1 /*
2 长城牌电视机
3 联想奔月5008PC机
4 */
5
6
7 package st;
8 //接口回调实例
9 interface ShowMessage
10 {
11 void 显示商标 (String s);
12 }
13 class TV implements ShowMessage
14 {
15 public void 显示商标(String s)
16 {
17 System.out.println(s);
18 }
19 }
20 class PC implements ShowMessage
21 {
22 public void 显示商标 (String s)
23 {
24 System.out.println(s);
25 }
26 }
27 public class example_1
28 {
29 public static void main(String args[])
30 {
31 ShowMessage sm; //声明接口变量
32 sm=new TV(); //接口变量中存放对象的引用
33 sm.显示商标("长城牌电视机"); //接口回调
34 sm=new PC();
35 sm.显示商标("联想奔月5008PC机");
36 }
37 }
1 /*
2 * 对于接口理解的一个列子
3 * 详情请关注龚细军(Gxjun)的博客
4 * */
5 package st;
6
7 abstract class Motorvehicles
8 {
9 abstract void brake();
10 }
11 // 接口1
12 interface ControlTemperature
13 {
14 void ControlAirTemperature();
15 }
16 //接口2
17 interface MonenyFare
18 {
19 void Charge();
20 }
21 class Bus extends Motorvehicles implements MonenyFare
22 {
23 void brake()
24 {
25 System.out.println("公交车来啦!,嘟嘟");
26 }
27 public void Charge()
28 {
29 System.out.println("公交车收费为5毛");
30 }
31 }
32 class taxi extends Motorvehicles implements MonenyFare , ControlTemperature
33 {
34
35 void brake()
36 {
37 System.out.println("taxi来啦!,嘟嘟");
38 }
39 public void Charge()
40 {
41 System.out.println("taxi收费为5毛");
42 }
43 public void ControlAirTemperature()
44 {
45 System.out.println("taxi执行温度控制开关!");
46 }
47 }
48 class Cinema implements MonenyFare , ControlTemperature
49 {
50 public void Charge()
51 {
52 System.out.println("电影院收费为5毛");
53 }
54 public void ControlAirTemperature()
55 {
56 System.out.println("电影院执行温度控制开关!");
57 }
58 }
59 public class example_1 {
60 public static void main(String args[])
61 {
62 Bus myBus = new Bus();
63 taxi mytaxi = new taxi();
64 Cinema mycinema = new Cinema();
65 myBus.brake();
66 myBus.Charge();
67 mytaxi.brake();
68 mytaxi.Charge();
69 mytaxi.ControlAirTemperature();
70 mycinema.Charge();
71 mycinema.ControlAirTemperature();
72 }
73 }
/*
公交车来啦!,嘟嘟
公交车收费为5毛
taxi来啦!,嘟嘟
taxi收费为5毛
taxi执行温度控制开关!
电影院收费为5毛
电影院执行温度控制开关!
*/
接口与多态:
1 /*
2 11.23 22.78
3 a和b的算术平均值为:17.005000000000003
4 a和b的几何平均值为:15.99435525427643
5
6 */
7
8
9 package st ;
10 import java.util.Scanner;
11 interface c_average
12 {
13 public double average(double a, double b);
14 }
15 // 求算术平均值
16 class A implements c_average
17 {
18 public double average(double a , double b)
19 {
20 return (a+b)/2;
21 }
22 }
23 class B implements c_average
24 {
25 public double average(double a,double b)
26 {
27 return Math.sqrt(a*b);
28 }
29 }
30 public class example_1
31 {
32 public static void main(String args[])
33 {
34 Scanner reader=new Scanner(System.in);
35 double a,b;
36 a=reader.nextDouble();
37 b=reader.nextDouble();
38 A mya = new A();
39 System.out.println("a和b的算术平均值为:"+mya.average(a, b));
40 B myb=new B();
41 System.out.println("a和b的几何平均值为:"+myb.average(a,b));
42 }
43 }
44