商品列表

商品名称	价格	购买数量	操作
商品1	100
商品2	200

@WebServlet("/cart") public class CartServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String item = request.getParameter("item"); int quantity = Integer.parseInt(request.getParameter("quantity")); // 将商品添加到购物车 ShoppingCart cart = (ShoppingCart) request.getSession().getAttribute("cart"); if (cart == null) { cart = new ShoppingCart(); request.getSession().setAttribute("cart", cart); } cart.addItem(item, quantity); // 显示购物车内容 response.setContentType("text/html;charset=utf-8"); PrintWriter out = response.getWriter(); out.println(""); out.println(""); out.println(""); out.println(""); out.println(""); out.println("

购物车

"); out.println("<table border="1">"); out.println(""); out.println("商品名称"); out.println("数量"); out.println(""); for (CartItem cartItem : cart.getItems()) { out.println(""); out.println("' + cartItem.getItem() + '"); out.println("' + cartItem.getQuantity() + '"); out.println(""); } out.println(""); out.println(""); out.println(""); } }

以上代码实现了购买商品并添加到购物车的功能，同时在后台处理页面中显示购物车内容。购物车的数据通过 Session 存储，可以在不同页面之间共享。