SE452: The deployment descriptor [20/24]

The deployment descriptor is written in xml. It is defined in either a DTD or an XML Schema depending on the version of the specification. For 2.4, it is an XML Schema, which allows a more flexible and controlled implementation. For 2.3 and 2.2, it uses a DTD, which a bit more rigid in how you write the XML document.

Here's a simple example using the 2.4 spec

        
        <?xml version="1.0" encoding="ISO-8859-1"?>
        <web-app xmlns="http://java.sun.com/xml/ns/j2ee"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
            http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
            version="2.4">

            <display-name>A Simple Application</display-name>
            <servlet>
                <servlet-name>catalog</servlet-name>
                <servlet-class>com.mycorp.CatalogServlet</servlet-class>
                <init-param>
                    <param-name>catalog</param-name>
                    <param-value>Spring</param-value>
                </init-param>
            </servlet>
            <servlet-mapping>
                <servlet-name>catalog</servlet-name>
                <url-pattern>/catalog/*</url-pattern>
            </servlet-mapping>
            <session-config>
                <session-timeout>30</session-timeout>
            </session-config>
            <welcome-file-list>
                <welcome-file>index.jsp</welcome-file>
                <welcome-file>index.html</welcome-file>
                <welcome-file>index.htm</welcome-file>
            </welcome-file-list>
        </web-app>
        
        

And an even simpler (minimal) example using the 2.3 spec...

        
        <?xml version="1.0" encoding="ISO-8859-1"?>
        <!DOCTYPE web-app PUBLIC 
        "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" 
        "http://java.sun.com/dtd/web-app_2_3.dtd">
        <web-app>
        </web-app>
        
        

The details of web.xml can be found in chapter 13 of the specification