Require login servlet to go to other pages

Question

There are a million examples on the web that shows how to create a basic Java Login Servlet, where the user has to enter a username and password which gets verified by some data

Answer 1

After getting the login details from the user, you can save the login details in session and in every page you can test or validate the session like...

<%
String strLoginId = (String)session.getAttribute("LoginID");
String strpassword = (String)session.getAttribute("Password");

if(strLoginId==null)  // Means session is not there
%>