For java application you need the Java 2 Platform, Standard Edition (J2SE) version 5.0 or later. You can download the JDK from Sun for a variety of hardware platforms and operating systems, either directly from the Sun Java web site at java.sun.com (for Windows, Solaris, and Linux operating systems) or from sites that you can link to from there. The JDK you’ll be using is available from java.sun.com/j2se. Versions of the Java Development Kit for Mac OS X are available from devworld.apple.com/java/.
Note that J2SE 5.0 succeeded J2SE 1.4. Normally, release 1.5 would have followed release 1.4, but it was decided to identify it as release 5.0 in recognition of the significance of the new features that are introduced by release 5.0 and the maturity of the product. Code module names in release 5.0 still use the denotation 1.5.0 so expect to see folder names incorporating 1.5.0 rather than 5.0, and you’ll see 1.5.0 popping up in a few other places too, so don’t let this confuse you.
One aspect of terminology also causes confusion sometimes - the Java Development Kit has been referred to at various times as the JDK - the Java Development Kit - and as the SDK - the Software Development Kit. The current usage with release 5.0 is JDK but with release 1.4 it was SDK, so if you see SDK this generally means the same as JDK. Just for consistency, I’ll use JDK to refer to any Java Development Kit in this blog of java.
To create the Java program source files that you will use with the JDK, you’ll need a plain text editor. Any editor will do as long as it does not introduce formatting codes into the contents of a file. Quite a number of shareware and freeware editors around are suitable, some of which are specific to Java, and you should have no trouble locating one. I find the JCreator editor is particularly good. There’s a free version and a fee version with more functionality, but the free version is perfectly adequate for learning.
A number of excellent professional Java program development environments are available, including products from Sun, Borland, Metrowerks, and Symantec. These all provide very friendly environments for creating and editing your Java source code and compiling and debugging your programs. These are powerful tools for the experienced programmer, but for learning Java using this blog of java, I recommend that you resist the temptation to use any of these, especially if you are relatively new to programming. Instead, stick to using the JDK from Sun together with a suitable simple program text editor for creating your source code. So why am I suggesting that you will be better off not using a tool that makes programming easier and faster? There are several reasons.
Firstly, the professional development systems tend to hide a lot of things you need to get to grips with so that you have a full understanding of how Java works. Secondly, the pro development environments are geared to managing complex applications with a large amount of code, which introduces complexity that you really are better off without while you are learning. Virtually all commercial Java development systems provide prebuilt facilities of their own to speed development. While this is very helpful for production program development, it really does get in the way when you are trying to learn Java. A further consideration is that productivity features supported by a commercial Java development are sometimes tied to a specific version of the Java 2 Platform. This means that some features of the latest version of Java may not work. The professional Java development tools are intended primarily for knowledgeable and experienced programmers, so start with one when you get to the end of the blog. Having said that, if you really do prefer to work with a commercial Java development system for whatever reason, and you have problems with running a particular example from the book, try it out with the JDK from the command line. The chances are good it will work okay.
