JavaWeb 购物车项目

今天是基于我们所学的服务器存储端和三层架构来完善该项目，今天先完善一部分的功能。

一.购物车项目思路

1.登录

• 先创建一个用户表，表中有id,name,pwd三个属性首。
• 需要具备一个登录页面，一个处理登录数据的页面，在该页面进行判断，当该用户存在，我们跳转到商城，用户不存在回到登录界面。

2.商城

• 创建一张商品表
• 当登录成功以后跳转到商城页面，商城有商品显示，商品数据来自于商品表中的数据。
• 点击加入购物车，如果点击加入的商品在购物车中存在的话，只增加商品数量，而不会在显示一条该商品数据。
• 点击加入购物车时携带商品id跳转到处理购物车数据的页面，我们把购物车中的数据存在session中。

**3.购物车 **

• 购物车今天我们只做从session中把数据拿出来，显示在页面上，可以把总价计算出来，其他功能在下一篇文章给大家讲解

二.项目的文件路径展示

** biz **: 存放业务逻辑层的接口
** biz.impl : 存放业务逻辑层的实现类
** dao : 存放数据访问层的接口
** dao.impl **: 存放数据访问层的实现

三.项目代码展示

1.ulit包下DBHeper类代码展示

作用:连接数据库oracle

package com.yjx.ulit;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

import oracle.jdbc.driver.OracleDriver;

public class DBHeper {
  static {
      try {
          Class.forName("oracle.jdbc.driver.OracleDriver");
    } catch (Exception e) {
          e.printStackTrace();
    }
      
  }
  
  private static final String URL="jdbc:oracle:thin:@localhost:1521:orcl";
  
  public static Connection getCon() {
      try {
     return    DriverManager.getConnection(URL,"scott","zking123");
    } catch (Exception e) {
        e.printStackTrace();
    }
      return null;
  }
  
  public static void getColes(Connection con,PreparedStatement ps,ResultSet rs) {
      try {
          if(con!=null&&!con.isClosed())con.close();
          if(ps!=null)ps.close();
          if(rs!=null)rs.close();
    } catch (Exception e) {
         e.printStackTrace();
    } 
      
  }
}

2.pojo包下方的实体类

user:用户实体类

package com.yjx.pojo;

public class User {
  private int id;
  private String name;
  private String pwd;
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 getPwd() {
    return pwd;
}
public void setPwd(String pwd) {
    this.pwd = pwd;
}
  
  
public User() {
    
}

public User(int id, String name, String pwd) {
    super();
    this.id = id;
    this.name = name;
    this.pwd = pwd;
}

@Override
public String toString() {
    return "User [id=" + id + ", name=" + name + ", pwd=" + pwd + "]";
}

}

shop：商品实体类

package com.yjx.pojo;

public class Shop {
   private int id;
   private String name;
   private Double price;
   private String text;
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 Double getPrice() {
    return price;
}
public void setPrice(Double price) {
    this.price = price;
}
public String getText() {
    return text;
}
public void setText(String text) {
    this.text = text;
}

public Shop(int id, String name, Double price, String text) {
    super();
    this.id = id;
    this.name = name;
    this.price = price;
    this.text = text;
}
   
   public Shop() {
    
}
   
@Override
public String toString() {
    return "Shop [id=" + id + ", name=" + name + ", price=" + price + ", text=" + text + "]";
}
   
   
   
}

3.vo包下购物车的实体类

package com.yjx.vo;

public class Car {
    private Integer id;
    private String name;
    private Integer count;
    private Double sum;
    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 getCount() {
        return count;
    }
    public void setCount(Integer count) {
        this.count = count;
    }
    public Double getSum() {
        return sum;
    }
    public void setSum(Double sum) {
        this.sum = sum;
    }
    @Override
    public String toString() {
        return "Car [id=" + id + ", name=" + name + ", count=" + count + ", sum=" + sum + "]";
    }
    public Car(Integer id, String name, Integer count, Double sum) {
        super();
        this.id = id;
        this.name = name;
        this.count = count;
        this.sum = sum;
    }
    
    public Car() {
        // TODO Auto-generated constructor stub
    }
    
    
}

4.数据访问层

** user的数据访问层**:** dao** : 存放数据访问层的接口(IUserDao)
** dao.impl **: 存放数据访问层的实现类(UserDaoImpl)

dao : 存放数据访问层的接口(IUserDao)

package com.yjx.dao;

import java.util.List;

import com.yjx.pojo.Shop;
import com.yjx.pojo.User;

public interface IUserDao {
   //登录方法
   User login(User u);
 
}

** dao.impl **: 存放数据访问层的实现类(UserDaoImpl)

package com.yjx.dao.impl;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import com.yjx.dao.IUserDao;
import com.yjx.pojo.Shop;
import com.yjx.pojo.User;
import com.yjx.ulit.DBHeper;

public class UserDaoimpl implements IUserDao{
        
    private Connection con;
    private PreparedStatement ps;
    private ResultSet rs;
    
    /**
     * 登录方法
     */
  
    public User login(User u) {
        try {
            con=DBHeper.getCon();
            ps=con.prepareStatement("select * from shop_user where uname=?");
            ps.setString(1,u.getName());
            rs=ps.executeQuery();
            if(rs.next()) {
            User user=new User();
            user.setId(rs.getInt(1));
            user.setName(rs.getString(2));
            user.setPwd(rs.getString(3));
            return user;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            DBHeper.getColes(con, ps, rs);
        }
        return null;
    }

}

** shop的数据访问层**:** dao** : 存放数据访问层的接口(IShopDao)
** dao.impl **: 存放数据访问层的实现类(ShoprDaoImpl)

dao : 存放数据访问层的接口(IShopDao)

package com.yjx.dao;

import java.util.List;

import com.yjx.pojo.Shop;

public interface IShopDao {
   //查询数据库中商品表中的所有数据
    List<Shop> select();
    
    //根据id查询数据

    Shop selectId(int id);
}

**dao.impl **: 存放数据访问层的实现类(ShoprDaoImpl)

package com.yjx.dao.impl;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import com.yjx.dao.IShopDao;
import com.yjx.pojo.Shop;
import com.yjx.ulit.DBHeper;

public class ShopDaoImpl implements IShopDao {
   private Connection con;
   private PreparedStatement ps;
   private ResultSet rs;

    public List<Shop> select() {
     List<Shop> list=new ArrayList();
     try {
        con=DBHeper.getCon();
        ps=con.prepareStatement("select * from shop");
        rs=ps.executeQuery();
        while(rs.next()) {
            Shop s=new Shop();
            s.setId(rs.getInt(1));
            s.setName(rs.getString(2));
            s.setPrice(rs.getDouble(3));
            s.setText(rs.getString(4));
            list.add(s);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }finally {
        DBHeper.getColes(con, ps, rs);
    }
         
        return list;
    }
    
    @Override
        public Shop selectId(int id) {
    
         try {
            con=DBHeper.getCon();
            ps=con.prepareStatement("select * from shop where sidd=?");
            ps.setInt(1, id);
            rs=ps.executeQuery();
            if(rs.next()) {
                Shop s=new Shop();
                s.setId(rs.getInt(1));
                s.setName(rs.getString(2));
                s.setPrice(rs.getDouble(3));
                s.setText(rs.getString(4));
                return s;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            DBHeper.getColes(con, ps, rs);
        }
             
            return null;
        }
}

5.业务逻辑层

user业务逻辑层： biz : 存放业务逻辑层的接口（IUserBiz）

** biz.imp**l : 存放业务逻辑层的实现类（UserBizImpl）

** biz** : 存放业务逻辑层的接口（IUserBiz）

package com.yjx.biz;

import com.yjx.pojo.User;

public interface IUserBiz {
    //登录方法
      User login(User u);

}

biz.impl : 存放业务逻辑层的实现类（UserBizImpl）

package com.yjx.biz.impl;

import com.yjx.biz.IUserBiz;
import com.yjx.dao.IUserDao;
import com.yjx.dao.impl.UserDaoimpl;
import com.yjx.pojo.User;

public class UserBizImpl implements IUserBiz{
    
    IUserDao dao=new UserDaoimpl();
 /**
  * 登录方法
  */
public User login(User u) {
    User user=dao.login(u);
    //当用户不为空
    if(user!=null) {
    if(user.getPwd().equals(u.getPwd())) {
        return user;
    }
    }
     return null;
}
}

shop业务逻辑层： biz : 存放业务逻辑层的接口（IShopBiz）

** biz.imp**l : 存放业务逻辑层的实现类（ShopBizImpl）

** biz** : 存放业务逻辑层的接口（IShopBiz

package com.yjx.biz;

import java.util.List;

import com.yjx.pojo.Shop;

public  interface IShopBiz {
 
    //查询数据库中商品表中的所有数据
    List<Shop> select();
    
    //根据id查询数据
    Shop selectId(int id);
}

biz.impl : 存放业务逻辑层的实现类（ShopBizImpl）

package com.yjx.biz.impl;

import java.util.List;

import com.yjx.biz.IShopBiz;
import com.yjx.dao.IShopDao;
import com.yjx.dao.impl.ShopDaoImpl;
import com.yjx.pojo.Shop;

public class ShopBizImpl implements IShopBiz{
  
     IShopDao dao=new ShopDaoImpl();
     /*
      *查询商品表的所有数据 
      */
     @Override
    public List<Shop> select() {
        List<Shop> list=dao.select();
        return list;
    }
     /**
      * 根据id查询数据
      */
    
    public Shop selectId(int id) {
        Shop s=dao.selectId(id);
        return s;
    }
}

6.登录界面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<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="${pageContext.request.contextPath}/bootstrap-3.3.7-dist/css/bootstrap.css">
    <script src="${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">
        <h3 class="text-center" style="text-shadow: 2px 2px 1px #ed3f3f;">欢迎光临胡阿玛超市</h3>
        <div class="form-group">
            <input name="username" type="text" class="form-control" placeholder="请输入您的用户名">
        </div>
        <div class="form-group">
            <input name="userpwd" 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>

7.处理登录数据页面

<%@page import="java.util.ArrayList"%>
<%@page import="com.yjx.pojo.Shop"%>
<%@page import="java.util.List"%>
<%@page import="com.yjx.pojo.User"%>
<%@page import="com.yjx.biz.impl.UserBizImpl"%>
<%@page import="com.yjx.biz.IUserBiz"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>

 <%
  //接收数据
   String name=request.getParameter("username");
   String pwd=request.getParameter("userpwd");
     //实例一个用户，得到一个用户
     User u=new User(1,name,pwd);
     
     IUserBiz userbiz=new UserBizImpl();
     //调用登录方法，得到一个用户
     User user=userbiz.login(u);
     
     //判断该用户是否存在
     if(user!=null){
         //将用户存入session中
         session.setAttribute("user",user);
         
         List<Shop> list=new ArrayList();
         //将购物车存入session中
         session.setAttribute("list",list);
         //跳转到首页
         response.sendRedirect("index.jsp");
     }else{
         //当用户为空不存在，回到登录界面
         response.sendRedirect("login.jsp");
     }
      
 %>

8.商城首页

<%@page import="com.yjx.vo.Car"%>
<%@page import="java.util.List"%>
<%@page import="com.yjx.pojo.Shop"%>

<%@page import="com.yjx.biz.impl.ShopBizImpl"%>
<%@page import="com.yjx.biz.IShopBiz"%>
<%@page import="com.yjx.pojo.User"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<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="${pageContext.request.contextPath}/bootstrap-3.3.7-dist/css/bootstrap.css">
    <script src="${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>

<%
 Object obj=session.getAttribute("user");
if(obj==null){
    response.sendRedirect("/login.jsp");
    return;
  }
%>
<body>
    <div class="jumbotron">
        <div class="container">
            <h1>欢迎光临胡阿玛SuperMarket</h1>
            <!-- 强转成一个用户，拿到用户名字 -->
            <p>尊贵的<%=((User)obj).getName()%></p>
            <a href="car.jsp">购物车</a>
        </div>
    </div>
    <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>
        <%
       
         IShopBiz shop=new ShopBizImpl();
       
         //获得一个集合
          List<Shop>list=shop.select();
         //遍历数据
          for(Shop s:list){
   %>
        <tr>
            <td><%=s.getId() %></td>
            <td><%=s.getName() %></td>
            <td><%=s.getPrice() %></td>
            <td><%=s.getText() %></td>
            <td>
                <div class="btn-group btn-group-xs">
                <!-- 当点击了加入购物车将数商品的id传过去 -->
                    <a class="btn btn-primary" href="${pageContext.request.contextPath}/doShop.jsp?id=<%=s.getId()%>">添加购物车</a>
                </div>
            </td>
        </tr>
        <%
          }
        %>
    </table>
</body></html>

9.购物车数据处理页面

<%@page import="com.yjx.vo.Car"%>
<%@page import="java.util.List"%>
<%@page import="com.yjx.biz.impl.ShopBizImpl"%>
<%@page import="com.yjx.biz.IShopBiz"%>
<%@page import="com.yjx.pojo.Shop"%>
<%@page import="com.yjx.dao.impl.ShopDaoImpl"%>
<%@page import="com.yjx.dao.IShopDao"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%

  List<Car> list=(List<Car>)session.getAttribute("list");
   //接收到传过来的数据
   String str=request.getParameter("id");
   
   //判断当在首页点击加入购物车时，已经存在购物车中的商品，只在数量上面新增
   int id=-1;
   if(str!=null){
       id=Integer.parseInt(str);
   }
    
   boolean f=true;
    //遍历集合
    for(Car c:list){
        if(c.getId()==id){
            //数量+1
          c.setCount(c.getCount()+1);
          //总价
          c.setSum(c.getSum()*c.getCount());
          f=false;
          break;
        }
    }
   
    if(f){
   IShopBiz sbiz=new ShopBizImpl();
   Shop s=sbiz.selectId(id);
   
   //将数据加入购物车中
   Car car=new Car();
   //id
   car.setId(s.getId());
   car.setName(s.getName());
   car.setCount(1);
   //总价
   car.setSum(s.getPrice()*car.getCount());
   list.add(car);
   
    }
   //更新购物车
   session.setAttribute("list",list);
   //跳回首页
   response.sendRedirect("index.jsp");
      
%>

10.购物车页面

<%@page import="com.yjx.vo.Car"%>
<%@page import="java.util.List"%>
<%@page import="com.yjx.pojo.User"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>购物车</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="${pageContext.request.contextPath}/bootstrap-3.3.7-dist/css/bootstrap.css">
    <script src="${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;
        }

        td,
        th {
            text-align: center;
        }

        input {
            text-align: center;
        }
        
    </style>
</head>

 <%
   Object obj=session.getAttribute("user");
 
 %>
<body>
    <div class="jumbotron">
        <div class="container">
            <h1>欢迎光临胡阿玛购物车🛒</h1>
            <p>尊贵的<%=((User)obj).getName()%></p>
        </div>
    </div>
     <a href="index.jsp" >商城</a>
    <table class="table">
        <tr>
            <th>商品序号</th>
            <th>商品名称</th>
            <th>商品个数</th>
            <th>商品总价</th>
            <th>操作</th>
        </tr>
        <%
         List<Car> list=(List<Car>)session.getAttribute("list");
         Double sum=0.00;
        //遍历
        for(Car c:list){
              sum+=c.getSum();
        %>
        <tr>
            <td style="line-height: 30.5px;"><%=c.getId()%></td>
            <td style="line-height: 30.5px;"><%=c.getName() %></td>
            <td>
                <div class="input-group" style="width: 120px;margin: auto;">
                    <span class="input-group-btn">
                        <a class="btn btn-default" type="button" href="doCar.jsp?math=1&id=<%=c.getId()%>">-</a>
                    </span>
                    <input value="<%=c.getCount()%>" type="text" class="form-control">
                    <span class="input-group-btn">
                        <a class="btn btn-default" type="button" href="doCar.jsp?math=2&id=<%=c.getId()%>">+</a>
                    </span>
                </div>
            </td>
            <td style="line-height: 30.5px;">$<%=c.getSum() %></td>
            <td style="line-height: 30.5px;">
                <button class="btn btn-primary">删除</button>
            </td>
        </tr>
       <%
        }
       %>
    </table>

    <h1 class="alert alert-info">
        当前购物车总价
        <small><%=sum %></small>
        <button class="btn btn-danger">点我结算</button>
    </h1>
    
  
</body></html>

今天的学习就到这里啦，明天在给大家完善该购物车项目。