Head First Servlets and JSP, 2nd Edition

Testing your ServletConfig

ServletConfig’s main job is to give you init parameters. It can also give you a ServletContext, but we’ll usually get a context in a different way, and the getServletName() method is rarely useful.

In the DD (web.xml) file:

<?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/web-app_2_4.xsd"
    version="2.4">
  <servlet>
    <servlet-name>BeerParamTests</servlet-name>
    <servlet-class>com.example.TestInitParams</servlet-class>
    <init-param>
      <param-name>adminEmail</param-name>
      <param-value>[e-mail]</param-value>
    </init-param>
    <init-param>
      <param-name>mainEmail</param-name>
      <param-value>[e-mail]</param-value>
    </init-param>
  </servlet>
  <servlet-mapping>
    <servlet-name>BeerParamTests</servlet-name>
    <url-pattern>/Tester.do</url-pattern>
  </servlet-mapping>
</web-app>

In a servlet class:

package com.example; import javax.servlet.*; import javax.servlet.http.*; import java.io.*; public class TestInitParams extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println("test init parameters<br>"); java.util.Enumeration e = getServletConfig().getInitParameterNames(); ...