JavaWeb购物车项目如何开发
JavaWeb购物车项目如何开发
发布时间：2022-06-16 10:05:18 来源：高防服务器网 阅读：93 作者：iii 栏目：开发技术
这篇文章主要介绍“JavaWeb购物车项目如何开发”，在日常操作中，相信很多人在JavaWeb购物车项目如何开发问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答”JavaWeb购物车项目如何开发”的疑惑有所帮助！接下来，请跟着小编一起来学习吧！
一、项目前提
1、购物车并不是一直放数据库
2、选择使用的技术：
session：（购物车项目使用session）
好处:快(放在内存当中)，存对象的
坏处:占用内存，服务器意外待机数据会丢失cookie
好处：不占用内存，存储很久
坏处：存在客户端上，只能存String,数据有泄露的风险
二、数据库的创建
用户表
create table shop_user ( id number primary key,--用户id account varchar2(30) not null,--用户账户 password varchar2(30)not null--用户密码 );
商品表
create table shop_goods( id number primary key,--商品id name varchar2(50) not null,--商品名称 price number default 0.0,--商品价格 info varchar2(255) default '三五产品' not null--商品介绍 );
三、eclipse进行创建包和类：
com.zking.util 帮助类com.zking.pojo 实体类com.zking.dao（放dao接口）com.zking.dao.imp (放dao接口实现类)com.zking.biz （业务逻辑层放dao方法）com.zking.biz.imp（业务逻辑层放dao实现类） com.zking.vo (view object 视图对象 前端用)
四、主要实现功能
1、购物车用户登录
login.jsp
界面效果
代码如下：
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html lang="zh"> <head> <meta charset="UTF-8"> <title>Document</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="${pageContext.request.contextPath}/bootstrap-3.3.7-dist/css/bootstrap.css" rel="external nofollow" rel="external nofollow" > <script src="${pageContext.request.contextPath}/bootstrap-3.3.7-dist/js/jquery-3.5.1.js"></script> <script src="${pageContext.request.contextPath}/bootstrap-3.3.7-dist/js/bootstrap.js"></script> <style> * { outline: none !important; } html, body { background: #1abe9c; } form { width: 300px; background: #ebeff2; box-shadow: 0px 0px 50px rgba(0, 0, 0, .5); border-radius: 5px; padding: 20px; position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%); } .btn-group { width: 100%; } .btn-group button { width: 50%; } </style> </head> <body> <form action="doLogin.jsp" method="post"> <h4 class="text-center" >欢迎光临苡桉超市</h4> <div class="form-group"> <input name="account" type="text" class="form-control" placeholder="请输入您的用户名"> </div> <div class="form-group"> <input name="password" type="password" class="form-control" placeholder="请输入您的密码"> </div> <div class="btn-group"> <button type="submit" class="btn btn-primary">登录</button> <button type="button" class="btn btn-danger">没有账号?</button> </div> </form> </body> </html>
doLogin.jsp(处理登录界面)
<%@page import="com.zking.vo.CarItem"%> <%@page import="java.util.ArrayList"%> <%@page import="java.util.List"%> <%@page import="com.zking.pojo.User"%> <%@page import="com.zking.biz.impl.UserBizImpl"%> <%@page import="com.zking.biz.IUserBiz"%> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <% request.setCharacterEncoding("UTF-8"); String account=request.getParameter("account"); String password=request.getParameter("password"); IUserBiz userBiz=new UserBizImpl(); User user=userBiz.login(new User(0,account,password)); if(user==null){ response.sendRedirect("login.jsp"); }else{ //首页需要登录数据 session.setAttribute("user",user); //分配购物车 List<CarItem>car=new ArrayList<>(); //放到session中（把购物车给我） session.setAttribute("car", car); response.sendRedirect("index.jsp"); } %>
用户实体类User.java
package com.zking.pojo; public class User { private Integer id; private String account; private String password; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getAccount() { return account; } public void setAccount(String account) { this.account = account; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public User(Integer id, String account, String password) { super(); this.id = id; this.account = account; this.password = password; } public User() { super(); } @Override public String toString() { return "User [id=" + id + ", account=" + account + ", password=" + password + "]"; } }
IUserBiz.java (用户逻辑接口)
package com.zking.biz; import com.zking.pojo.User; /** * 用户逻辑接口 * @author zjjt * */ public interface IUserBiz { User login(User user); }
UserBizImpl.java (用户逻辑接口实现类)
package com.zking.biz.impl; import com.zking.biz.IUserBiz; import com.zking.dao.IUserDao; import com.zking.dao.impl.UserDaoImpl; import com.zking.pojo.User; /** * 用户逻辑接口实现类 * @author zjjt * */ public class UserBizImpl implements IUserBiz{ private IUserDao userDao=new UserDaoImpl(); @Override public User login(User user) { User u = userDao.login(user); if(u!=null) { if(u.getPassword().equals(user.getPassword())) { return u; } } return null; } }
IUserDao.java（用户数据访问接口）
package com.zking.dao; import com.zking.pojo.User; /** * 用户数据访问接口 * @author zjjt * */ public interface IUserDao { User login(User user); }
UserDaoImpl.java（用户数据访问接口实现类）
package com.zking.dao.impl; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.util.List; import com.zking.dao.IUserDao; import com.zking.pojo.User; import com.zking.util.DBHelper; public class UserDaoImpl implements IUserDao { private Connection con; private PreparedStatement ps; private ResultSet rs; @Override public User login(User user) { try { con=DBHelper.getCon(); ps=con.prepareStatement("select * from shop_user where account=?"); ps.setString(1,user.getAccount()); rs=ps.executeQuery(); if(rs.next()) { User u=new User(); u.setId(rs.getInt(1)); u.setAccount(rs.getString(2)); u.setPassword(rs.getString(3)); return u; } } catch (Exception e) { e.printStackTrace(); }finally { DBHelper.close(con, ps, rs); } return null; } }
2、商品显示
实现效果如下：
将数据库存放的数据显示在页面上，尊贵的xxx通过session拿到登录的用户名
Goods.java（商品实体类）
package com.zking.pojo; public class Goods { private Integer id; private String name; private Integer price; private String info; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getPrice() { return price; } public void setPrice(Integer price) { this.price = price; } public String getInfo() { return info; } public void setInfo(String info) { this.info = info; } public Goods(Integer id, String name, Integer price, String info) { super(); this.id = id; this.name = name; this.price = price; this.info = info; } public Goods() { super(); } @Override public String toString() { return "Goods [id=" + id + ", name=" + name + ", price=" + price + ", info=" + info + "]"; } }
index.jsp（首页代码）
<%@page import="com.zking.pojo.Goods"%> <%@page import="com.zking.biz.impl.GoodsBizImpl"%> <%@page import="com.zking.biz.IGoodsBiz"%> <%@page import="com.zking.pojo.User"%> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html lang="zh"> <head> <meta charset="UTF-8"> <title>Document</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="${pageContext.request.contextPath}/bootstrap-3.3.7-dist/css/bootstrap.css" rel="external nofollow" rel="external nofollow" > <script src="${pageContext.request.contextPath}/bootstrap-3.3.7-dist/js/jquery-3.5.1.js"></script> <script src="${pageContext.request.contextPath}/bootstrap-3.3.7-dist/js/bootstrap.js"></script> <style> td:nth-child(3)::before{ content: "$"; } </style> </head> <body> <% Object obj=session.getAttribute("user"); if(obj==null){ response.sendRedirect("login.jsp"); return; } %> <div class="jumbotron"> <div class="container"> <h2>欢迎光临苡桉SuperMarket</h2> <p>尊贵的<%=((User)obj).getAccount() %></p> </div> </div> <%=session.getAttribute("car")%> <div class="container"> <table class="table"> <tr> <th>商品序号</th> <th>商品名称</th> <th>商品单价</th> <th>商品描述</th> <th>操作</th> </tr> <% IGoodsBiz goodsBiz=new GoodsBizImpl(); for(Goods goods:goodsBiz.getAll()){ %> <tr> <td><%=goods.getId() %></td> <td><%=goods.getName() %></td> <td><%=goods.getPrice() %></td> <td><%=goods.getInfo() %></td> <td> <div class="btn-group btn-group-xs"> <a href="doAddCar.jsp?id=<%=goods.getId() %>" rel="external nofollow" class="btn btn-primary">添加购物车</a> </div> </td> </tr> <% } %> </table> </div> </body> </html>
IGoodsBiz.java (商品逻辑接口)
package com.zking.biz; import java.util.List; import com.zking.pojo.Goods; /** * 商品逻辑接口 * @author zjjt * */ public interface IGoodsBiz { List<Goods>getAll(); //查询单个 Goods getOne(Integer id); }
GoodsBizImpl.java (商品逻辑接口实现类)
package com.zking.biz.impl; import java.util.List; import com.zking.biz.IGoodsBiz; import com.zking.dao.IGoodsDao; import com.zking.dao.impl.GoodsDaoImpl; import com.zking.pojo.Goods; /** * 商品逻辑接口实现类 * @author zjjt * */ public class GoodsBizImpl implements IGoodsBiz { private IGoodsDao goodsDao=new GoodsDaoImpl(); @Override public List<Goods> getAll() { return goodsDao.getAll(); } @Override public Goods getOne(Integer id) { return goodsDao.getOne(id); } }
IGoodsDao.java (商品数据访问接口)
package com.zking.dao; import java.util.List; import com.zking.pojo.Goods; /** * 商品数据访问接口 * @author zjjt * */ public interface IGoodsDao { //查询所有 List<Goods>getAll(); //查询单个 Goods getOne(Integer id); }
GoodsDaoImpl.java (商品数据访问接口实现类)
package com.zking.dao.impl; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.util.ArrayList; import java.util.List; import com.zking.dao.IGoodsDao; import com.zking.pojo.Goods; import com.zking.pojo.User; import com.zking.util.DBHelper; /** * 访问数据接口实现类 * @author zjjt * */ public class GoodsDaoImpl implements IGoodsDao{ private Connection con; private PreparedStatement ps; private ResultSet rs; /** * 查询全部商品 */ @Override public List<Goods> getAll() { List<Goods>list=new ArrayList<Goods>(); try { con=DBHelper.getCon(); ps=con.prepareStatement("select * from shop_goods "); rs=ps.executeQuery(); while(rs.next()) { Goods goods=new Goods(); goods.setId(rs.getInt(1)); goods.setName(rs.getString(2)); goods.setPrice(rs.getInt(3)); goods.setInfo(rs.getString(4)); list.add(goods); } return list; } catch (Exception e) { e.printStackTrace(); }finally { DBHelper.close(con, ps, rs); } return list; } /** * 根据id查询商品 */ @Override public Goods getOne(Integer id) { try { con=DBHelper.getCon(); ps=con.prepareStatement("select * from shop_goods where id=? "); ps.setInt(1, id); rs=ps.executeQuery(); if(rs.next()) { Goods goods=new Goods(); goods.setId(rs.getInt(1)); goods.setName(rs.getString(2)); goods.setPrice(rs.getInt(3)); goods.setInfo(rs.getString(4)); return goods; } } catch (Exception e) { e.printStackTrace(); }finally { DBHelper.close(con, ps, rs); } return null; } }
3、购物车添加&商品总数和价格的计算
doAddCar.java(处理添加购物车的页面)
<%@page import="java.util.List"%> <%@page import="com.zking.biz.impl.GoodsBizImpl"%> <%@page import="com.zking.biz.IGoodsBiz"%> <%@page import="com.zking.vo.CarItem"%> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <% //添加购物车的页面 //拿购物车 List<CarItem>car=(List<CarItem>)session.getAttribute("car"); IGoodsBiz goodsBiz=new GoodsBizImpl(); //1、得知道是那件商品 String str=request.getParameter("id"); int id=-1; if(str!=null){ id=Integer.parseInt(str); } //2-1 判断该商品是否存在 boolean f=true; for(CarItem item:car){ //item.getGoods().getId() 条目的商品id if(id==item.getGoods().getId()){ //商品应该是已经被添加了[购物车中某个条目的商品id和你需要添加的商品id相同了] item.setCount(item.getCount()+1);//数量+1 item.setSum(item.getCount()*item.getGoods().getPrice()); f=false; break; } } //只要判断f是否发生了改变 if(f){ //2-2、生成一个CarItem[如果购物车没有该商品] CarItem carItem=new CarItem(); //设置对应的商品数据 carItem.setGoods(goodsBiz.getOne(id)); //数量 carItem.setCount(1); //加车数量*商品单价 //carItem.getCount()商品加车的数量 //carItem.getGoods().getPrice() 商品的单价 carItem.setSum(carItem.getCount()*carItem.getGoods().getPrice()); //将购物条目carItem 绑定到购物车 car.add(carItem); } //更新购物车 session.setAttribute("car", car); //跳回首页 response.sendRedirect("index.jsp"); %>
CarItem.java（购物车中的每一项，每一个条目）
package com.zking.vo; import com.zking.pojo.Goods; /** * 购物车中的每一项，每一个条目 * @author zjjt * */ public class CarItem { private Integer count;//数量 private Integer sum;//条目总价 private Goods goods;//对应的商品 public Integer getCount() { return count; } public void setCount(Integer count) { this.count = count; } public Integer getSum() { return sum; } public void setSum(Integer sum) { this.sum = sum; } public Goods getGoods() { return goods; } public void setGoods(Goods goods) { this.goods = goods; } public CarItem(Integer count, Integer sum, Goods goods) { super(); this.count = count; this.sum = sum; this.goods = goods; } public CarItem() { // TODO Auto-generated constructor stub } @Override public String toString() { return "CarItem [count=" + count + ", sum=" + sum + ", goods=" + goods + "]"; } }
效果先简单打印到页面 之后会进行修改
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