JSP购物车的实现代码

package com.fendou.servlet; import java.io.IOException; import java.io.PrintWriter; import java.util.List; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import com.fendou.db.GoodsDB; import com.fendou.vo.CarManager; import com.fendou.vo.Goods; import com.fendou.vo.Item; public class UpdateGoodsCarServlet extends HttpServlet { /** * The doGet method of the servlet. <br> * * This method is called when a form has its tag value method equals to get. * * @param request the request send by the client to the server * @param response the response send by the server to the client * @throws ServletException if an error occurred * @throws IOException if an error occurred */ public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } /** * The doPost method of the servlet. <br> * * This method is called when a form has its tag value method equals to post. * * @param request the request send by the client to the server * @param response the response send by the server to the client * @throws ServletException if an error occurred * @throws IOException if an error occurred */ public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); //得到商品的ID int pid = Integer.parseInt(request.getParameter("gid")); //得到数量 int count = 1; try{ count = Integer.parseInt(request.getParameter("count")); }catch(Exception e){} //到数据库查找对应的商品信息 Goods g = GoodsDB.findById(pid); //创建session //从session中取出购物车 HttpSession session = request.getSession(); List<Item> itemList = (List<Item>)session.getAttribute("iList"); CarManager cm = new CarManager(); cm.setItemList(itemList); cm.updateCar(g, count); //得到最近的List itemList = cm.getItemList(); //System.out.println("itemList:" + itemList); double totalPrice = 0; //计算总价格 for (Item item : itemList) { totalPrice += item.getCount()*item.getGood().getPrice(); } session.setAttribute("iList", itemList); session.setAttribute("totalPrice", totalPrice); request.getRequestDispatcher("car.jsp").forward(request, response); } }