<?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/webapp_2_4.xsd" version="2.4">  
  <servlet>  
    <servlet-name>CheckedServlet</servlet-name>  
    <servlet-class>CheckedServlet</servlet-class>  
     <security-role-ref>  
      <role-name>ADM</role-name>  
      <role-link>admin</role-link>  
    </security-role-ref>  
    <load-on-startup>1</load-on-startup>      
  </servlet>  
  <servlet-mapping>  
    <servlet-name>CheckedServlet</servlet-name>  
    <url-pattern>/CheckedServlet</url-pattern>  
  </servlet-mapping>  
  
  <security-constraint>  
    <web-resource-collection>  
       <web-resource-name> The example of security constraints </web-resource-name>  
       <url-pattern>/CheckedServlet</url-pattern>   
    </web-resource-collection>  
    <auth-constraint>  
      <description>Any Authenticated Permissions</description>  
      <role-name>*</role-name>  
    </auth-constraint>  
  </security-constraint>   
  
  <security-role>  
    <role-name>admin</role-name>  
  </security-role>  
  
</web-app>

[code]<login-config>   
     <auth-method>BASIC</auth-method>  
  </login-config>