feat(playlist): 添加歌单收藏时间并优化相关功能

- 在 PlaylistDTO 中添加 collectTime 字段，用于显示收藏时间
- 修改收藏歌单逻辑，记录收藏时间
- 更新取消收藏歌单逻辑，使用 deleteByUserAndPlaylist 方法
- 在获取用户收藏的歌单列表时，添加收藏时间信息
- 重命名 UserCollectPlaylist

music-houduan/src/main/java/com/test/musichouduan/dto/PlaylistDTO.java

@@ -98,4 +98,9 @@ public class PlaylistDTO {
      * 热度分
      */
     private double hotScore;
+
+    /**
+     * 收藏时间
+     */
+    private LocalDateTime collectTime;
 }

music-houduan/src/main/java/com/test/musichouduan/entity/UserCollectPlaylist.java

@@ -33,9 +33,8 @@ public class UserCollectPlaylist {
     private Playlist playlist;
 
     /**
-     * 创建时间
+     * 收藏时间
      */
-    @CreationTimestamp
     @Column(nullable = false, updatable = false)
-    private LocalDateTime createTime;
+    private LocalDateTime collectTime;
 }

music-houduan/src/main/java/com/test/musichouduan/repository/UserCollectPlaylistRepository.java

@@ -99,4 +99,6 @@ public interface UserCollectPlaylistRepository extends JpaRepository<UserCollect
 
     @Query("SELECT ucp.playlist FROM UserCollectPlaylist ucp WHERE ucp.user.id = ?1")
     Page<Playlist> findCollectedPlaylist(Long userId, Pageable pageable);
+
+    Optional<UserCollectPlaylist> findByUserIdAndPlaylistId(Long userId, Long playlistId);
 }

music-houduan/src/main/java/com/test/musichouduan/service/impl/PlaylistServiceImpl.java

@@ -372,7 +372,11 @@ public class PlaylistServiceImpl implements PlaylistService {
         }
 
         // 收藏歌单
-        userCollectPlaylistRepository.collectPlaylist(user.getId(), playlist.getId());
+        com.test.musichouduan.entity.UserCollectPlaylist userCollectPlaylist = new com.test.musichouduan.entity.UserCollectPlaylist();
+        userCollectPlaylist.setUser(user);
+        userCollectPlaylist.setPlaylist(playlist);
+        userCollectPlaylist.setCollectTime(java.time.LocalDateTime.now());
+        userCollectPlaylistRepository.save(userCollectPlaylist);
 
         // 更新收藏数
         playlist.setCollectCount((playlist.getCollectCount() == null ? 0 : playlist.getCollectCount()) + 1);
@@ -399,7 +403,7 @@ public class PlaylistServiceImpl implements PlaylistService {
         }
 
         // 取消收藏歌单
-        userCollectPlaylistRepository.uncollectPlaylist(user.getId(), playlist.getId());
+        userCollectPlaylistRepository.deleteByUserAndPlaylist(user, playlist);
 
         // 更新收藏数
         playlist.setCollectCount((playlist.getCollectCount() == null ? 0 : playlist.getCollectCount()) - 1);
@@ -430,7 +434,13 @@ public class PlaylistServiceImpl implements PlaylistService {
 
         // 转换为DTO
         List<PlaylistDTO> playlistDTOs = playlistPage.getContent().stream()
-                .map(this::convertToDTO)
+                .map(playlist -> {
+                    PlaylistDTO dto = convertToDTO(playlist);
+                    // 从收藏记录中获取收藏时间
+                    userCollectPlaylistRepository.findByUserIdAndPlaylistId(userId, playlist.getId())
+                            .ifPresent(ucp -> dto.setCollectTime(ucp.getCollectTime()));
+                    return dto;
+                })
                 .collect(Collectors.toList());
 
         return new PageResult<>(