Getting undefined value while passing hidden value from jsp to servlet

Question

I have a hidden value in JSP.

<input type="hidden" name="selectedtxn" value="" />

And I access the value from servlet.

String selectedTxnNo = request.getParameter("selectedtxn");

But the value I get in servlet is undefined .

Am I doing anything wrong?

Answer 1

您隐藏的输入字段为空value=""这就是为什么您undefined 。给出一些诸如value="test"