How can I call an ASP page from JSP?
I'm not sure if you just want to redirect to an ASP page from a JSP page, in which case, you should use response.sendRedirect() eg
<% ... response.sendRedirect("http://ab.com/x.asp"); %>
Also note that whatever parameters sent to your jsp page will be sent to your asp page.
Once you have redirected to an ASP page, control is now turned over to the ASP page and there is no way to return to your original JSP page.
On the other hand, if you calling an ASP page to retrieve non html outputs (eg xml) so that you can parse it in your JSP page, consider opening a url connection to that ASP page. Retrieve the output back from the asp page and then parse the output for your own purpose.
Look at http://www.jguru.com/jguru/faq/view.jsp?EID=13198 for an example of the how you would do that except you want to embed the code in a JSP scriptlet and set the url to your asp in the URL object.