Refactoring: Improving the Design of Existing Code (Object Technology Series) [Hardcover]

Besides an introduction to what refactoring is, this handbook provides a catalogue of dozens of tips for improving code. The best thing about Refactoring is its remarkably clear presentation, along with excellent nuts-and-bolts advice, from object expert Martin Fowler. The author is also an authority on software patterns and UML, and this experience helps make this a better book, one that should be immediately accessible to any intermediate or advanced object-oriented developer. (Just like patterns, each refactoring tip is presented with a simple name, a "motivation," and examples using Java and UML.)

Early chapters stress the importance of testing in successful refactoring. (When you improve code, you have to test to verify that it still works.) After the discussion on how to detect the "smells" of bad code, readers get to the heart of the book, its catalogue of more than 70 "refactorings"--tips for better and simpler class design. Each tip is illustrated with "before" and "after" code, along with an explanation. Later chapters provide a quick look at refactoring research.

Like software patterns, refactoring may be an idea whose time has come. This groundbreaking title will surely help bring refactoring to the programming mainstream. With its clear advice on a hot new topic, Refactoring is sure to be essential reading for anyone who writes or maintains object- oriented software. --Richard Dragan

Topics Covered: Refactoring, improving software code, redesign, design tips, patterns, unit testing, refactoring research and tools.

Refactoring is about improving the design of existing code. It is the process of changing a software system in such a way that it does not alter the external behavior of the code, yet improves its internal structure. With refactoring you can even take a bad design and rework it into a good one. This book offers a thorough discussion of the principles of refactoring, including where to spot opportunities for refactoring, and how to set up the required tests. There is also a catalog of more than 40 proven refactorings with details as to when and why to use the refactoring, step by step instructions for implementing it, and an example illustrating how it works The book is written using Java as its principle language, but the ideas are applicable to any OO language.

As the application of object technology--particularly the Java programming language--has become commonplace, a new problem has emerged to confront the software development community. Significant numbers of poorly designed programs have been created by less-experienced developers, resulting in applications that are inefficient and hard to maintain and extend. Increasingly, software system professionals are discovering just how difficult it is to work with these inherited, "non-optimal" applications. For several years, expert-level object programmers have employed a growing collection of techniques to improve the structural integrity and performance of such existing software programs. Referred to as "refactoring," these practices have remained in the domain of experts because no attempt has been made to transcribe the lore into a form that all developers could use. . .until now. In Refactoring: Improving the Design of Existing Code, renowned object technology mentor Martin Fowler breaks new ground, demystifying these master practices and demonstrating how software practitioners can realize the significant benefits of this new process.

With proper training a skilled system designer can take a bad design and rework it into well-designed, robust code. In this book, Martin Fowler shows you where opportunities for refactoring typically can be found, and how to go about reworking a bad design into a good one. Each refactoring step is simple--seemingly too simple to be worth doing. Refactoring may involve moving a field from one class to another, or pulling some code out of a method to turn it into its own method, or even pushing some code up or down a hierarchy. While these individual steps may seem elementary, the cumulative effect of such small changes can radically improve the design. Refactoring is a proven way to prevent software decay.

In addition to discussing the various techniques of refactoring, the author provides a detailed catalog of more than seventy proven refactorings with helpful pointers that teach you when to apply them; step-by-step instructions for applying each refactoring; and an example illustrating how the refactoring works. The illustrative examples are written in Java, but the ideas are applicable to any object-oriented programming language.

Martin Fowler is the Chief Scientist of ThoughtWorks, an enterprise-application development and delivery company. He's been applying object-oriented techniques to enterprise software development for over a decade. He is notorious for his work on patterns, the UML, refactoring, and agile methods. Martin lives in Melrose, Massachusetts, with his wife, Cindy, and a very strange cat. His homepage is http://martinfowler.com.

Kent Beck consistently challenges software engineering dogma, promoting ideas like patterns, test-driven development, and Extreme Programming. Currently affiliated with Three Rivers Institute and Agitar Software, he is the author of many Addison-Wesley titles.

John Brant and Don Roberts are the authors of the Refactoring Browser for Smalltalk, which is found at http://st-www.cs.uiuc.edu/~brant/RefactoringBrowser/. They are also consultants who have studied both the practical and theoretical aspects of refactoring for six years.

William Opdyke's doctoral research on refactoring object-oriented frameworks at the University of Illinois led to the first major publication on this topic. He is currently a Distinguished Member of Technical Staff at Lucent Technologies/Bell Laboratories.

John Brant and Don Roberts are the authors of the Refactoring Browser for Smalltalk, which is found at http://st-www.cs.uiuc.edu/~brant/RefactoringBrowser/. They are also consultants who have studied both the practical and theoretical aspects of refactoring for six years.