Introduction

Some revolutions catch the world completely by surprise. The World Wide Web, the Linux operating system, and social networking all rose to prominence unexpectedly. The remarkable success of the Java programming language, on the other hand, caught no one by surprise. Java has been the source of great expectations since its introduction a decade ago. When Sun Microsystems launched Java by incorporating it into web browsers, a torrent of publicity welcomed the arrival of the new language.

Sun cofounder Bill Joy didn’t hedge his bets at all when describing the company’s new language. “This represents the end result of nearly 15 years of trying to come up with a better programming language and environment for building simpler and more reliable software,” he proclaimed.

In the ensuing years, Java lived up to a considerable amount of its hype. The language has become as strong a part of software development as the beverage of the same name. One kind of Java keeps programmers up nights. The other kind enables programmers to rest easier after they have developed their software.

Java was originally offered as a technology for enhancing websites with programs that run in web browsers. Today, it’s more likely to be found on servers, driving dynamic web applications backed by relational databases on some of the Web’s largest sites. Each new release of Java strengthens its capabilities as a general-purpose programming language for environments other than a web browser. Today, Java is being put to use in desktop applications, Internet servers, personal digital assistants, embedded devices, and many other environments.

Now in its seventh major release—Java 6—the Java language has matured into a full-featured competitor to other general-purpose development languages, such as C++, Perl, Python, Ruby, and Visual Basic.

You might be familiar with Java programming tools, such as Eclipse, Borland JBuilder, and the NetBeans Integrated Development Environment. These programs make it possible to develop functional Java programs, and you also can use Sun’s Java Development Kit. The kit, which is available for free on the Web at http://java.sun.com, is a set of command-line tools for writing, compiling, and testing Java programs.