前面的时候我写过一个商品浏记录的小例子,这一次我们使用实现购物车效果。前面的例子是:
http://blog.csdn.net/erlian1992/article/details/52047258。这一次在此基础上来采用的是MVC三层模型实现
(JSP+Servlet+dao)来实现这个小项目。
三层架构:
JSP视图层
Servlet控制层
dao模型层
DB数据库层
编码实现:
首先先来数据库脚本items.sql:
/* Navicat MySQL Data Transfer Source Server : MySQL50 Source Server Version : 50067 Source Host : localhost:3306 Source Database : shopping Target Server Type : MYSQL Target Server Version : 50067 File Encoding : 65001 Date: 2016-08-01 12:12:31 */ SET FOREIGN_KEY_CHECKS=0; -- ---------------------------- -- Table structure for items -- ---------------------------- DROP TABLE IF EXISTS `items`; CREATE TABLE `items` ( `id` int(11) NOT NULL auto_increment, `name` varchar(50) default NULL, `city` varchar(50) default NULL, `price` int(11) default NULL, `number` int(11) default NULL, `picture` varchar(500) default NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=11 DEFAULT CHARSET=utf8; -- ---------------------------- -- Records of items -- ---------------------------- INSERT INTO `items` VALUES (‘1‘, ‘沃特篮球鞋‘, ‘佛山‘, ‘180‘, ‘500‘, ‘001.jpg‘); INSERT INTO `items` VALUES (‘2‘, ‘安踏运动鞋‘, ‘福州‘, ‘120‘, ‘800‘, ‘002.jpg‘); INSERT INTO `items` VALUES (‘3‘, ‘耐克运动鞋‘, ‘广州‘, ‘500‘, ‘1000‘, ‘003.jpg‘); INSERT INTO `items` VALUES (‘4‘, ‘阿迪达斯T血衫‘, ‘上海‘, ‘388‘, ‘600‘, ‘004.jpg‘); INSERT INTO `items` VALUES (‘5‘, ‘李宁文化衫‘, ‘广州‘, ‘180‘, ‘900‘, ‘005.jpg‘); INSERT INTO `items` VALUES (‘6‘, ‘小米3‘, ‘北京‘, ‘1999‘, ‘3000‘, ‘006.jpg‘); INSERT INTO `items` VALUES (‘7‘, ‘小米2S‘, ‘北京‘, ‘1299‘, ‘1000‘, ‘007.jpg‘); INSERT INTO `items` VALUES (‘8‘, ‘thinkpad笔记本‘, ‘北京‘, ‘6999‘, ‘500‘, ‘008.jpg‘); INSERT INTO `items` VALUES (‘9‘, ‘dell笔记本‘, ‘北京‘, ‘3999‘, ‘500‘, ‘009.jpg‘); INSERT INTO `items` VALUES (‘10‘, ‘ipad5‘, ‘北京‘, ‘5999‘, ‘500‘, ‘010.jpg‘);
我们再来连接MySQL数据库工具类DBHelper:
package com.util; import java.sql.Connection; import java.sql.DriverManager; /** * 连接MySQL数据库工具类 * @author Administrator * @date 2016年08月01日 */ public class DBHelper { //数据库驱动 private static final String driver = "com.mysql.jdbc.Driver"; //连接数据库的URL地址 private static final String url="jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=UTF-8"; //数据库的用户名 private static final String username="root"; //数据库的密码 private static final String password="root"; //Connection连接对象conn private static Connection conn=null; //静态代码块负责加载驱动 static { try{ Class.forName(driver); }catch(Exception e){ e.printStackTrace(); } } //单例模式返回数据库连接对象 public static Connection getConnection() throws Exception{ if(conn==null){ conn = DriverManager.getConnection(url, username, password); return conn; }else{ return conn; } } public static void main(String[] args) { //测试数据库是否连接正常 try{ Connection conn = DBHelper.getConnection(); if(conn!=null){ System.out.println("数据库连接正常!"); }else{ System.out.println("数据库连接异常!"); } }catch(Exception e){ e.printStackTrace(); } } }
再来创建两个实体类,一个是对应items数据表的Items.java
package com.entity; /** * 商品实体类 * @author Administrator * @date 2016年08月01日 */ public class Items { private int id; // 商品编号 private String name; // 商品名称 private String city; // 产地 private int price; // 价格 private int number; // 库存 private String picture; // 商品图片 //保留此不带参数的构造方法 public Items(){ } //不带参数的构造方法 public Items(int id,String name,String city,int price,int number,String picture){ this.id = id; this.name = name; this.city = city; this.picture = picture; this.price = price; this.number = number; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getCity() { return city; } public void setCity(String city) { this.city = city; } public int getPrice() { return price; } public void setPrice(int price) { this.price = price; } public int getNumber() { return number; } public void setNumber(int number) { this.number = number; } public String getPicture() { return picture; } public void setPicture(String picture) { this.picture = picture; } @Override public int hashCode() { return this.getId()+this.getName().hashCode(); } @Override public boolean equals(Object obj) { if(this==obj){ return true; } if(obj instanceof Items){ Items i = (Items)obj; if(this.getId()==i.getId()&&this.getName().equals(i.getName())){ return true; }else{ return false; } }else{ return false; } } @Override public String toString(){ return "商品编号:"+this.getId()+",商品名称:"+this.getName(); } }
一个是Cart.java
package com.entity; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.Set; /** * 购物车实体类(添加、删除和计算价格) * @author Administrator * @date 2016年08月01日 */ public class Cart { //购买商品的集合 private HashMap<Items,Integer> goods; //购物车的总金额 private double totalPrice; //构造方法 public Cart(){ goods = new HashMap<Items,Integer>(); totalPrice = 0.0; } public HashMap<Items, Integer> getGoods() { return goods; } public void setGoods(HashMap<Items, Integer> goods) { this.goods = goods; } public double getTotalPrice() { return totalPrice; } public void setTotalPrice(double totalPrice) { this.totalPrice = totalPrice; } //添加商品进购物车的方法 public boolean addGoodsInCart(Items item ,int number){ if(goods.containsKey(item)){ goods.put(item, goods.get(item)+number); }else{ goods.put(item, number); } calTotalPrice(); //重新计算购物车的总金额 return true; } //删除商品的方法 public boolean removeGoodsFromCart(Items item){ goods.remove(item); calTotalPrice(); //重新计算购物车的总金额 return true; } //统计购物车的总金额 public double calTotalPrice(){ double sum = 0.0; Set<Items> keys = goods.keySet(); //获得键的集合 Iterator<Items> it = keys.iterator(); //获得迭代器对象 while(it.hasNext()){ Items i = it.next(); sum += i.getPrice()* goods.get(i); } this.setTotalPrice(sum); //设置购物车的总金额 return this.getTotalPrice(); } public static void main(String[] args) { //先创建两个商品对象 Items i1 = new Items(1,"沃特篮球鞋","温州",200,500,"001.jpg"); Items i2 = new Items(2,"李宁运动鞋","广州",300,500,"002.jpg"); Items i3 = new Items(1,"沃特篮球鞋","温州",200,500,"001.jpg"); Cart cart = new Cart(); cart.addGoodsInCart(i1, 1); cart.addGoodsInCart(i2, 2); //再次购买沃特篮球鞋,购买3双 cart.addGoodsInCart(i3, 3); //遍历购物车商品的集合 Set<Map.Entry<Items, Integer>> items= cart.getGoods().entrySet(); for(Map.Entry<Items, Integer> obj:items){ System.out.println(obj); } System.out.println("购物车的总金额:"+cart.getTotalPrice()); } }
接下来是dao层ItemsDAO.java
package com.dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.util.ArrayList; import com.util.DBHelper; import com.entity.Items; /** * 商品的业务逻辑类 * @author Administrator * @date 2016年08月01日 */ public class ItemsDAO { // 获得所有的商品信息 public ArrayList<Items> getAllItems() { Connection conn = null;//数据库连接对象 PreparedStatement stmt = null;//SQL语句对象 ResultSet rs = null;//数据集对象 ArrayList<Items> list = new ArrayList<Items>(); // 商品集合 try { conn = DBHelper.getConnection(); String sql = "select * from items;"; // 查询SQL语句 stmt = conn.prepareStatement(sql); rs = stmt.executeQuery();//获取数据集 while (rs.next()) { Items item = new Items(); item.setId(rs.getInt("id")); item.setName(rs.getString("name")); item.setCity(rs.getString("city")); item.setNumber(rs.getInt("number")); item.setPrice(rs.getInt("price")); item.setPicture(rs.getString("picture")); list.add(item);// 把一个商品加入集合 } return list; // 返回集合。 } catch (Exception e) { e.printStackTrace(); return null; } finally { // 释放数据集对象 if (rs != null) { try { rs.close(); rs = null; } catch (Exception e) { e.printStackTrace(); } } // 释放SQL语句对象 if (stmt != null) { try { stmt.close(); stmt = null; } catch (Exception e) { e.printStackTrace(); } } } } // 根据商品编号ID获得商品详细资料 public Items getItemsById(int id) { Connection conn = null; PreparedStatement stmt = null; ResultSet rs = null; try { conn = DBHelper.getConnection(); String sql = "select * from items where id=?;"; // SQL查询语句 stmt = conn.prepareStatement(sql); //把id的值赋给SQL查询语句中第一个问号 stmt.setInt(1, id); rs = stmt.executeQuery(); if (rs.next()) { Items item = new Items(); item.setId(rs.getInt("id")); item.setName(rs.getString("name")); item.setCity(rs.getString("city")); item.setNumber(rs.getInt("number")); item.setPrice(rs.getInt("price")); item.setPicture(rs.getString("picture")); return item; } else { return null; } } catch (Exception e) { e.printStackTrace(); return null; } finally { // 释放数据集对象 if (rs != null) { try { rs.close(); rs = null; } catch (Exception e) { e.printStackTrace(); } } // 释放语句对象 if (stmt != null) { try { stmt.close(); stmt = null; } catch (Exception e) { e.printStackTrace(); } } } } //获取最近浏览的前五条商品信息 public ArrayList<Items> getViewList(String list){ System.out.println("list:"+list); ArrayList<Items> itemlist = new ArrayList<Items>(); int iCount=5; //每次返回前五条记录 if(list!=null&&list.length()>0){ String[] arr = list.split(","); System.out.println("arr.length="+arr.length); //如果商品记录大于等于5条 if(arr.length>=5){ for(int i=arr.length-1;i>=arr.length-iCount;i--){ itemlist.add(getItemsById(Integer.parseInt(arr[i]))); } }else{ for(int i=arr.length-1;i>=0;i--){ itemlist.add(getItemsById(Integer.parseInt(arr[i]))); } } return itemlist; }else{ return null; } } }
最后是Servlet控制层中的CartServlet:
package com.servlet; import java.io.IOException; import javax.servlet.ServletConfig; 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 com.dao.ItemsDAO; import com.entity.Cart; import com.entity.Items; /** * Servlet implementation class CarServlet */ @WebServlet(name="CartServlet" ,urlPatterns={"/CartServlet"}) public class CartServlet extends HttpServlet { private static final long serialVersionUID = 1L; private String action;//表示购物车动作:add,show,delete private ItemsDAO idao = new ItemsDAO();//商品业务逻辑类对象 /** * @see HttpServlet#HttpServlet() */ public CartServlet() { super(); // TODO Auto-generated constructor stub } /** * @see Servlet#init(ServletConfig) */ public void init(ServletConfig config) throws ServletException { // TODO Auto-generated method stub } /** * @see Servlet#destroy() */ public void destroy() { // TODO Auto-generated method 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){ this.action = request.getParameter("action"); //添加商品进购物车 if(action.equals("add")) { if(addToCart(request,response)){ request.getRequestDispatcher("/success.jsp").forward(request, response); }else{ request.getRequestDispatcher("/failure.jsp").forward(request, response); } } //显示购物车 if(action.equals("show")){ request.getRequestDispatcher("/cart.jsp").forward(request, response); } //如果是执行删除购物车中的商品 if(action.equals("delete")) { if(deleteFromCart(request,response)){ 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)); //是否是第一次给购物车添加商品,需要给session中创建一个新的购物车对象 if(request.getSession().getAttribute("cart") == null){ Cart cart = new Cart(); request.getSession().setAttribute("cart",cart); } //不是第一次添加进购物车 Cart cart = (Cart)request.getSession().getAttribute("cart"); if(cart.addGoodsInCart(item, Integer.parseInt(number))){ return true; }else{ return false; } } //从购物车中删除商品 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.removeGoodsFromCart(item)){ return true; }else{ return false; } } }
再来视图层:
商品列表页面index.jsp
<%@page import="com.entity.Items"%> <%@page import="com.dao.ItemsDAO"%> <%@page import="java.util.ArrayList"%> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>商品列表页面</title> <style type="text/css"> hr{ border-color:FF7F00; } div{ float:left; margin: 10px; } div dd{ margin:0px; font-size:10pt; } div dd.dd_name{ color:blue; } div dd.dd_city{ color:#000; } </style> </head> <body> <h1>商品展示</h1> <hr> <center> <table width="750" height="60" cellpadding="0" cellspacing="0" border="0"> <tr> <td> <!-- 商品循环开始 --> <% //防止中文乱码 request.setCharacterEncoding("UTF-8"); ItemsDAO itemsDao = new ItemsDAO(); ArrayList<Items> list = itemsDao.getAllItems(); if(list!=null&&list.size()>0){ for(int i=0;i<list.size();i++){ Items item = list.get(i); %> <div> <dl> <dt> <a href="details.jsp?id=<%=item.getId()%>"> <img src="images/<%=item.getPicture()%>" width="120" height="90" border="1"/> </a> </dt> <dd class="dd_name"><%=item.getName() %></dd> <dd class="dd_city">产地:<%=item.getCity() %> 价格:¥ <%=item.getPrice() %></dd> </dl> </div> <!-- 商品循环结束 --> <% } } %> </td> </tr> </table> </center> </body> </html>
商品详情页面details.jsp
<%@page import="java.util.ArrayList"%> <%@ page import="com.entity.Items"%> <%@ page import="com.dao.ItemsDAO"%> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>商品详情页面</title> <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%>/CartServlet?id=‘+id+‘&num=‘+num+‘&action=add‘, cover:true}); } //商品数量增加 function add() { var num = parseInt(document.getElementById("number").value); if (num < 100) { document.getElementById("number").value = ++num; } } //商品数量减少 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="4"><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="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(); } } } //追加商品编号 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>您浏览过的商品</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>
购买成功页面success.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>购买成功页面</title> </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>
购买失败页面failure.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>购买失败页面</title> </head> <body> <center> <img src="images/add_cart_failure.jpg"/> <hr> <br> <br> <br> </center> </body> </html>
购物车页面cart.jsp
<%@page import="java.util.Iterator"%> <%@page import="java.util.Set"%> <%@page import="com.entity.Items"%> <%@page import="java.util.HashMap"%> <%@page import="com.entity.Cart"%> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>购物车页面</title> <link type="text/css" rel="stylesheet" href="css/style1.css" /> <script type="text/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="post"> <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 --> <% Cart cart = (Cart)request.getSession().getAttribute("cart"); HashMap<Items,Integer> goods = cart.getGoods(); 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)%></td> <td class="delete"><a href="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>
项目运行结果:
商品列表:
选择一个商品进入商品详情:
选择好数量,加入到购物车中:
查看购物车:
Java Web学习(33): 阶段小项目使用MVC模型实现购物车效果
原文:http://blog.csdn.net/erlian1992/article/details/52132486