How do I automatically log out user after submitting form

Question

<form method=“post” action=“mainServlet>

<button> Save<\button>

I want user to automatically logout after submitting form to main servlet. Servlet redirects to main page but if user clicks back button he can access the form again and I want to prevent that

Answer 1

<%
response.setHeader("Cache-Control","no-cache");
response.setHeader("Cache-Control","no-store");
response.setDateHeader("Expires", 0);
response.setHeader("Pragma","no-cache");
%>

try adding this in form page at top also add a check using session.getattribute and if its null redirect to page you want to

https://www.youtube.com/watch?v=gQLQ0t9B5yk

if you want to understand more