This article introduces you to the Java programming language. The first of two parts, it is excerpted from chapter one of Sams Teach Yourself Java 2 in 21 Days, 4th Edition, written by Rogers Cadenhead and Laura Lemay (Sams; ISBN: 0672326280).
Big companies like IBM are embracing Java far more than most people realize. Half of IBM is busy recoding billions of lines of software to Java. The other half is working to make Java run well on all platforms, and great on all future platforms.
—PBS technology commentator Robert X. Cringely
When Sun Microsystems first released the Java programming language in 1995, it was an inventive toy for the World Wide Web that had the potential to be much more.
The word "potential" is an unusual compliment because it comes with an expiration date. Sooner or later, potential must be realized or new words are used in its place such as "letdown," "waste," and "major disappointment to your mother and I."
As you develop your skills during the 21 one-day tutorials in SamsTeach Yourself Java 2 in 21 Days, Fourth Edition, you'll be in a good position to judge whether the language has lived up to years of hype.
You'll also become a Java programmer with a lot of potential.
The Java Language
Now in its sixth major release with Java 2 version 1.5, Java has lived up to the expectations that accompanied its arrival. More than 2.5 million programmers have learned the language and are using it in places such as NASA, IBM, Kaiser Permanente, ESPN, and New York's Museum of Modern Art. It's a standard part of the academic curriculum at many computer science departments around the world. First used to create simple programs on World Wide Web pages, Java can be found today in each of the following places and many more:
Personal digital assistants
Credit card–sized "smartcards"
Over the next 21 days, you will write Java programs that reflect how the language is being used in the twenty-first century. In some cases, this is very different from how it was originally envisioned.
Although Java remains useful for Web developers trying to enliven sites, it extends far beyond the Web browser. Java is now a popular general-purpose programming language.
History of the Language
The story of the Java language is well known by this point. James Gosling and other developers at Sun were working on an interactive TV project in the mid-1990s when Gosling became frustrated with the language being used—C++, an object-oriented programming language developed by Bjarne Stroustrup at AT&T Bell Laboratories 10 years earlier as an extension of the C language.
Gosling holed up in his office and created a new language that was suitable for his project and addressed some of the things that frustrated him about C++.
Sun's interactive TV effort failed, but its work on the language had unforeseen applicability to a new medium that was becoming popular at the same time: the World Wide Web.
Java was released by Sun in fall 1995 through a free development kit that could be downloaded from the company's Web site. Although most of the language's features were primitive compared with C++ (and Java today), Java programs called applets could be run as part of Web pages on the Netscape Navigator browser.
This functionality—the first interactive programming available on the Web—helped publicize the new language and attract several hundred thousand developers in its first six months.
Even after the novelty of Java Web programming wore off, the overall benefits of the language became clear, and the programmers stuck around. There are more professional Java programmers today than C++ programmers.