JSP 购物车实现

package com.east.servlet;import java.io.IOException;import java.io.PrintWriter;import java.util.HashMap;import java.util.Iterator;import java.util.Map;import java.util.Vector;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.east.foodBean.CateBean;import com.east.foodDao.CateDAO;/*** * 购物车的显示转到showcart.jsp中去 * @author Administrator * */public class ShopCartServlet extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {request.setCharacterEncoding("GBK");response.setContentType("text/html;charset=GBK");PrintWriter out = response.getWriter();HttpSession session = request.getSession();Vector food = (Vector)session.getAttribute("voCart");request.setAttribute("food", food);request.getRequestDispatcher("shopCart.jsp").forward(request, response);}public CateBean exitstCateBean (int id,Vector voCate){Iterator iter = voCate.iterator();while (iter.hasNext()){CateBean cateBean = (CateBean)(iter.next());if (cateBean.getCardId() ==id){return cateBean;}}return null;}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {response.setContentType("text/html");PrintWriter out = response.getWriter();doGet(request,response);}} package com.east.servlet;import java.io.IOException;import java.io.PrintWriter;import java.util.HashMap;import java.util.Iterator;import java.util.Map;import java.util.Vector;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.east.foodBean.CateBean;import com.east.foodDao.CateDAO;/*** * 购买食品的servlet * @author Administrator * */public class BuyServlet extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {request.setCharacterEncoding("GBK");response.setContentType("text/html;charset=GBK");PrintWriter out = response.getWriter();HttpSession session = request.getSession();CateDAO cateDAO = new CateDAO();int cateId = Integer.parseInt(request.getParameter("cateId"));if (session.getAttribute("voCart") == null){session.setAttribute("voCart", new Vector());}Vector voCart = (Vector)(session.getAttribute("voCart"));CateBean bean = isExistence(voCart,cateId);if (bean == null){bean = cateDAO.selectAll(cateId); bean.setCount(1);voCart.add(bean);}else{bean.setCount(bean.getCount()+1);}//计算总价格float allPrice = this.totalPrice(voCart);session.setAttribute("voCart", voCart);session.setAttribute("allPrice", allPrice);out.println("成功加入购物车");} public CateBean isExistence(Vector voCart,int id){ Iterator it = voCart.iterator(); while(it.hasNext()){ CateBean item = (CateBean)(it.next()); if(item.getCardId() == id){ return item; } } return null; } /** * 计算总价格 * @param voCart * @return */ public float totalPrice(Vector voCart){ Iterator it = voCart.iterator(); float price=0.0f; while(it.hasNext()){ CateBean cateBean = (CateBean)it.next(); price = price + cateBean.getCurPrice() * cateBean.getCount(); } System.out.println("总价格:"+price); return price; }public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { doGet(request,response);}}