Factory method pattern: Difference between revisions

Revision as of 09:21, 7 January 2004

Revision as of 23:27, 28 February 2004

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=== Factory design pattern in Java ===

The Factory pattern is useful to solve a common [[problem]]: Very often you'll have to construct an [[Object (computer science)|object]], based on some [[input]], and the [[function]]s inside the object will depend upon the input. A good example would be a [[class (computer science)|class]] to read [[image file]]s and make [[thumbnail]]s out of them. You could, of course, bung them all into one class and have it decide which bit of code to run on its own:

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This [[method]] has the [[advantage]] of abstracting the [[file type]] from the class that calls this ImageReader, but as the number of file types supported gets larger, the code will quickly become huge, unwieldy and hard to maintain.

Another [[solution]] that seems possible is to have a separate [[Object (computer science)|object]] for each of these file types:

public Interface ImageReader