views:

176

answers:

2

I don't remember exactly is it a common pattern but I have a class (Factory Method pattern) which has method for creating other classes (Abstract Factory pattern) depending on enum parameter:

public class FooFactoryFactory {
   public FooFactory createFactory (FooFactoryType type) {
      switch (type) {
         case AFoo:
            return new AFooFactory ();
            break;
         case BFoo:
            return new BFooFactory ();
            break;
         default:
            throw new RuntimeException ("...");
      }  
   }
}

public interface FooFactory {
   Foo createFoo ();
   FooItem createFooItem ();
}

FooFactory has several implementations as well as Foo interface and FooItem interface (common Abstract Factory pattern).

So, how to rename FooFactoryFactory?

Maybe, FooFactoryCreator? (Think of this name during writing this question). IMHO it's nice, how do you think?

+5  A: 
  • FooFactoryCreator
  • FooFactoryProvider

But you might want to rename your factories to, say, builders. Take a look at javax.xml.parsers.DocumentBuilderFactory, which procudes DocumentBuilder instances, which in turn produce Documents

Looking into the DocumentBuilderFactory example, another option arises:

  • have an abstract FooFactory
  • make a static newInstance() method there (with parameters)
  • let newInstance() return the appropriate implementation of FooFactory
Bozho
+1: Nice suggestions and alternatives. I was myself immediately thinking about `MotherFooFactory` :)
BalusC
the `Mother` convention is the one I'm using the next time I need this :)
Bozho
Agreeable solution, only comment is a word of caution that only in rare instances is a "factory of factories" a truly necessary design. It sounds convoluted, and I'd be surprised if there weren't a more elegant pattern to apply to whatever the problem is. Case-in-point, DocumentBuilderFactory is so often misused (especially from a thread safety perspective), that I would immediately question any code of mine that could be compared to it.
Justin Searls
+2  A: 

In Creating and Destroying Java Objects: Part 1, the author suggests, "One advantage of static factory methods is that, unlike constructors, they have names." –Joshua Bloch. You may get some ideas from the article.

trashgod
Very nice article!
Roman