Day13 - elm后端JDBC版管理员部分

使用JDBC作为数据库管理工具，做一个控制台模拟前端的简单外卖系统。

## 一、设计数据库

#### 1、数据库结构

| 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                   |

#### 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

##### business（商家表）

| No | 字段名        | 数据类型 | size  | 默认値 | 约束       | 说明     |
| -- | ------------- | -------- | ----- | ------ | ---------- | -------- |
| 1  | bid           | int      |       |        | PK、AI、NN | 商家编号 |
| 2  | password      | varchar  | 20    |        | NN         | 密码     |
| 3  | bname         | varchar  | 40    |        | NN         | 商家名称 |
| 4  | address       | varchar  | 50    |        |            | 商家地址 |
| 5  | explain       | varchar  | 100   |        |            | 商家介绍 |
| 6  | starPrice     | decimal  | (5,2) | 0.00   |            | 起送费   |
| 7  | deliveryPrice | decimal  | (5,2) | 0.00   |            | 配送费   |

##### food（食品表）

| No | 字段名  | 数据类型 | size  | 默认値 | 约束       | 说明         |
| -- | ------- | -------- | ----- | ------ | ---------- | ------------ |
| 1  | fid     | int      |       |        | PK、AI、NN | 食品编号     |
| 2  | fname   | varchar  | 30    |        | NN         | 食品名称     |
| 3  | explain | varchar  | 30    |        |            | 食品介绍     |
| 4  | price   | decimal  | (5,2) |        | NN         | 食品价格     |
| 5  | bid     | int      |       |        | FK、NN     | 所属商家编号 |

##### admin（管理员表）

| No | 字段名   | 数据类型 | size | 默认値 | 约束       | 说明       |
| -- | -------- | -------- | ---- | ------ | ---------- | ---------- |
| 1  | aid      | int      |      |        | PK、AI、NN | 管理员编号 |
| 2  | aname    | varchar  | 20   |        | NN、UQ     | 管理员名称 |
| 3  | password | varchar  | 20   |        | NN         | 密码       |

#### 3、SQL语句

```SQL
CREATE DATABASE IF NOT EXISTS elm CHARSET utf8;
USE elm;
CREATE TABLE IF NOT EXISTS business
(
    bid           INT UNSIGNED PRIMARY KEY AUTO_INCREMENT COMMENT '商家编号',
    password      VARCHAR(20) NOT NULL COMMENT '密码',
    bname         VARCHAR(40) NOT NULL COMMENT '商家名称',
    address       VARCHAR(50) COMMENT '商家地址',
    `explain`     VARCHAR(100) COMMENT '商家介绍',
    startPrice    DECIMAL(5, 2) DEFAULT 0.00 COMMENT '起送费',
    deliveryPrice DECIMAL(5, 2) DEFAULT 0.00 COMMENT '配送费'
);

CREATE TABLE IF NOT EXISTS food
(
    fid       INT UNSIGNED PRIMARY KEY AUTO_INCREMENT COMMENT '食品编号',
    fname     VARCHAR(30)   NOT NULL COMMENT '食品名称',
    `explain` VARCHAR(30) COMMENT '食品介绍',
    price     DECIMAL(5, 2) NOT NULL COMMENT '食品价格',
    bid       INT UNSIGNED  NOT NULL COMMENT '所属商家编号',
    FOREIGN KEY (bid) REFERENCES business (bid)
);

CREATE TABLE IF NOT EXISTS admin
(
    aid      INT UNSIGNED PRIMARY KEY AUTO_INCREMENT COMMENT '管理员编号',
    aname    VARCHAR(20) NOT NULL UNIQUE COMMENT '管理员名称',
    password VARCHAR(20) NOT NULL COMMENT '密码'
);
INSERT INTO admin(aname, `password`)
VALUES ('admin', 'admin');
```

## 二、添加JDBC库

在根目录下新建`lib`文件夹，将`mysqlconnectorjava5.1.10bin.jar`存放进去，导入仓库。

[香肠狗网盘](https://pan.soki.me/s/vrUj)

## 三、创建项目各层

#### 1、`po`层

新建`com.doooog.elm.po`包，创建`Admin.java`类

```java
package com.doooog.elm.po;

public class Admin {
    private Integer aid;
    private String aname;
    private String password;

public Admin() {
    }

public Admin(Integer aid, String aname, String password) {
        this.aid = aid;
        this.aname = aname;
        this.password = password;
    }

@Override
    public String toString() {
        return "Admin{" +
                "aid=" + aid +
                ", aname='" + aname + '\'' +
                ", password='" + password + '\'' +
                '}';
    }

public boolean isEmpty() {
        return aid == null && (aname == null || aname.isEmpty()) && (password == null || password.isEmpty());
    }

public boolean isUnsafe(boolean withPK) {
        if (!withPK) {
            return isEmpty() || aname == null || aname.isEmpty() || password == null || password.isEmpty();
        } else {
            return isEmpty() || aid == null || aid <= 0 || aname == null || aname.isEmpty() || password == null || password.isEmpty();
        }
    }

public Integer getAid() {
        return aid;
    }

public void setAid(Integer aid) {
        this.aid = aid;
    }

public String getAname() {
        return aname;
    }

public void setAname(String aname) {
        this.aname = aname;
    }

public String getPassword() {
        return password;
    }

public void setPassword(String password) {
        this.password = password;
    }
}
```

创建`Business.java`类

```java
package com.doooog.elm.po;

import java.util.List;

public class Business {
    private Integer bid;
    private String password;
    private String bname;
    private String address;
    private String explain;
    private Double startPrice;
    private Double deliveryPrice;

private List<Food> foodList;

public Business() {
    }

public Business(Integer bid, String password, String bname, String address, String explain, Double startPrice, Double deliveryPrice) {
        this.bid = bid;
        this.password = password;
        this.bname = bname;
        this.address = address;
        this.explain = explain;
        this.startPrice = startPrice;
        this.deliveryPrice = deliveryPrice;
    }

public Business(Integer bid, String password, String bname, String address, String explain, Double startPrice, Double deliveryPrice, List<Food> foodList) {
        this.bid = bid;
        this.password = password;
        this.bname = bname;
        this.address = address;
        this.explain = explain;
        this.startPrice = startPrice;
        this.deliveryPrice = deliveryPrice;
        this.foodList = foodList;
    }

@Override
    public String toString() {
        return "Business{" +
                "bid=" + bid +
                ", password='" + password + '\'' +
                ", bname='" + bname + '\'' +
                ", address='" + address + '\'' +
                ", explain='" + explain + '\'' +
                ", startPrice=" + startPrice +
                ", deliveryPrice=" + deliveryPrice +
                '}';
    }

public boolean isEmpty() {
        return bid == null && (bname == null || bname.isEmpty()) && (address == null || address.isEmpty()) && (explain == null || explain.isEmpty()) && startPrice == null && deliveryPrice == null && (foodList == null || foodList.isEmpty());
    }

public boolean isUnsafe(boolean withPK) {
        if (!withPK) {
            return isEmpty() || password == null || password.isEmpty() || bname == null || bname.isEmpty();
        } else {
            return isEmpty() || bid == null || bid <= 0 || password == null || password.isEmpty() || bname == null || bname.isEmpty();
        }
    }

public List<Food> getFoodList() {
        return foodList;
    }

public void setFoodList(List<Food> foodList) {
        this.foodList = foodList;
    }

public Integer getBid() {
        return bid;
    }

public void setBid(Integer bid) {
        this.bid = bid;
    }

public String getPassword() {
        return password;
    }

public void setPassword(String password) {
        this.password = password;
    }

public String getBname() {
        return bname;
    }

public void setBname(String bname) {
        this.bname = bname;
    }

public String getAddress() {
        return address;
    }

public void setAddress(String address) {
        this.address = address;
    }

public String getExplain() {
        return explain;
    }

public void setExplain(String explain) {
        this.explain = explain;
    }

public Double getStartPrice() {
        return startPrice;
    }

public void setStartPrice(Double startPrice) {
        this.startPrice = startPrice;
    }

public Double getDeliveryPrice() {
        return deliveryPrice;
    }

public void setDeliveryPrice(Double deliveryPrice) {
        this.deliveryPrice = deliveryPrice;
    }
}
```

创建`Food.java`类

```java
package com.doooog.elm.po;

public class Food {
    private Integer fid;
    private String fname;
    private String explain;
    private Double price;
    private Integer bid;

private Business business;

public Food() {
    }

public Food(Integer fid, String fname, String explain, Double price, Integer bid) {
        this.fid = fid;
        this.fname = fname;
        this.explain = explain;
        this.price = price;
        this.bid = bid;
    }

public Food(Integer fid, String fname, String explain, Double price, Integer bid, Business business) {
        this.fid = fid;
        this.fname = fname;
        this.explain = explain;
        this.price = price;
        this.bid = bid;
        this.business = business;
    }

@Override
    public String toString() {
        return "Food{" +
                "fid=" + fid +
                ", fname='" + fname + '\'' +
                ", explain='" + explain + '\'' +
                ", price=" + price +
                ", bid=" + bid +
                '}';
    }

public boolean isEmpty() {
        return fid == null && (fname == null || fname.isEmpty()) && (explain == null || explain.isEmpty()) && price == null && bid == null && (business == null || business.isEmpty());
    }

public boolean isUnsafe(boolean withPK) {
        if (!withPK) {
            return this.isEmpty() || bid == null || bid <= 0 || fname == null || fname.isEmpty() || price == null || price <= 0;
        } else {
            return this.isEmpty() || fid == null || fid <= 0 || bid == null || bid <= 0 || fname == null || fname.isEmpty() || price == null || price <= 0;
        }
    }

public Integer getFid() {
        return fid;
    }

public void setFid(Integer fid) {
        this.fid = fid;
    }

public String getFname() {
        return fname;
    }

public void setFname(String fname) {
        this.fname = fname;
    }

public String getExplain() {
        return explain;
    }

public void setExplain(String explain) {
        this.explain = explain;
    }

public Double getPrice() {
        return price;
    }

public void setPrice(Double price) {
        this.price = price;
    }

public Integer getBid() {
        return bid;
    }

public void setBid(Integer bid) {
        this.bid = bid;
    }

public Business getBusiness() {
        return business;
    }

public void setBusiness(Business business) {
        this.business = business;
    }
}
```

#### 2、`util`层

在`rescources`资源包根目录下创建配置文件`db.properties`用来存放数据库连接信息

```properties
com.doooog.elm.mysql.driverClassName=com.mysql.jdbc.Driver
com.doooog.elm.mysql.url=jdbc:mysql://localhost:3306/elm?useUnicode=true&useSSL=false&serverTimezone=Asia/Shanghai&characterEncoding=utf8
com.doooog.elm.mysql.username=username
com.doooog.elm.mysql.password=password
```

新建`com.doooog.elm.util`包，创建`DBUtil.java`类

```java
package com.doooog.elm.util;

import java.io.IOException;
import java.sql.*;
import java.util.Properties;

public class DBUtil {
    public static Connection getConnection() {
        Connection con = null;
        try {
            // 操作Properties的类
            Properties properties = new Properties();
            properties.load(DBUtil.class.getClassLoader().getResourceAsStream("db.properties"));
            Class.forName(properties.getProperty("com.doooog.elm.mysql.driverClassName"));
            con = DriverManager.getConnection(
                    properties.getProperty("com.doooog.elm.mysql.url"),
                    properties.getProperty("com.doooog.elm.mysql.username"),
                    properties.getProperty("com.doooog.elm.mysql.password"));
        } catch (ClassNotFoundException | SQLException e) {
            throw new RuntimeException(e);
        } catch (IOException e) {
            System.out.println("未找到db.properties");
            throw new RuntimeException(e);
        }
        return con;
    }
  
    public static void closeConnection(Connection con, PreparedStatement pst, ResultSet rs) {
        try {
            if (rs != null) rs.close();
            if (pst != null) pst.close();
            if (con != null) con.close();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
}
```

创建`CommonUtil.java`类

```java
package com.doooog.elm.util;

public class CommonUtil {
    public static String copyChar(char c, int num) {
        if (num <= 0) return "";
        return String.valueOf(c).repeat(num);
    }
}
```

创建`InputUtil.java`类

```java
package com.doooog.elm.util;

import java.util.InputMismatchException;
import java.util.Scanner;

public class InputUtil {
    private static final Scanner INPUT = new Scanner(System.in);
    public static int menuInputInteger(String msg) {
        int data;
        try {
            data = INPUT.nextInt();
            if (data < -2) throw new InputMismatchException();
        } catch (InputMismatchException e) {
            INPUT.nextLine();
            if (!msg.isEmpty()) {
                System.out.print("输入的类型错误！请重新输入" + msg + ":");
            } else {
                System.out.print("输入的类型错误！请重新输入:");
            }
            data = menuInputInteger(msg);
        }
        return data;
    }
    public static double menuInputDouble(String msg) {
        double data;
        try {
            data = INPUT.nextDouble();
            if (data < 0 && data != -1) throw new InputMismatchException();
        } catch (InputMismatchException e) {
            INPUT.nextLine();
            if (!msg.isEmpty()) {
                System.out.print("输入的类型错误！请重新输入" + msg + ":");
            } else {
                System.out.print("输入的类型错误！请重新输入:");
            }
            data = menuInputDouble(msg);
        }
        return data;
    }

public static String menuInputString(String msg) {
        String data;
        try {
            data = INPUT.next();
        } catch (InputMismatchException e) {
            INPUT.nextLine();
            if (!msg.isEmpty()) {
                System.out.print("输入的类型错误！请重新输入" + msg + ":");
            } else {
                System.out.print("输入的类型错误！请重新输入:");
            }
            data = menuInputString(msg);
        }
        return data;
    }
}
```

#### 3、`dao`层

新建`com.doooog.elm.dao`包，创建`AdminDao.java`接口

```java
package com.doooog.elm.dao;

import com.doooog.elm.po.Admin;

import java.util.List;

public interface AdminDao {
    Admin getAdminByLogin(String username, String password);

Admin getAdminById(int aid);

boolean isExistById(int aid);

List<Admin> listAdminAll();

int addAdmin(Admin admin);

int addAdminWithId(Admin admin);

int deleteAdminById(int aid);

int updateAdminPasswordById(int aid, String password);
}
```

创建`BusinessDao.java`接口

```java
package com.doooog.elm.dao;

import com.doooog.elm.po.Business;

import java.util.List;

public interface BusinessDao {
    Business getBusinessById(int bid);

Business getBusinessByName(String bname);

List<Business> listBusinessByName(String bname);

List<Business> listBusinessAll();

Business getLastBusiness();

int addBusiness(Business business);

int addBusinessWithId(Business business);

int updateBusinessById(Business business);

int deleteBusinessById(int bid);
}
```

创建`FoodDao.java`接口

```java
package com.doooog.elm.dao;

import com.doooog.elm.po.Food;

import java.util.List;

public interface FoodDao {
    Food getFoodById(int fid);

List<Food> getFoodByName(String fname);

List<Food> listFoodByName(String fname);

List<Food> listFoodAll();

List<Food> listFoodByBusinessId(int bid);

int updateFoodById(Food food);

int updateFoodPriceById(int fid, double price);

int addFood(Food food);

int addFoodWithId(Food food);

int deleteFoodById(int fid);
}
```

新建`com.doooog.elm.dao.impl`包，创建`AdminDaoImpl.java`类

```java
package com.doooog.elm.dao.impl;

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

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

public class AdminDaoImpl implements AdminDao {
    @Override
    public Admin getAdminByLogin(String username, String password) {
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        ResultSet rs = null;
        Admin admin = null;
        try {
            String sql = "select * from admin where aname=? and password=?";
            pst = con.prepareStatement(sql);
            pst.setString(1, username);
            pst.setString(2, password);
            rs = pst.executeQuery();
            if (rs.next()) {
                admin = fillAdmin(rs);
            }
            if (admin != null && !admin.getPassword().equals(password)) {
                admin = null;
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return admin;
    }

@Override
    public Admin getAdminById(int aid) {
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        ResultSet rs = null;
        Admin admin = null;
        try {
            String sql = "select * from admin where aid=?";
            pst = con.prepareStatement(sql);
            pst.setInt(1, aid);
            rs = pst.executeQuery();
            if (rs.next()) {
                admin = fillAdmin(rs);
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return admin;
    }

@Override
    public boolean isExistById(int aid) {
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        ResultSet rs = null;
        boolean result = false;
        try {
            String sql = "select count(aid) 'num' from admin where aid=?";
            pst = con.prepareStatement(sql);
            pst.setInt(1, aid);
            rs = pst.executeQuery();
            if (rs.next()) {
                int i = rs.getInt("num");
                if (i > 1) result = true;
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, null);
        }
        return result;
    }

@Override
    public List<Admin> listAdminAll() {
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        ResultSet rs = null;
        List<Admin> list = null;
        try {
            String sql = "select * from admin";
            pst = con.prepareStatement(sql);
            rs = pst.executeQuery();
            list = new ArrayList<>();
            while (rs.next()) {
                list.add(fillAdmin(rs));
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return list;
    }

@Override
    public int addAdmin(Admin admin) {
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        int result = 0;
        try {
            String sql = "insert into admin(aname, password) VALUES (?,?)";
            pst = con.prepareStatement(sql);
            pst.setString(1, admin.getAname());
            pst.setString(2, admin.getPassword());
            result = pst.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, null);
        }
        return result;
    }

@Override
    public int addAdminWithId(Admin admin) {
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        int result = 0;
        try {
            String sql = "insert into admin VALUES (?,?,?)";
            pst = con.prepareStatement(sql);
            pst.setInt(1, admin.getAid());
            pst.setString(2, admin.getAname());
            pst.setString(3, admin.getPassword());
            result = pst.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, null);
        }
        return result;
    }

@Override
    public int deleteAdminById(int aid) {
        if (aid <= 0) return 0;
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        int result = 0;
        try {
            String sql = "delete from admin where aid=?";
            pst = con.prepareStatement(sql);
            pst.setInt(1, aid);
            result = pst.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, null);
        }
        return result;
    }

@Override
    public int updateAdminPasswordById(int aid, String password) {
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        int result = 0;
        try {
            String sql = "update admin set password=? where aid=?";
            pst = con.prepareStatement(sql);
            pst.setInt(2, aid);
            pst.setString(1, password);
            result = pst.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, null);
        }
        return result;
    }

private Admin fillAdmin(ResultSet rs) throws SQLException {
        return new Admin(
                rs.getInt("aid"),
                rs.getString("aname"),
                rs.getString("password")
        );
    }
}
```

创建`BusinessDaoImpl.java`类

```java
package com.doooog.elm.dao.impl;

import com.doooog.elm.dao.BusinessDao;
import com.doooog.elm.po.Business;
import com.doooog.elm.util.DBUtil;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class BusinessDaoImpl implements BusinessDao {
    @Override
    public Business getBusinessById(int bid) {
        if (bid <= 0) return null;
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        ResultSet rs = null;
        Business business = null;
        try {
            String sql = "select * from business where bid=?";
            pst = con.prepareStatement(sql);
            pst.setInt(1, bid);
            rs = pst.executeQuery();
            if (rs.next()) {
                business = fillBusiness(rs);
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return business;
    }

@Override
    public Business getBusinessByName(String bname) {
        if (bname == null || bname.isEmpty()) return null;
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        ResultSet rs = null;
        Business business = null;
        try {
            String sql = "select * from business where bname=?";
            pst = con.prepareStatement(sql);
            pst.setString(1, bname);
            rs = pst.executeQuery();
            if (rs.next()) {
                business = fillBusiness(rs);
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return business;
    }

@Override
    public List<Business> listBusinessByName(String bname) {
        if (bname == null || bname.isEmpty()) return null;
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        ResultSet rs = null;
        List<Business> list = null;
        try {
            String sql = "select * from business where bname=concat('%',?,'%')";
            pst = con.prepareStatement(sql);
            pst.setString(1, bname);
            rs = pst.executeQuery();
            list = new ArrayList<>();
            while (rs.next()) {
                list.add(fillBusiness(rs));
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return list;
    }

@Override
    public List<Business> listBusinessAll() {
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        ResultSet rs = null;
        List<Business> list = null;
        try {
            String sql = "select * from business";
            pst = con.prepareStatement(sql);
            rs = pst.executeQuery();
            list = new ArrayList<>();
            while (rs.next()) {
                list.add(fillBusiness(rs));
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return list;
    }

@Override
    public Business getLastBusiness() {
        //SELECT * FROM your_table ORDER BY created_at DESC LIMIT 1;
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        ResultSet rs = null;
        Business business = null;
        try {
            String sql = "select * from business order by bid desc limit 1";
            pst = con.prepareStatement(sql);
            rs = pst.executeQuery();
            if (rs.next()) {
                business = fillBusiness(rs);
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return business;
    }

@Override
    public int addBusiness(Business business) {
        if (business == null || business.isEmpty()) return 0;
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        ResultSet rs = null;
        int result = 0;
        try {
            String sql = "insert into business(password, bname, address, `explain`, startPrice, deliveryPrice) values(?,?,?,?,?,?)";
            pst = con.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);
            if (business.getPassword() != null && !business.getPassword().isEmpty()) {
                pst.setString(1, business.getPassword());
            } else {
                pst.setNull(1, Types.VARCHAR);
            }
            if (business.getBname() != null && !business.getBname().isEmpty()) {
                pst.setString(2, business.getBname());
            } else {
                pst.setNull(2, Types.VARCHAR);
            }
            if (business.getAddress() != null && !business.getAddress().isEmpty()) {
                pst.setString(3, business.getAddress());
            } else {
                pst.setNull(3, Types.VARCHAR);
            }
            if (business.getExplain() != null && !business.getExplain().isEmpty()) {
                pst.setString(4, business.getExplain());
            } else {
                pst.setNull(4, Types.VARCHAR);
            }
            if (business.getStartPrice() != null && business.getStartPrice() >= 0) {
                pst.setDouble(5, business.getStartPrice());
            } else {
                pst.setNull(5, Types.DECIMAL);
            }
            if (business.getDeliveryPrice() != null && business.getDeliveryPrice() >= 0) {
                pst.setDouble(6, business.getDeliveryPrice());
            } else {
                pst.setNull(6, Types.DECIMAL);
            }
            result = pst.executeUpdate();
            rs = pst.getGeneratedKeys();
            if (rs.next()) result = rs.getInt(1);
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return result;
    }

@Override
    public int addBusinessWithId(Business business) {
        if (business == null || business.isEmpty() || business.getBid() <= 0) return 0;
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        int result = 0;
        try {
            String sql = "insert into business values(?,?,?,?,?,?,?)";
            pst = con.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);
            if (business.getBid() != null && business.getBid() >= 0) {
                pst.setInt(1, business.getBid());
            } else {
                pst.setNull(1, Types.INTEGER);
            }
            if (business.getPassword() != null && !business.getPassword().isEmpty()) {
                pst.setString(2, business.getPassword());
            } else {
                pst.setNull(2, Types.VARCHAR);
            }
            if (business.getBname() != null && !business.getBname().isEmpty()) {
                pst.setString(3, business.getBname());
            } else {
                pst.setNull(3, Types.VARCHAR);
            }
            if (business.getAddress() != null && !business.getAddress().isEmpty()) {
                pst.setString(4, business.getAddress());
            } else {
                pst.setNull(4, Types.VARCHAR);
            }
            if (business.getExplain() != null && !business.getExplain().isEmpty()) {
                pst.setString(5, business.getExplain());
            } else {
                pst.setNull(5, Types.VARCHAR);
            }
            if (business.getStartPrice() != null && business.getStartPrice() >= 0) {
                pst.setDouble(6, business.getStartPrice());
            } else {
                pst.setNull(6, Types.DECIMAL);
            }
            if (business.getDeliveryPrice() != null && business.getDeliveryPrice() >= 0) {
                pst.setDouble(7, business.getDeliveryPrice());
            } else {
                pst.setNull(7, Types.DECIMAL);
            }
            result = pst.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, null);
        }
        return result;
    }

@Override
    public int updateBusinessById(Business business) {
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        int result = 0;
        try {
            String sql = "update business set password=?, bname=?, address=?, `explain`=?, startPrice=?, deliveryPrice=? where bid=?";
            pst = con.prepareStatement(sql);
            pst.setString(1, business.getPassword());
            pst.setString(2, business.getBname());
            if (business.getAddress() != null && !business.getAddress().isEmpty()) {
                pst.setString(3, business.getAddress());
            } else {
                pst.setNull(3, Types.VARCHAR);
            }
            if (business.getExplain() != null && !business.getExplain().isEmpty()) {
                pst.setString(4, business.getExplain());
            } else {
                pst.setNull(4, Types.VARCHAR);
            }
            if (business.getStartPrice() != null && business.getStartPrice() >= 0) {
                pst.setDouble(5, business.getStartPrice());
            } else {
                pst.setNull(5, Types.DECIMAL);
            }
            if (business.getDeliveryPrice() != null && business.getDeliveryPrice() >= 0) {
                pst.setDouble(6, business.getDeliveryPrice());
            } else {
                pst.setNull(6, Types.DECIMAL);
            }
            pst.setInt(7, business.getBid());
            result = pst.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, null);
        }
        return result;
    }

@Override
    public int deleteBusinessById(int bid) {
        if (bid <= 0) return 0;
        Connection con = DBUtil.getConnection();
        PreparedStatement pst = null;
        int result = 0;
        try {
            String sql = "delete from business where bid=?";
            pst = con.prepareStatement(sql);
            pst.setInt(1, bid);
            result = pst.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, null);
        }
        return result;
    }

private Business fillBusiness(ResultSet rs) throws SQLException {
        return new Business(
                rs.getInt("bid"),
                rs.getString("password"),
                rs.getString("bname"),
                rs.getString("address"),
                rs.getString("explain"),
                rs.getDouble("startPrice"),
                rs.getDouble("deliveryPrice")
        );
    }
}
```

创建`FoodDaoImpl.java`类

```java
package com.doooog.elm.dao.impl;

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

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class FoodDaoImpl implements FoodDao {
    @Override
    public Food getFoodById(int fid) {
        if (fid <= 0) return null;
        PreparedStatement pst = null;
        ResultSet rs = null;
        Food food = null;
        Connection con = DBUtil.getConnection();
        try {
            String sql = "select * from food where fid=?";
            pst = con.prepareStatement(sql);
            pst.setInt(1, fid);
            rs = pst.executeQuery();
            if (rs.next()) {
                food = fillFood(rs);
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return food;
    }

@Override
    public List<Food> getFoodByName(String fname) {
        if (fname == null || fname.isEmpty()) return null;
        PreparedStatement pst = null;
        ResultSet rs = null;
        List<Food> list = null;
        Connection con = DBUtil.getConnection();
        try {
            String sql = "select * from food where fname=?";
            pst = con.prepareStatement(sql);
            pst.setString(1, fname);
            rs = pst.executeQuery();
            list = new ArrayList<>();
            while (rs.next()) {
                list.add(fillFood(rs));
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return list;
    }

@Override
    public List<Food> listFoodByName(String fname) {
        if (fname == null || fname.isEmpty()) return null;
        PreparedStatement pst = null;
        ResultSet rs = null;
        List<Food> list = null;
        Connection con = DBUtil.getConnection();
        try {
            String sql = "select * from food where fname like concat('%',?,'%')";
            pst = con.prepareStatement(sql);
            pst.setString(1, fname);
            rs = pst.executeQuery();
            list = new ArrayList<>();
            while (rs.next()) {
                list.add(fillFood(rs));
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return list;
    }

@Override
    public List<Food> listFoodAll() {
        PreparedStatement pst = null;
        ResultSet rs = null;
        List<Food> list = null;
        Connection con = DBUtil.getConnection();
        try {
            String sql = "select * from food";
            pst = con.prepareStatement(sql);
            rs = pst.executeQuery();
            list = new ArrayList<>();
            while (rs.next()) {
                list.add(fillFood(rs));
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return list;
    }

@Override
    public List<Food> listFoodByBusinessId(int bid) {
        if (bid <= 0) return null;
        PreparedStatement pst = null;
        ResultSet rs = null;
        List<Food> list = null;
        Connection con = DBUtil.getConnection();
        try {
            String sql = "select * from food where bid=?";
            pst = con.prepareStatement(sql);
            pst.setInt(1, bid);
            rs = pst.executeQuery();
            list = new ArrayList<>();
            while (rs.next()) {
                list.add(fillFood(rs));
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, rs);
        }
        return list;
    }

@Override
    public int updateFoodById(Food food) {
        if (food == null || food.isUnsafe(true))
            return 0;
        PreparedStatement pst = null;
        int result = 0;
        Connection con = DBUtil.getConnection();
        try {
            String sql = "update food set fname=?,`explain`=?,price=? where fid=?";
            pst = con.prepareStatement(sql);
            pst.setString(1, food.getFname());
            if (food.getExplain() != null && !food.getExplain().isEmpty()) {
                pst.setString(2, food.getExplain());
            } else {
                pst.setNull(2, Types.VARCHAR);
            }
            pst.setDouble(3, food.getPrice());
            pst.setInt(4, food.getFid());
            result = pst.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, null);
        }
        return result;
    }

@Override
    public int updateFoodPriceById(int fid, double price) {
        if (fid <= 0 || price <= 0) return 0;
        PreparedStatement pst = null;
        int result = 0;
        Connection con = DBUtil.getConnection();
        try {
            String sql = "update food set price=? where fid=?";
            pst = con.prepareStatement(sql);
            pst.setDouble(1, price);
            pst.setInt(2, fid);
            result = pst.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, null);
        }
        return result;
    }

@Override
    public int addFood(Food food) {
        if (food == null || food.isUnsafe(false))
            return 0;
        PreparedStatement pst = null;
        int result = 0;
        Connection con = DBUtil.getConnection();
        try {
            String sql = "insert into food(fname, `explain`, price, bid) VALUES (?,?,?,?)";
            pst = con.prepareStatement(sql);
            pst.setString(1, food.getFname());
            if (food.getExplain() != null && !food.getExplain().isEmpty()) {
                pst.setString(2, food.getExplain());
            } else {
                pst.setNull(2, Types.VARCHAR);
            }
            pst.setDouble(3, food.getPrice());
            pst.setInt(4, food.getBid());
            result = pst.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, null);
        }
        return result;
    }

@Override
    public int addFoodWithId(Food food) {
        if (food == null || food.isUnsafe(true))
            return 0;
        PreparedStatement pst = null;
        int result = 0;
        Connection con = DBUtil.getConnection();
        try {
            String sql = "insert into food VALUES (?,?,?,?,?)";
            pst = con.prepareStatement(sql);
            pst.setInt(1, food.getFid());
            pst.setString(2, food.getFname());
            if (food.getExplain() != null && !food.getExplain().isEmpty()) {
                pst.setString(3, food.getExplain());
            } else {
                pst.setNull(3, Types.VARCHAR);
            }
            pst.setDouble(4, food.getPrice());
            pst.setInt(5, food.getBid());
            result = pst.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, null);
        }
        return result;
    }

@Override
    public int deleteFoodById(int fid) {
        if (fid <= 0)
            return 0;
        PreparedStatement pst = null;
        int result = 0;
        Connection con = DBUtil.getConnection();
        try {
            String sql = "delete from food where fid=?";
            pst = con.prepareStatement(sql);
            pst.setInt(1, fid);
            result = pst.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            DBUtil.closeConnection(con, pst, null);
        }
        return result;
    }

private Food fillFood(ResultSet rs) throws SQLException {
        return new Food(
                rs.getInt("fid"),
                rs.getString("fname"),
                rs.getString("explain"),
                rs.getDouble("price"),
                rs.getInt("bid")
        );
    }
}
```

#### 4、`controller`层

新建`com.doooog.elm.controller`包，创建`AdminCtrl.java`接口

```java
package com.doooog.elm.controller;

import com.doooog.elm.po.Admin;
import com.doooog.elm.po.Business;

public interface AdminCtrl {
    // 管理员部分
    boolean login(String username, String password);

boolean addAdmin(Admin admin);

boolean deleteAdminById(int aid);

void listAdminAll();

boolean updateAdminPasswordById(int aid, String oldPW, String newPW);

boolean getAdminById(int aid);

// 商家部分
    boolean addBusiness(Business business);

boolean deleteBusinessById(int bid);

boolean getBusinessById(int bid);

void listBusinessAll();

boolean updateBusinessPasswordById(int bid, String oldPW, String newPW);

boolean updateBusinessNameById(int bid, String name);

boolean updateBusinessAddressById(int bid, String address);

boolean updateBusinessExplainById(int bid, String explain);

boolean updateBusinessPriceById(int bid,double startPrice, double deliveryPrice);

}
```

新建`com.doooog.elm.controller.impl`包，创建`AdminCtrlImpl.java`类

```java
package com.doooog.elm.controller.impl;

import com.doooog.elm.controller.AdminCtrl;
import com.doooog.elm.dao.AdminDao;
import com.doooog.elm.dao.BusinessDao;
import com.doooog.elm.dao.impl.AdminDaoImpl;
import com.doooog.elm.dao.impl.BusinessDaoImpl;
import com.doooog.elm.po.Admin;
import com.doooog.elm.po.Business;

import java.util.List;

public class AdminCtrlImpl implements AdminCtrl {
    public boolean login(String username, String password) {
        if (username == null || password == null || username.isEmpty() || password.isEmpty()) return false;
        AdminDao adminDao = new AdminDaoImpl();
        Admin admin = adminDao.getAdminByLogin(username, password);
        return admin != null && !admin.isEmpty();
    }

@Override
    public boolean addAdmin(Admin admin) {
        if (admin == null) return false;
        if ((admin.getAid() == null || admin.getAid() <= 0) && !admin.isUnsafe(false)) {
            AdminDao adminDao = new AdminDaoImpl();
            return adminDao.addAdmin(admin) == 1;
        } else if (!admin.isUnsafe(true)) {
            AdminDao adminDao = new AdminDaoImpl();
            return adminDao.addAdminWithId(admin) == 1;
        }
        return false;
    }

@Override
    public boolean deleteAdminById(int aid) {
        if (aid <= 0) return false;
        AdminDao adminDao = new AdminDaoImpl();
        return adminDao.deleteAdminById(aid) == 1;
    }

@Override
    public void listAdminAll() {
        AdminDao adminDao = new AdminDaoImpl();
        List<Admin> list = adminDao.listAdminAll();
        if (list.isEmpty()) {
            System.out.println("未查询到信息");
            return;
        }
        for (Admin admin : list) {
            System.out.println(admin);
        }
    }

@Override
    public boolean updateAdminPasswordById(int aid, String oldPW, String newPW) {
        if (aid <= 0 || oldPW == null || oldPW.isEmpty() || newPW == null || newPW.isEmpty()) return false;
        AdminDao adminDao = new AdminDaoImpl();
        Admin admin = adminDao.getAdminById(aid);
        if (admin == null || !admin.getPassword().equals(oldPW)) return false;
        return adminDao.updateAdminPasswordById(aid, newPW) == 1;
    }

@Override
    public boolean getAdminById(int aid) {
        if (aid <= 0) {
            System.out.println("输入ID有误>0");
            return false;
        }
        AdminDao adminDao = new AdminDaoImpl();
        Admin admin = adminDao.getAdminById(aid);
        if (admin == null) {
            System.out.println("未查询到信息");
            return false;
        }
        System.out.println(admin);
        return true;
    }

@Override
    public boolean addBusiness(Business business) {
        if (business == null) return false;
        if ((business.getBid() == null || business.getBid() <= 0) && !business.isUnsafe(false)) {
            BusinessDao businessDao = new BusinessDaoImpl();
            int rs = businessDao.addBusiness(business);
            business.setBid(rs);
            return rs != 0;
        } else if (!business.isUnsafe(true)) {
            BusinessDao businessDao = new BusinessDaoImpl();
            int rs = businessDao.addBusinessWithId(business);
            business.setBid(rs);
            return rs != 0;
        }
        return false;
    }

@Override
    public boolean deleteBusinessById(int bid) {
        if (bid <= 0) return false;
        BusinessDao businessDao = new BusinessDaoImpl();
        return businessDao.deleteBusinessById(bid) == 1;
    }

@Override
    public boolean getBusinessById(int bid) {
        if (bid <= 0) {
            System.out.println("输入ID有误>0");
            return false;
        }
        BusinessDao businessDao = new BusinessDaoImpl();
        Business b = businessDao.getBusinessById(bid);
        if (b == null) {
            System.out.println("未查询到信息");
            return false;
        }
        System.out.println(b);
        return true;
    }

@Override
    public void listBusinessAll() {
        BusinessDao businessDao = new BusinessDaoImpl();
        List<Business> list = businessDao.listBusinessAll();
        if (list.isEmpty()) {
            System.out.println("未查询到信息");
            return;
        }
        for (Business b : list) {
            System.out.println(b);
        }
    }

@Override
    public boolean updateBusinessPasswordById(int bid, String oldPW, String newPW) {
        if (bid <= 0 || oldPW == null || oldPW.isEmpty() || newPW == null || newPW.isEmpty()) return false;
        BusinessDao businessDao = new BusinessDaoImpl();
        Business b = businessDao.getBusinessById(bid);
        if (b == null || !b.getPassword().equals(oldPW)) return false;
        b.setPassword(newPW);
        if (!b.isUnsafe(true)) return businessDao.updateBusinessById(b) == 1;
        return false;
    }

@Override
    public boolean updateBusinessNameById(int bid, String name) {
        if (bid <= 0 || name == null || name.isEmpty()) return false;
        BusinessDao businessDao = new BusinessDaoImpl();
        Business b = businessDao.getBusinessById(bid);
        if (b == null) return false;
        b.setBname(name);
        if (!b.isUnsafe(true)) return businessDao.updateBusinessById(b) == 1;
        return false;
    }

@Override
    public boolean updateBusinessAddressById(int bid, String address) {
        if (bid <= 0 || address == null || address.isEmpty()) return false;
        BusinessDao businessDao = new BusinessDaoImpl();
        Business b = businessDao.getBusinessById(bid);
        if (b == null) return false;
        b.setAddress(address);
        if (!b.isUnsafe(true)) return businessDao.updateBusinessById(b) == 1;
        return false;
    }

@Override
    public boolean updateBusinessExplainById(int bid, String explain) {
        if (bid <= 0 || explain == null || explain.isEmpty()) return false;
        BusinessDao businessDao = new BusinessDaoImpl();
        Business b = businessDao.getBusinessById(bid);
        if (b == null) return false;
        b.setExplain(explain);
        if (!b.isUnsafe(true)) return businessDao.updateBusinessById(b) == 1;
        return false;
    }

@Override
    public boolean updateBusinessPriceById(int bid, double startPrice, double deliveryPrice) {
        if (bid <= 0 || startPrice <= 0 || deliveryPrice <= 0) return false;
        BusinessDao businessDao = new BusinessDaoImpl();
        Business b = businessDao.getBusinessById(bid);
        if (b == null) return false;
        b.setStartPrice(startPrice);
        b.setDeliveryPrice(deliveryPrice);
        if (!b.isUnsafe(true)) return businessDao.updateBusinessById(b) == 1;
        return false;
    }
}
```

#### 5、`view`层

新建`com.doooog.elm.view`包，创建`MainEntry.java`类作为程序入口。

```java
package com.doooog.elm.view;

import com.doooog.elm.util.CommonUtil;
import com.doooog.elm.util.InputUtil;

public class MainEntry {
    public static void main(String[] args) {
        System.out.println(CommonUtil.copyChar('=', 30));
        System.out.println("|-- 欢迎进入饿了么后台管理系统 --|");
        MainEntry main = new MainEntry();
        main.menuMain();
    }

public void menuMain() {
        System.out.println("|-- 1.系统管理员  2.商家");
        System.out.print("|-- 请输入编号(-1退出):");
        int choice = InputUtil.menuInputInteger("(整数)");
        switch (choice) {
            case 1 -> new AdminView().menuLogin();
            case 2 -> new BusinessView().menuLogin();
            default -> {
            }
        }
    }
}
```

创建`AdminView.java`类

```java
package com.doooog.elm.view;

import com.doooog.elm.controller.impl.AdminCtrlImpl;
import com.doooog.elm.po.Admin;
import com.doooog.elm.po.Business;
import com.doooog.elm.util.CommonUtil;
import com.doooog.elm.util.InputUtil;

public class AdminView {
    private AdminCtrlImpl ctrl = new AdminCtrlImpl();

public void menuLogin() {
        System.out.println("|-- 请使用管理员身份进行登录 --|");
        System.out.print("|-- 请输入用户名:");
        String username = InputUtil.menuInputString("");
        System.out.print("|-- 请输入密码:");
        String password = InputUtil.menuInputString("");
        if (ctrl.login(username, password)) {
            System.out.println("登录成功!");
            menuMain();
        } else {
            System.out.println("登录失败，请检查账号或密码是否有误!");
        }
    }

public void menuMain() {
        boolean exit = false;
        while (!exit) {
            System.out.println(CommonUtil.copyChar('=', 30));
            System.out.println("|--        管理员菜单        --|");
            System.out.println("|-- 管理员操作-----------------");
            System.out.println("|-- 1.查看所有管理员");
            System.out.println("|-- 2.新增管理员");
            System.out.println("|-- 3.更改管理员密码");
            System.out.println("|-- 4.删除管理员");
            System.out.println("|-- 商家操作------------------");
            System.out.println("|-- 5.查看所有商家");
            System.out.println("|-- 6.新增商家");
            System.out.println("|-- 7.更改商家密码");
            System.out.println("|-- 8.更改商家名称");
            System.out.println("|-- 9.更改商家地址");
            System.out.println("|-- 10.更改商家介绍");
            System.out.println("|-- 11.更改商家配送价格");
            System.out.println("|-- 12.删除商家");
            System.out.println("|-- 0.退出系统");
            System.out.println(CommonUtil.copyChar('-', 30));
            System.out.print("|-- 请输入编号(0~12整数):");
            int choice = InputUtil.menuInputInteger("(0~12整数)");
            switch (choice) {
                case 0 -> exit = true;
                case 1 -> ctrl.listAdminAll();
                case 2 -> menuAddAdmin();
                case 3 -> menuRePasswordAdmin();
                case 4 -> menuDeleteAdmin();
                case 5 -> ctrl.listBusinessAll();
                case 6 -> menuAddBusiness();
                case 7 -> menuRePasswordBusiness();
                case 8 -> menuRename();
                case 9 -> menuReAddress();
                case 10 -> menuReExplain();
                case 11 -> menuRePrice();
                case 12 -> menuDeleteBusiness();
            }
        }
    }

public void menuAddAdmin() {
        Admin admin = new Admin();
        int tmp;
        String tmp2;
        System.out.println(CommonUtil.copyChar('=', 30));
        System.out.println("|-- 没有(必填)项输入0可跳过,输入-1返回上级菜单");
        System.out.print("|-- ID(整数):");
        tmp = InputUtil.menuInputInteger("(请输入整数,或0跳过)");
        if (tmp == -1) return;
        if (tmp != 0) admin.setAid(tmp);
        System.out.print("|-- 账号(字母+数字)(必填):");
        tmp2 = InputUtil.menuInputString("(字母+数字)(必填)");
        if (tmp2.equals("-1") || tmp2.equals("0")) return;
        admin.setAname(tmp2);
        System.out.print("|-- 密码(字母+数字)(必填):");
        tmp2 = InputUtil.menuInputString("(字母+数字)(必填)");
        if (tmp2.equals("-1") || tmp2.equals("0")) return;
        admin.setPassword(tmp2);
        if (ctrl.addAdmin(admin)) {
            System.out.println("添加成功!");
            return;
        }
        System.out.println("添加失败,请检查输入是否有误,ID可以为空");
    }

public void menuRePasswordAdmin() {
        Admin admin = new Admin();
        int tmp;
        String tmp2;
        System.out.println(CommonUtil.copyChar('=', 30));
        System.out.println("|-- 没有(必填)项输入0可跳过,输入-1返回上级菜单");
        System.out.print("|-- 需要更改的ID(整数)(必填):");
        tmp = InputUtil.menuInputInteger("(整数)提取方法…");
        if (tmp == -1 || tmp == 0) return;
        admin.setAid(tmp);
        System.out.print("|-- 旧密码(字母+数字)(必填):");
        tmp2 = InputUtil.menuInputString("(字母+数字)(必填)");
        if (tmp2.equals("-1") || tmp2.equals("0")) return;
        admin.setAname(tmp2);
        System.out.print("|-- 新密码(字母+数字)(必填):");
        tmp2 = InputUtil.menuInputString("(字母+数字)(必填)");
        if (tmp2.equals("-1") || tmp2.equals("0")) return;
        admin.setPassword(tmp2);
        if (ctrl.updateAdminPasswordById(admin.getAid(), admin.getAname(), admin.getPassword())) {
            System.out.println("修改成功!");
            return;
        }
        System.out.println("修改失败,请检查输入是否有误");
    }

public void menuDeleteAdmin() {
        int tmp;
        System.out.println(CommonUtil.copyChar('=', 30));
        System.out.println("|-- 没有(必填)项输入0可跳过,输入-1返回上级菜单");
        System.out.print("|-- 需要删除的ID(0以上整数)(必填):");
        tmp = InputUtil.menuInputInteger("(0以上整数)");
        if (tmp == -1) return;
        if (!ctrl.getAdminById(tmp)) return;
        if (!doChoice()) return;
        if (ctrl.deleteAdminById(tmp)) {
            System.out.println("删除成功!");
            return;
        }
        System.out.println("删除失败,未知错误");
    }

public void menuAddBusiness() {
        Business business = new Business();
        double tmp;
        String tmp2;
        System.out.println(CommonUtil.copyChar('=', 30));
        System.out.println("|-- 没有(必填)项输入0可跳过,输入-1返回上级菜单");

System.out.print("|-- 名称(必填):");
        tmp2 = InputUtil.menuInputString("(必填)");
        if (tmp2.equals("-1") || tmp2.equals("0")) return;
        business.setBname(tmp2);

System.out.print("|-- 密码(字母+数字)(必填):");
        tmp2 = InputUtil.menuInputString("(字母+数字)(必填)");
        if (tmp2.equals("-1") || tmp2.equals("0")) return;
        business.setPassword(tmp2);

System.out.print("|-- 地址:");
        tmp2 = InputUtil.menuInputString("");
        if (tmp2.equals("-1")) return;
        if (!tmp2.equals("0")) business.setAddress(tmp2);

System.out.print("|-- 介绍:");
        tmp2 = InputUtil.menuInputString("");
        if (tmp2.equals("-1")) return;
        if (!tmp2.equals("0")) business.setExplain(tmp2);

System.out.print("|-- 起送价格:");
        tmp = InputUtil.menuInputDouble("");
        if (tmp == -1) return;
        if (tmp != 0) business.setStartPrice(tmp);

System.out.print("|-- 配送价格:");
        tmp = InputUtil.menuInputDouble("");
        if (tmp == -1) return;
        if (tmp != 0) business.setDeliveryPrice(tmp);

System.out.print("|-- 确认信息:");
        System.out.println(business);
        if (!doChoice()) return;

if (ctrl.addBusiness(business)) {
            System.out.println("添加成功!");
            System.out.println("您用于登录的编号为:" + business.getBid());
            return;
        }
        System.out.println("添加失败,请检查输入是否有误");
    }

public void menuRePasswordBusiness() {
        Business business = new Business();
        int tmp;
        String tmp2;
        System.out.println(CommonUtil.copyChar('=', 30));
        System.out.println("|-- 没有(必填)项输入0可跳过,输入-1返回上级菜单");
        System.out.print("|-- 需要更改的ID(整数)(必填):");
        tmp = InputUtil.menuInputInteger("(整数)(必填)");
        if (tmp == -1 || tmp == 0) return;
        business.setBid(tmp);
        System.out.print("|-- 旧密码(字母+数字)(必填):");
        tmp2 = InputUtil.menuInputString("(字母+数字)(必填)");
        if (tmp2.equals("-1") || tmp2.equals("0")) return;
        business.setBname(tmp2);
        System.out.print("|-- 新密码(字母+数字)(必填):");
        tmp2 = InputUtil.menuInputString("(字母+数字)(必填)");
        if (tmp2.equals("-1") || tmp2.equals("0")) return;
        business.setPassword(tmp2);
        if (ctrl.updateBusinessPasswordById(business.getBid(), business.getBname(), business.getPassword())) {
            System.out.println("修改成功!");
            return;
        }
        System.out.println("修改失败,请检查输入是否有误");
    }

public void menuRename() {
        int tmp;
        String tmp2;
        System.out.println(CommonUtil.copyChar('=', 30));
        System.out.println("|-- 没有(必填)项输入0可跳过,输入-1返回上级菜单");
        System.out.print("|-- 需要更改的ID(整数)(必填):");
        tmp = InputUtil.menuInputInteger("(整数)(必填)");
        if (tmp == -1 || tmp == 0) return;
        System.out.print("|-- 新名称(必填):");
        tmp2 = InputUtil.menuInputString("(必填)");
        if (tmp2.equals("-1") || tmp2.equals("0")) return;
        if (ctrl.updateBusinessNameById(tmp, tmp2)) {
            System.out.println("修改成功!");
            return;
        }
        System.out.println("修改失败,请检查输入是否有误");
    }

public void menuReAddress() {
        int tmp;
        String tmp2;
        System.out.println(CommonUtil.copyChar('=', 30));
        System.out.println("|-- 没有(必填)项输入0可跳过,输入-1返回上级菜单");
        System.out.print("|-- 需要更改的ID(整数)(必填):");
        tmp = InputUtil.menuInputInteger("(整数)(必填)");
        if (tmp == -1 || tmp == 0) return;
        System.out.print("|-- 新地址(必填):");
        tmp2 = InputUtil.menuInputString("(必填)");
        if (tmp2.equals("-1") || tmp2.equals("0")) return;
        if (ctrl.updateBusinessAddressById(tmp, tmp2)) {
            System.out.println("修改成功!");
            return;
        }
        System.out.println("修改失败,请检查输入是否有误");
    }

public void menuReExplain() {
        int tmp;
        String tmp2;
        System.out.println(CommonUtil.copyChar('=', 30));
        System.out.println("|-- 没有(必填)项输入0可跳过,输入-1返回上级菜单");
        System.out.print("|-- 需要更改的ID(整数)(必填):");
        tmp = InputUtil.menuInputInteger("(整数)(必填)");
        if (tmp == -1 || tmp == 0) return;
        System.out.print("|-- 新介绍(必填):");
        tmp2 = InputUtil.menuInputString("(必填)");
        if (tmp2.equals("-1") || tmp2.equals("0")) return;
        if (ctrl.updateBusinessExplainById(tmp, tmp2)) {
            System.out.println("修改成功!");
            return;
        }
        System.out.println("修改失败,请检查输入是否有误");
    }

public void menuRePrice() {
        int tmp;
        double tmp2, tmp3;
        System.out.println(CommonUtil.copyChar('=', 30));
        System.out.println("|-- 没有(必填)项输入0可跳过,输入-1返回上级菜单");
        System.out.print("|-- 需要更改的ID(整数)(必填):");
        tmp = InputUtil.menuInputInteger("(整数)(必填)");
        if (tmp == -1 || tmp == 0) return;
        System.out.print("|-- 新起送价(大于0的小数)(必填):");
        tmp2 = InputUtil.menuInputDouble("(大于0的小数)(必填)");
        if (tmp2 == -1 || tmp2 == 0) return;
        System.out.print("|-- 新配送价(大于0的小数)(必填):");
        tmp3 = InputUtil.menuInputDouble("(大于0的小数)(必填)");
        if (tmp3 == -1 || tmp3 == 0) return;
        if (ctrl.updateBusinessPriceById(tmp, tmp2, tmp3)) {
            System.out.println("修改成功!");
            return;
        }
        System.out.println("修改失败,请检查输入是否有误");
    }

public void menuDeleteBusiness() {
        int tmp;
        System.out.println(CommonUtil.copyChar('=', 30));
        System.out.println("|-- 没有(必填)项输入0可跳过,输入-1返回上级菜单");
        System.out.print("|-- 需要删除的ID(整数)(必填):");
        tmp = InputUtil.menuInputInteger("(整数)(必填)");
        if (tmp == -1 || tmp == 0) return;
        if (!ctrl.getBusinessById(tmp)) return;
        if (!doChoice()) return;
        if (ctrl.deleteBusinessById(tmp)) {
            System.out.println("删除成功!");
            return;
        }
        System.out.println("删除失败,请检查输入是否有误");
    }

public boolean doChoice() {
        System.out.print("|-- 确认无误(1.是,2.否):");
        int tmp = InputUtil.menuInputInteger("(1.是,2.否)");
        return tmp == 1;
    }
}
```