There are two Web-related XML files, one of which is the J2EE-specific XML file and the other, the OC4J-specific XML file.

J2EE web.xml   All servlets, EJBs, and JSPs that are part of the J2EE application are described in the J2EE web.xml file. Here are the contents of a typical web.xml file:

  <web-app>
     <display-name>myapp web application</display-name>
     <description>
        Web module that contains an HTML welcome page, and 4
  JSP's.
     </description>
     <welcome-file-list>
        <welcome-file>index.html</welcome-file>
     </welcome-file-list>
     <ejb-ref>
        <ejb-ref-name>TemplateBean</ejb-ref-name>
        <ejb-ref-type>Entity</ejb-ref-type>
        <home>TemplateHome</home>
        <remote>Template</remote>
     </ejb-ref>
     <servlet>
        <servlet-name>template</servlet-name>
        <servlet-class>TemplateServlet</servlet-class>
        <init-param>
           <param-name>length</param-name>
           <param-value>1</param-value>
        </init-param>
     </servlet>
  </web-app>

OC4J-Specific orion-web.xml   The orion-web.xml file contains the mappings for Web settings. Here are important items that are part of this file:

1. Auto-reloading
   
2. Buffering
   
3. Directory browsing
   
4. Document root
   
5. Virtual directories
   
6. Clustering
   
7. Session tracking
   
8. JNDI mappings