Thinking in Java / Edition 4

by Bruce Eckel

Overview

“ Thinking in Java should be read cover to cover by every Java programmer, then kept close at hand for frequent reference. The exercises are challenging, and the chapter on Collections is superb! Not only did this book help me to pass the Sun Certified Java Programmer exam; it’s also the first book I turn to whenever I have a Java question.”
—Jim Pleger, Loudoun County (Virginia) Government “ Much better than any other Java book I’ve seen. Make that ‘by an order of magnitude’.... Very complete, with excellent right-to-the-point examples and intelligent, not dumbed-down, explanations.... In contrast to many other Java books I found it to be unusually mature, consistent, intellectually honest, well-written, and precise. IMHO, an ideal book for studying Java.”
—Anatoly Vorobey, Technion University, Haifa, Israel “Absolutely one of the best programming tutorials I’ve seen for any language.”
—Joakim Ziegler, FIX sysop “Thank you again for your awesome book. I was really floundering (being a non-C programmer), but your book has brought me up to speed as fast as I could read it. It’s really cool to be able to understand the underlying principles and concepts from the start, rather than having to try to build that conceptual model through trial and error. Hopefully I will be able to attend your seminar in the not-too-distant future.”
—Randall R. Hawley, automation technician, Eli Lilly & Co. “This is one of the best books I’ve read about a programming language.... The best book ever written on Java.”
—Ravindra Pai, Oracle Corporation, SUNOS product line “Bruce, your book is wonderful! Your explanations are clear and direct. Through your fantastic book I have gained a tremendous amount of Java knowledge. The exercises are also fantastic and do an excellent job reinforcing the ideas explained throughout the chapters. I look forward to reading more books written by you. Thank you for the tremendous service that you are providing by writing such great books. My code will be much better after reading Thinking in Java. I thank you and I’m sure any programmers who will have to maintain my code are also grateful to you.”
—Yvonne Watkins, Java artisan, Discover Technologies, Inc. “Other books cover the what of Java (describing the syntax and the libraries) or the how of Java (practical programming examples). Thinking in Java is the only book I know that explains the why of Java: Why it was designed the way it was, why it works the way it does, why it sometimes doesn’t work, why it’s better than C++, why it’s not. Although it also does a good job of teaching the what and how of the language, Thinking in Java is definitely the thinking person’s choice in a Java book.”
—Robert S. Stephenson Awards for Thinking in Java 2003 Software Development Magazine Jolt Award for Best Book
2003 Java Developer’s Journal Reader’s Choice Award for Best Book
2001 JavaWorld Editor’s Choice Award for Best Book
2000 JavaWorld Reader’s Choice Award for Best Book
1999 Software Development Magazine Productivity Award
1998 Java Developer’s Journal Editor’s Choice Award for Best Book

Thinking in Java has earned raves from programmers worldwide for its extraordinary clarity, careful organization, and small, direct programming examples. From the fundamentals of Java syntax to its most advanced features, Thinking in Java

Product Details

ISBN-13:	9780131872486
Publisher:	Pearson Education
Publication date:	02/10/2006
Edition description:	REV
Pages:	1520
Product dimensions:	7.15(w) x 9.30(h) x 2.40(d)

About the Author

Bruce Eckel is president of MindView, Inc. (www.MindView.net), which provides public and private training seminars, consulting, mentoring, and design reviews in object-oriented technology and design patterns. He is the author of several books, has written more than fifty articles, and has given lectures and seminars throughout the world for more than twenty years. Bruce has served as a voting member of the C++ Standards Committee. He holds a B.S. in applied physics and an M.S. in computer engineering.

Read an Excerpt

PREFACE:

Table of Contents

Preface 1

Introduction 13

Prerequisites 14

Learning Java 14

Goals 15

Teaching from this book 16

JDK HTML documentation 17

Exercises 17

Foundations for Java 18

Source code 18

Errors 21

Introduction to Objects 23

The progress of abstraction 24

An object has an interface 26

An object provides services 29

The hidden implementation 30

Reusing the implementation 32

Inheritance 33

Interchangeable objects with polymorphism 38

The singly rooted hierarchy 43

Containers 44

Object creation & lifetime 46

Exception handling: dealing with errors 49

Concurrent programming 50

Java and the Internet 51

Summary 60

Everything Is an Object 61

You manipulate objects with references 61

You must create all the objects 63

You never need to destroy an object 67

Creating new data types: class 69

Methods, arguments, and return values 72

Building a Java program 74

Your first Java program 78

Comments and embedded documentation 81

Coding style 88

Summary 89

Exercises 89

Operators 93

Simpler print statements 93

Using Java operators 94

Precedence 95

Assignment 95

Mathematical operators 98

Auto increment and decrement 101

Relational operators 103

Logical operators 105

Literals 108

Bitwise operators 111

Shift operators 112

Ternary if-else operator 116

String operator + and += 118

Common pitfalls when using operators 119

Casting operators 120

Java has no “sizeof” 122

A compendium of operators 123

Summary 133

Controlling Execution 135

true and false 135

if-else 135

Iteration 137

Foreach syntax 140

return 143

break and continue 144

The infamous “goto” 146

switch 151

Summary 154

Initialization & Cleanup 155

Guaranteed initialization with the constructor 155

Method overloading 158

Default constructors 166

The this keyword 167

Cleanup: finalization and garbage collection 173

Member initialization 181

Constructor initialization 185

Array initialization 193

Enumerated types 204

Summary 207

Access Control 209

package: the library unit 210

Java access specifiers 221

Interface and implementation 228

Class access 229

Summary 233

Reusing Classes 237

Composition syntax 237

Inheritance syntax 241

Delegation 246

Combining composition and inheritance 249

Choosing composition vs. inheritance 256

protected 258

Upcasting 260

The final keyword 262

Initialization and class loading 272

Summary 274

Polymorphism 277

Upcasting revisited 278

The twist 281

Constructors and polymorphism 293

Covariant return types 303

Designing with inheritance 304

Summary 310

Interfaces 311

Abstract classes and methods 311

Interfaces 316

Complete decoupling 320

“Multiple in heritance” in Java 326

Extending an interface with inheritance 329

Adapting to an interface 331

Fields in interfaces 335

Nesting interfaces 336

Interfaces and factories 339

Summary 343

Inner Classes 345

Creating inner classes 345

The link to the outer class 347

Using .this and .new 350

Inner classes and upcasting 352

Inner classes in methods and scopes 354

Anonymous inner classes 356

Nested classes 364

Why inner classes? 369

Inheriting from inner classes 382

Can inner classes be overridden? 383

Local inner classes 385

Inner-class identifiers 387

Summary 388

Holding Your Objects 389

Generics and type-safe containers 390

Basic concepts 394

Adding groups of elements 396

Printing containers 398

List 401

Iterator 406

LinkedList 410

Stack 412

Set 415

Map 419

Queue 423

Collection vs. Iterator 427

Foreach and iterators 431

Summary 437

Error Handling with Exceptions 443

Concepts 444

Basic exceptions 445

Catching an exception 447

Creating your own exceptions 449

The exception specification 457

Catching any exception 458

Standard Java exceptions 468

Performing cleanup with finally 471

Exception restrictions 479

Constructors 483

Exception matching 489

Alternative approaches 490

Exception guidelines 500

Summary 501

Strings 503

Immutable Strings 503

Overloading &8216;+’ vs. StringBuilder 504

Unintended recursion 509

Operations on Strings 511

Formatting output 514

Regular expressions 523

Scanning input 546

StringTokenizer 551

Summary 552

Type Information 553

The need for RTTI 553

The Class object 556

Checking before a cast 569

Registered factories 582

instanceof vs. Class equivalence 586

Reflection: runtime class information 588

Dynamic proxies 593

Null Objects 598

Interfaces and type information 607

Summary 613

Generics 617

Comparison with C++ 618

Simple generics 619

Generic interfaces 627

Generic methods 631

Anonymous inner classes 645

Building complex models 647

The mystery of erasure 650

Compensating for erasure 662

Bounds 673

Wildcards 677

Issues 694

Self-bounded types 701

Dynamic type safety 710

Exceptions 711

Mixins 713

Latent typing 721

Compensating for the lack of latent typing 726

Using function objects as strategies 737

Summary: Is casting really so bad? 743

Arrays 747

Why arrays are special 747

Arrays are first-class objects 749

Returning an array 753

Multidimensional arrays 754

Arrays and generics 759

Creating test data 762

Arrays utilities 775

Summary 786

Containers in Depth 791

Full container taxonomy 791

Filling containers 793

Collection functionality 809

Optional operations 813

List functionality 817

Sets and storage order 821

Queues 827

Understanding Maps 831

Hashing and hash codes 839

Choosing an implementation 858

Utilities 879

Holding references 889

Java 1.0/1.1 containers 893

Summary 900

I/O 901

The File class 901

Input and output 914

Adding attributes and useful interfaces 918

Readers & Writers 922

Off by itself: RandomAccessFile 926

Typical uses of I/O streams 927

File reading & writing utilities 936

Standard I/O 941

Process control 944

New I/O 946

Compression 973

Object serialization 980

XML 1003

Preferences 1006

Summary 1008

Enumerated Types 1011

Basic enum features 1011

Adding methods to an enum 1014

enums in switch statements 1016

The mystery of values() 1017

Implements, not inherits 1020

Random selection 1021

Using interfaces for organization 1022

Using EnumSet instead of flags 1028

Using EnumMap 1030

Constant-specific methods 1032

Multiple dispatching 1047

Summary 1057

Annotations 1059

Basic syntax 1060

Writing annotation processors 1064

Using apt to process annotations 1074

Using the Visitor pattern with apt 1079

Annotation-based unit testing 1083

Summary 1106

Concurrency 1109

The many faces of concurrency 1111

Basic threading 1116

Sharing resources 1150

Terminating tasks 1179

Cooperation between tasks 1197

Deadlock 1223

New Library components 1229

Simulation 1253

Performance tuning 1270

Active objects 1295

Summary 1300

Graphical User Interfaces 1303

Applets 1306

Swing basics 1307

Making a button 1311

Capturing an event 1312

Text areas 1315

Controlling layout 1317

The Swing event model 1321

A selection of Swing components 1332

JNLP and Java Web Start 1376

Concurrency & Swing 1382

Visual programming and JavaBeans 1393

Alternatives to Swing 1415

Building Flash Web clients with Flex 1416

Creating SWT applications 1430

Summary 1447

A: Supplements 1449

Downloadable supplements 1449

Thinking in C: Foundations for Java 1449

Thinking in Java seminar 1450

Hands-On Java seminar-on-CD 1450

Thinking in Objects seminar 1450

Thinking in Enterprise Java 1451

Thinking in Patterns (with Java) 1452

Thinking in Patterns seminar 1452

Design consulting and reviews 1453

B: Resources 1455

Software 1455

Editors & IDEs 1455

Books 1456

Index 1463

Preface

I originally approached Java as “just another programming language,” which in many senses it is.

But as time passed and I studied it more deeply, I began to see that the fundamental intent of this language was different from other languages I had seen up to that point.

Programming is about managing complexity: the complexity of the problem you want to solve, laid upon the complexity of the machine in which it is solved. Because of this complexity, most of our programming projects fail. And yet, of all the programming languages of which I am aware, almost none have gone all out and decided that their main design goal would be to conquer the complexity of developing and maintaining programs. ¹ Of course, many language design decisions were made with complexity in mind, but at some point there were always other issues that were considered essential to be added into the mix. Inevitably, those other issues are what cause programmers to eventually “hit the wall” with that language. For example, C++ had to be backwards-compatible with C (to allow easy migration for C programmers), as well as efficient. Those are both very useful goals and account for much of the success of C++, but they also expose extra complexity that prevents some projects from being finished (certainly, you can blame programmers and management, but if a language can help by catching your mistakes, why shouldn’t it?). As another example, Visual BASIC (VB) was tied to BASIC, which wasn’t really designed to be an extensible language, so all the extensions piled upon VB have produced some truly unmaintainable syntax. Perl is backwards-compatible with awk, sed, grep, and other Unix tools it was meant to replace, and as a result it is often accused of producing “write-only code” (that is, after a while you can’t read it). On the other hand, C++, VB, Perl, and other languages like Smalltalk had some of their design efforts focused on the issue of complexity and as a result are remarkably successful in solving certain types of problems.

What has impressed me most as I have come to understand Java is that somewhere in the mix of Sun’s design objectives, it seems that there was a goal of reducing complexity for the programmer. As if to say, “We care about reducing the time and difficulty of producing robust code.” In the early days, this goal resulted in code that didn’t run very fast (although this has improved over time), but it has indeed produced amazing reductions in development time—half or less of the time that it takes to create an equivalent C++ program. This result alone can save incredible amounts of time and money, but Java doesn’t stop there. It goes on to wrap many of the complex tasks that have become important, such as multithreading and network programming, in language features or libraries that can at times make those tasks easy. And finally, it tackles some really big complexity problems: cross-platform programs, dynamic code changes, and even security, each of which can fit on your complexity spectrum anywhere from “impediment” to “show-stopper.” So despite the performance problems that we’ve seen, the promise of Java is tremendous: It can make us significantly more productive programmers.

In all ways—creating the programs, working in teams, building user interfaces to communicate with the user, running the programs on different types of machines, and easily writing programs that communicate across the Internet—Java increases the communication bandwidth between people.

I think that the results of the communication revolution may not be seen from the effects of moving large quantities of bits around. We shall see the true revolution because we will all communicate with each other more easily: one-on-one, but also in groups and as a planet. I’ve heard it suggested that the next revolution is the formation of a kind of global mind that results from enough people and enough interconnectedness. Java may or may not be the tool that foments that revolution, but at least the possibility has made me feel like I’m doing something meaningful by attempting to teach the language.

Java SE5 and SE6

This edition of the book benefits greatly from the improvements made to the Java language in what Sun originally called JDK 1.5, and then later changed to JDK5 or J2SE5, then finally they dropped the outdated “2” and changed it to Java SE5. Many of the Java SE5 language changes were designed to improve the experience of the programmer. As you shall see, the Java language designers did not completely succeed at this task, but in general they made large steps in the right direction.

One of the important goals of this edition is to completely absorb the improvements of Java SE5/6, and to introduce and use them throughout this book. This means that this edition takes the somewhat bold step of being “Java SE5/6-only,” and much of the code in the book will not compile with earlier versions of Java; the build system will complain and stop if you try. However, I think the benefits are worth the risk.

If you are somehow fettered to earlier versions of Java, I have covered the bases by providing free downloads of previous editions of this book via www.MindView.net. For various reasons, I have decided not to provide the current edition of the book in free electronic form, but only the prior editions.

Java SE6

This book was a monumental, time-consuming project, and before it was published, Java SE6 (code-named mustang) appeared in beta form. Although there were a few minor changes in Java SE6 that improved some of the examples in the book, for the most part the focus of Java SE6 did not affect the content of this book; the features were primarily speed improvements and library features that were outside the purview of this text.

The code in this book was successfully tested with a release candidate of Java SE6, so I do not expect any changes that will affect the content of this book. If there are any important changes by the time Java SE6 is officially released, these will be reflected in the book’s source code, which is downloadable from www.MindView.net.

The cover indicates that this book is for “Java SE5/6,” which means “written for Java SE5 and the very significant changes that version introduced into the language, but is equally applicable to Java SE6.”

The 4th edition

The satisfaction of doing a new edition of a book is in getting things “right,” according to what I have learned since the last edition came out. Often these insights are in the nature of the saying “A learning experience is what you get when you don’t get what you want,” and my opportunity is to fix something embarrassing or simply tedious. Just as often, creating the next edition produces fascinating new ideas, and the embarrassment is far outweighed by the delight of discovery and the ability to express ideas in a better form than what I have previously achieved.

There is also the challenge that whispers in the back of my brain, that of making the book something that owners of previous editions will want to buy. This presses me to improve, rewrite and reorganize everything that I can, to make the book a new and valuable experience for dedicated readers.

Changes

The CD-ROM that has traditionally been packaged as part of this book is not part of this edition. The essential part of that CD, the Thinking in C multimedia seminar (created for MindView by Chuck Allison), is now available as a downloadable Flash presentation. The goal of that seminar is to prepare those who are not familiar enough with C syntax to understand the material presented in this book. Although two of the chapters in this book give decent introductory syntax coverage, they may not be enough for people without an adequate background, and Thinking in C is intended to help those people get to the necessary level.

The Concurrency chapter (formerly called “Multithreading”) has been completely rewritten to match the major changes in the Java SE5 concurrency libraries, but it still gives you a basic foundation in the core ideas of concurrency. Without that core, it’s hard to understand more complex issues of threading. I spent many months working on this, immersed in that netherworld called “concurrency,” and in the end the chapter is something that not only provides a basic foundation but also ventures into more advanced territory.

There is a new chapter on every significant new Java SE5 language feature, and the other new features have been woven into modifications made to the existing material. Because of my continuing study of design patterns, more patterns have been introduced throughout the book as well.

The book has undergone significant reorganization. Much of this has come from the teaching process together with a realization that, perhaps, my perception of what a “chapter” was could stand some rethought. I have tended towards an unconsidered belief that a topic had to be “big enough” to justify being a chapter. But especially while teaching design patterns, I find that seminar attendees do best if I introduce a single pattern and then we immediately do an exercise, even if it means I only speak for a brief time (I discovered that this pace was also more enjoyable for me as a teacher). So in this version of the book I’ve tried to break chapters up by topic, and not worry about the resulting length of the chapters. I think it has been an improvement.

I have also come to realize the importance of code testing. Without a built-in test framework with tests that are run every time you do a build of your system, you have no way of knowing if your code is reliable or not. To accomplish this in the book, I created a test framework to display and validate the output of each program. (The framework was written in Python; you can find it in the downloadable code for this book at www.MindView.net.) Testing in general is covered in the supplement you will find at http://MindView.net/Books/BetterJava, which introduces what I now believe are fundamental skills that all programmers should have in their basic toolkit.

In addition, I’ve gone over every single example in the book and asked myself, “Why did I do it this way?” In most cases I have done some modification and improvement, both to make the examples more consistent within themselves and also to demonstrate what I consider to be best practices in Java coding (at least, within the limitations of an introductory text). Many of the existing examples have had very significant redesign and reimplementation. Examples that no longer made sense to me were removed, and new examples have been added.

Readers have made many, many wonderful comments about the first three editions of this book, which has naturally been very pleasant for me. However, every now and then, someone will have complaints, and for some reason one complaint that comes up periodically is “The book is too big.” In my mind it is faint damnation indeed if “too many pages” is your only gripe. (One is reminded of the Emperor of Austria’s complaint about Mozart’s work: “Too many notes!” Not that I am in any way trying to compare myself to Mozart.) In addition, I can only assume that such a complaint comes from someone who is yet to be acquainted with the vastness of the Java language itself and has not seen the rest of the books on the subject. Despite this, one of the things I have attempted to do in this edition is trim out the portions that have become obsolete, or at least nonessential. In general, I’ve tried to go over everything, remove what is no longer necessary, include changes, and improve everything I could. I feel comfortable removing portions because the original material remains on the Web site (www.MindView.net), in the form of the freely downloadable 1st through 3rd editions of the book, and in the downloadable supplements for this book. For those of you who still can’t stand the size of the book, I do apologize. Believe it or not, I have worked hard to keep the size down.

Note on the cover design

The cover of Thinking in Java is inspired by the American Arts & Crafts Movement that began near the turn of the century and reached its zenith between 1900 and 1920. It began in England as a reaction to both the machine production of the Industrial Revolution and the highly ornamental style of the Victorian era. Arts & Crafts emphasized spare design, the forms of nature as seen in the art nouveau movement, hand-crafting, and the importance of the individual craftsperson, and yet it did not eschew the use of modern tools. There are many echoes with the situation we have today: the turn of the century, the evolution from the raw beginnings of the computer revolution to something more refined and meaningful, and the emphasis on software craftsmanship rather than just manufacturing code.

I see Java in this same way: as an attempt to elevate the programmer away from an operating system mechanic and toward being a “software craftsman.”

Both the author and the book/cover designer (who have been friends since childhood) find inspiration in this movement, and both own furniture, lamps, and other pieces that are either original or inspired by this period.

The other theme in this cover suggests a collection box that a naturalist might use to display the insect specimens that he or she has preserved. These insects are objects that are placed within the box objects. The box objects are themselves placed within the “cover object,” which illustrates the fundamental concept of aggregation in object-oriented programming. Of course, a programmer cannot help but make the association with “bugs,” and here the bugs have been captured and presumably killed in a specimen jar, and finally confined within a small display box, as if to imply Java’s ability to find, display, and subdue bugs (which is truly one of its most powerful attributes).

In this edition, I created the watercolor painting that you see as the cover background.

Acknowledgements

First, thanks to associates who have worked with me to give seminars, provide consulting, and develop teaching projects: Dave Bartlett, Bill Venners, Chuck Allison, Jeremy Meyer, and Jamie King. I appreciate your patience as I continue to try to develop the best model for independent folks like us to work together.

Recently, no doubt because of the Internet, I have become associated with a surprisingly large number of people who assist me in my endeavors, usually working from their own home offices. In the past, I would have had to pay for a pretty big office space to accommodate all these folks, but because of the Net, FedEx, and the telephone, I’m able to benefit from their help without the extra costs. In my attempts to learn to “play well with others,” you have all been very helpful, and I hope to continue learning how to make my own work better through the efforts of others. Paula Steuer has been invaluable in taking over my haphazard business practices and making them sane (thanks for prodding me when I don’t want to do something, Paula). Jonathan Wilcox, Esq., has sifted through my corporate structure and turned over every possible rock that might hide scorpions, and frog-marched us through the process of putting everything straight, legally. Thanks for your care and persistence. Sharlynn Cobaugh has made herself an expert in sound processing and an essential part of creating the multimedia training experiences, as well as tackling other problems. Thanks for your perseverance when faced with intractable computer problems. The folks at Amaio in Prague have helped me out with several projects. Daniel Will-Harris was the original work-by-Internet inspiration, and he is of course fundamental to all my graphic design solutions.

Over the years, through his conferences and workshops, Gerald Weinberg has become my unofficial coach and mentor, for which I thank him.

Ervin Varga was exceptionally helpful with technical corrections on the 4th edition—although other people helped on various chapters and examples, Ervin was my primary technical reviewer for the book, and he also took on the task of rewriting the solution guide for the 4th edition. Ervin found errors and made improvements to the book that were invaluable additions to this text. His thoroughness and attention to detail are amazing, and he’s far and away the best technical reader I’ve ever had. Thanks, Ervin.

My weblog on Bill Venners’ www.Artima.com has been a source of assistance when I’ve needed to bounce ideas around. Thanks to the readers that have helped me clarify concepts by submitting comments, including James Watson, Howard Lovatt, Michael Barker, and others, in particular those who helped with generics.

Thanks to Mark Welsh for his continuing assistance.

Evan Cofsky continues to be very supportive by knowing off the top of his head all the arcane details of setting up and maintaining Linux-based Web servers, and keeping the MindView server tuned and secure.

A special thanks to my new friend, coffee, who generated nearly boundless enthusiasm for this project. Camp4 Coffee in Crested Butte, Colorado, has become the standard hangout when people have come up to take MindView seminars, and during seminar breaks it is the best catering I’ve ever had. Thanks to my buddy Al Smith for creating it and making it such a great place, and for being such an interesting and entertaining part of the Crested Butte experience. And to all the Camp4 barristas who so cheerfully dole out beverages.

Thanks to the folks at Prentice Hall for continuing to give me what I want, putting up with all my special requirements, and for going out of their way to make things run smoothly for me.

Certain tools have proved invaluable during my development process and I am very grateful to the creators every time I use these. Cygwin (www.cygwin.com) has solved innumerable problems for me that Windows can’t/won’t and I become more attached to it each day (if I only had this 15 years ago when my brain was still hard-wired with Gnu Emacs). IBM’s Eclipse (www.eclipse.org) is a truly wonderful contribution to the development community, and I expect to see great things from it as it continues to evolve (how did IBM become hip? I must have missed a memo). JetBrains IntelliJ Idea continues to forge creative new paths in development tools.

I began using Enterprise Architect from Sparxsystems on this book, and it has rapidly become my UML tool of choice. Marco Hunsicker’s Jalopy code formatter (www.triemax.com) came in handy on numerous occasions, and Marco was very helpful in configuring it to my particular needs. I’ve also found Slava Pestov’s JEdit and plug-ins to be helpful at times (www.jedit.org) and it’s quite a reasonable beginner’s editor for seminars.

And of course, if I don’t say it enough everywhere else, I use Python (www.Python.org) constantly to solve problems, the brainchild of my buddy Guido Van Rossum and the gang of goofy geniuses with whom I spent a few great days sprinting (Tim Peters, I’ve now framed that mouse you borrowed, officially named the “TimBotMouse”). You guys need to find healthier places to eat lunch. (Also, thanks to the entire Python community, an amazing bunch of people.)

Lots of people sent in corrections and I am indebted to them all, but particular thanks go to (for the 1st edition): Kevin Raulerson (found tons of great bugs), Bob Resendes (simply incredible), John Pinto, Joe Dante, Joe Sharp (all three were fabulous), David Combs (many grammar and clarification corrections), Dr. Robert Stephenson, John Cook, Franklin Chen, Zev Griner, David Karr, Leander A. Stroschein, Steve Clark, Charles A. Lee, Austin Maher, Dennis P. Roth, Roque Oliveira, Douglas Dunn, Dejan Ristic, Neil Galarneau, David B. Malkovsky, Steve Wilkinson, and a host of others. Prof. Ir. Marc Meurrens put in a great deal of effort to publicize and make the electronic version of the 1st edition of the book available in Europe.

Thanks to those who helped me rewrite the examples to use the Swing library (for the 2nd edition), and for other assistance: Jon Shvarts, Thomas Kirsch, Rahim Adatia, Rajesh Jain, Ravi Manthena, Banu Rajamani, Jens Brandt, Nitin Shivaram, Malcolm Davis, and everyone who expressed support.

In the 4th edition, Chris Grindstaff was very helpful during the development of the SWT section, and Sean Neville wrote the first draft of the Flex section for me.

Kraig Brockschmidt and Gen Kiyooka have been some of the smart technical people in my life who have become friends and have also been both influential and unusual in that they do yoga and practice other forms of spiritual enhancement, which I find quite inspirational and instructional.

It’s not that much of a surprise to me that understanding Delphi helped me understand Java, since there are many concepts and language design decisions in common. My Delphi friends provided assistance by helping me gain insight into that marvelous programming environment. They are Marco Cantu (another Italian—perhaps being steeped in Latin gives one aptitude for programming languages?), Neil Rubenking (who used to do the yoga/vegetarian/Zen thing until he discovered computers), and of course Zack Urlocker (the original Delphi product manager), a long-time pal whom I’ve traveled the world with. We’re all indebted to the brilliance of Anders Hejlsberg, who continues to toil away at C# (which, as you’ll learn in this book, was a major inspiration for Java SE5).

My friend Richard Hale Shaw’s insights and support have been very helpful (and Kim’s, too). Richard and I spent many months giving seminars together and trying to work out the perfect learning experience for the attendees.

The book design, cover design, and cover photo were created by my friend Daniel Will-Harris, noted author and designer (www.Will-Harris.com), who used to play with rub-on letters in junior high school while he awaited the invention of computers and desktop publishing, and complained of me mumbling over my algebra problems. However, I produced the camera-ready pages myself, so the typesetting errors are mine. Microsoft ^® Word XP for Windows was used to write the book and to create camera-ready pages in Adobe Acrobat; the book was created directly from the Acrobat PDF files. As a tribute to the electronic age, I happened to be overseas when I produced the final versions of the 1st and 2nd editions of the book—the 1st edition was sent from Cape Town, South Africa, and the 2nd edition was posted from Prague. The 3rd and 4th came from Crested Butte, Colorado. The body typeface is Georgia and the headlines are in Verdana. The cover typeface is ITC Rennie Mackintosh.

A special thanks to all my teachers and all my students (who are my teachers as well).

Molly the cat often sat in my lap while I worked on this edition, and thus offered her own kind of warm, furry support.

The supporting cast of friends includes, but is not limited to: Patty Gast (Masseuse extraordinaire), Andrew Binstock, Steve Sinofsky, JD Hildebrandt, Tom Keffer, Brian McElhinney, Brinkley Barr, Bill Gates at Midnight Engineering Magazine, Larry Constantine and Lucy Lockwood, Gene Wang, Dave Mayer, David Intersimone, Chris and Laura Strand, the Almquists, Brad Jerbic, Marilyn Cvitanic, Mark Mabry, the Robbins families, the Moelter families (and the McMillans), Michael Wilk, Dave Stoner, the Cranstons, Larry Fogg, Mike Sequeira, Gary Entsminger, Kevin and Sonda Donovan, Joe Lordi, Dave and Brenda Bartlett, Patti Gast, Blake, Annette & Jade, the Rentschlers, the Sudeks, Dick, Patty, and Lee Eckel, Lynn and Todd, and their families. And of course, Mom and Dad.

Note

1. However, I believe that the Python language comes closest to doing exactly that. See www.Python.org.

Editorial Reviews

The Barnes & Noble Review
Wonderfully organized, full of high-quality examples, and polished to reflect today’s best practices, Bruce Eckel’s Thinking in Java, Third Edition may be the world's best way to learn Java.

Previous editions have earned worldwide praise and prizes -- notably the Java Developer's Journal Editor's Choice award, and Software Development's Productivity Award. This new Third Edition is the best yet. Yes, it fully reflects Sun’s recent Java 2 SDK 1.4 release. But if you’re accustomed to “run of the mill” programming books, you’ll be astounded at how much attention Eckel has given to improving the coverage of features that haven’t changed.

Among this book’s strengths have always been its structure and careful choice of topics. In this edition, Eckel thoroughly revisits both, to ensure that the book still give programmers a rock-solid grasp of today’s fundamentals. For instance, while most authors would’ve been thrilled with the multithreading coverage presented in earlier editions, Eckel has thoroughly rewritten this chapter (now renamed “Concurrency”) to offer far deeper insight for real-world development.

Even more important, Eckel has increasingly recognized the crucial role of unit testing for high-quality Java development. (Of course, he’s not the only one to realize this: Testing is at the heart of agile methodologies like Extreme Programming, which Eckel admires. Chances are you’ll be called upon to become much more actively involved in testing in coming days. This book will prepare you.)

With unit testing, Eckel points out, “the build process can check for more than just syntax errors, since you teach it how to check for semantic errors as well.” By integrating unit testing into the build process, you can “be bolder in the changes that you make, more easily refactor your code when you discover design or implementation flaws, and in general produce a better product, faster.”

To this end, Eckel has used unit testing throughout this edition to validate his code and display the expected output. (Much of that output now appears in the book, responding to one of the few criticisms made of earlier editions.)

As part of a detailed new chapter on “Discovering Problems,” he also walks through the construction of a simple unit testing framework -- and offers detailed coverage of using the latest version of JUnit to perform more sophisticated functionality testing. The same chapter also covers JDK 1.4’s new logging and assertions support, as well as debugging and profiling techniques every Java developer needs.

Since there’s more to cover in Java than ever before, Eckel’s had to battle to keep this book down to size. (People have actually complained that Thinking in Java is too big -- which is like complaining that someone’s given you too many diamonds.) So he’s moved J2EE coverage out of this book (they’re downloadable, and will become part of his forthcoming Thinking in Enterprise Java). That means more space for crucial topics like analysis and design; class reuse techniques; collections; and I/O -- including Java 1.4’s newio.

As always, Eckel approaches Java with short, “bite-size” examples, each explaining one concept with total clarity, and organized to build step-by-step, from simple to sophisticated. For this edition, Eckel has revisited virtually all of his code examples. Some old examples are gone; many new ones have been added. In many cases, he’s thoroughly redesigned and reimplemented his examples, to improve consistency and to reflect today’s best practices for Java programming. In rewriting his code, he has a huge advantage over most other authors: the extensive feedback he gets in his seminars, event appearances, and at his hugely popular web site.

The accompanying CD-ROM contains electronic versions of the book plus all of its source code. But it also contains the solution to one of the key obstacles that face many developers trying to learn Java for the first time. Java’s roots are in C. To really instinctively “get” Java, it helps to know at least the rudiments of C. So Eckel has bundled a complete interactive “Thinking in C” training course that covers everything you ought to know before you start learning Java. Just another example of how committed Eckel is to making sure you really get it. Bill Camarda

Bill Camarda is a consultant, writer, and web/multimedia content developer. His 15 books include Special Edition Using Word 2000 and Upgrading & Fixing Networks For Dummies®, Second Edition.