How to access a javascript variable from Java?

Question

Here is my code:
function validateLoginForm() {
    var username = document.getElementById('un');
    setCookie('un', username, 3650);
    //etc.
<%   
    HttpSession httpSession = request.getSession();
    httpSession.setMaxInactiveInterval(30 * 60); //30 minutes
    httpSession.setAttribute("un", username); //!prob here - cannot resolve 'username'
%>
}...but how do I access the javascript variable 'username' from the Java code?
Thanks,
James

Answer 1

The only way to pass values between JavaScript and JSP is through cookies. It sucks, I know, but right now that is the only option.
You already are creating a cookie in JavaScript. So go ahead and read it in Java:
Cookie[] cookies = request.getCookies();
for(int i = 0; i < cookies.length; i++) {
    Cookie c = cookies;
if (c.getName().equals("un")) {
// Do what you need here.