I'm looking to track a user session if they have "logged in" using my
own user manager, but i was having trouble passing my user object back
to the session once the app was deployed. I will give this a shot but
i wonder if this was because i was redirecting instead of forwarding.
I was doing this in my servlet
List<MyUser> results = (List<MyUser>)
query.execute(email,password);
if (results.size() == 0) { redirect = "/index.html"; }
else {
req.getSession().setAttribute("user", results.get(0));
}
resp.sendRedirect(redirect);
and this in my jsp
<%
MyUser u = (MyUser) request.getSession().getAttribute("user");
if (u != null) {
....
} else { %>
User is null
<% } %>
So i was always getting null even though i was redirected properly.
Can you explain
On Nov 10, 1:36 pm, "Ikai L (Google)" <ika...@google.com> wrote:
> Ilya,
>
> Are you looking to persist objects for a lifetime of a session, or are you
> looking to minimize the logic you are using in your JSPs?
> As a general design principle, we recommend that you minimize usage of
> session scope. Variables bound to session scope are serialized and stored to
> distributed memory, and as a result, it will work best if you use it to pass
> around small, simple, immutable objects.
>
> If you're looking to pass a variable to a view, Java Servlets have a concept
> of page scope as well as session scope. You don't need to store a variable
> in session scope if you just want to dispatch the request to a JSP. For
> instance, you can define a Servlet that looks like this:
>
> public class MyServlet extends HttpServlet {
>
> protected void doGet(HttpServletRequest request, HttpServletResponse
> response) throws ServletException, IOException {
> String myVar = "this is a string that will be passed to the JSP";
> request.setAttribute("myVar", myVar);
> RequestDispatcher dispatcher =
> request.getRequestDispatcher("/WEB-INF/my.jsp");
>
> dispatcher.forward(request, response);
>
> }
>
> }
>
> In my.jsp, you can now refer to this variable:
>
> <%@ page isELIgnored="false" %>
> <body>
> <h1>${myVar}</h1>
> </body>
>
> Ikai Lan
> Developer Programs Engineer, Google App Engine
>
>
>
> On Tue, Nov 10, 2009 at 2:39 PM, IlyaE <ilyaelk...@gmail.com> wrote:
>
> > Well as i found out, session attributes don't always guarantee that
> > they are sent back to the same JVM thus i keep getting null objects in
> > my view. While i saw a similar discussion before the only examples i
> > found were for Python. I'm looking for a simple java example that
> > saves an object in the servlet and retrieves it in the jsp.
>
> > On Nov 9, 5:44 pm, victor <victoraco...@gmail.com> wrote:
> > > What issue are you encountering?
>
> > > When you make changes to a session object state, make sure to
> > > explicitly call the session.setAttribute("<you session ID>", <you
> > > modified session state object>) again.
>
> > > i think there is an issue discussed about this before.
>
> > > On Nov 9, 10:58 am, IlyaE <ilyaelk...@gmail.com> wrote:
>
> > > > Does anyone have a java session handleing example? It seems that
> > > > saving objects in the session only works locally.
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