---
layout: pattern
title: Factory Method
folder: factory-method
permalink: /patterns/factory-method/
categories: Creational
tags: 
 - Java
 - Difficulty-Beginner
 - Gang Of Four
---

## Also known as
Virtual Constructor

## Intent
Define an interface for creating an object, but let subclasses
decide which class to instantiate. Factory Method lets a class defer
instantiation to subclasses.

![alt text](./etc/factory-method_1.png "Factory Method")

## Applicability
Use the Factory Method pattern when

* a class can't anticipate the class of objects it must create
* a class wants its subclasses to specify the objects it creates
* classes delegate responsibility to one of several helper subclasses, and you want to localize the knowledge of which helper subclass is the delegate

## Credits

* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)

---
layout: pattern
title: Factory Method
folder: factory-method
permalink: /patterns/factory-method/
categories: Creational
tags: 
 - Java
 - Difficulty-Beginner
 - Gang Of Four
---

## Also known as
Virtual Constructor

## Intent
Define an interface for creating an object, but let subclasses
decide which class to instantiate. Factory Method lets a class defer
instantiation to subclasses.

![alt text](./etc/factory-method_1.png "Factory Method")

## Applicability
Use the Factory Method pattern when

* a class can't anticipate the class of objects it must create
* a class wants its subclasses to specify the objects it creates
* classes delegate responsibility to one of several helper subclasses, and you want to localize the knowledge of which helper subclass is the delegate

## Known uses

java.util.Calendar
java.util.ResourceBundle
java.text.NumberFormat#getInstance()

## Credits

* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)

Add known uses to Factory Method
Add known uses to Factory Method
