Factory Method

Abstractions

public abstract class PizzaStore {
 
	abstract Pizza createPizza(String item);
 
	public Pizza orderPizza(String type) {
		Pizza pizza = createPizza(type);
		System.out.println("--- Making a " + pizza.getName() + " ---");
		pizza.prepare();
		pizza.bake();
		pizza.cut();
		pizza.box();
		return pizza;
	}
}

import java.util.ArrayList;

public abstract class Pizza {
	String name;
	String dough;
	String sauce;
	ArrayList toppings = new ArrayList();
 
	void prepare() {
		System.out.println("Preparing " + name);
		System.out.println("Tossing dough...");
		System.out.println("Adding sauce...");
		System.out.println("Adding toppings: ");
		for (int i = 0; i < toppings.size(); i++) {
			System.out.println("   " + toppings.get(i));
		}
	}
  
	void bake() {
		System.out.println("Bake for 25 minutes at 350");
	}
 
	void cut() {
		System.out.println("Cutting the pizza into diagonal slices");
	}
  
	void box() {
		System.out.println("Place pizza in official PizzaStore box");
	}
 
	public String getName() {
		return name;
	}

	public String toString() {
		StringBuffer display = new StringBuffer();
		display.append("---- " + name + " ----\n");
		display.append(dough + "\n");
		display.append(sauce + "\n");
		for (int i = 0; i < toppings.size(); i++) {
			display.append((String )toppings.get(i) + "\n");
		}
		return display.toString();
	}
}

Implementations

public class NYPizzaStore extends PizzaStore {

	Pizza createPizza(String item) {
		if (item.equals("cheese")) {
			return new NYStyleCheesePizza();
		} else if (item.equals("veggie")) {
			return new NYStyleVeggiePizza();
		} else if (item.equals("clam")) {
			return new NYStyleClamPizza();
		} else if (item.equals("pepperoni")) {
			return new NYStylePepperoniPizza();
		} else return null;
	}
}

public class NYStyleCheesePizza extends Pizza {

	public NYStyleCheesePizza() { 
		name = "NY Style Sauce and Cheese Pizza";
		dough = "Thin Crust Dough";
		sauce = "Marinara Sauce";
 
		toppings.add("Grated Reggiano Cheese");
	}
}

public class ChicagoPizzaStore extends PizzaStore {

	Pizza createPizza(String item) {
        	if (item.equals("cheese")) {
            		return new ChicagoStyleCheesePizza();
        	} else if (item.equals("veggie")) {
        	    	return new ChicagoStyleVeggiePizza();
        	} else if (item.equals("clam")) {
        	    	return new ChicagoStyleClamPizza();
        	} else if (item.equals("pepperoni")) {
            		return new ChicagoStylePepperoniPizza();
        	} else return null;
	}
}

public class ChicagoPizzaStore extends PizzaStore {

	Pizza createPizza(String item) {
        	if (item.equals("cheese")) {
            		return new ChicagoStyleCheesePizza();
        	} else if (item.equals("veggie")) {
        	    	return new ChicagoStyleVeggiePizza();
        	} else if (item.equals("clam")) {
        	    	return new ChicagoStyleClamPizza();
        	} else if (item.equals("pepperoni")) {
            		return new ChicagoStylePepperoniPizza();
        	} else return null;
	}
}

Runner

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");

		pizza = nyStore.orderPizza("clam");
		System.out.println("Ethan ordered a " + pizza.getName() + "\n");
 
		pizza = chicagoStore.orderPizza("clam");
		System.out.println("Joel ordered a " + pizza.getName() + "\n");

		pizza = nyStore.orderPizza("pepperoni");
		System.out.println("Ethan ordered a " + pizza.getName() + "\n");
 
		pizza = chicagoStore.orderPizza("pepperoni");
		System.out.println("Joel ordered a " + pizza.getName() + "\n");

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