Java结构性设计模式中的装饰器模式介绍使用

public abstract class Phone {
    public abstract String call();
    public abstract double price();
}

public class BasePhone extends Phone {
    @Override
    public String call() {
     return "BasePhone call";
    }
    @Override
    public double price() {
        return 0.1;
    }
}

public abstract class PhoneDecorator extends Phone {
    private Phone phone;
    public PhoneDecorator(Phone phone) {
        this.phone = phone;
    }
    @Override
    public String call() {
        return phone.call();
    }
    @Override
    public double price() {
        return phone.price();
    }
    /**
     * 扩展功能
     */
    public abstract void sendMsg();
}

public class SatellitePhoneDecorator extends PhoneDecorator{
    public SatellitePhoneDecorator(Phone phone) {
        super(phone);
    }
    public void sendMsg() {
        System.out.println("PhoneCallDecorator sendMsg");
    }
    @Override
    public String call() {
        return  "SatellitePhone call";
    }
    @Override
    public double price() {
        return super.price()+100;
    }
}

    public static void main(String[] args) {
        // 创建需要被装饰的原始对象(即要被装饰的对象)
        Phone phone = new BasePhone();
        System.out.println("使用: "+phone.call()+" 方式打电话,每分钟单价：" + phone.price());
        // 给对象透明的增加额外功能并调用
        PhoneDecorator phoneDecorator = new SatellitePhoneDecorator(phone);
        System.out.println("使用: "+phoneDecorator.call()+" 方式打电话,每分钟单价：" + phoneDecorator.price());
        // 装饰器也可以装饰具体的装饰对象，相当于给对象在增加的功能基础上在添加功能,这里体现在单价100.1基础上再+100
        PhoneDecorator satellitePhoneDecorator = new SatellitePhoneDecorator(phoneDecorator);
        System.out.println("使用: "+satellitePhoneDecorator.call()+" 方式打电话,每分钟单价：" + satellitePhoneDecorator.price());
        satellitePhoneDecorator.sendMsg();
    }