1 abstract class SIM {
2 public abstract void setNumber(String n);
3 public abstract String giveNumber();
4 public abstract String giveCorpName();
5 }
6 class MobileTelephone {
7 SIM card;
8 public void useSIM(SIM card) {
9 this.card=card;
10 }
11 public void showMess() {
12 System.out.println("使用的卡是:"+card.giveCorpName()+"提供的");
13 System.out.println("手机号码是:"+card.giveNumber());
14 }
15 }
16 class SIMOfChinaMobile extends SIM {
17 String number;
18 public void setNumber(String n) {
19 number=n;
20 }
21 public String giveNumber() {
22 return number;
23 }
24 public String giveCorpName() {
25 return "中国移动";
26 }
27 }
28 class SIMOfChinaUnicom extends SIM {
29 String number;
30 public void setNumber(String n) {
31 number=n;
32 }
33 public String giveNumber() {
34 return number;
35 }
36 public String giveCorpName() {
37 return "中国联通";
38 }
39 }
40 public class Example5_14 {
41 public static void main(String[] args) {
42 MobileTelephone telephone=new MobileTelephone();
43 SIM sim=new SIMOfChinaMobile();
44 sim.setNumber("13887656432");
45 telephone.useSIM(sim);
46 telephone.showMess();
47 sim=new SIMOfChinaUnicom();
48 sim.setNumber("13097656437");
49 telephone.useSIM(sim);
50 telephone.showMess();
51 }
52 }
