Receiving a value from servlet

[tatiana erm]

Hello!
I'm trying to receive the "result" attribute (wich is equal to expression) to my jsp, but i always get "nul" there

actually it should be like that :
1. insert some expression
2. click Calculate
3. see the "expression" in the "result" field

could anyone spot my mistake?

thank you very much!

regards, tania.

servlet:

private void process(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
    response.setStatus(200);
    String action = request.getParameter("action");

    Object expression;
    String result = "";
    if ("calculate".equals(action)) {
       expression =  request.getParameter("expression");

        request.setAttribute("result", expression);
        RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/WEB-INF/index.jsp");
        dispatcher.forward(request, response);


    }

JSP:

</form>

        <form action="">

            <div>

                <input type="text" name="expression" value="" />
                <input type="text" readonly="readonly" value= <%= request.getAttribute("result") %>  />
                <hr />

                <button name="action" value="calculate" >Calculate</button>

                <button name="action" value="clear" >Clear</button>

            </div>

        </form>

[Seetharaman Venkatasamy]

just clarification: <input type="text" readonly="readonly" value= <%= request.getAttribute("result") %> /> why is this?

[EDIT] Ok, understand to display result .

[Seetharaman Venkatasamy]

one doubt: how do you submitting the form?

[tatiana erm]

I click "Calculate" button :)

[Seetharaman Venkatasamy]

tatiana erm wrote:I click "Calculate" button :)

interesting dude :) . is tere any work around in javascript or how is it submitting form to servlet?

[tatiana erm]

i get parameter

String action = request.getParameter("action");

and if it is calculate, i do the job

[Seetharaman Venkatasamy]

Ok, actually <button/> tag is new to me... :wink:

[Seetharaman Venkatasamy]

Ah,
Tips and Notes
Note: If you use the <button> element in an HTML form, different browsers may submit different values. Use <input> to create buttons in an HTML form.

Source:Here

Thanks dude. now I know <button> :thumbup:

[tatiana erm]

I'm afraid THIS does not help me anyhow

[Seetharaman Venkatasamy]

Sounds like you are using more than one form.
</form>

<form action=""> ?

what is the action url?

[Bear Bibeault]

Is this about submitting the form, or getting the value of the scoped variable "result"? If the latter, the form is irrelevant.