Get Information About Server in Servlet

Server port number, Server Name, Protocol or parameter name or value of client side.

The Body of Index.jsp page

< form action = servlet / First_Servlet method = "post" > < br > First_Name < input type = "text"
name = "user_name" > < input type = "submit"
value = "Submit" > < /form><br></body >

First_Servlet

import javax.servlet.*;
import java.util.Enumeration;
import java.io.IOException;
public class First_Servlet implements Servlet {
 public void destroy() {}
 public ServletConfig getServletConfig() {
  return null;
 }
 public String getServletInfo() {
  return null;
 }
 public void init(ServletConfig config) throws ServletException {}
 public void service(ServletRequest req, ServletResponse res)
 throws ServletException, IOException {
  System.out.println("server_port_Number++++++++++++++++++++++++++++++++++++++++++++++++++++" + req.getServerPort());
  System.out.println("Server_Name" + req.getServerName());
  System.out.println("Protocol" + req.getProtocol());
  System.out.println("charcter encoding" + req.getCharacterEncoding());
  Enumeration parameter = req.getParameterNames();
  while (parameter.hasMoreElements()) {
   String parameter_name = (String) parameter.nextElement();
   System.out.println("parameter_name" + parameter_name);
   System.out.println("parameter_value" + req.getParameter(parameter_name));
  }
  Enumeration attributes = req.getAttributeNames();
  while (attributes.hasMoreElements()) {
   String attribute = (String) attributes.nextElement();
   System.out.println("parameter_name" + attribute);
   System.out.println("parameter_value" + req.getParameter(attribute));
  }
 }