1    package bookExamples.ch08ArraysAndVectors; 
2     
3    import java.util.Vector; 
4     
5    public class Queues { 
6        Vector v = new Vector(); 
7     
8        public void enqueue(Object o) { 
9            v.addElement(o); 
10       } 
11    
12       public Object dequeue() { 
13           try { 
14               return v.remove(0); 
15           } catch (java.lang.ArrayIndexOutOfBoundsException e) { 
16               return null; 
17           } 
18       } 
19    
20       public static void main(String args[]) { 
21           Queues q = new Queues(); 
22           q.enqueue("first"); 
23           q.enqueue("second"); 
24           q.enqueue("third"); 
25           for (Object o = q.dequeue(); o != null; o = q.dequeue()) 
26               System.out.println(o); 
27       } 
28   }