Amazon.co.uk
Bloch provides 57 items (did he reject "varieties"?) grouped by subject. Each item highlights a "gotcha", expands on best practice or argues for deprecating a common practice. For example, among the gotchas, he points out problems with relying on finalisers, whose implementation varies from one JVM to another and may not run at all under some circumstances.
Best practice also gets a lot of airing. A neat example is not relying on Java's default object serialisation API, which--among other problems--can cause the object to break if you make any changes. This can result in a code maintenance nightmare. In the last category he discusses the string concatenation, "+". Using this can be a hundred times slower than appending to a StringBuffer. No problem for a one-off string but using it repeatedly can cripple performance.
Many of the items discussed are fairly trivial, such as returning zero rather than null for zero length arrays or avoiding the use of floats when you need precise answers--perhaps they were thrown in to make the magic "57"--but despite these Effective Java Programming Language Guide offers a fascinating insight into Java's architecture and solid, easily assimilated guidance on its effective usage.
Unlike most books for programmers, this is one you really will find difficult to put down. Every serious Java programmer should read it. --Steve Patient
Amazon.com
As a veteran developer at Sun, the author shares his considerable insight into the design choices made over the years in Sun's own Java libraries (which the author acknowledges haven't always been perfect). Based on his experience working with Sun's best minds, the author provides a compilation of 57 tips for better Java code organized by category. Many of these ideas will let you write more robust classes that better cooperate with built-in Java APIs. Many of the tips make use of software patterns and demonstrate an up-to-the-minute sense of what works best in today's design. Each tip is clearly introduced and explained with code snippets used to demonstrate each programming principle.
Early sections on creating and destroying objects show you ways to make better use of resources, including how to avoid duplicate objects. Next comes an absolutely indispensable guide to implementing "required" methods for custom classes. This material will help you write new classes that cooperate with old ones (with advice on implementing essential requirements like the equals() and hashCode() methods).
The author has a lot to say about class design, whether using inheritance or composition. Tips on designing methods show you how to create understandable, maintainable, and robust classes that can be easily reused by others on your team. Sections on mapping C code (like structures, unions, and enumerated types) onto Java will help C programmers bring their existing skills to Sun's new language. Later sections delve into some general programming tips, like using exceptions effectively. The book closes with advice on using threads and synchronization techniques, plus some worthwhile advice on object serialization.
Whatever your level of Java knowledge, this title can make you a more effective programmer. Wisely written, yet never pompous or doctrinaire, the author has succeeded in packaging some really valuable nuggets of advice into a concise and very accessible guidebook that arguably deserves a place on most any developer's bookshelf. --Richard Dragan
Topics covered:
- Best practices and tips for Java
- Creating and destroying objects (static factory methods, singletons, avoiding duplicate objects and finalizers)
- Required methods for custom classes (overriding equals(), hashCode(), toString(), clone(), and compareTo() properly)
- Hints for class and interface design (minimizing class and member accessibility, immutability, composition versus inheritance, interfaces versus abstract classes, preventing subclassing, static versus nonstatic classes)
- C constructs in Java (structures, unions, enumerated types, and function pointers in Java)
- Tips for designing methods (parameter validation, defensive copies, method signatures, method overloading, zero-length arrays, hints for Javadoc comments)
- General programming advice (local variable scope, using Java API libraries, avoiding float and double for exact comparisons, when to avoid strings, string concatenation, interfaces and reflection, avoid native methods, optimizing hints, naming conventions)
- Programming with exceptions (checked versus run-time exceptions, standard exceptions, documenting exceptions, failure-capture information, failure atomicity)
- Threading and multitasking (synchronization and scheduling hints, thread safety, avoiding thread groups)
- Serialization (when to implement Serializable, the readObject(), and readResolve() methods)
Kurzbeschreibung
Synopsis
Über den Autor
Prolog. Abdruck erfolgt mit freundlicher Genehmigung der Rechteinhaber. Alle Rechte vorbehalten.
In 1996 I pulled up stakes and headed west to work for JavaSoft, as it was then known, because it was clear that was where the action was. In the intervening five years I've served as Java Platform Libraries Architect. I've designed, implemented and maintained many of the libraries, and served as a consultant for many others. Presiding over these libraries as the Java platform matured was a once-in-a-lifetime opportunity. It is no exaggeration to say that I had the privilege to work with some of the great software engineers of our generation. In the process, I learned a lot about the Java programming language--what works, what doesn't, and how to use the language and its libraries to best effect.
This book is my attempt to share my experience with you, so that you can imitate my successes while avoiding my failures. I borrowed the format from Scott Meyers's Effective C++ Meyers98, which consists of fifty items, each conveying one specific rule for improving your programs and designs. I found the format to be singularly effective and I hope you do too.
In many cases, I took the liberty of illustrating the items with real-world examples from the Java platform libraries. When describing something that could have been done better, I tried to pick on code that I wrote myself, but occasionally I pick on something written by a colleague. I sincerely apologize if, despite my best efforts, I've offended anyone. Negative examples are cited not to cast blame but in the spirit of cooperation, so that all of us can benefit from the experience of those who've gone before.
While this book is not targeted solely at developers of reusable components, it is inevitably colored by my experience writing such components over the past two decades. I naturally think in terms of exported APIs (Application Programming Interfaces) and I encourage you to do likewise. Even if you aren't developing reusable components, thinking in these terms tends to improve the quality of the software you write. Furthermore, it's not uncommon to write a reusable component without knowing it: you write something useful, share it with your buddy across the hall, and before long you have half a dozen users. At this point, you no longer have the flexibility to change the API at will, and are thankful for all the effort that you put into designing the API when you first wrote the software.
My focus on API design may seem a bit unnatural to devotees of the new lightweight software development methodologies, such as Extreme Programming Explained Beck99. These methodologies emphasize writing the simplest program that could possibly work. If you're using one of these methodologies you'll find that a focus on API design serves you well in the refactoring process. The fundamental goals of refactoring are the improvement of system structure and the avoidance of code duplication. These goals are impossible to achieve in the absence of well-designed APIs for the components of the system.
No language is perfect, but some of them are excellent. I have found the Java programming language and its libraries to be immensely conducive to quality and productivity, and a joy to work with. I hope this book captures my enthusiasm and helps make your use of the language more effective and enjoyable.
Josh Bloch
Cupertino, California
April, 2001
0201310058P04232001
