Class PriorityQueue<E extends Comparable<E>>

java.lang.Object
gaiasky.event.PriorityQueue<E>
Type Parameters:
E - Object type.
public class PriorityQueue<E extends Comparable<E>> extends Object
Simple implementation of a priority queue.

  • Constructor Summary

    Constructors
    Constructor
    Description
    PriorityQueue()
    Creates a PriorityQueue with the default initial capacity (11) that orders its elements according to their natural ordering.
    PriorityQueue(int initialCapacity)
    Creates a PriorityQueue with the specified initial capacity that orders its elements according to their natural ordering.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    add(E e)
    Inserts the specified element into this priority queue.
    void
    clear()
    Removes all of the elements from this priority queue.
    E
    get(int index)
    Retrieves the element at the specified index.
    boolean
    getUniqueness()
    Returns a value indicating whether only unique elements are allowed to be inserted.
    E
    peek()
    Retrieves, but does not remove, the head of this queue.
    E
    poll()
    Retrieves and removes the head of this queue, or returns null if this queue is empty.
    void
    setUniqueness(boolean uniqueness)
    Sets a flag indicating whether only unique elements are allowed to be inserted.
    int
    size()
    Returns the number of elements in this queue.

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • PriorityQueue

      public PriorityQueue()
      Creates a PriorityQueue with the default initial capacity (11) that orders its elements according to their natural ordering.

    • PriorityQueue

      public PriorityQueue(int initialCapacity)
      Creates a PriorityQueue with the specified initial capacity that orders its elements according to their natural ordering.
      Parameters:
      initialCapacity - the initial capacity for this priority queue

  • Method Details

    • getUniqueness

      public boolean getUniqueness()
      Returns a value indicating whether only unique elements are allowed to be inserted.

    • setUniqueness

      public void setUniqueness(boolean uniqueness)
      Sets a flag indicating whether only unique elements are allowed to be inserted.

    • add

      public boolean add(E e)
      Inserts the specified element into this priority queue. If uniqueness is enabled and this priority queue already contains the element, the call leaves the queue unchanged and returns false.
      Returns:
      true if the element was added to this queue, else false
      Throws:
      ClassCastException - if the specified element cannot be compared with elements currently in this priority queue according to the priority queue's ordering
      NullPointerException - if the specified element is null

    • peek

      public E peek()
      Retrieves, but does not remove, the head of this queue. If this queue is empty null is returned.
      Returns:
      the head of this queue

    • get

      public E get(int index)
      Retrieves the element at the specified index. If such an element doesn't exist null is returned.

      Iterating the queue by index is not guaranteed to traverse the elements in any particular order.

      Returns:
      the element at the specified index in this queue.

    • size

      public int size()
      Returns the number of elements in this queue.

    • clear

      public void clear()
      Removes all of the elements from this priority queue. The queue will be empty after this call returns.

    • poll

      public E poll()
      Retrieves and removes the head of this queue, or returns null if this queue is empty.
      Returns:
      the head of this queue, or null if this queue is empty.