Example4_9.java
public class Example4_9 {
public static void main(String args[]) {
SIM simOne = new SIM(13889776509L);
MobileTelephone mobile = new MobileTelephone();
mobile.setSIM(simOne);
System.out.println("手机号码:"+mobile.lookNumber());
SIM simTwo = new SIM(15967563567L);
mobile.setSIM(simTwo);
System.out.println("手机号码:"+mobile.lookNumber());
}
}
MobileTelephone.java
public class MobileTelephone {
SIM sim;
void setSIM(SIM card) {
sim = card;
}
long lookNumber(){
return sim.getNumber();
}
}
SIM.java
public class SIM {
long number;
SIM(long number){
this.number = number;
}
long getNumber() {
return number;
}
}