• Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

What is a factory class?

 
Bindu Puvvala
Greenhorn
Posts: 12
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Book says java.util.Collections is a factory class. What is a factory class at all?
 
wise owen
Ranch Hand
Posts: 2023
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
A factory class is a standard design pattern that gives you the ability to manufacture classes as needed.
 
Bindu Puvvala
Greenhorn
Posts: 12
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Do you mean a factory class can be used as a base class, from which required classes can be derived?
 
Priya Balaraman
Greenhorn
Posts: 6
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
absolutely. U state your requirements and it shall be manufactured
 
Marcus Green
arch rival
Rancher
Posts: 2813
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
"Do you mean a factory class can be used as a base class, from which required classes can be derived?"

That doesn't really encapsulate the expectations of what a factory class is,

"The Factory Pattern is all about "Define an interface for creating an object, but let the subclasses decide which class to instantiate. The Factory method lets a class defer instantiation to subclasses" Thus, as defined by Gamma et al, "The Factory Method lets a class defer instantiation to subclasses".

http://gsraj.tripod.com/design/creational/factory/factory.html

However the SCJP exam has absolutely no expectation of an understanding of Design Patterns so don't worry about it too much. Design patterns are a big deal in the world of Java programming, but not the SCJP. Design Patterns are covered by the SCWCD exam (but as it so happens not the Factory pattern).
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic