The minimum requirement for this tip to work is to have Internet Explorer with MSXML objects installed when Windows is installed. The DOMDocument is also available in the new versions of Netscape. This example displays user information based on the login id without submitting the form.

Create a servlet that will submit an .xml document based on the request parameter “login” value:

import javax.servlet.*;import javax.servlet.http.*;import java.io.*;public class UserInfoServlet    extends HttpServlet {  private static final String CONTENT_TYPE = "text/xml";  //Process the HTTP Get request  public void doGet(HttpServletRequest request, HttpServletResponse response) throws      ServletException, IOException {    doPost(request, response);  }  //Process the HTTP Post request  public void doPost(HttpServletRequest request, HttpServletResponse response) throws      ServletException, IOException {    String login = request.getParameter("login");    String info = null;    if (login != null && "guest".equalsIgnoreCase(login)) {      info = "Guest";    }    else {      info = "Unknown";    }    response.setContentType(CONTENT_TYPE);    PrintWriter out = response.getWriter();    out.println("");    out.println("
");    out.println(info);    out.println("
");  }}

Add servlet mapping for this servlet in the web.xml file as follows:

  userinfo  UserInfoServlet  userinfo  /ui

Following is the HTML page:

        
      Enter Login Id:            User Information: (Readonly)          
   

Now, if you type “guest” in the login input, “Guest” or otherwise Unknown will be displayed automatically.