@WebService
public class ShoppingCart {
   @Resource    // Step 1
   private WebServiceContext wsContext;    // Step 2
   public int addToCart(Item item) {
      // Find the HttpSession
      MessageContext mc = wsContext.getMessageContext();    // Step 3
      HttpSession session = ((javax.servlet.http.HttpServletRequest)mc.get(MessageContext.SERVLET_REQUEST)).getSession();
      if (session == null)
         throw new WebServiceException("No HTTP Session found");
      // Get the cart object from the HttpSession (or create a new one)
      List<Item> cart = (List<Item>)session.getAttribute("myCart");  // Step 4
      if (cart == null)
         cart = new ArrayList<Item>();
      // Add the item to the cart (note that Item is a class defined 
      // in the WSDL)
      cart.add(item);
      // Save the updated cart in the HTTPSession (since we use the same 
      // "myCart" name, the old cart object will be replaced)
      session.setAttribute("myCart", cart);
      // return the number of items in the stateful cart
      return cart.size();
   }
}