/*
\t提交订单
\tpublic void submitOrder(HttpServletRequest req, HttpServletResponse resp)
\t\t\tthrows ServletException, IOException {
\t\tHttpSession session = req.getSession();
\t\t// 验证用户是否登录
\t\tUser user = (User) session.getAttribute("user");
\t\t\tif (user == null) {
\t\t\t\t// 未登录状态
\t\t\t\tresp.sendRedirect(req.getContextPath() + "/login.jsp");
\t\t\t\treturn;
\t\t\t}
\t\tCart cart =(Cart) session.getAttribute("cart"); // 获取购物车
\t\tOrder order = new Order(); // 创建Order对象
\t\torder.setOid(CommonUtil.generateUUID()); // 订单编号
\t\torder.setTotal(cart.getTotal()); // 总金额,从购物车中获取
\t\t// 设置购买用户
\t\torder.setUser(user);
\t\t// 设List orderitems;
\t\tList orderitems = new ArrayList<>();
\t\t// 从购物车中获取CartItem转成OrderItem
\t\tMap<String, CartItem> cartItems = cart.getCartItems();
\t\tSet keyset= cartItems.keySet();
\t\tfor (String pid: keyset) {
\t\t\tCartItem cartItem = cartItems.get(pid); // 得到每一个购物项
\t\t\tOrderItem orderitem = new OrderItem(); // 准备OrderItem，从CartItem转换数据
\t\t\torderitem.setItemid(CommonUtil.generateUUID()); // private String itemid;
\t\t\torderitem.setCount(cartItem.getBuyNum()); // private int count;//购买的数量
\t\t\torderitem.setSubtotal(cartItem.getSubToal()); // private double subtotal;//小计
\t\t\torderitem.setProduct(cartItem.getProduct()); // private Product product;//该项中购买的商品对象
\t\t\t// private Order order;
\t\t\torderitem.setOrder(order);
\t\t\torderitems.add(orderitem);
\t\t\t// 将订单项存入到order中的订单项的集合中
\t\t}
\t\torder.setOrderItems(orderitems);
\t\tresp.sendRedirect(req.getContextPath() + "/order_info.jsp");
\t}
*/