Java代码实现班级通讯录系统(连接mysql数据库)

Java代码实现班级通讯录系统(连接mysql数据库)

package one;

import java.sql.*;
import java.util.Scanner;

public class AddressBook_Pro {
         private static String connect = "jdbc:mysql:///studentinformation";
         private static String user = "root";
         private static String passward = "root";
         private static String driver="com.mysql.cj.jdbc.Driver";
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        while(true){
            welcome();

            System.out.println("请输入您的选择:");
            int choice = sc.nextInt();
            switch (choice){
                case 1:
                    DataBaseAdd();
                    break;
                case 2:
                    DataBaseDelete();
                    break;
                case 3:
                    DataBaseChange();
                    break;
                case 4:
                    DataBaseFindAll();
                    break;
                case 5:
                    DataBaseFindsingle();
                    break;
                case 6:
                    System.out.println("谢谢使用!");
                    System.exit(0);
                    break;
                default:
                    System.out.println("您输入的信息有误");
                    break;
            }
        }
    }


    public static void welcome(){
        System.out.println("***************欢迎来到学生信息管理系统!!****************");
        System.out.println("----------1.添加学生通讯录信息--------------");
        System.out.println("----------2.删除学生通讯录信息--------------");
        System.out.println("----------3.修改学生通讯录信息--------------");
        System.out.println("----------4.查询所有学生的通讯录信息---------");
        System.out.println("----------5.按学号查询单个学生的通讯录信息----");
        System.out.println("----------6.退出-------------------------");
    }


    public static void DataBaseAdd(){
        Scanner sc = new Scanner(System.in);
        Connection();
        Connection conn = null;
        Statement stmt = null;
        ResultSet resultSet = null;
        try {
            String id;
            String name;
            String qq;
            String phone;
            String address;

            //定义sql语句
            String sql1 = "select * from addressbook";
            //3.获取连接对象
            conn = DriverManager.getConnection(connect, user, passward);
            stmt = conn.createStatement();

            resultSet = stmt.executeQuery(sql1);

            while(true){
                resultSet = stmt.executeQuery(sql1);
                resultSet.next();
                System.out.println("请输入学生学号:");
                id = sc.next();
                if(resultSet.isAfterLast()!=resultSet.isBeforeFirst()){
                ////isBeforeFirst()的作用是获取光标是否位于此 ResultSet 对象的第一行之前，而isAfterLast()的作用是获取光标是否位于此ResultSet 对象的最后一行之后，若这两个得到的值相等，则说明rs获得的内容为空；注意一点是rs获得的内容的判断不能用null来进行判断，若使用，则不能实现所要的结果。
                    if(resultSet.getString("id").equals(id)) {
                        System.out.println("您输入的学号已经存在，请重新输入!");
                        continue;
                    }else {
                        resultSet.close();
                        break;
                    }
                }else {
                    resultSet.close();
                    break;
                }
            }

            System.out.println("请输入学生姓名:");
            name = sc.next();

            System.out.println("请输入学生QQ:");
            qq = sc.next();

            System.out.println("请输入学生phone");
            phone = sc.next();

            System.out.println("请输入学生address");
            address = sc.next();
            //定义SQL
            String sql = "insert into addressbook(id,name,qq,phone,address) value('"+id+"','"+name+"','"+ qq +"','"+phone+"','"+address+"')";

            int count = stmt.executeUpdate(sql);
            if(count>0){
                System.out.println("添加成功！");
            }else{
                System.out.println("添加失败！");
            }

        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (resultSet != null) {
                try {
                    resultSet.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
    }


    public static void DataBaseChange(){
        Scanner sc = new Scanner(System.in);
        Connection();
        Connection conn = null;
        Statement stmt = null;
        ResultSet resultSet = null;
        try{
            int count =0;
            String qq ;
            String name ;
            String phone ;
            String address ;

            System.out.println("请输入您要修改的学号: ");
            String id = sc.next();
            //获取连接对象
            conn = DriverManager.getConnection(connect, user, passward);
            //定义sql语句
            String sql1 =  "select * from addressbook where id = ('"+id+"')";
            stmt = conn.createStatement();
            resultSet = stmt.executeQuery(sql1);

            while(resultSet.next()){
                if(resultSet.getString("id").equals(id)) {
                    System.out.println("请输入学生姓名:");
                    name = sc.next();

                    System.out.println("请输入学生QQ:");
                    qq = sc.next();

                    System.out.println("请输入学生phone");
                    phone = sc.next();

                    System.out.println("请输入学生address");
                    address = sc.next();

                    String sql =  "update addressbook set name='"+name+"',qq='"+qq+"',phone='"+phone+"',address='"+address+"' where id = '"+id+"' ";
                    int num = stmt.executeUpdate(sql);

                    if (num > 0) {
                        System.out.println("修改成功!");
                    } else {
                        System.out.println("修改失败!");
                        System.out.println("请检查输入的学号!");
                    }
                    count++;
                    break;
                }
            }
            if(count ==0){
                System.out.println("very sorry,您要输入的学生信息不存在,请重新输入!");
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (resultSet != null) {
                try {
                    resultSet.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
    }


    public static void DataBaseDelete(){
        Scanner sc = new Scanner(System.in);
        Connection();
        Connection conn = null;
        Statement stmt = null;
        try{//获取连接对象
            conn = DriverManager.getConnection(connect, user, passward);
            stmt = conn.createStatement();

            System.out.println("请输入您要删除的学号: ");
            String input = sc.next();
            //定义sql语句
            String sql =  "delete from addressbook where id = ('"+input+"')";
            int count = stmt.executeUpdate(sql);

            if (count > 0) {
                System.out.println("删除成功!");
            } else {
                System.out.println("删除失败!");
                System.out.println("非常抱歉,您要删除的学生不存在,请重新输入!!!");
            }

        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
    }


    public static void DataBaseFindsingle(){
        Scanner sc = new Scanner(System.in);
        Connection();
        Connection conn = null;
        Statement stmt = null;
        ResultSet resultSet = null;
        try{//获取连接对象
            conn = DriverManager.getConnection(connect, user, passward);
            stmt = conn.createStatement();

            int count = 0;

            System.out.println("请输入您要查询的学号: ");
            String input = sc.next();
            //定义sql语句
            String sql =  "select * from addressbook where id = ('"+input+"')";
            resultSet = stmt.executeQuery(sql);

            while(resultSet.next()){
                if(resultSet.getString("id").equals(input)) {
                    String id;
                    String name;
                    String QQ;
                    String phone;
                    String address;
                    id = resultSet.getString("id");
                    name = resultSet.getString("name");
                    QQ = resultSet.getString("QQ");
                    phone = resultSet.getString("phone");
                    address = resultSet.getString("address");
                    System.out.println("学号" + "\t" + "\t" + "姓名" + "\t" + "\t" + "QQ" + "\t" + "\t" + "phone" + "\t" + "\t" + "address");
                    System.out.println(id + '\t' + "\t" + name + '\t' + "\t" + QQ + '\t' + "\t" + phone + '\t' + "\t" + address);
                    count++;
                    break;
                }
            }
               if(count ==0){
                   System.out.println("没有该学号学生的通讯录信息,请检查输入的学号!!");
               }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (resultSet != null) {
                try {
                    resultSet.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }

    }


    public static void DataBaseFindAll(){
        Connection conn = null;
        Statement stmt =null ;
        Connection();
        try {
            //定义sql
            String sql = "select * from addressbook";
            //3.获取连接对象
            conn = DriverManager.getConnection(connect,user,passward);
            stmt = conn.createStatement();

            ResultSet count = stmt.executeQuery(sql);
            if(count.next()==false){
                System.out.println("非常抱歉,当前没有学生信息可供查看!");
                conn.close();
            }else {
                ResultSet resultSet = stmt.executeQuery(sql);
                String id;
                String name;
                String QQ;
                String phone;
                String address;
                System.out.println("学号" + "\t" + "\t" + "姓名" + "\t" + "\t" + "QQ" + "\t" + "\t" + "phone" + "\t" + "\t" + "address");
                while (resultSet.next()) {
                    id = resultSet.getString("id");
                    name = resultSet.getString("name");
                    QQ = resultSet.getString("QQ");
                    phone = resultSet.getString("phone");
                    address = resultSet.getString("address");
                    System.out.println(id + '\t' + "\t" + name + '\t' + "\t" + QQ + '\t' + "\t" + phone + '\t' + "\t" + address);
                }
                resultSet.close();
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
    }


    public static void Connection(){
        try {
            //1.注册驱动
            Class.forName(driver);

        }catch (Exception e){
            e.printStackTrace();
        }
    }
}

java版本：11
MySQL版本:8.0
数据库管理工具：Navicat

实现结果：

写的若有不对的的地方希望大佬多多指正。