图解Java设计模式之装饰者模式

package com.example.demo.decorator;

public abstract class Drink {
	
	/**
	 * 描述
	 */
	public String des;

	private float price = 0.0f;
	
	/**
	 * 计算费用的抽象方法
	 * 子类去实现
	 * @return
	 */
	public abstract float cost();

	public String getDes() {
		return des;
	}

	public void setDes(String des) {
		this.des = des;
	}

	public float getPrice() {
		return price;
	}

	public void setPrice(float price) {
		this.price = price;
	}
}
package com.example.demo.decorator;

public class Decorator extends Drink{
	
	private Drink obj;
	
	/**
	 * 组合的方式
	 * @param objDrink
	 */
	public Decorator(Drink objDrink) {
		this.obj = objDrink;
	}

	@Override
	public float cost() {
		// TODO Auto-generated method stub
		// getPrice 自己价格
		return super.getPrice() + obj.cost();
	}
	
	@Override
	public String getDes() {
		// TODO Auto-generated method stub
		// obj.getDes() 输出被装饰者的信息
		return des + " " + getPrice() + " && " + obj.getDes();
	}

}
package com.example.demo.decorator;

/**
 * 具体的Decotator，这里就是调味品
 * @author zhaozhaohai
 *
 */
public class Chocolate extends Decorator{

	
	public Chocolate(Drink obj) {
		super(obj);
		setDes(" 巧克力 ");
		// 调位品的价格
		setPrice(3.0f);
	}
}
package com.example.demo.decorator;

public class Coffee extends Drink{

	@Override
	public float cost() {
		// TODO Auto-generated method stub
		return super.getPrice();
	}

}
package com.example.demo.decorator;

public class DeCof extends Coffee{

	public DeCof() {
		setDes(" 无因咖啡 ");
		setPrice(9.6f);
	}
}
package com.example.demo.decorator;

public class CoffeeBar {
	public static void main(String[] args) {
		// 装饰者模式下的订单 ：2份巧克力 + 一份牛奶的LongBlack
		// 1. 点一份 LongBlack
		Drink orderDrink = new LongBlack();
		System.out.println("费用 1 = " + orderDrink.cost());
		System.out.println("描述 = " + orderDrink.getDes());
		// 2. orderDrink 加一份牛奶
		orderDrink = new Milk(orderDrink);
		System.out.println("order 加一份牛奶 费用 = " + orderDrink.cost());
		System.out.println("order 加一份牛奶 描述 = " + orderDrink.getDes());
		// 3. orderDrink 加一份巧克力
		orderDrink = new Chocolate(orderDrink);
		System.out.println("order 加一份牛奶 加一份巧克力 费用 = " + orderDrink.cost());
		System.out.println("order 加一份牛奶 加一份巧克力 描述 = " + orderDrink.getDes());
		// 4. orderDrink 第二份巧克力
		orderDrink = new Chocolate(orderDrink);
		System.out.println("order 加一份牛奶 加2份巧克力 费用 = " + orderDrink.cost());
		System.out.println("order 加一份牛奶 加2份巧克力 描述 = " + orderDrink.getDes());
		System.out.println("=========================");
		Drink drink2 = new DeCof();
		System.out.println("drink2 无因咖啡 费用 = " + drink2.cost());
		System.out.println("drink2 无因咖啡 描述 = " + drink2.getDes());
		
		drink2 = new Milk(drink2);
		System.out.println("order2 无因咖啡 加入一份牛奶 费用 = " + drink2.cost());
		System.out.println("order2 无因咖啡 加入一份牛奶 描述 = " + drink2.getDes());
	}
}
package com.example.demo.decorator;

public class Espresso extends Coffee{
	
	public Espresso() {
		setDes(" 意大利咖啡 ");
		setPrice(6.6f);
	}

}
package com.example.demo.decorator;

public class LongBlack extends Coffee{

	public LongBlack() {
		setDes(" longBlack ");
		setPrice(5.0f);
	}
	
}
package com.example.demo.decorator;

public class Milk extends Decorator{

	public Milk(Drink obj) {
		super(obj);
		setDes(" 牛奶 ");
		setPrice(2.0f);
	}
	
}
package com.example.demo.decorator;

public class ShortBlack extends Coffee{

	public ShortBlack() {
		setDes(" shortBlack ");
		setPrice(8.0f);
	}
	
}
package com.example.demo.decorator;

public class Soy extends Decorator{

	public Soy(Drink obj) {
		super(obj);
		setDes(" 豆浆 ");
		setPrice(1.5f);
	}
	
}