i get an error "org.apache.jasper.JasperException: An exception occurred processing JSP page /index.jsp at line 18" i think my exception code is wrong. i don't know how to return an empty string when the user doesn't enter any number and clicks "continue". any suggestions
OK, just to bring you up to date. Putting Java code in a JSP is an old practice from JSP 1 days before 2002. Continuing to put Java into JSP pages is now considered a poor practice.
As of 10 years ago, with the introduction of JSP 2, the JSTL (JSP Standard Tag Library) and the EL (Expression Language) are the accepted means to make JSP pages dynamic.
I would suggest finding yourself a modern tutorial to work from that focuses on JSTL and EL rather than Java scriptlets. The latter isn't a bad skill to know about in case you end up supporting legacy pages, but new pages should never use scriptlets.
I recommend that all newcomers read the following articles: