Axis Technical Details

The Axis toolkit is a Java implementation of the SOAP and WSDL specifications. Using Axis, a developer can create or consume Web Services. Because of the inherent cross-platform and cross-toolkit nature of Web Services, a Web Service created by Axis can be consumed by a toolkit other than Axis running on a different platform, and vice versa.

Details of Building and Configuring Axis

We don't recommend that you build the Axis sources because the CVS sources could contain bugs or problems. The CVS sources may be too recent and unstable, or their fixes could cause other problems. We strongly urge you to download stable builds, or if necessary stable beta or release candidate builds.

It's beyond the scope of this chapter to discuss the development configuration details for the Axis toolkit. However, in Chapter 11, we discuss the details of managing a Web Services project.

How Axis Works

Axis is not that complicated in essence. However, there are few pieces that you have to properly organize. You can download it from http://ws.apache.org/axis/index.html . When you download a binary archive, within the archive is the directory webapps . Beneath the webapps directory is the directory axis . The axis directory contains the Axis Web Service application. Following the installation instructions, we recommend that you copy the entire axis directory to a particular servlet container (this will make for an easy installation).

Table 10.1 defines some of the major files found in the axis Web Service application.

Table 10.1: Major Axis Web Service application files and purpose (legend: [axis] axis web application installation directory).

File	Details
[axis]/EchoHeaders.jws	A sample Web Service that returns the various headers.
[axis]/ fingerprint .jsp	A Web page that loads, iterates, and displays the available jar files to the Axis application.
[axis]/happyaxis.jsp	A Web page that should be loaded first to verify the installation of Axis. Loading this page will help you find the reason for any problems.
[axis]/index.html	The welcome page for the Axis toolkit. This page should be referenced first because the page provides links to the other pieces of functionality.
[axis]/ web-inf /lib/axis.jar	A jar file that contains the entire Axis application.
[axis]/web-inf/lib/ jaxrpc .jar	A jar file that contains the JAX RPC API definitions.
[axis]/web-inf/lib/saaj.jar	A jar file that contains the SOAP and Attachments API definitions.
[axis]/web-inf/lib/wsdl4j.jar	A jar file that contains the SOAP WSDL API definitions.
[axis]/web-inf/web.xml	A configuration file that contains the axis details. Modify this file when you re integrating Axis with already-existing applications.
[axis]/web-inf/perms.lst	Permissions of specific users using Axis-specific security.
[axis]/web-inf/users.lst	A security list that contains users using Axis-specific security.

Axis can be integrated into any other Web application so long as you follow these rules:

1. Axis must execute within a servlet container.

2. All of the jar files in the directory [axis]/web-inf/lib must exist in the other Web application.

3. The settings found in the web.xml file must be applied in the other Web application's web.xml file.

These rules provide a basic minimum Axis Web Services infrastructure. The other files and settings are optional and do not need to exist in the other Web application.