재생 목록 클래스 음악 데이터베이스

Question

간단한 음악 데이터베이스와 ATM을 쓰고 있습니다. 이전에 데이터베이스 클래스에 입력 한 4 곡의 음악을 3 곡의 재생 목록으로 구성 할 수있는 재생 목록 클래스를 만들려고합니다. .

사용자가 재생 목록에 넣을 노래를 선택하면 메서드는 newplaylist에서 가장 가까운 빈 슬롯을 검색하고 Song 변수 (아티스트, 이름, 기간, & 파일 크기)를 안에 넣습니다.

나는 이것을 받고 있습니다. 재생 목록 도구 입력

---

...

 
Hello, welcome to the playlist builder! 
Please select a track to add to the new playlist from the database below(using keys 1-4) 
Slot 1:Trees:Breeze:2.34:128 
1 
Error: there is no free space in the database 
Slot A : Song@3a1ec6 
Slot B : Song@1ba6076 
Slot C : Song@112e7f7 
    MENU 
0 EXIT 
1 IMPORT TRACK 
2 SHOW ALL 
3 Build a playlist(requires atleast 1 track in database) 

---

내가 옳은 일을 반환되는 것은 변수가 아닌 변수 자신의 위치에 대한 참조입니다 추측에 있습니까?

Playlist.class의 코드는 다음과 같습니다.

public class Playlist { 

    Song songDataPlay = new Song(); 
    static UserInterface UI = new UserInterface(); 

    static Song playlisttrackA = new Song(); 
    static Song playlisttrackB = new Song(); 
    static Song playlisttrackC = new Song(); 

    private int MAX_TIME; 
    private double totalSize; 
    private double totalTIme; 

    String playlistClassArtist, playlistClassName; 
    double playlistClassDuration; 
    int playlistClassFileSize; 

    static String playlistArtist; 
    static String playlistName; 
    static double playlistDuration; 
    static int playlistFileSize; 
    static Song newplaySong; 
    static Song newSong; 

    static Song carryfromuserintoplaylist = UI.newPlaylistSongIN; 

    public void playlistObject(Song a, Song b, Song c) { 
     this.playlisttrackA = a; 
     this.playlisttrackB = b; 
     this.playlisttrackC = c; 
    } 


    public static void playlistAllocation() { 
     newSong = UI.newPlaylistSongIN; 
     Playlist plu = new Playlist(); 
     SongDatabase SD = new SongDatabase(); 
     Song newSong = carryfromuserintoplaylist; 


     if (playlisttrackA.songfileSize == 0) { 

      setSongA(newplaySong); 

      System.out.println("Slot A : " + playlisttrackA); 
      System.out.println("Slot B : " + playlisttrackB); 
      System.out.println("Slot C : " + playlisttrackC); 

      newplaySong = newSong; 

     } else if (playlisttrackB.songfileSize == 0) { 

      setSongB(newplaySong); 

      System.out.println("Slot A : " + playlisttrackA); 
      System.out.println("Slot B : " + playlisttrackB); 
      System.out.println("Slot C : " + playlisttrackC); 

      newplaySong = newSong; 

     } else if (playlisttrackC.songfileSize == 0) { 

      setSongC(newplaySong); 

      System.out.println("Slot A : " + playlisttrackA); 
      System.out.println("Slot B : " + playlisttrackB); 
      System.out.println("Slot C : " + playlisttrackC); 

      newplaySong = newSong; 

     } else { 

      System.out.println("Error: there is no free space in the database"); 

      System.out.println("Slot A : " + playlisttrackA); 
      System.out.println("Slot B : " + playlisttrackB); 
      System.out.println("Slot C : " + playlisttrackC); 

     } 
    } 

    public static void setSongA(Song newSong) { 

     playlisttrackA = newplaySong; 

     playlisttrackA.songartist = newplaySong.songartist; 
     playlisttrackA.songname = newplaySong.songname; 
     playlisttrackA.songduration = newplaySong.songduration; 
     playlisttrackA.songfileSize = newplaySong.songfileSize; 

    } 

    public Song getSongA() { 

     return (playlisttrackA); 
    } 


    public static void setSongB(Song newSong) { 

     playlisttrackB = newplaySong; 

     playlisttrackB.songartist = newplaySong.songartist; 
     playlisttrackB.songname = newplaySong.songname; 
     playlisttrackB.songduration = newplaySong.songduration; 
     playlisttrackB.songfileSize = newplaySong.songfileSize; 

    } 


    public Song getSongB() { 

     return (playlisttrackB); 
    } 


    public static void setSongC(Song newSongC) { 

     playlisttrackC = newplaySong; 

     playlisttrackC.songartist = newplaySong.songartist; 
     playlisttrackC.songname = newplaySong.songname; 
     playlisttrackC.songduration = newplaySong.songduration; 
     playlisttrackC.songfileSize = newplaySong.songfileSize; 

    } 

    public Song getSongC() { 

     return (playlisttrackC); 

    } 

    public String returnPlaylist() { 


     if (playlisttrackA.songfileSize == 0 && playlisttrackB.songfileSize == 0 && playlisttrackC.songfileSize == 0) { 
      return ("Error ; No new playlists have been added."); 
     } else if (playlisttrackB.songfileSize == 0 && playlisttrackC.songfileSize == 0) { 
      return ("You have imported:" + newplaySong.songname + " By " + newplaySong.songartist + " to slot A in the new playlist"); 
     } else if (newplaySong.songfileSize == 0) { 
      return ("You have imported:" + newplaySong.songname + " By " + newplaySong.songartist + " to slot B in the new playlist"); 
     } else { 
      return ("You have imported:" + newplaySong.songname + " By " + newplaySong.songartist + " to slot C in the new playlist"); 
     } 

    } 


} 

어떤 도움도 큰 감사 것,

Answer 1

System.out.println("Slot A : "+playlisttrackA);이 (Object에서 파생) Song의 toString() 메소드를 호출합니다. 기본적으로 오브젝트의 hash code을 인쇄합니다.

코드를 올바르게 이해하면 playlisttrackA.songname을 더 잘 인쇄해야합니다.