팩토리 패턴(factory pattern)

팩토리 패턴이란?

객체를 사용하는 코드에서 객체 생성 부분을 떼어내 추상화한 패턴이자 상속관계에 있는 두 클래스에서 상위 클래스가 중요한 벼대를 결정하고, 하위 클래스에서 객체 생성에 관한 구체적인 내용을 결정하는 패턴

 

<자바스크립트>

class Latte {
	constructor() {
    	this.name = "latte"
    }
}

class Espresso {
	constructor() {
    	this.name = "Espresso"
    }
}

class LatteFactory() {
	static createCoffee() {
    	return new Latte();
    }
}

class EspressoFactory() {
	static createCoffee() {
    	return new Espresso();
    }
}

const factoryList = { LatteFactory , EspressoFactory }

class CoffeeFactory {
	static createCoffee(type) {
    	const factory = factoryList[type]
        return factory.createCoffee()
    }
}

const main = () => {
	const coffee = CoffeeFactory.createCoffee("LatteFactory")
    console.log(coffee.name)
}

main()

 

<자바>

abstract class Coffee {
	public abstract int getPrice();
    
    @Override
    public String toString() {
    	return "Hi this coffee is " + this.getPrice();
    }
}

class CoffeeFactory {
	public static Coffee getCoffee(String type, int price){
    	if("Latte".equalsIgnoreCase(type)) return new Latte(price);
        else if("Americano".equalsIgnoreCase(type)) return new Americano(price);
        else {
        	return new DefaultCoffee();
        }
    }
}

class DefaultCoffee extends Coffee {
	private int price;
    
    public DefaultCoffee() {
    	this.price = -1;
    }
    
    @Override
    public int getPrice() {
    	return this.price;
    }
}

class Latte extends Coffee {
	private int price;
    
    public Latte() {
    	this.price = -1;
    }
    
    @Override
    public int getPrice() {
    	return this.price;
    }
}

class Americano extends Coffee {
	private int price;
    
    public Americano() {
    	this.price = -1;
    }
    
    @Override
    public int getPrice() {
    	return this.price;
    }
}

public class HelloWorld {
	public static void main(String[] args) {
    	Coffee latte = CoffeeFactory.getCoffee("Latte", 4000);
        Coffee ame = CoffeeFactory.getCoffee("Americano", 3000);
        System.out.println("Factory latte ::" + latte);
        System.out.println("Factory ame ::" + ame);
    }
}

 

출처: 면접을 위한 CS전공 지식