16.5

 1 import java.awt.*;
 2 import java.awt.event.ActionEvent;
 3 import java.awt.event.ActionListener;
 4
 5 import javax.swing.*;
 6
 7 public class Test_16_5 extends JFrame{
 8     private JTextField JT1 = new JTextField();
 9     private JTextField JT2 = new JTextField();
10     private JTextField JT3 = new JTextField();
11     private JTextField JT4 = new JTextField();
12     private JLabel JL1 = new JLabel("investmentAmount");
13     private JLabel JL2 = new JLabel("years");
14     private JLabel JL3 = new JLabel("monthlyInterestRate");
15     private JLabel JL4 = new JLabel("Future Value");
16     private JButton JB = new JButton("Calculate");
17
18     public Test_16_5(){
19         JPanel JP1 = new JPanel(new GridLayout(4,2));
20         JPanel JP2 = new JPanel(new FlowLayout(FlowLayout.RIGHT));
21
22
23         JP1.add(JL1);JP1.add(JT1);
24         JP1.add(JL2);JP1.add(JT2);
25         JP1.add(JL3);JP1.add(JT3);
26         JP1.add(JL4);JP1.add(JT4);
27
28         JP2.add(JB);
29         add(JP1,BorderLayout.CENTER);
30         add(JP2,BorderLayout.SOUTH);
31
32         JB.addActionListener(new ComputeListener());
33     }
34     public static void main(String[] args) {
35         // TODO Auto-generated method stub
36         Test_16_5 T1 = new Test_16_5();
37         T1.setTitle("Test_16.5");
38         T1.pack();
39         T1.setLocationRelativeTo(null);
40         T1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
41         T1.setVisible(true);
42     }
43
44     class ComputeListener implements ActionListener{
45
46         @Override
47         public void actionPerformed(ActionEvent e) {
48             // TODO Auto-generated method stub
49             double investmentAmount = Double.parseDouble(JT1.getText());
50             int years = Integer.parseInt(JT2.getText());
51             double monthlyInterestRate = Double.parseDouble(JT3.getText());
52             Interests interes = new Interests(investmentAmount,monthlyInterestRate,years);
53             JT4.setText(interes.getFutureValue()+"");
54         }
55     }
56     class Interests{
57         private double inves;
58         private double monthly;
59         private int year;
60         public Interests(double inves,double monthly,int year){
61             this.inves = inves;
62             this.year = year;
63             this.monthly = monthly;
64         }
65         public double getFutureValue(){
66             return inves*Math.pow(1+monthly, year*12);
67         }
68     }
69
70 }

Test_16_5.java

效果图：