Setting request parameters ?

Question

Hi there
I tried the following:
request.setAttribute("myVar", "myValue");
pageContext.forward("/main");
When it loads the main page, my variables are not being set.
I have tried the <jsp:forward> page directive and this works for a simple test example I've used, but not when I try it in my application main page ( which consists of 3 frames). The 3 frames are all JSP pages, so does the time they get loaded affect the request and <jsp:forward> attributes being sent ?
Or can I not just set request parameters?
I'm stumped !
Aaron

Answer 1

No, thats not the case. getParameter and getAttribute return from different internal collections.
An HttpServletRequest object will have two different HashMap objects (at least, they're probably HashMaps).
One stores the parameters that were passed by the client's request (That's why they're always Strings - the client passes text using the HTTP GET and POST protocols). getParameter returns Strings from here.
The other HashMap maintains objects that you add on the server side to pass between your servlets. You may want to add any type of object, so that's why these aren't required to be Strings.
Think of neville's example (which allows you to use getParameter on the next page) as creating a new request that works as if the client had appended the extra parameters to the query string. You can't add non-String Objects using that method.
If you try your simple example again using getAttribute, you'll probably find that it works.