You can do that in 2 steps:
1. Make ajaxswing the default (root) application in your web server. For Tomcat you can read
http://benhutchison.wordpress.com/2008/07/30/how-to-configure-tomcat-root-context/2. Register a servlet iin web.xml and giving it the name that you want to appear in the URL (default AjaxSwing installation has this example for application WindowsThemeDemo):
<servlet>
<servlet-name>WindowsThemeDemo</servlet-name>
<servlet-class>com.creamtec.ajaxswing.AjaxSwingRouter</servlet-class>
<init-param>
<param-name>appName</param-name>
<param-value>WindowsThemeDemo</param-value>
</init-param>
<!-- propsFileName can be used to spacify non-default path to the application properties file
<init-param>
<param-name>propsFileName</param-name>
<param-value>WindowsThemeDemo</param-value>
</init-param>
-->
</servlet>
<servlet-mapping>
<servlet-name>WindowsThemeDemo</servlet-name>
<url-pattern>/WindowsThemeDemo/*</url-pattern>
</servlet-mapping>