2.6. Application Deployment Descriptor
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2.6. Application Deployment Descriptor

web.xml. 

<?xml version="1.0"?>
<!DOCTYPE web-app PUBLIC
    "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
    "http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">

<web-app>
    <servlet>
        <servlet-name>Welcome</servlet-name>
        <servlet-class>
            org.apache.tapestry.ApplicationServlet 1 
        </servlet-class>
        <init-param>
            <param-name>
            	org.apache.tapestry.application-specification
            </param-name>
            <param-value>
                /org/apache/tapestrydoc/welcome/Welcome.application 2 
            </param-value>
        </init-param>
        <load-on-startup>0</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>Welcome</servlet-name>
        <url-pattern>/app</url-pattern> 3 
    </servlet-mapping>
</web-app>

1

The gateway servlet. We only ever need one servlet for a Tapestry application. And like the page and engine, there is the Tapestry provided servlet, ApplicationServlet, that we use, but the difference is that this servlet is rarely extended unlike the BasePage or the BaseEngine

2

The application declaration. The application is declared via the standard servlet <init-param>. This is where we would let Tapestry know where to find the application specification. org.apache.tapestry.application-specification is the key Tapestry will use to retrieve the specification file path. The path here is a classpath.

3

Servlet path. The path to which our servlet is mapped. User requests containing this path will be forwarded to our gateway servlet.

Now if the application is deployed on the localhost at port 8080 at context "welcome" (and if it is error-free!), the request, http://localhost:8080/welcome/app, will display the greeting, "Welcome to Tapestry!".

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