Advanced Web Design: A Primer

Java

Java is a full-featured programming language like C++, but simpler and more tightly structured. Java programs, instead of running directly on a computer's operating system, run on a "Java Virtual Machine", which itself is a program that runs on the computer's operating system. This means that, in theory, any operating system that has a Java Virtual Machine (pretty much all major operating systems these days) can run any Java program. Since the production of Java Virtual Machines is highly standardized, incompatibilities between the various platforms are minimal. The disadvantage is that Java programs tend to run slower as the Virtual Machine has to convert Java program instructions and pass them to the operating system on which it is running.

What does all this have to do with advanced Web design? Well, modern Web browsers usually have Java Virtual Machines embedded within them. This allows a Web designer to embed small Java applications (called Applets) into Web pages. While learning Java and programming Java applets is far from simple, Java applets can do just about anything a regular program can do, except they can do it in a rectangular area inside a Web page.

Common uses of Java applets include chat programs and online games. For security reasons, however, Java applets cannot access files or other potentially sensitive information on your computer, and they cannot connect to computers other than the Web server that sent them.

Resources:

• The Java Tutorial from Sun Microsystems