java - 适配器和装饰器的区别

Question

我正在学习设计模式，现在我试图理解适配器和装饰器之间的区别。考虑列表中的以下装饰器:

Collections.synchronizedList(List<T> lst)

在指定的List上创建一个同步装饰器。反过来，适配器模式也将其封装起来，如所述 here 。示例:

public interface Chief {

    public Object makeBreakfast();
    public Object makeDinner();
    public Object makeSupper();

}

public class Plumber {

    public Object getPipe(){
        return new Object();
    }

    public Object getKey(){
        return new Object();
    }

    public Object getScrewDriver(){
        return new Object();
    }

}

public class ChiefAdapter implements Chief{

    private Plumber plumber = new Plumber();

    @Override
    public Object makeBreakfast() {
        return plumber.getKey();
    }

    @Override
    public Object makeDinner() {
        return plumber.getScrewDriver();
    }

    @Override
    public Object makeSupper() {
        return plumber.getPipe();
    }

}

没有人能解释一下其中的区别吗？

Answer 1

装饰器模式主要用于为类承担/引入额外的责任。例如，您可以采用对象序列的类容器并实现迭代器来赋予额外的责任，能够在类内迭代该集合。

戈夫

attach additional responsibilities to an object dynamically. Decorators provide a flexible alternative to subclassing for extending functionality.

另一方面，适配器将一个类转换为另一个职责，如您所显示的示例中，适配器将水管工转换为厨师。

戈夫

convert the interface of a class into another interface clients expect. Adapater lets classes work together that couldn't otherwise because of incompatible interfaces.