Introduction This tutorial shows how to check username availability using Servlet, AJAX and MySQL. Sometimes we need to check username availability instantly before a user presses the submit button after filling a long-sized signup form. In this case we can use AJAX with any technologies like PHP, Codeigniter, Servlet, Struts, JSF, Spring etc. for checking…

Introduction In this post we will see how to show warning message to user when session expires in a web application. So we will redirect user to login page once session has expired. We know that we let users login to the web application before a user can perform some sensitive activities like online transactions,…