java代码基础练习，音乐管理系统（无页码）_用户音乐收藏夹综合练习java-优快云博客

先写好框架，框架有model层，dao层，util层，最后在view.java里写主程序。

model层
User.java

package com.zhongruan.model;

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

    public User(String username, String password) {
        this.username = username;
        this.password = password;
    }

    public User() {
    }

    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;
    }

    public int getType() {
        return type;
    }

    public void setType(int type) {
        this.type = type;
    }

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

Music.java

package com.zhongruan.model;

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

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAuthor() {
        return author;
    }

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

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

然后在util 里写DBUtil.java 来连接数据库
Util.java

package com.zhongruan.util;

import java.sql.*;

public class DBUtil {
    public static Connection getConnection() throws ClassNotFoundException, SQLException {
        Class.forName("com.mysql.jdbc.Driver");
        Connection connection= DriverManager.getConnection("jdbc:mysql://localhost/zjgm?user=root&password=123456&characterEncoding=utf-8&useSSL=true");

        return connection;
    }
    public static void ZYClose(ResultSet resultSet, Statement statement, Connection connection){
        if (resultSet!=null){
            try {
                resultSet.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(statement!=null){
            try {
                statement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (connection!=null){
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

    }
}

之后再到dao层里写增删改查的方法
Userdao.java

package com.zhongruan.dao;

import com.zhongruan.model.User;
import com.zhongruan.util.DBUtil;

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

public class UserDao {
    public static User selectDB(String username) throws SQLException, ClassNotFoundException {
        Connection connection= DBUtil.getConnection();
        String sql="select * from tb_user where username=?";
        PreparedStatement statement=connection.prepareStatement(sql);
        statement.setString(1,username);
        ResultSet resultSet =statement.executeQuery();
        User user=null;
        while (resultSet.next()){
            user=new User();
            user.setUsername(resultSet.getString(2));
            user.setPassword(resultSet.getString(3));
        }
        DBUtil.ZYClose(resultSet,statement,connection);
        return user;
    }
    public static void insertDB(String username,String password,int i) throws SQLException, ClassNotFoundException {
        Connection connection=DBUtil.getConnection();
        String sql="insert into tb_user(username,password,type) values(?,?,?) ";
        PreparedStatement statement=connection.prepareStatement(sql);
        statement.setString(1,username);
        statement.setString(2,password);
        statement.setInt(3,i);
        statement.executeUpdate();
        DBUtil.ZYClose(null,statement,connection);

    }
}

MusicDao.java

package com.zhongruan.dao;

import com.zhongruan.model.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> selectMusic() throws SQLException, ClassNotFoundException {
        Connection connection=null;
        PreparedStatement statement=null;
        ResultSet resultSet=null;
        List<Music> musics=new ArrayList<>();
        connection= DBUtil.getConnection();
        String sql="select * from music";
        statement= connection.prepareStatement(sql);
        resultSet=statement.executeQuery();
        while (resultSet.next()){
            Music music=new Music();
            music.setId(resultSet.getInt(1));
            music.setName(resultSet.getString(2));
            music.setAuthor(resultSet.getString(3));
            //System.out.println(music.toString());
            musics.add(music);
        }
        DBUtil.ZYClose(resultSet,statement,connection);
        return musics;
    }

    public static void insertMusic(String name,String author) throws SQLException, ClassNotFoundException {
        Connection connection=null;
        PreparedStatement statement=null;
        connection=DBUtil.getConnection();
        String sql="insert into music(id,name,author) values(null ,?,?)";
        statement=connection.prepareStatement(sql);
        statement.setString(1,name);
        statement.setString(2,author);
        statement.executeUpdate();
        System.out.println("增加音乐成功");
        DBUtil.ZYClose(null,statement,connection);


    }

    public static void deleteMusic(int id) throws SQLException, ClassNotFoundException {
        Connection connection=null;
        PreparedStatement statement=null;
        connection=DBUtil.getConnection();
        String sql="delete from music where id=?";
        statement=connection.prepareStatement(sql);
        statement.setInt(1,id);
        statement.executeUpdate();
        System.out.println("删除音乐成功");
        DBUtil.ZYClose(null,statement,connection);

    }

    public static void updateMusic(int id,String newname,String author ) throws SQLException, ClassNotFoundException {
        Connection connection=null;
        PreparedStatement statement=null;
        connection=DBUtil.getConnection();
        String sql="update  music set name=?,author=? where id=?";
        statement=connection.prepareStatement(sql);
        statement.setString(1,newname);
        statement.setString(2,author);
        statement.setInt(3,id);
        statement.executeUpdate();
        System.out.println("更新音乐成功");
        DBUtil.ZYClose(null,statement,connection);

    }
}

最后在写view
view.java

package com.zhongruan;

import com.zhongruan.dao.MusicDao;
import com.zhongruan.dao.UserDao;
import com.zhongruan.model.Music;
import com.zhongruan.model.User;

import javax.security.auth.login.LoginException;
import java.sql.SQLException;
import java.util.List;
import java.util.Scanner;

public class View {
    public static void caseMusic(boolean b) throws SQLException, ClassNotFoundException {
        Scanner input=new Scanner(System.in);
        System.out.println("1.查询音乐 2.增加音乐 3.删除音乐 4.更新音乐  5.退出登录");
        int n=input.nextInt();
        switch (n){
            case 1:
                List<Music> list=MusicDao.selectMusic();
                System.out.println(list);
                break;
            case 2:
                System.out.println("请输入要增加音乐的名字：");
                String name=input.next();
                System.out.println("请输入要增加音乐的作作者：");
                String author=input.next();
                MusicDao.insertMusic(name,author);
                break;
            case 3:
                System.out.println("请输入要删除音乐的id：");
                int id3=input.nextInt();
                MusicDao.deleteMusic(id3);
                break;
            case 4:
                System.out.println("请输入要修改音乐的id");
                int id4=input.nextInt();
                System.out.println("请输入新的歌名");
                String newname4=input.next();
                System.out.println("请输入新的作者");
                String newauthor4=input.next();
                MusicDao.updateMusic(id4,newname4,newauthor4);
                break;
            case 5:
                b=false;
                break;

             default:
                 System.out.println("输入数字错误，请重新输入");

        }
    }
    public static void main(String[] args) throws SQLException, ClassNotFoundException {
        Scanner input=new Scanner(System.in);

        boolean b=true;
        while (b){
            System.out.println("请输入你的账号：");
            String username=input.next();
            System.out.println("请输入你的密码：");
            String password=input.next();
            User user=UserDao.selectDB(username);
            if (user==null){
                System.out.println("账号不存在,请注册");
                System.out.println("请输入你要注册的用户名");
                String newname=input.next();
                System.out.println("请输入你的密码");
                String newpassword=input.next();
                UserDao.insertDB(newname,newpassword,1);
            }else if (user.getPassword().equals(password)){
                System.out.println("登录成功,欢迎来到音乐管理系统");
                caseMusic(b);
            }else {
                //System.out.println("密码错误，请重新输入");
                try {
                    throw new LoginException("密码错误，请重新输入");
                } catch (LoginException e) {
                    e.printStackTrace();
                }
            }

        }


    }
}