8.16 Improve music management system

Additional code:

public  void getMenu() throws SQLException{
    MusicDao musicDao=new MusicDao();
    UserDao userDao=new UserDao();
    Scanner input=new Scanner(System.in);
    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);
                break;
            case 5:
                getMenu();
                break;
        }
    }else if(j==2){
        System.out.println("-----欢迎进入用户管理模块-----");
        System.out.println("\t1.查询用户\t2.添加用户\t3.修改用户\t4.删除用户\t5.返回上一层");
    }
    int b=input.nextInt();
    switch (b){
        case 1:
            List<User> users= UserDao.findAll();
            System.out.println(users);
            break;
        case 2:
            System.out.println("请输入注册用户名：");
            String yh = input.next();
            System.out.println("请输入注册密码：");
            String mm = input.next();
            System.out.println("请输入注册用户权限：");
            int t = input.nextInt();
            User user=new User();
            user.setUsername(yh);
            user.setPassword(mm);
            user.settype(t);
            userDao.zhuce(user.getUsername(),user.getPassword(),user.gettype());
        case 3:
            System.out.println("请输入要修改的ID:");
            int id=input.nextInt();
            System.out.println("请输入要修改后的密码：");
            String password=input.next();
            userDao.xiugai(id,password);
            break;
        case 4:
        case 5:
    }
}

public void xiugai(int id,String password) throws SQLException{
    Connection connection=DBUtil.getconnection();
    PreparedStatement statement=connection.prepareStatement("update tb_user set password=? where id=?");
    statement.setString(1,password);
    statement.setInt(2,id);
    statement.executeUpdate();
}
public static List<User> findAll()throws SQLException {
    List<User> 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);
        User user=new User();
        user.setUsername(musicname);
        user.setPassword(author);
        user.setType(resultSet.getType());
        musics.add(user);
    }
    return musics;
}