection.
Retrieves and removes the head of this queue, waiting if no elements are present on this queue.
| InterruptedException |
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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 this Collection, the array element following the collection elements is set to null.
| a | the array |
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Returns a new array containing all elements contained in this Collection. All the elements in the array will not be referenced by the collection. The elements in the returned array will be sorted to the same order as those returned by the iterator of this collection itself if the collection guarantees the order.
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).