title: How to Implement SSO on existing tomcat web application
body: <p>I have a tomcat 7 setup with oldApp.war and newApp.war deployed on it. Both the applications share the same login credentials for users on the database. </p>
  
  <p>I can access the apps using <code>https://localhost/oldApp</code> and <code>https:localhost/newApp</code> respectively. </p>
  
  <p>My oldApp is a Spring MVC java application and when the user is logged into the oldApp I want to have a link which will take the user into the newApp without asking for the login credentials. </p>
  
  <p>I want to know how to implement SSO to do this. I preferably don't want to run any external service to handle this.</p>
  
  <p>Thanks in advance. </p>