Abstract Factory

Abstract Factory Pattern에 대해 설명하는 페이지입니다.

Posted Oct 11, 2023

By HyunJinNo

Tags

Design Pattern, Java

1. Introduction

• Purpose
  • Provide an interface that delegates creation calls to one or more concrete classes in order to deliver specific objects.
• Use When
  • The creation of objects should be independent of the system utilizing them.
  • Systems should be capable of using multiple families of objects.
  • Families of objects must be used together.
  • Libraries must be published without exposing implementation details.
  • Concrete classes should be decoupled from clients.
• Characteristics
  • Delegates object creation to a factory object.
  • Uses composition and delegation.

2. Participants

• AbstractFactory
  • Declares an interface for operations that create abstract product objects.
• ConcreteFactory
  • Implements the operations to create product objects.
• AbstractProduct
  • Declares an interface for a type of product object.
• ConcreteProduct
  • Defines a product object to be created by the corresponding concrete factory.
  • Implements the AbstractProduct interface.
• Client
  • Uses only interfaces declared by AbstractFactory and AbstractProduct classes.

3. How to Use (Example)

• Abstract Factory

  java

  1public interface IngredientFactory {
  2    public IngredientA createIngredientA();
  3    public IngredientB createIngredientB();
  4    public IngredientC createIngredientC();
  5}

• Concrete Factory

  java

  1public class MyIngredientFactory implements IngredientFactory {
  2    public IngredientA createIngredientA() {
  3        return new MyIngredientA();
  4    }
  5
  6    public IngredientB createIngredientB() {
  7        return new MyIngredientB();
  8    }
  9
  10    public IngredientC createIngredientC() {
  11        return new MyIngredientC();
  12    }
  13}

• Abstract Product

  java

  1public abstract class Product {
  2    IngredientA ingredientA;
  3    IngredientB ingredientB;
  4    IngredientC ingredientC;
  5
  6    public abstract void prepare();
  7}

• Concrete Product

  java

  1public class MyProduct extends Product {
  2    MyIngredientFactory myIngredientFactory;
  3
  4    public MyProduct(MyIngredientFactory myIngredientFactory) {
  5        this.myIngredientFactory = myIngredientFactory;
  6    }
  7
  8    public void prepare() {
  9        ingredientA = myIngredientFactory.createIngredientA();
  10        ingredientB = myIngredientFactory.createIngredientB();
  11        ingredientC = myIngredientFactory.createIngredientC();
  12    }
  13}