Using request.setAttribute in a JSP page

Question

Is it possible to use request.setAttribute on a JSP page and then on HTML Submit get the same request attribute in the Servlet?

Solution 1

The reply by Phil Sacre was correct however the session shouldn't be used just for the hell of it. You should only use this for values which really need to live for the lifetime of the session, such as a user login. It's common to see people overuse the session and run into more issues, especially when dealing with a collection or when users return to a page they previously visited only to find they have values still remaining from a previous visit. A smart program minimizes the scope of variables as much as possible, a bad one uses session too much.

Solution 2

If you want your requests to persists try this:

example: on your JSP or servlet page

request.getSession().setAttribute("SUBFAMILY", subFam);

and on any receiving page use the below lines to retrieve your session and data:

SubFamily subFam = (SubFamily)request.getSession().getAttribute("SUBFAMILY");

Solution 3

You can do it using pageContext attributes, though:

In the JSP:

<form action="Enter.do">
    <button type="SUBMIT" id="btnSubmit" name="btnSubmit">SUBMIT</button>
</form>
<% String s="opportunity";
pageContext.setAttribute("opp", s, PageContext.APPLICATION_SCOPE); %>

In the Servlet (linked to the "Enter.do" url-pattern):

String s=(String) request.getServletContext().getAttribute("opp");

There are other scopes besides APPLICATION_SCOPE like SESSION_SCOPE. APPLICATION_SCOPE is used for ServletContext attributes.

Solution 4

Try

request.getSession().setAttribute("SUBFAMILY", subFam);
request.getSession().getAttribute("SUBFAMILY");

Solution 5

Correct me if wrong...I think request does persist between consecutive pages..

Think you traverse from page 1--> page 2-->page 3.

You have some value set in the request object using setAttribute from page 1, which you retrieve in page 2 using getAttribute,then if you try setting something again in same request object to retrieve it in page 3 then it fails giving you null value as "the request that created the JSP, and the request that gets generated when the JSP is submitted are completely different requests and any attributes placed on the first one will not be available on the second".

I mean something like this in page 2 fails:

Where as the same thing has worked in case of page 1 like:

So I think I would need to proceed with either of the two options suggested by Phill.

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