SESSIONS are NOT Maintained

Question

Hello Everyone!
I am using Servlets, JSP and JDBC for my Web Application.
I am using SESSION Variables. My entry point is Login Screen "www.man.com/proj/servlet/login" where user enters USERNAME/PASSWROD.
This FORM calls PROCESS.JAVA Servlet which creates a SESSION for them as shown:
HttpSession session = req.getSession(true);
String uname = (String)session.getValue("uname");
// code coonects to JDBC and see if they match
// IF MATCH
session.putValue("uname",req.getParameter("username"));
String uid = "";
uid = uid.valueOf(rs.getInt("uid"));
session.putValue("uid",uid);
//I then redirect to MENU Page ....which list options availabe for this user.
res.sendRedirect(menuURL);
on my menu page (MENU.JAVA), I have following:
HttpSession session = req.getSession(true);
String uname = (String)session.getValue("uname");
String uid = (String)session.getValue("uid");
if (uname == null)
     PRINT ERROR.....
Later then user selects one of the MENU options and it takes to another Servlet (say OPT1.JAVA)...
OPT1 Servlet is processed and at the end it displays a LINK which will take a User back to MENU.JAVA Page....
But When users clicks this LINK (A HREF) it takes to MENU.JAVA Page but shows UNAME as NULL...... How is it possible...? SHOULD IT NOT RETAIN the SESSION....?
HOW CAN I RETAIN my PREVIOUS Session Variables...?
Any related informaiton on this is appreciated.
THANKS!

Answer 1

on my menu page (MENU.JAVA), I have following:
HttpSession session = req.getSession(true);
String uname = (String)session.getValue("uname");
String uid = (String)session.getValue("uid");
if (uname == null)
PRINT ERROR.....
Here when you are getting the Session from the Request object you need to use
HttpSession session = req.getSession(false);
to retain the old Session. If you use true, it creates a new Session