package coreservlets; import java.io.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.*; /** Servlet that displays a list of items being ordered. * Accumulates them in an ArrayList with no attempt at * detecting repeated items. Used to demonstrate basic * session tracking. Updated to Java 5. *

* Taken from Core Servlets and JavaServer Pages 2nd Edition * from Prentice Hall and Sun Microsystems Press, * http://www.coreservlets.com/. * © 2003 Marty Hall; may be freely used or adapted. */ @SuppressWarnings("unchecked") public class ShowItems extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { HttpSession session = request.getSession(); ArrayList previousItems = (ArrayList)session.getAttribute("previousItems"); if (previousItems == null) { previousItems = new ArrayList(); session.setAttribute("previousItems", previousItems); } String newItem = request.getParameter("newItem"); if ((newItem != null) && (!newItem.trim().equals(""))) { previousItems.add(newItem); } response.setContentType("text/html"); PrintWriter out = response.getWriter(); String title = "Items Purchased"; String docType = "\n"; out.println(docType + "\n" + "" + title + "\n" + "\n" + "

" + title + "

"); if (previousItems.size() == 0) { out.println("No items"); } else { out.println("

" + item); } out.println("

"); } out.println(""); } }