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CHAPTER 1. THE INTERNET

1.6

The Tomcat Server

Most current personal computers come with a preinstalled browser as well as

a preinstalled web server. In this book we shall use an open source web server

(called the Jakarta Tomcat server) that allows you to easily build sophisticated

interactive web programs fairly easily.

Appendix A explains how to download and setup the Tomcat server on your

PC, Mac, or Linux platform. When you install the tomcat server, a folder

scheme will be created. This folder represents the public web services that you

will offer to the world. The types of service that you can currently offer using

this version of Tomcat are listed below and are determined by the suffix of the

filename. Each different suffix refers to a different web programming language

that is handled by the server:

html Files ending in .html are simply sent directly to the client as text/html

files.

css These are cascading style sheet files and are used to define extensions of

the basic HTML language.

servlet These are scheme XML files which provide a mechanism for reading in 

formation from HTML forms and using that information to generate web

pages which are then sent to the client. (There are two other variants of

this type of file with the extensions sssp and sxml. They are essentially

the same language, but have slightly different grammars).

applet These are programs that run on the browser that downloads the page.

These programs usually pop up windows with menus, buttons, textfields,

choices, and all the usual facets of graphical user interfaces that you have

become accustomed to.

snlp These are programs that also run on the client machine, but they require

the Java Web Start plugin and, once downloaded, they can be run without

the browser. One particular interesting type of snlp program that we

will consider is the class of peer to peer programs. The Napster and IM

programs are a well known examples of this type of application. But there

are many others possible uses for peer to peer computing.