adapter

适配器模式(类适配器)，将220v电压转为5v

class Voltage220V{

public int output220V(){
    int src = 220;
    System.out.println("220v");
    return src;
}

}

//适配接口
interface Voltage5V{
public int output5V();
}

//adpater实现5v
class Adpater extends Voltage220V implements Voltage5V{
public int output5V(){
int srcV = output220V();
int desV = srcV/44; //转5v
return desV;
}

}

class Phone{
public void charge(Voltage5V v){
if(v.output5V() == 5){
System.out.println(“充电”);
}
else if(v.output5V() > 5){
System.out.println(“不能充电”);
}
}
}

public class Main{
public static void main(String[] args){
Phone phone = new Phone();
phone.charge(new Adpater());
}

}

最终输出为:
220v
充电
也就是将220v电压转成了5v