FactoryMethod Pattern

FactoryMethodSample.java

// http://ja.wikipedia.org/wiki/Factory_Method_%E3%83%91%E3%82%BF%E3%83%BC%E3%83%B3
public class FactoryMethodSample {
	public static void main(String[] args) {
		Creator creator;
		Product product;
		
		creator = new CreatorA();
		product = creator.factoryMethod();
		product.whoAreYou();
		
		creator = new CreatorB();
		product = creator.factoryMethod();
		product.whoAreYou();
	}
}

abstract class Creator {
	abstract Product factoryMethod();
}

class CreatorA extends Creator {
	Product factoryMethod() {
		return new ProductA();
	}
}

class CreatorB extends Creator {
	Product factoryMethod() {
		return new ProductB();
	}
}

abstract class Product {
	abstract void whoAreYou();
}

class ProductA extends Product {
	void whoAreYou() { System.out.println("I'm A");}
}

class ProductB extends Product {
	void whoAreYou() { System.out.println("I'm B");}
}