设计模式--适配器模式

将一个类的接口转成另一种接口，使原本不兼容的类可以兼容
source (220v)-- adapter — dst(5V)

方法一、类适配
adapter类，继承source，实现dst，实现src-dst

public class Phone {
    void charging(IVolt5V volt5V) {
        if(volt5V.Output5v() == 5){
            System.out.println("charging--------");
        }else{
            System.out.println("not  charging--------");
        }
    }
}

source (220v)

public class Volt220V {
    public int Output220V() {
        System.out.println("输入---220V");
        return 220;
    }
}

目标接口

public interface IVolt5V {
  public int   Output5v();
}

源转为目标的适配器

public class VoltAdapter extends Volt220V implements IVolt5V {

    @Override
    public int Output5v() {
        int srcV = Output220V();
        int dstV = srcV / 44;
        System.out.println("输出5v-----");
        return dstV;
    }
}

public class AdapterClient {
    public static void main(String[] args) {
        Phone phone = new Phone();
        phone.charging(new VoltAdapter());
    }
}

方法二、对象适配模式：用组合代替继承；适配器由继承的方式，改为构造方法传人

public class AdapterClient {
    public static void main(String[] args) {
        Phone phone = new Phone();
        phone.charging(new VoltAdapter2(new Volt220V()));
    }
}

public class VoltAdapter2 implements IVolt5V {
    Volt220V volt220V;

    public VoltAdapter2(Volt220V volt220V) {
        this.volt220V = volt220V;
    }

    @Override
    public int Output5v() {
        int srcV = volt220V.Output220V();
        int dstV = srcV / 44;
        System.out.println("输出5v-----");
        return dstV;
    }
}