This document discusses the abstract factory design pattern. It begins by showing how a pizza store creates different types of pizzas using if/else statements. This leads to hard-coded dependencies. The document then introduces factories to encapsulate object creation. However, this leads to new factories needing to be created for different product families. Finally, the document explains how abstract factories solve this by providing a common interface for creating related product objects without specifying the concrete classes.

1. Abstract Factory
Manohar Thummala
Bharat Khatri
Govind Chintapalli
Mohana Sai Cherukuri

2. Pizza Store

3. Pizza orderPizza(String type) {
Pizza pizza;
if (type.equals(“cheese”)) {
pizza = new CheesePizza();
} else if (type.equals(“greek”) {
pizza = new GreekPizza();
} else if (type.equals(“pepperoni”) {
pizza = new PepperoniPizza();
}
pizza.prepare();
pizza.bake();
pizza.cut();
pizza.box();
return pizza;
}
Pizza Store

4. Problem ?
The problem starts with objects' creation
(new in Java).

5. Pizza orderPizza(String type) {
Pizza pizza;
if (type.equals(“cheese”)) {
pizza = new CheesePizza();
} else if (type.equals(“greek”) {
pizza = new GreekPizza();
} else if (type.equals(“pepperoni”) {
pizza = new PepperoniPizza();
}
pizza.prepare();
pizza.bake();
pizza.cut();
pizza.box();
return pizza;
}
New Pizza Store
Pizza orderPizza(String type) {
Pizza pizza;
if (type.equals(“cheese”)) {
pizza = new CheesePizza();
} else if (type.equals(“greek”) {
pizza = new GreekPizza();
} else if (type.equals(“pepperoni”) {
pizza = new PepperoniPizza();
}
pizza.prepare();
pizza.bake();
pizza.cut();
pizza.box();
return pizza;
}
Pizza Store

6. Solution
Encapsulate the change into a class which
creates objects.
Product - Objects (that need to be
instantiated)
Factory - The class that encapsulates the
creation of products.
Client - The class that performs actions on the
products.

7. Pizza orderPizza(String type) {
Pizza pizza;
pizza = new SimplePizzafactory
.createPizza(type);
pizza.prepare();
pizza.bake();
pizza.cut();
pizza.box();
return pizza;
}
public class SimplePizzaFactory {
public Pizza createPizza(String type) {
Pizza pizza = null;
if (type.equals(“cheese”)) {
pizza = new CheesePizza();
}
else if(type.equals(“pepperoni”)) {
pizza = new PepperoniPizza();
} else if (type.equals(“clam”)) {
pizza = new ClamPizza();
} else if (type.equals(“veggie”)) {
pizza = new VeggiePizza();
}
return pizza;
}
}

8. We got a Factory !

9. Another Problem ?
Our factory is a concrete class.
New family of products will require new
Factory.

10. DC Pizza Factory
public class DCPizzaFactory{
Pizza createPizza(String item) {
if (item.equals(“cheese”)) {
return new DCCheesePizza();
} else if (item.equals(“veggie”)) {
return new DCVeggiePizza();
} else if (item.equals(“clam”)) {
return new DCClamPizza();
} else if (item.equals(“pepperoni”)) {
return new DCPepperoniPizza();
} else return null;
}
}
NY Pizza Factory
public class NYPizzaFactory{
Pizza createPizza(String item) {
if (item.equals(“cheese”)) {
return new NYCheesePizza();
} else if (item.equals(“veggie”)) {
return new NYVeggiePizza();
} else if (item.equals(“clam”)) {
return new NYClamPizza();
} else if (item.equals(“pepperoni”)) {
return new NYPepperoniPizza();
} else return null;
}
}

11. Another Problem ?
Our factory is a concrete class.
New family of products will require a new
Factory.
New concrete Factory implementation would
lead to change in the client.

12. Abstract Factory

13. Abstract Factory - Intent
Provide an interface for creating families of
related or dependent objects without
specifying their concrete classes.

14. Let's get formal !
●AbstractFactory - declares an interface for operations that create
abstract products.
●ConcreteFactory - implements operations to create concrete
products.
●AbstractProduct - declares an interface for a type of product
objects.
●Product - defines a product to be created by the corresponding
ConcreteFactory; it implements the AbstractProduct interface.
●Client - uses the interfaces declared by the AbstractFactory and
AbstractProduct classes.

15. Demonstration

16. Questions ?