layout	title	folder	permalink	pumlid	categories	tags
pattern	Factory Method	factory-method	/patterns/factory-method/	NSZB3G8n30N0Lg20n7UwCOxPP9MVx6TMT0zdRgEvjoazYeRrMmMsFuYChtmqr7Y6gycQq8aiQr3hSJ7OwEGtfwBUZfas0shJQR3_G2yMBFkaeQYha4B-AeUDl6FqBm00	Creational	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.

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
• java.nio.charset.Charset
• java.net.URLStreamHandlerFactory
• java.util.EnumSet
• javax.xml.bind.JAXBContext

Credits

• Design Patterns: Elements of Reusable Object-Oriented Software