Java Glossary : factory method

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factory method

A factory is a sort of generic constructor that might produce any of a number of different kinds of objects. You have to implement it as a static method, rather than a constructor. Inside you can implement in several ways:

Have a big switch and select the right constructor.
Use a Hashtable and .clone() to reproduce pre-initialised exemplar objects.
use getInstanceOf to create arbitrary objects from just the class name provided as a String.

If you want to give others the ability to add new types to the factory, the static method pretty well has to fob the work off on a factory delegate object or objects that can be changed. You can can't directly override a static factory method, and others would ignore a overridden instance factory method.

design patterns ¤ prototype

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