Session

Scenario:
We have an inhouse application(http://www.a.com) that 'posts' to a different java application's servlet (http://www.b.com/GetAppServlet?token=1234)
In this servlet, I store a parameter sent over into the session.
I display a jsp page (At this time the session is still the same as prior)
Click a button, posts to another servlet (http://www.b.com/SetAppServlet?...) in the same application.... this is creating a new session.

why?

Hi Kieth,
Please post some code snippets for the same. i think you are creating a new session in your another servlet. please check.

Hi Pravin,

First Servlet:
HttpSession session = request.getSession( true);
session.setAttribute("x", request.getParameter("x"));

Render jsp page:
...servletcontext.getRequestDispatcher(page.jsp.forward(req,res);

JSP:
<a href="/SetServlet?a=1&b=2"

SetServlet:
HttpSession session = request.getSession(true);
session.getAttribute("x") - THIS IS NULL BECAUSE IT'S A DIFF SESSION (VERIFIED BY DISPLAYING SESSIONID)

Would it matter if this first application 'a' does a 'response.sendRedirect' vs setting the action of a form and submitting that form
'

Kieth Lyman wrote:Would it matter if this first application 'a' does a 'response.sendRedirect' vs setting the action of a form and submitting that form

No. They are identical.

Kieth Lyman wrote:Hi Pravin,

First Servlet:
HttpSession session = request.getSession( true);
session.setAttribute("x", request.getParameter("x"));

Render jsp page:
...servletcontext.getRequestDispatcher(page.jsp.forward(req,res);

JSP:
<a href="/SetServlet?a=1&b=2"

SetServlet:
HttpSession session = request.getSession(true);
session.getAttribute("x") - THIS IS NULL BECAUSE IT'S A DIFF SESSION (VERIFIED BY DISPLAYING SESSIONID)

If I am not mistaken, <a href> tag will not forward the session related data that you created in the previous jsp. Try using c:url JSTL tag instead.

Shefali Naik wrote:If I am not mistake....

You are mistaken. An anchor link will have no affect on sessions within the same web applications. And, of course, sessions aren't shared across web applications. The use of <c:url> or not is irrelevant.

response.sendRedirect created a new session on the second webapp from the first servlet...that did work. This is different than the 'submit'.

Kieth Lyman wrote:response.sendRedirect created a new session on the second webapp from the first servlet...that did work. This is different than the 'submit'.

Hum... I was checking the API and there is nothing about it. They don't metion a new session: http://download.oracle.com/javaee/1.4/api/javax/servlet/http/HttpServletResponse.html#sendRedirect%28java.lang.String%29
Do you have any link about it?

I was thinking and maybe it's because the redirect method it's sending the user to another JVM.

Bear, did you mean 'context' is not shared between apps.
Session should not be a problem as it is based on the session id of the client which is passed in a cookie in the request.

No, he meant session. (Which is a context, btw.)

Passing a session ID from one webapp into another doesn't mean they're sharing sessions.

You can't share sessions between web apps. Period.