generated from Java-2025Fall/final-vibevault-template
91 lines
2.3 KiB
Java
91 lines
2.3 KiB
Java
package com.vibevault.model;
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import jakarta.persistence.*;
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import java.util.ArrayList;
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import java.util.List;
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/**
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* 歌单实体类
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*
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* 需要实现:
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* - 将此类映射为数据库表 "playlists"
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* - id 作为自增主键
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* - name 不能为空
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* - 每个歌单属于一个用户（多对一关系）
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* - 一个歌单包含多首歌曲（一对多关系）
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* - 删除歌单时应级联删除其中的歌曲
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*/
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@Entity // 实现：将此类映射为数据库表
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@Table(name = "playlists") // 实现：指定表名为"playlists"
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public class Playlist {
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@Id // 实现：标记id为主键
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@GeneratedValue(strategy = GenerationType.IDENTITY) // 实现：id作为自增主键
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private Long id;
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@Column(nullable = false) // 实现：name不能为空
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private String name;
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// 实现：每个歌单属于一个用户（多对一关系）
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@ManyToOne(fetch = FetchType.LAZY, optional = false) // 多对一，用户不能为空
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@JoinColumn(name = "user_id") // 数据库中关联用户的字段名
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private User owner;
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// 实现：一个歌单包含多首歌曲（一对多关系） + 删除歌单时级联删除歌曲
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@OneToMany(mappedBy = "playlist", cascade = CascadeType.ALL, orphanRemoval = true)
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private List<Song> songs = new ArrayList<>();
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public Playlist() {
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}
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// 带参数的构造方法（方便创建歌单）
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public Playlist(String name, User owner) {
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this.name = name;
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this.owner = owner;
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}
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// 维护双向关系：添加歌曲到歌单
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public void addSong(Song song) {
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songs.add(song);
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song.setPlaylist(this);
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}
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// 维护双向关系：从歌单移除歌曲
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public void removeSong(Song song) {
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songs.remove(song);
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song.setPlaylist(null);
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}
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// 必要的getter/setter方法
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public Long getId() {
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return id;
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}
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public void setId(Long id) {
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this.id = id;
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}
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public String getName() {
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return name;
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}
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public void setName(String name) {
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this.name = name;
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}
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public User getOwner() {
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return owner;
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}
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public void setOwner(User owner) {
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this.owner = owner;
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}
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public List<Song> getSongs() {
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return songs;
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}
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public void setSongs(List<Song> songs) {
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this.songs = songs;
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}
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} |