3. The Java Programming Language
The Java Programming Language
The Java Programming Language had its origins in a language called simply 'Green', and developed by the software engineers at Sun Microsystems to be simple and architecture-neutral, so that it could be run safely and securely by intelligent consumer devices such as television 'set-top' boxes. Sun never found any customers for this language, but the developers realised that this language would allow them to write a really cool Web browser. This led to the development of the original 'HotJava' browser which was demonstrated for the first time at the SunWorld exhibition in 1995. The most interesting feature of this browser was that it could safely and securely download and run programs called applets from the Web. These applets, written in the language now called Java, allowed Web developers to provide a wide variety of sophisticated animation and interaction to the users, which greatly extended the functionality of Web pages. Since 1996, most major browsers have supported Java applets.
Since then, Java has grown at a phenomenal rate because it's simpler than its rival C++, and has a rich library that makes it possible to write portable code that bypasses proprietary operating systems such as Microsoft's Windows. This ability to be platform-independent has been greatly welcomed by software developers, but has often made Java unpopular with the vendors of proprietary systems.
Java was designed for use on the Web, so it has two features that make it suitable for beginners - safety and portability. Why are these important? Well, if you open a Web page in your browser, applets embedded in the page run automatically. This means that users have to be able to trust applets to be inherently safe. If applets could do evil things to your computer, you would be in danger every time you browsed the Web! Java has security features that guarantee that evil applets cannot run on your computer, no matter how hard they try. As an added benefit, the security features actually make it easier to learn the language because they closely inspect Java code and report accurately on errors and illegalities. Other languages such as C that don't have this capability, often produce code that runs in random or strange ways for reasons which are often not obvious to beginners. As far as portability goes, this is good because your Java program will run without any changes on any platform - Windows, Linux, Mac, etc. Java has established itself as one of the most important programming languages for general-purpose programming.
Although it is a good language for beginners, it does have a few drawbacks. Firstly, it wasn't specifically designed with beginners in mind, so the developers never gave any thought to making it really simple to write small, basic programs. Even the smallest, simplest program in Java requires a certain amount of technical machinery and know-how to produce. This means that while you are in the learning stages, there will be many things that you will have to just accept a preliminary explanation for, and catch up with the full story later.
Java is also a huge subject, in the sense that it has a vast and bewildering number of packages of code accompanied by an equally bewildering and vast amount of documentation. This means that you cannot hope to learn Java completely in just one semester, or even in a couple of years! Hardly any Java programmers are experts on all parts of the language; the secret is to concentrate on those bits that you need to know for what's at hand right now. The good news is that for an object-oriented language, Java is fairly simple, and in the beginning the aim is to get you to think about programming and not to get you to remember large quantities of Java details.
© G. Hearn, & University of the Western Cape, 2006