// From "Professional Java Server Programming", Patzer et al., // Edition J2EE, pg 412. // Import Servlet Libraries import javax.servlet.*; import javax.servlet.http.*; // Import Java Libraries import java.io.*; import java.util.*; public class ShoppingCart extends HttpServlet { public void doPost (HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException { // Get session object HttpSession session = req.getSession (true); // Get the cart ArrayList cart = (ArrayList) session.getAttribute ("cart"); // if the session is new, the cart won't exist. if (cart == null) { cart = new ArrayList (); session.setAttribute ("cart", cart); } res.setContentType ("text/html"); PrintWriter out = res.getWriter (); // Retrieve Form Data String[] itemsSelected; String itemName; itemsSelected = req.getParameterValues ("item"); // if items selected, add them to the session object. if (itemsSelected != null) { // Loop through selected items for (int i=0; i"); out.println (""); out.println (" Shopping Cart Contents"); out.println (""); out.println (""); out.println ("

Items currently in your cart

"); out.println ("

"); Iterator iterator = cart.iterator(); // Convert the array list into an iterator while (iterator.hasNext()) { out.println ("

"); out.println (iterator.next()); out.println ("

"); } out.println ("

"); out.println ("

"); out.print ("Back to the shop"); out.println ("

"); out.println (""); out.println (""); out.close(); } // End doPost() }