8.15java上课内容：Music项目系统(未完整版本1.0.0.0)

废话不多说，直接上步骤（加粗字体的步骤注意看，个人认为我的步骤比较完善了，但是我表达能力有问题，如果看不懂可以在下方评论里留言，楼主在线时间：早上：8：30-11：30，下午：14：00-17：00）。

首先我们需要新建一个项目。
1.File-New-Project.

2.next-next-改名字-finish.

到这里，我们的新项目建立完成，会出现一个灰色空界面：

1.接下来将老师给的资源copy进去。（右击music文件夹，建一个新的包，命名为jar,将图中划红线的文件拷贝进去并且解压。）解压是A的英文名是Add…

2.新建包的步骤：对src包右击-new-package.

3.建四个包。（再放一遍图）

4.新建java文件(图标是圆形蓝底带C字的)，开始做项目。
下面是部分源代码
1.MusicService.java代码

package com.zhongruan.service;

import com.zhongruan.bean.Music;
import com.zhongruan.dao.MusicDao;
import com.zhongruan.dao.UserDao;

import java.sql.SQLException;
import java.util.List;
import java.util.Scanner;

public class MusicService {
    public static void main(String[] args) throws SQLException {
        while (true) {
            System.out.println("-----请输入用户名：");
            Scanner input = new Scanner(System.in);
            String username = input.next();
            System.out.println("-----请输入密码：");
            String password = input.next();
            System.out.println(username + password);
            UserDao UserDao = new UserDao();
            boolean flag = UserDao.login(username, password);
            if (flag) {
                System.out.println("--------登入成功--------");
                System.out.println("----欢迎来到音乐管理系统----");
                System.out.println("\t1.音乐管理\t2.用户管理\t3.退出系统");
                int j=input.nextInt();
                if (j==1){
                    System.out.println("----欢迎进入音乐管理系统----");
                    System.out.println("\t1.查询音乐\t2.添加音乐\t3.修改音乐\t4.删除音乐");
                    int a=input.nextInt();
                    switch (a){
                        case 1:
                            List<Music> musics= MusicDao.findAll();
                            System.out.println(musics);
                            break;
                        case 2:
                            System.out.println(2);
                            System.out.println("请输入要添加的音乐名称：");
                            String n=input.next();
                            System.out.println("请输入作者：");
                            String au=input.next();
                            Music music=new Music();
                            music.setMusicname(n);
                            music.setAuthor(au);
                            MusicDao.add(music);
                        case 3:
                            System.out.println(3);
                        case 4:
                            System.out.println("请输入要删除歌曲的ID:");
                            int id=input.nextInt();
                            MusicDao.delete(id);
                            System.out.println(4);
                    }
                }
            } else {
                System.out.println("-----登入失败-----");
                System.out.println("-------请先注册--------");
                System.out.println("请输入注册名：");
                String zcm = input.next();
                System.out.println("请输入注册密码：");
                String zcmm1 = input.next();
                System.out.println("请确认密码：");
                String zcmm2 = input.next();
                if (zcmm1.equals(zcmm2)) {
                    UserDao.zhuce(zcm, zcmm1);
                    System.out.println("是否登入还是输出Y/N");
                    String i=input.next();
                    if (i.equals("N")){
                        System.exit(0);
                    }else if (!i.equals("Y")){
                        System.out.println("傻子输错了！");
                        System.exit(0);
                    }
                } else {
                    System.out.println("密码有误，请重新注册！");
                }

            }

        }

    }
}

2.User.java

package com.zhongruan.bean;

public class User {
    private int id;
    private String username;
    private String password;

    public int getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

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

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

3.DBUtil.java

package com.zhongruan.util;

import java.sql.*;

public class DBUtil {
    public static Connection getconnection() {
        Connection connection = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            connection = DriverManager.getConnection
                    ("jdbc:mysql://127.0.0.1:3306/nbcj?useSSL=true&characterEncoding=utf-8&user=root&password=123456");
            System.out.println("创建连接成功");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return connection;
    }

    public static void closeAll(ResultSet rs, PreparedStatement preparedStatement, Connection connection) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (preparedStatement != null) {
            try {
                preparedStatement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (connection != null) {
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

4.UserDao.java

package com.zhongruan.dao;

import com.zhongruan.util.DBUtil;


import java.sql.*;


public class UserDao {

    public boolean zhuce(String username, String password) throws SQLException {
        Connection connection = DBUtil.getconnection();
        String sql = "INSERT INTO tb_user (username,password) VALUES (?,?)";
        PreparedStatement statement = connection.prepareStatement(sql);
        statement.setString(1, username);
        statement.setString(2, password);
        int i = statement.executeUpdate();
        if (i != 0) {
            return true;
        } else {
            return false;
        }
    }

    public boolean login(String username, String password) throws SQLException {
        Connection connection = DBUtil.getconnection();
        String sql = "select * from tb_user where username=? and password=?";
        PreparedStatement statement = connection.prepareStatement(sql);
        statement.setString(1, username);
        statement.setString(2, password);
        ResultSet resultSet = statement.executeQuery();
        if (resultSet.next()) {
            return true;
        } else {
            return false;
        }
    }
}

5.Music.java

package com.zhongruan.bean;

public class Music {
    private int id;
    private String musicname;
    private String author;

    public int getId() {
        return id;
    }

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

    public String getMusicname() {
        return musicname;
    }

    public void setMusicname(String musicname) {
        this.musicname = musicname;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    @Override
    public String toString() {
        return "Music{" +
                "id=" + id +
                ", musicname='" + musicname + '\'' +
                ", author='" + author + '\'' +
                '}';
    }
}

6.MusicDao.java

package com.zhongruan.dao;

import com.zhongruan.bean.Music;
import com.zhongruan.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 MusicDao {

    public static List<Music>findAll()throws SQLException {
        List<Music> musics=new ArrayList<>();
        Connection connection= DBUtil.getconnection();
        PreparedStatement statement=connection.prepareStatement("select * from music");
        ResultSet resultSet=statement.executeQuery();
        while (resultSet.next()){
            int id=resultSet.getInt(1);
            String musicname=resultSet.getString(2);
            String author=resultSet.getString(3);
            Music music=new Music();
            music.setId(id);
            music.setMusicname(musicname);
            music.setAuthor(author);
            musics.add(music);
        }
        return musics;
    }
    public static void delete(int id)throws SQLException{
        PreparedStatement statement=null;
        Connection connection=null;
        connection=DBUtil.getconnection();
        int i=0;
        try {
            statement=connection.prepareStatement("delete from music where id=?");
            statement.setInt(1,id);

            i=statement.executeUpdate();
            if (i!=0){
                System.out.println("删除成功");
            } else {
                System.out.println("删除失败");
            }

        }catch (SQLException e){
            e.printStackTrace();
        }
    }
    public static void add(Music music)throws SQLException{
        Connection connection=DBUtil.getconnection();
        PreparedStatement statement=
                connection.prepareStatement("inser into music(musicname,author) values (?,?)");
        statement.setString(1,"123");
        statement.setString(2,"123");
        statement.executeUpdate();
    }
}