New Article: The Match Maker Design Pattern - a New Place for the Actions

We've just published Michael Bar-Sinai's new article, The Match Maker Design Pattern - a New Place for the Actions. In this article, Michael tackles some of the problems associated with object-oriented design within the context of the changing requirements that the real-life business world imposes on software applications over time. To see what I mean, here's Michael's opening paragraph: Software systems often deal with similar concepts, whose behavior differs only slightly. Classic Object-Oriented design deals with such cases using inheritance; overriding the calculateSalary() method in different Employee subclasses allows the rest of the application to remain oblivious to the subtle differences between the salary algorithms of Manager, Engineer, and AnnoyingCeoNephew. In the article, Michael presents a solution that, while not a "silver bullet", provides benefits that work in a majority of real-life cases where you're updating software applications to address changed business requirements. His section "Dealing With New Classes On The Fly" opens with: A MatchMaker instance does hold a Map mapping classes to handlers, but with a twist. When it is given an instance of a class for which a handler was not explicitly specified, it embarks on a breadth-first search (BFS) up the class hierarchy, starting from that object's class, looking for a class for which a handler was explicitly specified. A prop...

Date: April, 27 2010
Url: http://www.java.net/blog/editor/archive/2010/04/27/new-article-match-maker-design-pattern-new-place-actions

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