Java面向对象接口的应用实例练习详解编程语言

 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 }