Next Stop: Java

Before you can start writing Java programs, you need to acquire and set up some kind of Java programming software. Although several different products are available for the development of Java programs, including many terrific ones that make programming much easier, the starting place for most new Java programmers is the Java Development Kit, a set of tools for writing, debugging, and running Java programs. All of the examples in this book were created and tested using the Kit, but they can be created with any Java development tool that supports the current version of the language.

The Java Development Kit (also referred to as the JDK) is in version 5 as of this writing. Whenever Sun releases a new version of Java, the first tool that supports it is the Kit.

To create all of the programs in this book, you must either use Java Development Kit 5 or another Java programming tool that fully supports all of version 5's features.

There are many different software packages that offer the capability to create Java programs, but all are not created equal when language support is concerned. Some of these programming tools only support Java 1.0, the initial version of the language, which was released by Sun Microsystems in late 1995. Other tools support Java 1.1, which was released in mid-1997, version 1.2 (1998), version 1.3 (2000), or version 1.4 (2003).

Some operating systems such as Mac OS X and Red Hat Enterprise Linux include a copy of the JDK, but it's probably not the current version. Before using an JDK that was included with your operating system, make sure it supports Java version 5.

Users of Microsoft Windows systems may be dismayed to learn that the Java Development Kit is not graphical. You run programs from a command line (the C:\> or D:\> prompt that will be familiar to MS-DOS users) instead of using a mouse and a point-and-click environment. Figure 1.2 shows the Kit in use in an MS-DOS window on a Windows XP system. The Java program WarGames.java is compiled, and then it is run.

Watch Out! The examples in this book were prepared on the Microsoft Windows XP and Red Hat Linux operating systems. For this reason, some advice is offered for Windows and Linux users running the Java Development Kit. However, all of the Java code in this book will work regardless of the operating system you are using, as long as you have development software that supports all the features of JDK 5.

Official Documentation

Sun Microsystems offers comprehensive documentation for the Java language in web page format. You don't need this information to use this book because each topic is discussed fully as it is introduced, but these pages will come in handy when you write your own programs.

You can download the entire documentation, but it might be more convenient to browse it as needed from Sun's website. The most up-to-date Java documentation is available at http://java.sun.com/j2se/1.5.0/docs/api.