装饰者模式（Decorator）

通过一种对客户端透明的方式来扩展对象的功能，是extend的替代方案。比如开发一种车，能飞，能跑，还能游。

避免过多的子类生成（能飞能游的车。 能跑能飞的车。等等）

public interface Car {
    void show();
}

public class BMWCar implements Car {
    @Override
    public void show() {
        System.out.println("i am bao ma car");
    }
}

public abstract class CarDecorator implements Car {
    public Car car;
    public CarDecorator(Car car){
        this.car = car;
    }
}

 */
public class SwimCarDecorator extends CarDecorator {

    public SwimCarDecorator(Car car) {
        super(car);
    }

    @Override
    public void show() {
        this.car.show();
        this.swim();
    }

    public void swim(){
        System.out.println("i can swim");
    }
}

public class FlyCarDecorator extends CarDecorator {

    public FlyCarDecorator(Car car) {
        super(car);
    }

    @Override
    public void show() {
        this.car.show();
        this.fly();
    }

    public void fly(){
        System.out.println("i can fly");
    }
}

Car bmw = new BMWCar();
    bmw.show();
    LOGGER.info("****************");
    Car flyCar = new FlyCarDecorator(bmw);
    flyCar.show();
    LOGGER.info("****************");
    Car swimCar = new SwimCarDecorator(bmw);
    swimCar.show();
    LOGGER.info("****************");
    Car swimFlyCar = new SwimCarDecorator(flyCar);
    swimFlyCar.show();