装饰器模式 - 代码指南

本文档详细说明装饰器模式的代码实现和使用方法

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一、项目结构

decorator/
├── IBread.java              # 抽象组件接口
├── NormalBread.java         # 具体组件
├── Decorator.java           # 抽象装饰类
└── CornDecorator.java       # 具体装饰类

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二、代码详解

2.1 IBread - 抽象组件接口

package com.linsir.designpattern.decorator;

public interface IBread {
    void paint();
}

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2.2 NormalBread - 具体组件

package com.linsir.designpattern.decorator;

public class NormalBread implements IBread {
    @Override
    public void paint() {
        System.out.println("普通面包");
    }
}

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2.3 Decorator - 抽象装饰类

package com.linsir.designpattern.decorator;

public abstract class Decorator implements IBread {
    protected IBread bread;

    public Decorator(IBread bread) {
        this.bread = bread;
    }

    @Override
    public void paint() {
        bread.paint();
    }
}

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2.4 CornDecorator - 具体装饰类

package com.linsir.designpattern.decorator;

public class CornDecorator extends Decorator {
    public CornDecorator(IBread bread) {
        super(bread);
    }

    @Override
    public void paint() {
        super.paint();
        System.out.println("添加玉米");
    }
}

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三、使用示例

public class DecoratorTest {
    public static void main(String[] args) {
        // 创建普通面包
        IBread normalBread = new NormalBread();
        normalBread.paint();
        
        System.out.println("---");
        
        // 创建玉米面包（装饰普通面包）
        IBread cornBread = new CornDecorator(normalBread);
        cornBread.paint();
    }
}

输出：

普通面包
---
普通面包
添加玉米

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四、相关文档

• 设计模式概述