Java 設計模式之裝飾模式，Java 裝飾模式

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©Copyright 蕃薯耀2021-07-01

https://www.cnblogs.com/fanshuyao/

一、Java 裝飾模式

1、介面

public interface FastFood {

    /**
     * 花費金額
     * @return
     */
    public double cost();
    
    /**
     * 描述
     * @return
     */
    public String desc();
}

2、具體的實現類

/**
 * 炒飯，具體的類
 *
 */
public class FriedRice implements FastFood{

    @Override
    public double cost() {
        return 10;
    }

    @Override
    public String desc() {
        return "炒飯";
    }

}

3、裝飾抽象類

/**
 * 配菜抽象類
 *
 */
public abstract class SideDish implements FastFood{

    //快餐類
    private
 
 FastFood fastFood;
    
    public SideDish(FastFood fastFood) {
        this.fastFood = fastFood;
    }

    @Override
    public double cost() {
        return fastFood.cost();
    }

    @Override
    public String desc() {
        return fastFood.desc();
    }
    
}

4、裝飾類子類

public class SideDishEgg extends
 
 SideDish {

    
    public SideDishEgg(FastFood fastFood) {
        super(fastFood);
    }

    
    @Override
    public double cost() {
        return 1 + super.cost();
    }

    @Override
    public String desc() {
        return "雞蛋" + " + " + super.desc();
    }
    
    

}

5、裝飾類子類2

public class SideDishPork extends SideDish {

    public SideDishPork(FastFood fastFood) {
        super(fastFood);
    }

    @Override
    public double cost() {
        return 2 + super.cost();
    }

    @Override
    public String desc() {
        return "豬肉" + " + " + super.desc();
    }

}

6、測試結果

炒飯
10.0
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雞蛋 + 炒飯
11.0
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雞蛋 + 雞蛋 + 炒飯
12.0
--------------------------------------------------
豬肉 + 雞蛋 + 雞蛋 + 炒飯
14.0

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©Copyright 蕃薯耀2021-07-01

https://www.cnblogs.com/fanshuyao/