Java™ How to Program, Seventh Edition

19.8. Class PriorityQueue and Interface Queue

In Section 17.8, we introduced the queue data structure and created our own implementation of it. In this section we investigate interface Queue and class PriorityQueue in the Java utilities package (java.util). Queue, a new collection interface introduced in Java SE 5, extends interface Collection and provides additional operations for inserting, removing and inspecting elements in a queue. PriorityQueue, one of the classes that implements the Queue interface, orders elements by their natural ordering as specified by Comparable elements’ compareTo method or by a Comparator object that is supplied through the constructor.

Class PriorityQueue provides functionality that enables insertions in sorted ...