我目前通過(guò)一個(gè)構(gòu)造函數(shù)傳遞我的數(shù)據(jù)，該構(gòu)造函數(shù)填充從我的抽象類和擴(kuò)展類（即擴(kuò)展的 MusicItem Abstract 和 CD 和 Vinyl 類）請(qǐng)求的數(shù)據(jù)我試圖從我的控制器使用 JavaFX 將它們打印到表視圖中，但即使放置了 system.out 行也沒(méi)有顯示任何內(nèi)容。我已經(jīng)嘗試將它們放入可觀察列表以及普通數(shù)組列表中，我已經(jīng)三次檢查數(shù)據(jù)字段以查看它們是否與表格匹配并且我嘗試在輸入時(shí)查看對(duì)象但是當(dāng)我這樣做時(shí)，該對(duì)象的十六進(jìn)制代碼出現(xiàn)。它正確連接到數(shù)據(jù)庫(kù)但不顯示任何內(nèi)容abstract class MusicItem {    @Id    private int songID;    private String name;    private String artist;    private String genre;    private String releaseDate;    private double price;public MusicItem(int songID, String name, String artist, String genre, String releaseDate, double price) {    this.songID = songID;    this.name = name;    this.artist = artist;    this.genre = genre;    this.releaseDate = releaseDate;    this.price = price;    }}@Entityclass Vinyl extends MusicItem{private double speed;private double diameter;Vinyl(int songID, String name, String artist, String genre, String releaseDate, double price, double speed, double diameter) {    super(songID, name, artist, genre, releaseDate, price);    this.speed = speed;    this.diameter = diameter;    }}@Entityclass CD extends MusicItem{private double duration;CD(int songID, String name, String artist, String genre, String releaseDate, double price, double duration) {    super(songID, name, artist, genre, releaseDate, price);    this.duration = duration;   }}