Question

混凝土工厂和抽象工厂有什么区别？

PS：我最初问的是问题“ what is a concrete factory”。在一个单独的问题中问我的疑问，以使两个讨论分开。

Answer 1

事情是抽象工厂只是抽象类，具体工厂给出了抽象类的真实实现

Answer 2

The difference will be easier to see from the perspective of a client class which makes use of the factory class.

If the client class uses a concrete factory class, then it will be difficult to reuse the client class in another context. We cannot replace the current in-used concrete factory class by another concrete factory class without modifying source code of the client class.

In contrast, if the client uses an abstract factory class (or interface), we can easily reuse the client class with another (concrete) factory class because the source code of the client class does not mention any concrete factory class. For example, consider the code below:

interface AbstractFactory { Product create(); }
class Client {
    private AbstractFactory factory;
    public Client(AbstractFactory factory) { this.factory = factory; }
    public void foo() { /* use this.factory */  }
}
// Now we can reuse the Client class with any concrete factory class
class ConcreteFactory1 implements AbstractFactory { ... }
class ConcreteFactory2 implements AbstractFactory { ... }
Client client1 = new Client(new ConcreteFactory1());
client1.foo();
Client client2 = new Client(new ConcreteFactory2());
client2.foo();

As you see, in any case, source code of the Client class does not need to be modified, but it still works with different concrete factory class.

JavaScript设计模式：抽象工厂与混凝土工厂

2 个答案: