// Fig. 20.13: Queue.java
// Class Queue.
package com.deitel.jhtp5.ch20;

public class Queue {
   private List queueList;

   // construct queue
   public Queue() 
   { 
      queueList = new List( "queue" ); 
   }

   // add object to queue
   public synchronized void enqueue( Object object )
   { 
      queueList.insertAtBack( object ); 
   }

   // remove object from queue
   public synchronized Object dequeue() throws EmptyListException
   { 
      return queueList.removeFromFront(); 
   }

   // determine if queue is empty
   public synchronized boolean isEmpty()
   {
      return queueList.isEmpty();
   }

   // output queue contents
   public synchronized void print()
   {
      queueList.print();
   }

} // end class Queue


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