Interfaces and Polymorphism - Java Concepts - page 551

39 }
40
41 /**
42 Gets the largest of the added data.
43 @return the maximum or 0 if no data has been added
44 */
45 public Object getMaximum()
46 {
47 return maximum;
48 }
49
50 private double sum;
51 private Object maximum;
52 private int count;
53 private Measurer measurer;
54 }
ch09/measure2/DataSetTester2.java
1 import java.awt.Rectangle;
2
3 /**
4 This program demonstrates the use of a Measurer.
5 */
6 public class DataSetTester2
7 {
8 public static void main(String[] args)
9 {
47 Measurer m = new RectangleMeasurer();
11
12 DataSet data = new DataSet(m);
13
14 data.add( new Rectangle( 5 , 10 , 20 , 30 ));
15 data.add( new Rectangle( 10 , 20 , 30 , 40 ));
16 data.add( new Rectangle( 20 , 30 , 5 , 15 ));
17
18 System.out.println( "Average area: " +
data.getAverage());
19 System.out.println( "Expected: 625" );
20
21 Rectangle max = (Rectangle)
data.getMaximum();
22 System.out.println( "Maximum area
rectangle: " + max);