The AHA! Installation
AHA! is a software package that works together with a Java-enabled
Web-server. The installation for end-users consists of the following items:
- A Java Runtime Environment or JRE.
For different operating systems a JRE can be obtained from
JavaSoft.
- A Java-enabled Webserver. AHA! has been tested thoroughly with
the (free) JSWDK server from JavaSoft.
But since AHA follows the Java Servlet standard any server that
obeys that standard should be usable.
- The AHA software, which consists of four directories with
Java files (and class files). These are AHA, Expression,
Filter and XmlUtils.
- Libraries, used by the JSWDK server and/or AHA are
jspengine.jar, servlet.jar, webserver.jar
and xml.jar. These should be in the Java classpath for the
Webserver.
- Two applets that authors may use to create (meta)information for
performing adaptation. (See the
authoring aspects for
more information on this part.)
- Scripts to start and stop the server. In these scripts one needs
to set a few variables that tell the Webserver where things are.
The scripts are startserver and stopserver for Unix
and startserver.bat and stopserver.bat for Windows.
One server installation may contain several adaptive hyperdocuments.
The server has a "documentroot" directory, which we call WWW here
(the default name in the JSWDK server).
All files related to one hyperdocument are stored in a single directory
under WWW. This directory is reachable from the Web using the URL
http://localhost:8080/name-of-this-directory/.
From one browser instantiation a user can use only one adaptive
application on the same server at the same time.
The server uses the HTTP Cookie mechanism to maintain a session state.
It gets confused when sessions for different applications exist
simultaneously on one client machine.
There is no problem however when users from different machines access
(different or the same) adaptive applications on a single server
simultaneously.