This maybe caused by jar conflict. Remove the servlet-api.jar in your servlet/WEB-INF/ directory, %Tomcat home%/lib already have this lib.
The problem is caused because you need to import the pageNumber.Member class in your JSP. Make sure to also include another packages and classes like java.util.List.
<%@ page import="pageNumber.*, java.util.*" %>
Still, you have a major problem by using scriptlets in your JSP. Refer to How to avoid Java Code in JSP-Files? and start practicing EL and JSTL and focusing more on a MVC solution instead.