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This article will explain in detail the example analysis of abstract factories in java design patterns. The editor thinks it is very practical, so I share it with you for reference. I hope you can get something after reading this article.

First of all, let's take a look at the problem of the abstract factory pattern left over last time. Abstract factories allow customers to use abstract interfaces to create a set of related products without knowing (or caring about) what the actual product is. In this way, the customer is decoupled from the specific product. Let's look at the class diagram to understand the relationship.

This is a rather complex class diagram: let's look at it from PizzaStore's point of view:

Is the factory method lurking in an abstract factory?

We notice that every method of an abstract factory actually looks like a factory method. Each method can be declared abstract, and the methods of the subclass override these methods to create certain objects.

So, abstract factory methods are often implemented as factory methods, which makes a lot of sense, right? The task of an abstract factory is to define an interface responsible for creating a set of products. Each method in this interface is responsible for creating a concrete product, and we use subclasses that implement the abstract factory to provide these concrete practices. Therefore, it is quite natural to use the factory method to implement the production method in an abstract factory.

Compare factory methods with abstract factories

Because the relationship of contrast is depicted in the picture in the book, and the editor strives to combine it with the book, you don't mind posting the class diagram in the book here.

Design the tools in the box

Let's follow the previous routine and summarize the new tools in the toolbox.

OO Foundation

Abstraction, encapsulation, inheritance, polymorphism

OO principle

Encapsulation change

Use more combinations and less inheritance

Programming for interfaces, not for implementation

Strive for loosely coupled design between interactive objects

Rely on abstraction, not concrete classes (we have a new principle until we keep things as abstract as possible)

OO mode

"Strategy mode", "observer mode", "decorator mode"

Abstract Factory pattern provides an interface for creating families of related or dependent objects without explicitly specifying concrete classes

The Factory method pattern defines an interface for creating objects, but it is up to the subclass to decide which class to instantiate. The factory method causes the class to defer instantiation to subclasses

This is the end of this article on "sample analysis of abstract factories in java design patterns". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, please share it for more people to see.

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