RE: [patterns-discussion] Abstract Factory vs. Factory Method

[Bruce Trask]

Hi Pablo,   The best answer I've found for this is the following post to comp.object from Robert Martin (Uncle Bob):   "The difference is the same as the difference between Strategy and Template Method.  In Strategy we create a whole new class to contain the polymorphic methods we want to call.  In Template method we put the polymorhic methods we want to call in our own class, and depend upon derivatives to implement them.   In Abstract factory we create a whole new class to hold the create methods for the objects we need to create.  In Factory Method we put abstract methods in our own class to create objects and depend upon our derivatives to implement them.   public class MyAbstractFactoryUser. {   public void f()   {     MyObject o = MyFactory.createObject();     o.doSomething();   } } ============= public class MyFactoryMethoduser {   public abstract MyObject createObject();   public void f()   {     MyObject o = createObject();     o.doSomething();   } } ==========   Abstract factories are a little more flexible, but a little more complex than Factory methods.  You can change factories at runtime, but you can't change Factory Method implementations at runtime. Abstract Factories have to be created by someone, and references to them have to be available to the users.  Template Methods live in the using object and are therefore created with it, and always available to it."   Hope this helps, Bruce -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of Pablo Schor Sent: Thursday, October 30, 2003 7:11 AM To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: [patterns-discussion] Abstract Factory vs. Factory Method I've been using the factory pattern for a while, but don't know exactly if I'm using the Abstract Factory or the Factory Method. They look the same to me, but what are the differences? thank you, Pablo