Init parameters are set in the web.xml and access in the servlet class . Init parameter are set in the web.xml as :

<?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>
<servlet>

 <init-param>
   <param-name>Email</param-name>
   <param-value>userEmail@gmail.com</param-value>
 </init-param>
 <init-param>
  <param-name>Address</param-name>
  <param-value>Dehli</param-value>
 </init-param> 

  <servlet-name>InitParameter</servlet-name>
  <servlet-class>InitServlet</servlet-class>
 </servlet>

 <servlet-mapping>
  <servlet-name>InitParameter</servlet-name>
  <url-pattern>/InitServlet</url-pattern>
 </servlet-mapping>

</web-app>

Again access parameter in the servlet as :

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.*;

public class InitServlet extends HttpServlet {
  public void doGet(HttpServletRequest request, HttpServletResponse response)
                                  throws ServletException, IOException {
    PrintWriter pw = response.getWriter();
    pw.print("Init Parameters are : ");
    Enumeration enumeration = getServletConfig().getInitParameterNames();        
    pw.println("\nThe Email : " + getServletConfig().getInitParameter("Email"));
    pw.println("The address : " + getServletConfig().getInitParameter("Address"));       
  }
}