《基于JDBC实现一个简易的人员信息管理系统》

一、基本思想

基于MVC经典的架构模式，各层之间分工明确，保证了低耦合。具体如下：

• Model layer：数据库连接，实体类，DAO层
• View layer：调用Control layer
• Control layer：调用Model layer

---

二、需求分析

基于JDBC实现一个简易的人员信息管理系统，该系统基本可以完成人员信息的添加、删除、查询、更新（修改）等过程（即CRUD），视图层使用简单的控制台方式来展示（因为视图层在这里不是重点）。

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三、前期准备

1. 创建人员信息数据库

打开Navicat 12 for MySQL，新建一个连接，这里为“mysql”，然后创建一个数据库，这里为“mydatabase”，然后右键该数据库名，进入命令列界面输入如下MySQL语句建立人员信息表：

create table people_information(
     id int primary key auto_increment,
     userName varchar(30) not null,
     sex int,
     age int,
     birthday date,
     email varchar(30),
     mobile varchar(11),
     createUser varchar(30),
     createDate date,
     updateUser varchar(30),
     updateDate date,
     isDel int
     )engine=innodb default charset=utf8 auto_increment=1;

alter database mysql default character set 'utf8';
SET character_set_client='utf8';
SET character_set_connection='utf8';
SET character_set_results='utf8';

执行语句之后，界面如下：

2. 工程目录组织

---

四、代码实现

1. Model layer

Code：

JDBC_Connection.java

package com.wuchangi.Model_Layer;

import java.sql.*;

/*
 * @program: JDBC_PeopleInformation
 * @description: Tool Class to get the connection to the MySQL Database.
 * @author: WuchangI
 * @create: 2018-05-13-10-23
 **/

public class JDBC_Connection
{

    private static final String URL = "jdbc:mysql://localhost:3306/mysql?serverTimezone=GMT&useSSL=false";
    private static final String USER = "root";
    private static final String PASSWORD = "123456";

    private static Connection connection = null;

    static
    {
        //1.Loading driver using class name by reflection
        //Old loading method： "com.mysql.jdbc.Driver"
        try
        {
            Class.forName("com.mysql.cj.jdbc.Driver");
        }
        catch (ClassNotFoundException e)
        {
            e.printStackTrace();
        }


        //2.Get the connection to the MySQL Database
        try
        {
            connection = DriverManager.getConnection(URL, USER, PASSWORD);
        }
        catch (SQLException e)
        {
            e.printStackTrace();
        }

    }

    public static Connection getConnection()
    {
        return connection;
    }

}

Code：

PeopleInformation.java

package com.wuchangi.Model_Layer;

import java.util.Date;


/*
 * @program: JDBC_PeopleInformation
 * @description: PeopleInformation Model Class
 * @author: WuchangI
 * @create: 2018-05-13-10-23
 **/

public class PeopleInformation
{
    //人员唯一的编号，设置为主键且自增
    private Integer id;
    //人员的姓名
    private String userName;
    //人员的性别，0为男性，1为女性
    private Integer sex;
    //人员的年龄
    private Integer age;
    //人员的生日
    private Date birthday;
    //人员的邮箱
    private String email;
    //人员的手机号码
    private String mobile;
    //创建该记录的人的名称
    private String createUser;
    //更新该记录的人的名称
    private String updateUser;
    //该记录创建日期
    private Date createDate;
    //该记录更新日期
    private Date updateDate;
    //是否删除，1为删除，0为不删除
    private Integer isDel;

    public Integer getId()
    {
        return id;
    }

    public void setId(Integer id)
    {
        this.id = id;
    }

    public String getUserName()
    {
        return userName;
    }

    public void setUserName(String userName)
    {
        this.userName = userName;
    }

    public Integer getSex()
    {
        return sex;
    }

    public void setSex(Integer sex)
    {
        this.sex = sex;
    }

    public Integer getAge()
    {
        return age;
    }

    public void setAge(Integer age)
    {
        this.age = age;
    }

    public Date getBirthday()
    {
        return birthday;
    }

    public void setBirthday(Date birthday)
    {
        this.birthday = birthday;
    }

    public String getEmail()
    {
        return email;
    }

    public void setEmail(String email)
    {
        this.email = email;
    }

    public String getMobile()
    {
        return mobile;
    }

    public void setMobile(String mobile)
    {
        this.mobile = mobile;
    }

    public String getCreateUser()
    {
        return createUser;
    }

    public void setCreateUser(String createUser)
    {
        this.createUser = createUser;
    }

    public String getUpdateUser()
    {
        return updateUser;
    }

    public void setUpdateUser(String updateUser)
    {
        this.updateUser = updateUser;
    }

    public Date getCreateDate()
    {
        return createDate;
    }

    public void setCreateDate(Date createDate)
    {
        this.createDate = createDate;
    }

    public Date getUpdateDate()
    {
        return updateDate;
    }

    public void setUpdateDate(Date updateDate)
    {
        this.updateDate = updateDate;
    }

    public Integer getIsDel()
    {
        return isDel;
    }

    public void setIsDel(Integer isDel)
    {
        this.isDel = isDel;
    }

    @Override
    public String toString()
    {
        return "PeopleInformation{" + "id=" + id + ", userName='" + userName + '\'' + ", sex=" + sex + ", age=" + age + ", birthday=" + birthday + ", email='" + email + '\'' + ", mobile='" + mobile + '\'' + ", createUser='" + createUser + '\'' + ", updateUser='" + updateUser + '\'' + ", createDate=" + createDate + ", updateDate=" + updateDate + ", isDel=" + isDel + '}';
    }

}

Code:

DAO.java

package com.wuchangi.Model_Layer;

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

/*
 * @program: JDBC_PeopleInformation
 * @description: DAO Layer
 * @author: WuchangI
 * @create: 2018-05-13-10-23
 **/

public class DAO
{
    //添加一个新的人员信息
    public void addPeopleInformation(PeopleInformation peopleInformation) throws SQLException
    {
        //拿到数据库的连接
        Connection connection = JDBC_Connection.getConnection();

        String sql = "" +
                " insert into mydatabase.people_information(userName, sex, age, birthday, email, mobile," +
                "createUser, createDate, updateUser, updateDate, isDel)"+
                " values(" + "?,?,?,?,?,?,?,current_date(),?,current_date(),?6)";

        //预编译SQL语句,并不直接执行
        PreparedStatement preparedStatement = connection.prepareStatement(sql);

        //设置SQL语句的参数
        preparedStatement.setString(1, peopleInformation.getUserName());
        preparedStatement.setInt(2, peopleInformation.getSex());
        preparedStatement.setInt(3, peopleInformation.getAge());

        //注意getBirthday返回的是java.util.Date,而setDate的参数是java.sql.Date,需要进行转换
        preparedStatement.setDate(4, new Date(peopleInformation.getBirthday().getTime()));
        preparedStatement.setString(5, peopleInformation.getEmail());
        preparedStatement.setString(6, peopleInformation.getMobile());
        preparedStatement.setString(7, peopleInformation.getCreateUser());
        preparedStatement.setString(8, peopleInformation.getUpdateUser());
        preparedStatement.setInt(9, peopleInformation.getIsDel());

        //执行SQL语句
        preparedStatement.execute();
    }


    //更新id为peopleInformation.getId()的人员的信息
    public void updatePeopleInformation(PeopleInformation peopleInformation) throws SQLException
    {
        //拿到数据库的连接
        Connection connection = JDBC_Connection.getConnection();

        String sql = "" +
                " update mydatabase.people_information"+
                " set userName=?, sex=?, age=?, birthday=?, email=?, mobile=?, updateUser=?, updateDate=current_date(), isDel=?"+
                " where id=?";

        //预编译SQL语句,并不直接执行
        PreparedStatement preparedStatement = connection.prepareStatement(sql);

        //设置SQL语句的参数
        preparedStatement.setString(1, peopleInformation.getUserName());
        preparedStatement.setInt(2, peopleInformation.getSex());
        preparedStatement.setInt(3, peopleInformation.getAge());
        //注意getBirthday返回的是java.util.Date,而setDate的参数是java.sql.Date,需要进行转换
        preparedStatement.setDate(4, new Date(peopleInformation.getBirthday().getTime()));
        preparedStatement.setString(5, peopleInformation.getEmail());
        preparedStatement.setString(6, peopleInformation.getMobile());
        preparedStatement.setString(7, peopleInformation.getUpdateUser());
        preparedStatement.setInt(8, peopleInformation.getIsDel());
        preparedStatement.setInt(9, peopleInformation.getId());

        //执行SQL语句
        preparedStatement.execute();
    }

    //删除指定id的人员的信息
    public void deletePeopleInformation(Integer id) throws SQLException
    {
        //拿到数据库的连接
        Connection connection = JDBC_Connection.getConnection();

        String sql = "" +
                " delete from mydatabase.people_information" +
                " where id=?";

        //预编译SQL语句,并不直接执行
        PreparedStatement preparedStatement = connection.prepareStatement(sql);

        //设置SQL语句的参数
        preparedStatement.setInt(1, id);

        //执行SQL语句
        preparedStatement.execute();

    }


    //查询数据库中所有人员的基本信息（id + 姓名 + 年龄）
    public List queryPeopleInformation() throws SQLException
    {
        Connection connection = JDBC_Connection.getConnection();

        //通过数据库的连接操纵数据库，实现增删查改
        Statement stmt = connection.createStatement();

        //其中ResultSet使用的是java.sql.ResultSet
        ResultSet resultSet = stmt.executeQuery("select id, userName, age from mydatabase.people_information");

        List peopleInformations = new ArrayList();
        PeopleInformation peopleInformation = null;

        while(resultSet.next())
        {
            peopleInformation = new PeopleInformation();
            peopleInformation.setId(resultSet.getInt("id"));
            peopleInformation.setUserName(resultSet.getString("userName"));
            peopleInformation.setAge(resultSet.getInt("age"));
            peopleInformations.add(peopleInformation);
        }

        return peopleInformations;
    }

    //根据指定条件检索数据库中的所有人员的信息
    //一个Map存储一个条件表达式，比如 userName = '小美'
    public List queryPeopleInformation(List> params) throws SQLException
    {
        //拿到数据库的连接
        Connection connection = JDBC_Connection.getConnection();

        StringBuilder sql = new StringBuilder();
        sql.append("select * from mydatabase.people_information where 1=1");

        //设置SQL语句的参数
        if(params!=null &¶ms.size() > 0)
        {
            for(int i = 0; i < params.size(); i++)
            {
                Map map = params.get(i);
                sql.append(" and " + map.get("name") + " " + map.get("relation") + " " + map.get("value"));
            }
        }

        //预编译SQL语句,并不直接执行
        PreparedStatement preparedStatement = connection.prepareStatement(sql.toString());

        ResultSet resultSet = preparedStatement.executeQuery();

        List peopleInformations = new ArrayList();
        PeopleInformation peopleInformation = null;

        while(resultSet.next())
        {
            peopleInformation = new PeopleInformation();

            peopleInformation.setId(resultSet.getInt("id"));
            peopleInformation.setUserName(resultSet.getString("userName"));
            peopleInformation.setAge(resultSet.getInt("age"));
            peopleInformation.setSex(resultSet.getInt("sex"));
            //getDate()返回的是java.sql.Date，不过不必转换，直接使用，因为java.sql.Date是java.util.Date的子集
            peopleInformation.setBirthday(resultSet.getDate("birthday"));
            peopleInformation.setEmail(resultSet.getString("email"));
            peopleInformation.setMobile(resultSet.getString("mobile"));
            peopleInformation.setCreateUser(resultSet.getString("createUser"));
            peopleInformation.setCreateDate(resultSet.getDate("createDate"));
            peopleInformation.setUpdateUser(resultSet.getString("updateUser"));
            peopleInformation.setUpdateDate(resultSet.getDate("updateDate"));
            peopleInformation.setIsDel(resultSet.getInt("isDel"));

            peopleInformations.add(peopleInformation);
        }

        return peopleInformations;
    }


    //查询指定id的人员的信息（只能有一个）
    public PeopleInformation getPeopleInformation(Integer id) throws SQLException
    {

        PeopleInformation peopleInformation = null;

        //拿到数据库的连接
        Connection connection = JDBC_Connection.getConnection();

        String sql = "" +
                " select * from mydatabase.people_information"+
                " where id=?";

        //预编译SQL语句,并不直接执行
        PreparedStatement preparedStatement = connection.prepareStatement(sql);

        //设置SQL语句的参数
        preparedStatement.setInt(1, id);

        //执行查询操作
        ResultSet resultSet = preparedStatement.executeQuery();
        while(resultSet.next())
        {
            peopleInformation = new PeopleInformation();

            peopleInformation.setId(resultSet.getInt("id"));
            peopleInformation.setUserName(resultSet.getString("userName"));
            peopleInformation.setAge(resultSet.getInt("age"));
            peopleInformation.setSex(resultSet.getInt("sex"));
            //getDate()返回的是java.sql.Date，不过不必转换，直接使用，因为java.sql.Date是java.util.Date的子集
            peopleInformation.setBirthday(resultSet.getDate("birthday"));
            peopleInformation.setEmail(resultSet.getString("email"));
            peopleInformation.setMobile(resultSet.getString("mobile"));
            peopleInformation.setCreateUser(resultSet.getString("createUser"));
            peopleInformation.setCreateDate(resultSet.getDate("createDate"));
            peopleInformation.setUpdateUser(resultSet.getString("updateUser"));
            peopleInformation.setUpdateDate(resultSet.getDate("updateDate"));
            peopleInformation.setIsDel(resultSet.getInt("isDel"));
        }

        return peopleInformation;
    }

}

2. View layer

Code:

View.java

package com.wuchangi.View_Layer;


import com.wuchangi.Model_Layer.PeopleInformation;
import com.wuchangi.Control_Layer.Control;

import java.sql.SQLException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;

/*
 * @program: JDBC_PeopleInformation
 * @description: View Layer
 * @author: WuchangI
 * @create: 2018-05-13-10-23
 **/

//使用控制台作为视图层
public class View
{

    //主菜单提示信息
    private static final String MAIN_MENU_CONTENT = "\t\t****欢迎使用人员信息管理系统!****\n\n" +
            "下面是该系统的功能列表：\n\n" +
            "[QUERY/Q]:  查看全部人员的基本信息(id、姓名、年龄)\n" +
            "[GET/G]:    查看某个人的具体信息\n" +
            "[ADD/A]:    添加新的人员信息\n" +
            "[UPDATE/U]: 更新人员信息\n" +
            "[DELETE/D]: 删除人员信息\n" +
            "[SEARCH/S]: 查询指定的人员信息(根据姓名、手机号码查询)\n" +
            "[EXIT/E]:   退出系统\n" +
            "\n请输入您想使用的功能项：";

    //相关操作标记
    private static final String OPERATION_QUERY = "QUERY";
    private static final String OPERATION_GET = "GET";
    private static final String OPERATION_ADD = "ADD";
    private static final String OPERATION_UPDATE = "UPDATE";
    private static final String OPERATION_DELETE = "DELETE";
    private static final String OPERATION_SEARCH = "SEARCH";
    private static final String OPERATION_EXIT = "EXIT";
    private static final String OPERATION_BREAK = "BREAK";


    public static void main(String[] args)
    {
        //展示主菜单界面
        System.out.println(MAIN_MENU_CONTENT);

        Scanner scan = new Scanner(System.in);

        Control control = new Control();

        //记录之前执行的条件分支
        String previousBranch = "";

        Integer step = 1;

        String inputValue = null;

        PeopleInformation peopleInformation = new PeopleInformation();

        List> params = new ArrayList>();

        Map map = new HashMap();

        while (scan.hasNext())
        {
            inputValue = scan.next().toString();

            if (inputValue.toUpperCase().equals(OPERATION_EXIT) || inputValue.toUpperCase().equals(OPERATION_EXIT.substring(0, 1)))
            {
                System.out.println("您已成功退出系统！");
                break;
            }
            else if (inputValue.toUpperCase().equals(OPERATION_QUERY) || inputValue.toUpperCase().equals(OPERATION_QUERY.substring(0, 1)))
            {
                try
                {
                    System.out.println("当前数据库中已有的人员基本信息如下：\n");
                    List plist = control.query();
                    for (PeopleInformation p : plist)
                    {
                        System.out.println("id:" + p.getId() + " , 姓名:" + p.getUserName() + ", 年龄:" + p.getAge());
                    }

                    System.out.println("\n退出当前功能，返回主菜单，请输入[BREAK/B]; 退出系统，请输入[EXIT/E]：");
                }
                catch (SQLException e)
                {
                    System.out.println("查看人员基本信息失败！");
                    e.printStackTrace();
                }

            }
            else if (inputValue.toUpperCase().equals(OPERATION_GET) || inputValue.toUpperCase().equals(OPERATION_GET.substring(0, 1)) || previousBranch.equals(OPERATION_GET))
            {
                previousBranch = OPERATION_GET;

                switch (step)
                {
                    case 1:
                        System.out.println("请输入您所要查询的人员的id号：");
                        break;

                    case 2:
                        Integer idTobeSearched = Integer.valueOf(inputValue);
                        try
                        {
                            PeopleInformation p = control.get(idTobeSearched);
                            System.out.println("该人员的具体信息如下：");
                            System.out.println("id：" + p.getId() + " ,姓名：" + p.getUserName() + " ,性别：" + p.getSex() +
                            " ,年龄：" + p.getAge() + " ,生日：" + p.getBirthday() + " ,邮箱：" + p.getEmail() + " ,手机号码：" +
                            p.getMobile());
                        }
                        catch (SQLException e)
                        {
                            System.out.println("查询人员信息失败！");
                            e.printStackTrace();
                        }
                        break;
                }

                if (step == 2)
                {
                    step = 1;
                    previousBranch = "";
                    System.out.println("\n退出当前功能，返回主菜单，请输入[BREAK/B]; 退出系统，请输入[EXIT/E]：");
                }
                else
                {
                    step++;
                }
            }
            //添加新的人员信息(只需添加新增人员的 姓名 + 性别 + 年龄+ 生日 + 邮箱 + 手机号码)
            else if (inputValue.toUpperCase().equals(OPERATION_ADD) || inputValue.toUpperCase().equals(OPERATION_ADD.substring(0, 1)) || previousBranch.equals(OPERATION_ADD))
            {
                previousBranch = OPERATION_ADD;

                switch (step)
                {
                    case 1:
                        System.out.println("请输入新增人员的[姓名]：");
                        break;

                    case 2:
                        peopleInformation.setUserName(inputValue);
                        System.out.println("请输入新增人员的[性别]：(0为男性，1为女性)");
                        break;

                    case 3:
                        System.out.println(Integer.valueOf(inputValue));
                        peopleInformation.setSex(Integer.valueOf(inputValue));
                        System.out.println("请输入新增人员的[年龄]：");
                        break;

                    case 4:
                        peopleInformation.setAge(Integer.valueOf(inputValue));
                        System.out.println("请输入新增人员的[生日]：（格式为：yyyy-MM-dd）");
                        break;

                    case 5:
                        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
                        Date birthday = null;

                        try
                        {
                            birthday = sdf.parse(inputValue);
                            peopleInformation.setBirthday(birthday);
                            System.out.println("请输入新增人员的[邮箱]：");
                        }
                        catch (ParseException e)
                        {
                            System.out.println("您输入的格式有误！");
                            e.printStackTrace();
                        }
                        break;

                    case 6:
                        peopleInformation.setEmail(inputValue);
                        System.out.println("请输入新增人员的[手机号码]：");
                        break;

                    case 7:
                        peopleInformation.setMobile(inputValue);
                        try
                        {
                            control.add(peopleInformation);
                            System.out.println("添加新的人员信息成功！");
                        }
                        catch (SQLException e)
                        {
                            System.out.println("添加新的人员信息失败！");
                            e.printStackTrace();
                        }
                        break;
                }

                if (step == 7)
                {
                    step = 1;
                    previousBranch = "";
                    System.out.println("\n退出当前功能，返回主菜单，请输入[BREAK/B]; 退出系统，请输入[EXIT/E]：");
                }
                else
                {
                    step++;
                }
            }
            else if (inputValue.toUpperCase().equals(OPERATION_UPDATE) || inputValue.toUpperCase().equals(OPERATION_UPDATE.substring(0, 1)) || previousBranch.equals(OPERATION_UPDATE))
            {
                previousBranch = OPERATION_UPDATE;

                switch (step)
                {
                    case 1:
                        System.out.println("请输入待更新的人员的[姓名]：");
                        break;

                    case 2:
                        peopleInformation.setUserName(inputValue);
                        System.out.println("请输入待更新人员的[性别]：(0为男性，1为女性)");
                        break;

                    case 3:
                        peopleInformation.setSex(Integer.valueOf(inputValue));
                        System.out.println("请输入待更新人员的[年龄]：");
                        break;

                    case 4:
                        peopleInformation.setAge(Integer.valueOf(inputValue));
                        System.out.println("请输入待更新人员的[生日]：（格式为：yyyy-MM-dd）");
                        break;

                    case 5:
                        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
                        Date birthday = null;

                        try
                        {
                            birthday = sdf.parse(inputValue);
                            peopleInformation.setBirthday(birthday);
                            System.out.println("请输入待更新人员的[邮箱]：");
                        }
                        catch (ParseException e)
                        {
                            e.printStackTrace();
                            System.out.println("您输入的格式有误，请重新输入!");
                            step = 4;
                        }
                        break;

                    case 6:
                        peopleInformation.setEmail(inputValue);
                        System.out.println("请输入待更新人员的[手机号码]：");
                        break;

                    case 7:
                        peopleInformation.setMobile(inputValue);
                        System.out.println("请输入待更新人员的[id]：");
                        break;

                    case 8:
                        peopleInformation.setId(Integer.valueOf(inputValue));
                        try
                        {
                            control.update(peopleInformation);
                            System.out.println("更新人员信息成功！");

                        }
                        catch (SQLException e)
                        {
                            System.out.println("更新人员信息失败！");
                            e.printStackTrace();
                        }
                        break;
                }

                if (step == 8)
                {
                    step = 1;
                    previousBranch = "";
                    System.out.println("\n退出当前功能，返回主菜单，请输入[BREAK/B]; 退出系统，请输入[EXIT/E]：");
                }
                else
                {
                    step++;
                }

            }
            else if (inputValue.toUpperCase().equals(OPERATION_DELETE) || inputValue.toUpperCase().equals(OPERATION_DELETE.substring(0, 1)) || previousBranch.equals(OPERATION_DELETE))
            {
                previousBranch = OPERATION_DELETE;

                switch (step)
                {
                    case 1:
                        System.out.println("请输入您要删除的人员的id号：");
                        break;

                    case 2:
                        Integer idTobeSearched = Integer.valueOf(inputValue);
                        try
                        {
                            control.del(idTobeSearched);
                            System.out.println("删除该人员信息成功！");
                        }
                        catch (SQLException e)
                        {
                            System.out.println("删除该人员信息失败！");
                            e.printStackTrace();
                        }
                        break;
                }

                if (step == 2)
                {
                    step = 1;
                    previousBranch = "";
                    System.out.println("\n退出当前功能，返回主菜单，请输入[BREAK/B]; 退出系统，请输入[EXIT/E]：");
                }
                else
                {
                    step++;
                }

            }
            else if (inputValue.toUpperCase().equals(OPERATION_SEARCH) || inputValue.toUpperCase().equals(OPERATION_SEARCH.substring(0, 1)) || previousBranch.equals(OPERATION_SEARCH))
            {
                previousBranch = OPERATION_SEARCH;

                switch(step)
                {
                    case 1:
                        System.out.println("请输入所要查找的人员的姓名：");
                        map.put("name", "userName");
                        map.put("relation", "=");
                        break;
                    case 2:
                        map.put("value", inputValue);
                        params.add(map);
                        System.out.println("请输入所要查找的人员的手机号码：");
                        map.put("name", "mobile");
                        map.put("relation", "=");
                        break;
                    case 3:
                        map.put("value", inputValue);
                        params.add(map);
                        break;
                }

                if (step == 3)
                {
                    try
                    {
                        System.out.println("符合您查询条件的人员信息如下：");
                        List pList = control.query(params);
                        for(PeopleInformation p: pList)
                        {
                            System.out.println("id：" + p.getId() + " ,姓名：" + p.getUserName() + " ,性别：" + p.getSex() +
                                    " ,年龄：" + p.getAge() + " ,生日：" + p.getBirthday() + " ,邮箱：" + p.getEmail() + " ,手机号码：" +
                                    p.getMobile());
                        }
                    }
                    catch (SQLException e)
                    {
                        System.out.println("查询人员信息失败！");
                        e.printStackTrace();
                    }

                    step = 1;
                    previousBranch = "";
                    params = new ArrayList>();
                    System.out.println("\n退出当前功能，返回主菜单，请输入[BREAK/B]; 退出系统，请输入[EXIT/E]：");
                }
                else
                {
                    step++;
                }
            }
            else if (inputValue.toUpperCase().equals(OPERATION_BREAK) || inputValue.toUpperCase().equals(OPERATION_BREAK.substring(0, 1)))
            {
                System.out.println("\n" + MAIN_MENU_CONTENT);
            }
        }

    }

}

3. Control layer

Code:

Control.java

package com.wuchangi.Control_Layer;

import com.wuchangi.Model_Layer.DAO;
import com.wuchangi.Model_Layer.PeopleInformation;

import java.sql.SQLException;
import java.util.*;

/*
 * @program: JDBC_PeopleInformation
 * @description: Control Layer
 * @author: WuchangI
 * @create: 2018-05-13-10-23
 **/

public class Control
{
    //查看某个人的详细信息
    public PeopleInformation get(Integer id) throws SQLException
    {
        DAO dao = new DAO();
        return dao.getPeopleInformation(id);
    }

    //添加某个人的信息
    public void add(PeopleInformation peopleInformation) throws SQLException
    {
        DAO dao = new DAO();

        peopleInformation.setCreateUser("ADMIN");
        peopleInformation.setUpdateUser("ADMIN");
        peopleInformation.setIsDel(0);

        dao.addPeopleInformation(peopleInformation);
    }

    //更新某个人（id为peopleInformation.getId()）的人的信息
    public void update(PeopleInformation peopleInformation) throws SQLException
    {
        DAO dao = new DAO();

        peopleInformation.setCreateUser("ADMIN");
        peopleInformation.setUpdateUser("ADMIN");
        peopleInformation.setIsDel(0);

        dao.updatePeopleInformation(peopleInformation);
    }

    //删除某个人的信息
    public void del(Integer id) throws SQLException
    {
        DAO dao = new DAO();
        dao.deletePeopleInformation(id);
    }

    //查询数据库中所有人员的基本信息（id + 姓名 + 年龄）
    public List query() throws SQLException
    {
        DAO dao = new DAO();
        List peopleInformationList =dao.queryPeopleInformation();
        return peopleInformationList;
    }

    //查询数据库中符合指定条件的所有人员的信息
    public List query(List> params) throws SQLException
    {
        DAO dao = new DAO();
        List peopleInformationsList = dao.queryPeopleInformation(params);
        return peopleInformationsList;
    }
}