点击显示购物车 但出来的却是添加购物车成功页面（也就是success页面）并且数量显示null，id也显示null。不知道代码哪里出了错误
来源：2-11 显示购物车
夏均可不是均可
2018-09-01 14:57
package servlet;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import dao.ItemsDAO;import entity.Cart;import entity.Items;/** * Servlet implementation class CartServlet */@WebServlet("/CartServlet")public class CartServlet extends HttpServlet { private static final long serialVersionUID = 1L; private String action;//表示购物车的动作 ,add,show,delete private ItemsDAO idao = new ItemsDAO();//商品业务逻辑类的对象,比如根据编号获得商品 /** * @see HttpServlet#HttpServlet() */ public CartServlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doPost(request, response); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub response.setContentType("text/html;charset=utf-8"); PrintWriter out = response.getWriter(); if(request.getParameter("action")!=null) { //把获得的动作赋给action属性 this.action = request.getParameter("action"); if(action.equals("add")) //如果是添加商品进购物车 { if(addToCart(request,response)) { request.getRequestDispatcher("/success.jsp").forward(request, response); } else { request.getRequestDispatcher("/failure.jsp").forward(request, response); } } if(action.equals("show"))//如果是显示购物车 { request.getRequestDispatcher("/cart.jsp").forward(request, response); } if(action.equals("delete")) //如果是执行删除购物车中的商品 { if(deleteFromCart(request,response))//如果删除成功 { request.getRequestDispatcher("/cart.jsp").forward(request, response); } else { request.getRequestDispatcher("/cart.jsp").forward(request, response); } } } } //添加商品进购物车的方法 private boolean addToCart(HttpServletRequest request, HttpServletResponse response) { String id=request.getParameter("id"); String number=request.getParameter("num"); Items item=idao.getItemsById(Integer.parseInt(id));//根据商品id获取商品资料 //是否第一次给购物车添加商品。若是，则session中以前没有购物车对象 if(request.getSession().getAttribute("cart")==null) { Cart cart= new Cart(); request.getSession().setAttribute("cart", cart); } //若不是第一次购买则直接获得一个cart对象 Cart cart=(Cart) request.getSession().getAttribute("cart"); if(cart.addGoodsInCart(item, Integer.parseInt(number))) { return true; } else { return false; } } private boolean deleteFromCart(HttpServletRequest request, HttpServletResponse response) { String id = request.getParameter("id"); Cart cart = (Cart)request.getSession().getAttribute("cart"); Items item = idao.getItemsById(Integer.parseInt(id)); if(cart.removeGoodsInCart(item)) { return true; } else { return false; } }} <%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8" %><%@ page import="entity.Items"%><%@ page import="dao.ItemsDAO"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <base href="<%=basePath%>"> <title>My JSP 'details.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> <link href="css/main.css" rel="stylesheet" type="text/css"> <script type="text/javascript" src="js/lhgcore.js"></script> <script type="text/javascript" src="js/lhgdialog.js"></script> <script type="text/javascript"> function selflog_show(id) { var num = document.getElementById("number").value; J.dialog.get({id: 'haoyue_creat',title: '购物成功',width: 600,height:400, link: '<%=path%>/servlet/CartServlet?id='+id+'&num='+num+'&action=add', cover:true}); } function add() { var num = parseInt(document.getElementById("number").value); if(num<100) { document.getElementById("number").value = ++num; } } function sub() { var num = parseInt(document.getElementById("number").value); if(num>1) { document.getElementById("number").value = --num; } } </script> <style type="text/css"> hr{ border-color:FF7F00; } div{ float:left; margin-left: 30px; margin-right:30px; margin-top: 5px; margin-bottom: 5px; } div dd{ margin:0px; font-size:10pt; } div dd.dd_name { color:blue; } div dd.dd_city { color:#000; } div #cart { margin:0px auto; text-align:right; } span{ padding:0 2px;border:1px #c0c0c0 solid;cursor:pointer; } a{ text-decoration: none; } </style> </head> <body> <h1>商品详情</h1> <a href="index.jsp">首页</a> >> <a href="index.jsp">商品列表</a> <hr> <center> <table width="750" height="60" cellpadding="0" cellspacing="0" border="0"> <tr> <!-- 商品详情 --> <% ItemsDAO itemDao = new ItemsDAO(); Items item = itemDao.getItemsById(Integer.parseInt(request.getParameter("id"))); if(item!=null) { %> <td width="70%" valign="top"> <table> <tr> <td rowspan="5"><img src="images/<%=item.getPicture()%>" width="200" height="160"/></td> </tr> <tr> <td><B><%=item.getName() %></B></td> </tr> <tr> <td>产地：<%=item.getCity()%></td> </tr> <tr> <td>价格：<%=item.getPrice() %>￥</td> </tr> <tr> <td>购买数量：<span id="sub" onclick="sub();">-</span><input type="text" id="number" name="number" value="1" size="2"/><span id="add" onclick="add();">+</span></td> </tr> </table> <div id="cart"> <img src="images/buy_now.png"> <a href="javascript:selflog_show(<%=item.getId()%>)"><img src="images/in_cart.png"></a> <a href="servlet/CartServlet?action=show"><img src="images/view_cart.jpg"/></a> </div> </td> <% } %> <% String list =""; //从客户端获得Cookies集合 Cookie[] cookies = request.getCookies(); //遍历这个Cookies集合 if(cookies!=null&&cookies.length>0) { for(Cookie c:cookies) { if(c.getName().equals("ListViewCookie")) { list = c.getValue(); } } } list+=request.getParameter("id")+"#"; //如果浏览记录超过1000条，清零. String[] arr = list.split("#"); if(arr!=null&&arr.length>0) { if(arr.length>=1000) { list=""; } } Cookie cookie = new Cookie("ListViewCookie",list); response.addCookie(cookie); %> <!-- 浏览过的商品 --> <td width="30%" bgcolor="#EEE" align="center"> <br> <b><font color="#FF7F00">您浏览过的商品</font></b><br> <!-- 循环开始 --> <% ArrayList<Items> itemlist = itemDao.getViewList(list); if(itemlist!=null&&itemlist.size()>0 ) { System.out.println("itemlist.size="+itemlist.size()); for(Items i:itemlist) { %> <div> <dl> <dt> <a href="details.jsp?id=<%=i.getId()%>"><img src="images/<%=i.getPicture() %>" width="120" height="90" border="1"/></a> </dt> <dd class="dd_name"><%=i.getName() %></dd> <dd class="dd_city">产地:<%=i.getCity() %> 价格:<%=i.getPrice() %> ￥ </dd> </dl> </div> <% } } %> <!-- 循环结束 --> </td> </tr> </table> </center> </body></html><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8" %><%@ page import="entity.Cart" %><%@ page import="entity.Items" %><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <base href="<%=basePath%>"> <title>My JSP 'cart.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> <link type="text/css" rel="stylesheet" href="css/style1.css" /> <script language="javascript"> function delcfm() { if (!confirm("确认要删除？")) { window.event.returnValue = false; } } </script> </head> <body><h1>我的购物车</h1> <a href="index.jsp">首页</a> <a href="index.jsp">商品列表</a> <hr> <div id="shopping"> <form action="" method=""> <table> <tr> <th>商品名称</th> <th>商品单价</th> <th>商品价格</th> <th>购买数量</th> <th>操作</th> </tr> <% //首先判断session中是否有购物车对象 if(request.getSession().getAttribute("cart")!=null) { %> <!-- 循环的开始 --> <% //先获得一个购物车 Cart cart = (Cart)request.getSession().getAttribute("cart"); //接下来开始遍历购物车 HashMap<Items,Integer> goods = cart.getGoods(); //先获得键的集合 Set<Items> items = goods.keySet(); Iterator<Items> it = items.iterator(); while(it.hasNext()) { Items i = it.next(); %> <tr name="products" id="product_id_1"> <td class="thumb"><img src="images/<%=i.getPicture()%>" /><a href=""><%=i.getName()%></a></td> <td class="number"><%=i.getPrice() %></td> <td class="price" id="price_id_1"> <span><%=i.getPrice()*goods.get(i) %></span> <input type="hidden" value="" /> </td> <td class="number"> <%=goods.get(i)/*获得否买数量*/%> </td> <td class="delete"> <a href="servlet/CartServlet?action=delete&id=<%=i.getId()%>" onclick="delcfm();">删除</a> </td> </tr> <% } %> <!--循环的结束--> </table> <div class="total"><span id="total">总计：<%=cart.getTotalPrice() %>￥</span></div> <% } %> <div class="button"><input type="submit" value="" /></div> </form> </div> </body></html><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8" %><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <base href="<%=basePath%>"> <title>My JSP 'success.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <center> <img src="images/add_cart_success.jpg"/> <hr> <% String id = request.getParameter("id"); String num = request.getParameter("num"); %> 您成功购买了<%=num%>件商品编号为<%=id%>的商品 <br> <br> <br> </center> </body></html>
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2回答
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- KDwin
- 2018-09-22 16:15:53
代码格式整理一下啊。。。这么乱怎么看
-
- 有梦想的小伙子SY
- 2018-11-23 14:25:24
代码格式太乱了，ctrl+shift+F键格式化一下代码再发出来吧。
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