This class is a Queue implementation that orders its elements according to a specified Comparator or orders Comparable elements according to their compareTo( ) methods . The head of the queue (the element removed by remove( ) and poll( ) ) is the smallest element on the queue according to this ordering. The Iterator return by the iterator( ) method is not guaranteed to iterate the elements in their sorted order. PriorityQueue is unbounded and prohibits null elements. It is not threadsafe. Figure 16-47. java.util.PriorityQueue<E>public class PriorityQueue<E> extends AbstractQueue<E> implements Serializable { // Public Constructors public PriorityQueue ( ); public PriorityQueue (int initialCapacity ); public PriorityQueue (SortedSet<? extends E> c ); public PriorityQueue (PriorityQueue<? extends E> c ); public PriorityQueue (Collection<? extends E> c ); public PriorityQueue (int initialCapacity , Comparator<? super E> comparator ); // Public Instance Methods public Comparator<? super E> comparator ( ); // Methods Implementing Collection public Iterator<E> iterator ( ); public boolean remove (Object o ); public int size ( ); // Methods Implementing Queue public boolean offer (E o ); public E peek ( ); public E poll ( ); // Public Methods Overriding AbstractQueue public boolean add (E o ); public void clear ( ); } |