Web Archive (WAR) Files
Web applications can be packaged into a Web ARchive (WAR) file using Java's standard
archiving tool jar . The only difference would be its extension. For this text we could package
all our examples into a file called djs.war . However, as stated earlier, we don't package them
as a WAR because we develop the examples as we progress through the topic.
To begin a development effort using Java servlets, you will need to decide what tools you will
use to both write and run your servlets.
You will need only a minimal set of tools to actually write Java servlets. The two most impor-
tant requirements are the Java Development Kit (JDK), and the Java Servlet Development Kit
(JSDK), also on version 2.2. Both of these development kits can be downloaded from the
JavaSoft home page at http://www.javasoft.com at no cost.
You will also need the Tomcat server, which we will discuss in the next section.
Tomcat is the flagship product of The Apache Software Foundation's Jakarta Project. It is
intended to be a reference implementation of Sun's Java Servlet SDK 2.2 and JavaServer Pages
Installing the Tomcat Server
The first thing you need to do is get a copy of Tomcat from the Jakarta Project's Web site. You
can find the necessary links at the http://jakarta.apache.org/ site. Figure A.1 shows the
Jakarta Project's home page.