Design a music juke box

A music juke box will possibly need: a CD player, A set of CDs, a program to set tracks and a user.

The rule of OOD suggests that we should wrap up data with their operating functions in a single entity class, so we need to following classes"

• JukeBox: Of course, that's what we are designing.
• CD player: to play CDs
• CD: well, to play
• Playlist: a user defined playlist that allows the user to query the songs he/she wants to play
• Song: yeah, it's music...
• TrackSelector: that is the program to set and get the track
• User: who is playing? The current design only allows for one user at a time. 

JukeBox:

public class JukeBox{
 private CDPlayer cdPlayer;
 private User user;
 private Set cdCollection;
 private TrackSelector ts;
 
 public JukeBox(CDPlayer cdPlayer, User user, Set cdCollection, TrackSelector ts){
 }
 public Song getCurrentTrack(){
  return ts.getCurrentSong();
 }
        public void setCurrentTrack(Song s){
  ts.setCurrentSong(s);
 }
 public void setNextTrack(Song s){
  ts.setNext(s);
 }
 public void processOneUser(User u){
  this.user = u;
 }
}

CD player:
CD player contains a playlist, the CD that it is currently playing, and the button to play a track.

public class CDPlayer{
 private Playlist p;
 private CD c;
 public Playlist getPlaylist(){
  return p;
 }
 public void setPlaylist(Playlist p){
  this.p = p;
 }
 public CD getCD(){
  return c;
 }
 public void setCD(CD c){
  this.c = c;
 }
 public CDPlayer(Playlist p){
  this.p = p;
 }
 public CDPlayer(CD c, Playlist p){
  
 }
 public CDPlayer(CD c){
  this.c = c;
 }
 public void playTrack(Song s){
 }
}

CD: 
Well, as you can imagine, a CD contains name, and list of songs. Of course we can also add artist, number of songs and so on, but just for simplicity, I only include the first two.

public class CDPlayer{
 private Playlist p;
 private CD c;
 public Playlist getPlaylist(){
  return p;
 }
 public void setPlaylist(Playlist p){
  this.p = p;
 }
 public CD getCD(){
  return c;
 }
 public void setCD(CD c){
  this.c = c;
 }
 public CDPlayer(Playlist p){
  this.p = p;
 }
 public CDPlayer(CD c, Playlist p){
  
 }
 public CDPlayer(CD c){
  this.c = c;
 }
 public void playTrack(Song s){
 }
}

Playlist:
A playlist will include, the CD that creates the play list and a queue of songs in the list.

public class Playlist{
 private CD cd;
 private Queue queue;
}

Song: 
The song, as you can imagine, may include the name of the song, lyrics the artist who create the song and so on.

public class Song{
 private String songName;
 private String lyrics;
 private String artist;
 public String getName(){
  return songName;
 }
}

TrackSelector: 
The track selector definitely allows us to select tracks, so it includes a song that is currently playing, set a song that the user wants to play next, switch the current playing song, and get the current playing song.

public class TrackSelector{
 private Song currentSong;
 private Song nextSong;
 //assume not playing any song at the beginning 
 public TrackSelector(){
  currentSong = "";
  nextSong = "";
 }
 public void setCurrent(Song s){
  currentSong = s;
 }
 public void setNext(Song s){
  nextSong = s;
 }
 public Song getCurrentSong(){
  return currentSong;
 }
}

User: 
The user will have a name (Who doesn't? ) and a unique ID.

public class User{
 private String name;
 private long ID;
 public User(String name, long id){
  this.name = name;
  ID = id;
 }
 public String getName(){
  return name;
 }
 public void setName(String name){
  this.name = name;
 }
 public long getID(){
  return ID;
 }
 public void setID(long id){
  ID = id;
 }
 public User getUser(){
  return this;
 }
}