Servlet Deployment and Web Archives

A descriptor based on XML is used in the deployment of servlets on a Web server. The compiled servlet class, additional supporting Java classes, and the deployment descriptor are packaged together into a Web archive file, also known as a “.war” file.

The deployment descriptor is an XML-based file that contains specific configuration and deployment information for use by the servlet container.

Figure 10-11 shows an example of a vanilla XML deployment descriptor for an HttpServlet. Additional required fields in the descriptor are filled in during configuration and deployment on the Web server.

Figure 10-11. A simple vanilla XML deployment descriptor for a sample HttpServlet

<?xml version="1.0" encoding="UTF-8"?>
<!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>LoginServlet</servlet-name>
    <servlet-class>LoginServlet</servlet-class>
  </servlet>
</web-app>

We discuss servlet deployment descriptors and Web archive files and their role in the context of modeling in Chapter 15.