PriorityQueue Class

Definition

[Android.Runtime.Register("java/util/PriorityQueue", DoNotGenerateAcw=true)]
[Java.Interop.JavaTypeParameters(new System.String[] { "E" })]
public class PriorityQueue : Java.Util.AbstractQueue, IDisposable, Java.Interop.IJavaPeerable, Java.IO.ISerializable

[<Android.Runtime.Register("java/util/PriorityQueue", DoNotGenerateAcw=true)>]
[<Java.Interop.JavaTypeParameters(new System.String[] { "E" })>]
type PriorityQueue = class
    inherit AbstractQueue
    interface ISerializable
    interface IJavaObject
    interface IDisposable
    interface IJavaPeerable

Inheritance

Object

Object

AbstractCollection

AbstractQueue

PriorityQueue

Attributes

RegisterAttribute JavaTypeParametersAttribute

Implements

IJavaObject IJavaPeerable ISerializable IDisposable

Remarks

An unbounded priority Queue queue based on a priority heap. The elements of the priority queue are ordered according to their Comparable natural ordering, or by a Comparator provided at queue construction time, depending on which constructor is used. A priority queue does not permit null elements. A priority queue relying on natural ordering also does not permit insertion of non-comparable objects (doing so may result in ClassCastException).

The <em>head</em> of this queue is the <em>least</em> element with respect to the specified ordering. If multiple elements are tied for least value, the head is one of those elements -- ties are broken arbitrarily. The queue retrieval operations poll, remove, peek, and element access the element at the head of the queue.

A priority queue is unbounded, but has an internal capacity governing the size of an array used to store the elements on the queue. It is always at least as large as the queue size. As elements are added to a priority queue, its capacity grows automatically. The details of the growth policy are not specified.

This class and its iterator implement all of the <em>optional</em> methods of the Collection and Iterator interfaces. The Iterator provided in method #iterator() and the Spliterator provided in method #spliterator() are <em>not</em> guaranteed to traverse the elements of the priority queue in any particular order. If you need ordered traversal, consider using Arrays.sort(pq.toArray()).

<strong>Note that this implementation is not synchronized.</strong> Multiple threads should not access a PriorityQueue instance concurrently if any of the threads modifies the queue. Instead, use the thread-safe java.util.concurrent.PriorityBlockingQueue class.

Implementation note: this implementation provides O(log(n)) time for the enqueuing and dequeuing methods (offer, poll, remove() and add); linear time for the remove(Object) and contains(Object) methods; and constant time for the retrieval methods (peek, element, and size).

This class is a member of the Java Collections Framework.

Added in 1.5.

Java documentation for java.util.PriorityQueue.

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Constructors

Properties

Methods

Explicit Interface Implementations

Extension Methods

Applies to