الگوی طراحی Factory Method (روش کارخانه)

public class PizzaStore {
    public Pizza orderPizza(String type) {
        Pizza pizza;

        if (type.equals("cheese")) {
            pizza = new CheesePizza();
        } else if (type.equals("pepperoni")) {
            pizza = new PepperoniPizza();
        } else {
            return null;
        }

        pizza.prepare();
        pizza.bake();
        pizza.cut();
        pizza.box();
        return pizza;
    }
}

public abstract class Pizza {
    String name;

    void prepare() {
        System.out.println("Preparing " + name);
    }
    void bake() {
        System.out.println("Baking " + name);
    }
    void cut() {
        System.out.println("Cutting " + name);
    }
    void box() {
        System.out.println("Boxing " + name);
    }

    public String getName() {
        return name;
    }
}

public class CheesePizza extends Pizza {
    public CheesePizza() {
        name = "Cheese Pizza";
    }
}

public class PepperoniPizza extends Pizza {
    public PepperoniPizza() {
        name = "Pepperoni Pizza";
    }
}

public abstract class PizzaStore {
    public Pizza orderPizza(String type) {
        Pizza pizza = createPizza(type); // Factory Method

        pizza.prepare();
        pizza.bake();
        pizza.cut();
        pizza.box();

        return pizza;
    }

    protected abstract Pizza createPizza(String type);
}

public class NYPizzaStore extends PizzaStore {
    @Override
    protected Pizza createPizza(String type) {
        if (type.equals("cheese")) {
            return new CheesePizza();
        } else if (type.equals("pepperoni")) {
            return new PepperoniPizza();
        } else {
            return null;
        }
    }
}

public class ChicagoPizzaStore extends PizzaStore {
    @Override
    protected Pizza createPizza(String type) {
        if (type.equals("cheese")) {
            return new CheesePizza();
        } else if (type.equals("pepperoni")) {
            return new PepperoniPizza();
        } else {
            return null;
        }
    }
}

public class PizzaTestDrive {
    public static void main(String[] args) {
        PizzaStore nyStore = new NYPizzaStore();
        PizzaStore chicagoStore = new ChicagoPizzaStore();

        Pizza pizza = nyStore.orderPizza("cheese");
        System.out.println("Ethan ordered a " + pizza.getName() + "\n");

        pizza = chicagoStore.orderPizza("cheese");
        System.out.println("Joel ordered a " + pizza.getName() + "\n");
    }
}

Preparing Cheese Pizza
Baking Cheese Pizza
Cutting Cheese Pizza
Boxing Cheese Pizza
Ethan ordered a Cheese Pizza

Preparing Cheese Pizza
Baking Cheese Pizza
Cutting Cheese Pizza
Boxing Cheese Pizza
Joel ordered a Cheese Pizza