我对模式很新,我正在研究装饰模式,我必须编写一个程序.

在线学习,我找到了一个Decorator模式的例子(它是Java伪代码)：

class Solution1

{

static interface Component

{

void doStuff();

}

static class MyComponent implements Component

{

public void doStuff()

{

// ...

}

}

static class ComponentDecorator implements Component // This is the Decorator pattern.

{

private final Component component;

public ComponentDecorator(Component component)

{

this.component = component;

}

public void doStuff()

{

this.component.doStuff();

}

}

static class ComponentDecorator1 extends ComponentDecorator

{

public ComponentDecorator1(Component component)

{

super(component);

}

private void doExtraStuff1()

{

// ...

}

public void doStuff()

{

super.doStuff();

doExtraStuff1();

}

}

static class ComponentDecorator2 extends ComponentDecorator

{

public ComponentDecorator2(Component component)

{

super(component);

}

private void doExtraStuff2()

{

// ...

}

public void doStuff()

{

super.doStuff();

doExtraStuff2();

}

}

public static void main(String[] args)

{

MyComponent c = new MyComponent();

ComponentDecorator1 cd1 = new ComponentDecorator1(c);

ComponentDecorator2 cd2 = new ComponentDecorator2(cd1);

cd2.doStuff(); // Executes Component.doStuff, ComponentDecorator1.doExtraStuff1, ComponentDecorator2.doExtraStuff2

}

};

当我分析这个例子时,我意识到在过去我做了一个非常相似的模式但是以不同的方式：

import java.util.*;

class Solution2

{

static interface Component

{

void doStuff();

}

static class MyComponent implements Component

{

public void doStuff()

{

// ...

}

}

static class ComponentDecorator implements Component // This is NOT the Decorator pattern!

{

private final List components = new ArrayList();

public ComponentDecorator()

{

}

public ComponentDecorator addComponent(Component component)

{

this.components.add(component);

return this;

}

public void removeComponent(Component component) // Can Decorator do this?

{

// ...

}

public void doStuff()

{

for(Component c : this.components) c.doStuff();

}

}

static class ComponentDecorator1 implements Component

{

public ComponentDecorator1()

{

}

private void doExtraStuff1()

{

// ...

}

public void doStuff()

{

doExtraStuff1();

}

}

static class ComponentDecorator2 implements Component

{

public ComponentDecorator2()

{

}

private void doExtraStuff2()

{

// ...

}

public void doStuff()

{

doExtraStuff2();

}

}

public static void main(String[] args)

{

ComponentDecorator cd = new ComponentDecorator();

cd.addComponent(new MyComponent());

cd.addComponent(new ComponentDecorator1());

cd.addComponent(new ComponentDecorator2());

cd.doStuff(); // Executes MyComponent.doStuff, ComponentDecorator1.doExtraStuff1, ComponentDecorator2.doExtraStuff2

}

}

在我看来,第二个例子可以在可以使用Decorator模式的相同情况下使用,但它更灵活(例如,您可以删除或重新排序列表中的组件),所以我的问题：

>解决方案1(正确的装饰模式)是否比解决方案2更好？为什么？

>是否可以添加用于删除解决方案1中的实例的函数？

>是否可以在解决方案1中添加重新排序实例的功能？