// // This file contains the Java code from Program 6.25 of // "Data Structures and Algorithms // with Object-Oriented Design Patterns in Java" // by Bruno R. Preiss. // // Copyright (c) 1998 by Bruno R. Preiss, P.Eng. All rights reserved. // // http://www.pads.uwaterloo.ca/Bruno.Preiss/books/opus5/programs/pgm06_25.txt // public class DequeAsLinkedList extends QueueAsLinkedList implements Deque { public Object getTail () { if (count == 0) throw new ContainerEmptyException (); return list.getLast (); } public void enqueueTail (Object object) { enqueue (object); } public Object dequeueTail () { if (count == 0) throw new ContainerEmptyException (); Object result = list.getLast (); list.extract (result); --count; return result; } // ... }