Get session by id in ajax call

Is there a way to have ac开发者_开发百科cess to session in a AJAX call made to a JAVA server.

On the server, the request object has both the session and cookies properties NULL.

I can pass though the session id as a parameter, but how can I access the session by ID?

Edit

Using session.getSession(false); returns null, while session.getSession(true); obviously returns a new session, with another id.

The best way to deal with this is to append ";jsessionid=" at the end of the url. For instance, in a jsp:

<script type="text/javascript">
...
    xhr.open("GET", url + ";jsessionid=<%=pageContext.getSession().getId()%>"); 
...
</script>

The line:

xhr.open("GET", url + ";jsessionid=<%=pageContext.getSession().getId()%>");

is rendered as:

xhr.open("GET", url + ";jsessionid=6EBA4F94838796DC6D653DCA1DD06373");

It sounds like you don't have a session!

Make sure when the load containing the AJAX script, the session is created on the server.

session.getSession(true);

If this is stored as a cookie, then your AJAX call will submit it back to the server when it fires.

In order to access the session you do not need the session id. This is all done for you behind the scenes by your servlet container. To get the session for a particluar request all you need to do is:

 HttpSession session = request.getSession(false);

where request is your HttpServletRequest. The false arg means "do not create session if it does not exist". Of course use "true" if you want the session to be created if it doesn't exist.