1.项目概述

1.1.项目演示

运行 “饿了么商家后台管理系统” ，演示应用程序效果。

1.2.项目目标

本项目为课程级贯穿项目中的第一个项目（JDBC项目、前端项目、javaWeb项目）。
本项目完成后，学员将能够使用javaSE+JDBC+MySql技术开发基于控制台的C/S结构应用程序。

1.3.项目中所涉及到相关知识点

封装JDBC
封装DAO
领域模型中的实体类
增删改查操作
多条件模糊查询
JDBC事务管理
表的主外键关系

1.4.数据库设计

1.4.1.DB一览表

No	表名称	中文名	说明
1	business	商家表	存储所有商家信息
2	food	食品表	存储每个商家所拥有的所有食品信息
3	admin	管理员表	存储管理员信息

1.5.2.表结构

约束类型标识：
PK：primary key 主键
FK：foreign key 外键
NN：not null 非空
UQ：unique 唯一索引
AI：auto increment 自增

1.5.2.1.business（商家表）

No	字段名	数据类型	size	默认値	约束	说明
1	businessId	int			PK、AI、NN	商家编号
2	password	varchar	20		NN	密码
3	businessName	varchar	40		NN	商家名称
4	businessAddress	varchar	50			商家地址
5	businessExplain	varchar	40			商家介绍
6	starPrice	decimal	(5,2)	0.00		起送费
7	deliveryPrice	decimal	(5,2)	0.00		配送费

1.5.2.2.food（食品表）

No	字段名	数据类型	size	约束	说明
1	foodId	int		PK、AI、NN	食品编号
2	foodName	varchar	30	NN	食品名称
3	foodExplain	varchar	30		食品介绍
4	foodPrice	decimal	(5,2)	NN	食品价格
5	businessId	int		FK、NN	所属商家编号

1.5.2.3.admin（管理员表）

No	字段名	数据类型	size	约束	说明
1	adminId	int		PK、AI、NN	管理员编号
2	adminName	varchar	20	NN、UQ	管理员名称
3	password	varchar	20	NN	密码

2.项目搭建

2.1.开发环境检查

开发工具：SpringToolSuite（STS）
检查开发工具的jdk配置：jdk8
检查开发工具的文件编码配置：utf-8

2.2.搭建javaWeb工程总体架构

2.2.1.工程类型

创建工程类型：java Project

2.2.2.导入jar包

mysql-connector-java-bin.jar

2.2.3.工程目录结构

4.项目代码

4.1.领域模型（PO）

4.1.1.Business

package com.neusoft.elm.po;

public class Business {

    private Integer businessId;
    private String password;
    private String businessName;
    private String businessAddress;
    private String businessExplain;
    private Double starPrice;
    private Double deliveryPrice;
    
    @Override
    public String toString() {
        return "\n商家编号："+this.businessId+
               "\n商家名称："+this.businessName+
               "\n商家地址："+this.businessAddress+
               "\n商家介绍："+this.businessExplain+
               "\n起送费：¥"+this.starPrice+
               "\n配送费：¥"+this.deliveryPrice+"\n";
    }
    
    //get、set ... ...
}

4.1.2.Food

package com.neusoft.elm.po;

public class Food {

    private Integer foodId;
    private String foodName;
    private String foodExplain;
    private Double foodPrice;
    private Integer businessId;
    
    @Override
    public String toString() {
        return "\n食品编号："+this.foodId+
               "\n食品名称："+this.foodName+
               "\n食品介绍："+this.foodExplain+
               "\n食品价格："+this.foodPrice+
               "\n所属商家："+this.businessId;
    }
    
    //get、set ... ...
}

4.1.3.Admin

package com.neusoft.elm.po;

public class Admin {

    private Integer adminId;
    private String adminName;
    private String password;
    
    //get、set ... ...
}

4.2.Dao层代码

4.2.1.Business

package com.neusoft.elm.dao;

import java.util.List;

import com.neusoft.elm.po.Business;

public interface BusinessDao {

    public List<Business> listBusiness(String businessName,String businessAddress);
    public int saveBusiness(String businessName);
    public int removeBusiness(int businessId);
    
    public Business getBusinessByIdByPass(Integer businessId,String password);
    public Business getBusinessById(Integer businessId);
    public int updateBusiness(Business business);
    public int updateBusinessByPassword(Integer businessId,String password);
}

package com.neusoft.elm.dao.impl;

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

import com.neusoft.elm.dao.BusinessDao;
import com.neusoft.elm.po.Admin;
import com.neusoft.elm.po.Business;
import com.neusoft.elm.util.DBUtil;

public class BusinessDaoImpl implements BusinessDao{
    
    private Connection con = null;
    private PreparedStatement pst = null;
    private ResultSet rs = null;

    @Override
    public List<Business> listBusiness(String businessName,String businessAddress) {
        List<Business> list = new ArrayList<>();
        StringBuffer sql = new StringBuffer("select * from business where 1=1 ");
        if(businessName!=null&&!businessName.equals("")) {
            sql.append(" and businessName like '%"+businessName+"%' ");
        }
        if(businessAddress!=null&&!businessAddress.equals("")) {
            sql.append(" and businessAddress like '%"+businessAddress+"%' ");
        }
        try {
            con = DBUtil.getConnection();
            pst = con.prepareStatement(sql.toString());
            rs = pst.executeQuery();
            while(rs.next()) {
                Business business = new Business();
                business.setBusinessId(rs.getInt("businessId"));
                business.setPassword(rs.getString("password"));
                business.setBusinessName(rs.getString("businessName"));
                business.setBusinessAddress(rs.getString("businessAddress"));
                business.setBusinessExplain(rs.getString("businessExplain"));
                business.setStarPrice(rs.getDouble("starPrice"));
                business.setDeliveryPrice(rs.getDouble("deliveryPrice"));
                list.add(business);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, pst, con);
        }
        return list;
    }
    
    @Override
    public int saveBusiness(String businessName) {
        int businessId = 0;
        String sql = "insert into business(businessName,password) values(?,'123')";
        try {
            con = DBUtil.getConnection();
            //设置返回自增长列值
            pst = con.prepareStatement(sql,PreparedStatement.RETURN_GENERATED_KEYS);
            pst.setString(1, businessName);
            pst.executeUpdate();
            //获取自增长列值（一行一列）
            rs = pst.getGeneratedKeys();
            if(rs.next()) {
                businessId = rs.getInt(1);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, pst, con);
        }
        return businessId;
    }
    
    @Override
    public int removeBusiness(int businessId) {
        int result = 0;
        String delFootSql = "delete from food where businessId=?";
        String delBusinessSql = "delete from business where businessId=?";
        try {
            con = DBUtil.getConnection();
            //开启一个事务
            con.setAutoCommit(false);
            
            pst = con.prepareStatement(delFootSql);
            pst.setInt(1, businessId);
            pst.executeUpdate();
            
            pst = con.prepareStatement(delBusinessSql);
            pst.setInt(1, businessId);
            result = pst.executeUpdate();
            
            con.commit();
        } catch (SQLException e) {
            result = 0;
            try {
                con.rollback();
            } catch (SQLException e1) {
                e1.printStackTrace();
            }
            e.printStackTrace();
        } finally {
            DBUtil.close(null, pst, con);
        }
        return result;
    }
    
    @Override
    public Business getBusinessByIdByPass(Integer businessId,String password) {
        Business business = null;
        String sql = "select * from business where businessId=? and password=?";
        try {
            con = DBUtil.getConnection();
            pst = con.prepareStatement(sql.toString());
            pst.setInt(1, businessId);
            pst.setString(2, password);
            rs = pst.executeQuery();
            while(rs.next()) {
                business = new Business();
                business.setBusinessId(rs.getInt("businessId"));
                business.setPassword(rs.getString("password"));
                business.setBusinessName(rs.getString("businessName"));
                business.setBusinessAddress(rs.getString("businessAddress"));
                business.setBusinessExplain(rs.getString("businessExplain"));
                business.setStarPrice(rs.getDouble("starPrice"));
                business.setDeliveryPrice(rs.getDouble("deliveryPrice"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, pst, con);
        }
        return business;
    }
    
    @Override
    public Business getBusinessById(Integer businessId) {
        Business business = null;
        String sql = "select * from business where businessId=?";
        try {
            con = DBUtil.getConnection();
            pst = con.prepareStatement(sql.toString());
            pst.setInt(1, businessId);
            rs = pst.executeQuery();
            while(rs.next()) {
                business = new Business();
                business.setBusinessId(rs.getInt("businessId"));
                business.setPassword(rs.getString("password"));
                business.setBusinessName(rs.getString("businessName"));
                business.setBusinessAddress(rs.getString("businessAddress"));
                business.setBusinessExplain(rs.getString("businessExplain"));
                business.setStarPrice(rs.getDouble("starPrice"));
                business.setDeliveryPrice(rs.getDouble("deliveryPrice"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, pst, con);
        }
        return business;
    }
    
    @Override
    public int updateBusiness(Business business) {
        int result = 0;
        String sql = "update business set businessName=?,businessAddress=?,businessExplain=?,starPrice=?,deliveryPrice=? where businessId=?";
        try {
            con = DBUtil.getConnection();
            pst = con.prepareStatement(sql);
            pst.setString(1, business.getBusinessName());
            pst.setString(2, business.getBusinessAddress());
            pst.setString(3, business.getBusinessExplain());
            pst.setDouble(4, business.getStarPrice());
            pst.setDouble(5, business.getDeliveryPrice());
            pst.setInt(6, business.getBusinessId());
            result = pst.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(null, pst, con);
        }
        return result;
    }
    
    @Override
    public int updateBusinessByPassword(Integer businessId,String password) {
        int result = 0;
        String sql = "update business set password=? where businessId=?";
        try {
            con = DBUtil.getConnection();
            pst = con.prepareStatement(sql);
            pst.setString(1, password);
            pst.setInt(2, businessId);
            result = pst.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(null, pst, con);
        }
        return result;
    }
}

4.2.2.Food

package com.neusoft.elm.dao;

import java.util.List;

import com.neusoft.elm.po.Food;

public interface FoodDao {

    public List<Food> listFoodByBusinessId(Integer businessId);
    public int saveFood(Food food);
    public Food getFoodById(Integer foodId);
    public int updateFood(Food food);
    public int removeFood(Integer foodId);
}

package com.neusoft.elm.dao.impl;

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

import com.neusoft.elm.dao.FoodDao;
import com.neusoft.elm.po.Food;
import com.neusoft.elm.util.DBUtil;

public class FoodDaoImpl implements FoodDao{
    
    private Connection con = null;
    private PreparedStatement pst = null;
    private ResultSet rs = null;

    @Override
    public List<Food> listFoodByBusinessId(Integer businessId) {
        List<Food> list = new ArrayList<>();
        String sql = "select * from food where businessId=?";
        try {
            con = DBUtil.getConnection();
            pst = con.prepareStatement(sql);
            pst.setInt(1, businessId);
            rs = pst.executeQuery();
            while(rs.next()) {
                Food food = new Food();
                food.setFoodId(rs.getInt("foodId"));
                food.setFoodName(rs.getString("foodName"));
                food.setFoodExplain(rs.getString("foodExplain"));
                food.setFoodPrice(rs.getDouble("foodPrice"));
                food.setBusinessId(rs.getInt("businessId"));
                list.add(food);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, pst, con);
        }
        return list;
    }
    
    @Override
    public int saveFood(Food food) {
        int result = 0;
        String sql = "insert into food values(null,?,?,?,?)";
        try {
            con = DBUtil.getConnection();
            pst = con.prepareStatement(sql);
            pst.setString(1, food.getFoodName());
            pst.setString(2, food.getFoodExplain());
            pst.setDouble(3, food.getFoodPrice());
            pst.setInt(4, food.getBusinessId());
            result = pst.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(null, pst, con);
        }
        return result;
    }
    
    @Override
    public Food getFoodById(Integer foodId) {
        Food food = null;
        String sql = "select * from food where foodId=?";
        try {
            con = DBUtil.getConnection();
            pst = con.prepareStatement(sql);
            pst.setInt(1, foodId);
            rs = pst.executeQuery();
            while(rs.next()) {
                food = new Food();
                food.setFoodId(rs.getInt("foodId"));
                food.setFoodName(rs.getString("foodName"));
                food.setFoodExplain(rs.getString("foodExplain"));
                food.setFoodPrice(rs.getDouble("foodPrice"));
                food.setBusinessId(rs.getInt("businessId"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, pst, con);
        }
        return food;
    }
    
    @Override
    public int updateFood(Food food) {
        int result = 0;
        String sql = "update food set foodName=?,foodExplain=?,foodPrice=? where foodId=?";
        try {
            con = DBUtil.getConnection();
            pst = con.prepareStatement(sql);
            pst.setString(1, food.getFoodName());
            pst.setString(2, food.getFoodExplain());
            pst.setDouble(3, food.getFoodPrice());
            pst.setInt(4, food.getFoodId());
            result = pst.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(null, pst, con);
        }
        return result;
    }
    
    @Override
    public int removeFood(Integer foodId) {
        int result = 0;
        String sql = "delete from food where foodId=?";
        try {
            con = DBUtil.getConnection();
            pst = con.prepareStatement(sql);
            pst.setInt(1, foodId);
            result = pst.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(null, pst, con);
        }
        return result;
    }
}

4.2.3.Admin

package com.neusoft.elm.dao;

import com.neusoft.elm.po.Admin;

public interface AdminDao {

    public Admin getAdminByNameByPass(String adminName,String password);
}

package com.neusoft.elm.dao.impl;

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

import com.neusoft.elm.dao.AdminDao;
import com.neusoft.elm.po.Admin;
import com.neusoft.elm.util.DBUtil;

public class AdminDaoImpl implements AdminDao{
    
    private Connection con = null;
    private PreparedStatement pst = null;
    private ResultSet rs = null;

    @Override
    public Admin getAdminByNameByPass(String adminName, String password) {
        Admin admin = null;
        String sql = "select * from admin where adminName=? and password=?";
        try {
            con = DBUtil.getConnection();
            pst = con.prepareStatement(sql);
            pst.setString(1, adminName);
            pst.setString(2, password);
            rs = pst.executeQuery();
            while(rs.next()) {
                admin = new Admin();
                admin.setAdminId(rs.getInt("adminId"));
                admin.setAdminName(rs.getString("adminName"));
                admin.setPassword(rs.getString("password"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, pst, con);
        }
        return admin;
    }
}

4.3.View层代码

4.3.1.Business

package com.neusoft.elm.view;

import com.neusoft.elm.po.Business;

public interface BusinessView {

    public void listBusinessAll();
    public void listBusiness();
    public void saveBusiness();
    public void removeBusiness();
    
    public Business login();
    public void showBusiness(Integer businessId);
    public void editBusiness(Integer businessId);
    public void updateBusinessByPassword(Integer businessId);
}

package com.neusoft.elm.view.impl;

import java.util.List;
import java.util.Scanner;

import com.neusoft.elm.dao.BusinessDao;
import com.neusoft.elm.dao.impl.BusinessDaoImpl;
import com.neusoft.elm.po.Business;
import com.neusoft.elm.view.BusinessView;

public class BusinessViewImpl implements BusinessView{
    
    private Scanner input = new Scanner(System.in);

    @Override
    public void listBusinessAll() {
        BusinessDao dao = new BusinessDaoImpl();
        List<Business> list = dao.listBusiness(null,null);
        System.out.println("商家编号\t商家名称\t商家地址\t商家介绍\t起送费\t配送费");
        for(Business b : list) {
            System.out.println(b.getBusinessId()+"\t"+b.getBusinessName()+"\t"+b.getBusinessAddress()+"\t"+b.getBusinessExplain()+"\t"+b.getStarPrice()+"\t"+b.getDeliveryPrice());
        }
    }
    
    @Override
    public void listBusiness() {
        String businessName = "";
        String businessAddress = "";
        
        String inputStr = "";
        System.out.println("是否需要输入商家名称关键词(y/n)：");
        inputStr = input.next();
        if(inputStr.equals("y")) {
            System.out.println("请输入商家名称关键词：");
            businessName = input.next();
        }
        
        System.out.println("是否需要输入商家地址关键词(y/n)：");
        inputStr = input.next();
        if(inputStr.equals("y")) {
            System.out.println("请输入商家地址关键词：");
            businessAddress = input.next();
        }
        
        BusinessDao dao = new BusinessDaoImpl();
        List<Business> list = dao.listBusiness(businessName, businessAddress);
        System.out.println("商家编号\t商家名称\t商家地址\t商家介绍\t起送费\t配送费");
        for(Business b : list) {
            System.out.println(b.getBusinessId()+"\t"+b.getBusinessName()+"\t"+b.getBusinessAddress()+"\t"+b.getBusinessExplain()+"\t"+b.getStarPrice()+"\t"+b.getDeliveryPrice());
        }
    }
    
    @Override
    public void saveBusiness() {
        System.out.println("请输入商家名称：");
        String businessName = input.next();
        BusinessDao dao = new BusinessDaoImpl();
        int businessId = dao.saveBusiness(businessName);
        if(businessId>0) {
            System.out.println("新建商家成功！商家编号为："+businessId);
        }else {
            System.out.println("新建商家失败！");
        }
    }
    
    @Override
    public void removeBusiness() {
        System.out.println("请输入商家编号：");
        int businessId = input.nextInt();
        
        BusinessDao dao = new BusinessDaoImpl();
        System.out.println("确认要删除吗(y/n)：");
        if(input.next().equals("y")) {
            int result = dao.removeBusiness(businessId);
            if(result==1) {
                System.out.println("删除商家成功！");
            }else {
                System.out.println("删除商家失败！");
            }
        }
    }
    
    @Override
    public Business login() {
        System.out.println("请输入商家编号：");
        int businessId = input.nextInt();
        System.out.println("请输入密码：");
        String password = input.next();
        
        BusinessDao dao = new BusinessDaoImpl();
        return dao.getBusinessByIdByPass(businessId, password);
    }
    
    @Override
    public void showBusiness(Integer businessId) {
        BusinessDao dao = new BusinessDaoImpl();
        Business business = dao.getBusinessById(businessId);
        System.out.println(business);
    }
    
    @Override
    public void editBusiness(Integer businessId) {
        //先将商家信息查询出来显示，然后用户才能更新
        BusinessDao dao = new BusinessDaoImpl();
        Business business = dao.getBusinessById(businessId);
        System.out.println(business);
        
        String inputStr = "";
        System.out.println("是否修改商家名称(y/n)：");
        inputStr = input.next();
        if(inputStr.equals("y")) {
            System.out.println("请输入新的商家名称：");
            business.setBusinessName(input.next());
        }
        
        System.out.println("是否修改商家地址(y/n)：");
        inputStr = input.next();
        if(inputStr.equals("y")) {
            System.out.println("请输入新的商家地址：");
            business.setBusinessAddress(input.next());
        }
        
        System.out.println("是否修改商家介绍(y/n)：");
        inputStr = input.next();
        if(inputStr.equals("y")) {
            System.out.println("请输入新的商家介绍：");
            business.setBusinessExplain(input.next());
        }
        
        System.out.println("是否修改起送费(y/n)：");
        inputStr = input.next();
        if(inputStr.equals("y")) {
            System.out.println("请输入新的起送费：");
            business.setStarPrice(input.nextDouble());
        }
        
        System.out.println("是否修改配送费(y/n)：");
        inputStr = input.next();
        if(inputStr.equals("y")) {
            System.out.println("请输入新的配送费：");
            business.setDeliveryPrice(input.nextDouble());
        }
        
        int result = dao.updateBusiness(business);
        if(result>0) {
            System.out.println("\n修改商家信息成功！\n");
        }else {
            System.out.println("\n修改商家信息失败！\n");
        }
    }
    
    @Override
    public void updateBusinessByPassword(Integer businessId) {
        BusinessDao dao = new BusinessDaoImpl();
        Business business = dao.getBusinessById(businessId);
        
        System.out.println("\n请输入旧密码：");
        String oldPass = input.next();
        System.out.println("\n请输入新密码：");
        String password = input.next();
        System.out.println("\n请再次输入新密码：");
        String beginPassword = input.next();
        
        if(!business.getPassword().equals(oldPass)) {
            System.out.println("\n旧密码输入错误！");
        }else if(!password.equals(beginPassword)) {
            System.out.println("\n两次输入密码不一致！");
        }else {
            int result = dao.updateBusinessByPassword(businessId, password);
            if(result>0) {
                System.out.println("\n修改密码成功！");
            }else {
                System.out.println("\n修改密码失败！");
            }
        }
    }
}

4.3.2.Food

package com.neusoft.elm.view;

import java.util.List;

import com.neusoft.elm.po.Food;

public interface FoodView {

    public List<Food> showFoodList(Integer businessId);
    public void saveFood(Integer businessId);
    public void updateFood(Integer businessId);
    public void removeFood(Integer businessId);
}

package com.neusoft.elm.view.impl;

import java.util.List;
import java.util.Scanner;

import com.neusoft.elm.dao.FoodDao;
import com.neusoft.elm.dao.impl.FoodDaoImpl;
import com.neusoft.elm.po.Food;
import com.neusoft.elm.view.FoodView;

public class FoodViewImpl implements FoodView{
    
    private Scanner input = new Scanner(System.in);

    @Override
    public List<Food> showFoodList(Integer businessId) {
        FoodDao dao = new FoodDaoImpl();
        List<Food> list = dao.listFoodByBusinessId(businessId);
        System.out.println("食品编号\t食品名称\t食品介绍\t食品价格");
        for(Food food : list) {
            System.out.println(food.getFoodId()+"\t"+food.getFoodName()+"\t"+food.getFoodExplain()+"\t"+food.getFoodPrice());
        }
        return list;
    }
    
    @Override
    public void saveFood(Integer businessId) {
        Food food = new Food();
        System.out.println("请输入食品名称：");
        food.setFoodName(input.next());
        System.out.println("请输入食品介绍：");
        food.setFoodExplain(input.next());
        System.out.println("请输入食品价格：");
        food.setFoodPrice(input.nextDouble());
        food.setBusinessId(businessId);
        
        FoodDao dao = new FoodDaoImpl();
        int result = dao.saveFood(food);
        if(result>0) {
            System.out.println("\n新增食品成功！\n");
        }else {
            System.out.println("\n新增食品失败！\n");
        }
    }
    
    @Override
    public void updateFood(Integer businessId) {
        FoodDao dao = new FoodDaoImpl();
        List<Food> list = showFoodList(businessId);
        
        if(list.size()==0) {
            System.out.println("没有任何食品！");
        }else {
            System.out.println("请选择要更新的食品编号：");
            int foodId = input.nextInt();
            Food food = dao.getFoodById(foodId);
            System.out.println(food);
            
            String inputStr = "";
            System.out.println("是否更新食品名称(y/n)：");
            inputStr = input.next();
            if(inputStr.equals("y")) {
                System.out.println("请输入新的食品名称：");
                food.setFoodName(input.next());
            }
            
            System.out.println("是否更新食品介绍(y/n)：");
            inputStr = input.next();
            if(inputStr.equals("y")) {
                System.out.println("请输入新的食品介绍：");
                food.setFoodExplain(input.next());
            }
            
            System.out.println("是否更新食品价格(y/n)：");
            inputStr = input.next();
            if(inputStr.equals("y")) {
                System.out.println("请输入新的食品价格：");
                food.setFoodPrice(input.nextDouble());
            }
            
            int result = dao.updateFood(food);
            if(result>0) {
                System.out.println("\n修改食品成功！\n");
            }else {
                System.out.println("\n修改食品失败！\n");
            }
        }
    }
    
    @Override
    public void removeFood(Integer businessId) {
        FoodDao dao = new FoodDaoImpl();
        List<Food> list = showFoodList(businessId);
        
        if(list.size()==0) {
            System.out.println("没有任何食品！");
        }else {
            System.out.println("请选择要删除的食品编号：");
            int foodId = input.nextInt();
            
            System.out.println("确认要删除吗(y/n)：");
            if(input.next().equals("y")) {
                int result = dao.removeFood(foodId);
                if(result>0) {
                    System.out.println("\n删除食品成功！\n");
                }else {
                    System.out.println("\n删除食品失败！\n");
                }
            }
        }
    }
}

4.3.3.Admin

package com.neusoft.elm.view;

import com.neusoft.elm.po.Admin;

public interface AdminView {

    public Admin login();
}

package com.neusoft.elm.view.impl;

import java.util.Scanner;

import com.neusoft.elm.dao.AdminDao;
import com.neusoft.elm.dao.impl.AdminDaoImpl;
import com.neusoft.elm.po.Admin;
import com.neusoft.elm.view.AdminView;

public class AdminViewImpl implements AdminView{
    
    private Scanner input = new Scanner(System.in);

    @Override
    public Admin login() {
        System.out.println("请输入管理员名称：");
        String adminName = input.next();
        System.out.println("请输入密码：");
        String password = input.next();
        
        AdminDao dao = new AdminDaoImpl();
        return dao.getAdminByNameByPass(adminName, password);
    }
}

4.4.程序入口

4.4.1.管理员入口

package com.neusoft.elm;

import java.util.Scanner;

import com.neusoft.elm.po.Admin;
import com.neusoft.elm.view.AdminView;
import com.neusoft.elm.view.BusinessView;
import com.neusoft.elm.view.impl.AdminViewImpl;
import com.neusoft.elm.view.impl.BusinessViewImpl;

public class ElmAdminEntry {

    public void work() {
        Scanner input = new Scanner(System.in);
        
        System.out.println("---------------------------------------------------------");
        System.out.println("|\t\t\t 饿了么后台管理系统  \t\t\t|");
        System.out.println("---------------------------------------------------------");
        
        AdminView adminView = new AdminViewImpl();
        BusinessView businessView = new BusinessViewImpl();
        Admin admin = adminView.login();
        
        //登录
        if(admin!=null) {
            int menu = 0;
            while(menu!=5) {
                //输出主菜单
                System.out.println("\n========= 1.所有商家列表=2.搜索商家=3.新建商家=4.删除商家=5.退出系统 =========");
                System.out.println("请输入你的选择：");
                menu = input.nextInt();
                switch(menu) {
                    case 1:
                        businessView.listBusinessAll();
                        break;
                    case 2:
                        businessView.listBusiness();
                        break;
                    case 3:
                        businessView.saveBusiness();
                        break;
                    case 4:
                        businessView.removeBusiness();
                        break;
                    case 5:
                        System.out.println("------------------------欢迎下次光临饿了么后台管理系统-----------------------");
                        break;  
                    default:
                        System.out.println("没有这个选项！\n");
                        break;
                }
            }
            
        }else {
            System.out.println("\n管理员名称或密码输入错误!\n");
        }
    }
    
    public static void main(String[] args) {
        new ElmAdminEntry().work();
    }

}

4.4.2.商家入口

package com.neusoft.elm;

import java.util.Scanner;

import com.neusoft.elm.po.Business;
import com.neusoft.elm.view.BusinessView;
import com.neusoft.elm.view.FoodView;
import com.neusoft.elm.view.impl.BusinessViewImpl;
import com.neusoft.elm.view.impl.FoodViewImpl;

public class ElmBusinessEntry {

    public void work() {
        Scanner input = new Scanner(System.in);
        
        System.out.println("---------------------------------------------------------");
        System.out.println("|\t\t\t 饿了么后台管理系统  \t\t\t|");
        System.out.println("---------------------------------------------------------");
        
        BusinessView businessView = new BusinessViewImpl();
        
        //商家登录
        Business business = businessView.login();
        
        if(business!=null) {
            int menu = 0;
            while(menu!=5) {
                //输出一级菜单
                System.out.println("\n======= 一级菜单（商家管理）1.查看商家信息=2.修改商家信息=3.更新密码=4.所属商品管理=5.退出系统=======");
                System.out.println("请输入你的选择：");
                menu = input.nextInt();
                
                switch(menu) {
                    case 1:
                        businessView.showBusiness(business.getBusinessId());
                        break;
                    case 2:
                        businessView.editBusiness(business.getBusinessId());
                        break;
                    case 3:
                        businessView.updateBusinessByPassword(business.getBusinessId());
                        break;
                    case 4:
                        foodManager(business.getBusinessId());
                        break;
                    case 5:
                        System.out.println("------------------------欢迎下次光临饿了么后台管理系统-----------------------");
                        break;  
                    default:
                        System.out.println("没有这个选项！\n");
                        break;
                }
            }
        }else {
            System.out.println("商家编号或密码输入错误！");
        }
        
    }
    
    private void foodManager(int businessId) {
        Scanner input = new Scanner(System.in);
        
        FoodView foodView = new FoodViewImpl();
        
        int menu = 0;
        while(menu!=5) {
            //输出二级菜单
            System.out.println("\n======= 二级菜单（食品管理）1.查看食品列表=2.新增食品=3.修改食品=4.删除食品=5.返回一级菜单 =======");
            System.out.println("请输入你的选择：");
            menu = input.nextInt();
            
            switch(menu) {
                case 1:
                    foodView.showFoodList(businessId);
                    break;
                case 2:
                    foodView.saveFood(businessId);
                    break;
                case 3:
                    foodView.updateFood(businessId);
                    break;
                case 4:
                    foodView.removeFood(businessId);
                    break;
                case 5:
                    break;  
                default:
                    System.out.println("没有这个选项！\n");
                    break;
            }
        }
    }
    
    public static void main(String[] args) {
        new ElmBusinessEntry().work();
    }
}

饿了么商家后台管理系统

1.项目概述

1.1.项目演示

1.2.项目目标

1.3.项目中所涉及到相关知识点

1.4.数据库设计

1.4.1.DB一览表

1.5.2.表结构

1.5.2.1.business（商家表）

1.5.2.2.food（食品表）

1.5.2.3.admin（管理员表）

2.项目搭建

2.1.开发环境检查

2.2.搭建javaWeb工程总体架构

2.2.1.工程类型

2.2.2.导入jar包

2.2.3.工程目录结构

4.项目代码

4.1.领域模型（PO）

4.1.1.Business

4.1.2.Food

4.1.3.Admin

4.2.Dao层代码

4.2.1.Business

4.2.2.Food

4.2.3.Admin

4.3.View层代码

4.3.1.Business

4.3.2.Food

4.3.3.Admin

4.4.程序入口

4.4.1.管理员入口

4.4.2.商家入口