1 interface USB
2 {
3 public void open();
4 public void close();
5 }
6
7 class Upan implements USB
8 {
9 public void open()
10 {
11 System.out.println("Upan open");
12 }
13 public void close()
14 {
15 System.out.println("Upan close");
16 }
17 }
18
19 class USBMouse implements USB
20 {
21 public void open()
22 {
23 System.out.println("USBMouse open");
24 }
25 public void close()
26 {
27 System.out.println("USBMouse close");
28 }
29 }
30
31 class BookPC
32 {
33 public static void main(String[] args)
34 {
35 useUSB(new Upan());
36 useUSB(new USBMouse());
37 }
38 public static void useUSB(USB u)
39 {
40 u.open();
41 u.close();
42 }
43 }