Effective Java

by Bloch, Joshua

• ISBN13: 9780321356680
• ISBN10: 0321356683
• Edition: 2nd
• Format: Paperback
• Copyright: 2008-05-08
• Publisher: Addison-Wesley Professional

Summary

Designed to help Java programmers make the most effective use of the Java programming language and its fundamental libraries, this updated edition includes more than 50 essays, each of which conveys one rule. Helping programmers sidestep common misconceptions and errors, each rule captures best practices that have been tested in the real world.

Author Biography

Joshua Bloch is chief Java architect at Google and a Jolt Award winner. He was previously a distinguished engineer at Sun Microsystems and a senior systems designer at Transarc. Bloch led the design and implementation of numerous Java platform features, including JDK 5.0 language enhancements and the award-winning Java Collections Framework. He coauthored Java™ Puzzlers (Addison-Wesley, 2005) and Java™ Concurrency in Practice (Addison-Wesley, 2006).

Table of Contents

Foreword	p. xi
Preface	p. xiii
Acknowledgments	p. xvii
Introduction	p. 1
Creating and Destroying Objects	p. 5
Consider static factory methods instead of constructors	p. 5
Consider a builder when faced with many constructorparameters	p. 11
Enforce the singleton property with a private constructor	p. 17
Enforce noninstantiability with a private constructor	p. 19
Avoid creating unnecessary objects	p. 20
Eliminate obsolete object references	p. 24
Avoid finalizers	p. 27
Methods Common to All Objects	p. 33
Obey the general contract when overriding equals	p. 33
Always override hashCode when you override equals	p. 45
Always override toString	p. 51
Override clone judiciously	p. 54
Consider implementing Comparable	p. 62
Classes and Interfaces	p. 67
Minimize the accessibility of classes and members	p. 67
In public classes, use accessor methods, not public fields	p. 71
Minimize mutability	p. 73
Favor composition over inheritance	p. 81
Design and document for inheritance or else prohibit it	p. 87
Prefer interfaces to abstract classes	p. 93
Use interfaces only to define types	p. 98
Prefer class hierarchies to tagged classes	p. 100
Use function objects to represent strategies	p. 103
Favor static member classes over nonstatic	p. 106
Generics	p. 109
Don't use raw types in new code	p. 109
Eliminate unchecked warnings	p. 116
Prefer lists to arrays	p. 119
Favor generic types	p. 124
Favor generic methods	p. 129
Use bounded wildcards to increase API flexibility	p. 134
Consider typesafe heterogeneous containers	p. 142
Enums and Annotations	p. 147
Use enums instead of int constants	p. 147
Use instance fields instead of ordinals	p. 158
Use EnumSet instead of bit fields	p. 159
Use EnumMap instead of ordinal indexing	p. 161
Emulate extensible enums with interfaces	p. 165
Prefer annotations to naming patterns	p. 169
Consistently use the Override annotation	p. 176
Use marker interfaces to define types	p. 179
Methods	p. 181
Check parameters for validity	p. 181
Make defensive copies when needed	p. 184
Design method signatures carefully	p. 189
Use overloading judiciously	p. 191
Use varargs judiciously	p. 197
Return empty arrays or collections, not nulls	p. 201
Write doc comments for all exposed API elements	p. 203
General Programming	p. 209
Minimize the scope of local variables	p. 209
Prefer for-each loops to traditional for loops	p. 212
Know and use the libraries	p. 215
Avoid float and double if exact answers are required	p. 218
Prefer primitive type
Table of Contents provided by Publisher. All Rights Reserved.

Excerpts

Preface to the Second EditionA lot has happened to the Java platform since I wrote the first edition of this book in 2001, and it's high time for a second edition. The most significant set of changes was the addition of generics, enum types, annotations, autoboxing, and the for-each loop in Java 5. A close second was the addition of the new concurrency library, java.util.concurrent , also released in Java 5. With Gilad Bracha, I had the good fortune to lead the teams that designed the new language features. I also had the good fortune to serve on the team that designed and developed the concurrency library, which was led by Doug Lea.The other big change in the platform is the widespread adoption of modern Integrated Development Environments (IDEs), such as Eclipse, IntelliJ IDEA, and NetBeans, and of static analysis tools, such as FindBugs. While I have not been involved in these efforts, I've benefited from them immensely and learned how they affect the Java development experience.In 2004, I moved from Sun to Google, but I've continued my involvement in the development of the Java platform over the past four years, contributing to the concurrency and collections APIs through the good offices of Google and the Java Community Process. I've also had the pleasure of using the Java platform to develop libraries for use within Google. Now I know what it feels like to be a user.As was the case in 2001 when I wrote the first edition, my primary goal is to share my experience with you so that you can imitate my successes while avoiding my failures. The new material continues to make liberal use of real-world examples from the Java platform libraries.The first edition succeeded beyond my wildest expectations, and I've done my best to stay true to its spirit while covering all of the new material that was required to bring the book up to date. It was inevitable that the book would grow, and grow it did, from fifty-seven items to seventy-eight. Not only did I add twenty-three items, but I thoroughly revised all the original material and retired a few items whose better days had passed. In the Appendix, you can see how the material in this edition relates to the material in the first edition.In the Preface to the First Edition, I wrote that the Java programming language and its libraries were immensely conducive to quality and productivity, and a joy to work with. The changes in releases 5 and 6 have taken a good thing and made it better. The platform is much bigger now than it was in 2001 and more complex, but once you learn the patterns and idioms for using the new features, they make your programs better and your life easier. I hope this edition captures my continued enthusiasm for the platform and helps make your use of the platform and its new features more effective and enjoyable.San Jose, California April 2008