diff --git a/src/main/java/com/vibevault/controller/PlaylistController.java b/src/main/java/com/vibevault/controller/PlaylistController.java
index f333a5c..fc3eba8 100644
--- a/src/main/java/com/vibevault/controller/PlaylistController.java
+++ b/src/main/java/com/vibevault/controller/PlaylistController.java
@@ -1,8 +1,11 @@
 package com.vibevault.controller;
 
+import java.security.Principal;
 import java.util.List;
 
 import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.security.core.Authentication;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
@@ -14,6 +17,7 @@ import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.ResponseStatus;
 import org.springframework.web.bind.annotation.RestController;
 
+import com.vibevault.dto.CopyPlaylistRequest;
 import com.vibevault.dto.PlaylistCreateDTO;
 import com.vibevault.dto.PlaylistDTO;
 import com.vibevault.dto.SongCreateDTO;
@@ -76,6 +80,52 @@ public class PlaylistController {
         return playlistService.addSongToPlaylist(id, songCreateDTO, username);
     }
 
+    // POST /api/playlists/{id}/songs/batch - 批量添加歌曲（需认证）
+    @PostMapping("/{id}/songs/batch")
+    @PreAuthorize("hasRole('USER')")
+    public ResponseEntity<PlaylistDTO> addSongsToPlaylist(@PathVariable Long id, @RequestBody List<SongCreateDTO> songs, Principal principal) {
+        PlaylistDTO updatedPlaylist = playlistService.addSongsToPlaylist(id, songs, principal.getName());
+        return ResponseEntity.ok(updatedPlaylist);
+    }
+    
+    /**
+     * [Advanced] 复制歌单
+     * 
+     * @param id 要复制的歌单ID
+     * @param request 复制请求（包含新歌单名称）
+     * @param principal 当前用户
+     * @return 新创建的歌单DTO
+     */
+    @PostMapping("/{id}/copy")
+    @PreAuthorize("hasRole('USER')")
+    public ResponseEntity<PlaylistDTO> copyPlaylist(@PathVariable Long id, @RequestBody CopyPlaylistRequest request, Principal principal) {
+        PlaylistDTO copiedPlaylist = playlistService.copyPlaylist(id, request.getNewName(), principal.getName());
+        return ResponseEntity.status(HttpStatus.CREATED).body(copiedPlaylist);
+    }
+    
+    /**
+     * [Advanced] 按条件筛选歌单
+     * 
+     * @param ownerName 歌单拥有者名称（可选）
+     * @param nameKeyword 歌单名称关键词（可选）
+     * @param sortBy 排序字段（name或createdAt）
+     * @param sortDirection 排序方向（asc或desc）
+     * @param principal 当前用户
+     * @return 筛选后的歌单列表
+     */
+    @GetMapping("/filter")
+    @PreAuthorize("hasRole('USER')")
+    public ResponseEntity<List<PlaylistDTO>> filterPlaylists(
+            @RequestParam(required = false) String ownerName,
+            @RequestParam(required = false) String nameKeyword,
+            @RequestParam(required = false, defaultValue = "name") String sortBy,
+            @RequestParam(required = false, defaultValue = "asc") String sortDirection,
+            Principal principal) {
+        List<PlaylistDTO> filteredPlaylists = playlistService.filterPlaylists(
+                principal.getName(), ownerName, nameKeyword, sortBy, sortDirection);
+        return ResponseEntity.ok(filteredPlaylists);
+    }
+
     // DELETE /api/playlists/{playlistId}/songs/{songId} - 移除歌曲（需认证）
     @DeleteMapping("/{playlistId}/songs/{songId}")
     @ResponseStatus(HttpStatus.NO_CONTENT)
@@ -98,11 +148,5 @@ public class PlaylistController {
         return playlistService.searchPlaylists(keyword);
     }
 
-    // [Advanced] POST /api/playlists/{id}/copy?newName=xxx - 复制歌单
-    @PostMapping("/{id}/copy")
-    @ResponseStatus(HttpStatus.CREATED)
-    public PlaylistDTO copyPlaylist(@PathVariable Long id, @RequestParam String newName, Authentication authentication) {
-        String username = authentication.getName();
-        return playlistService.copyPlaylist(id, newName, username);
-    }
+
 }
diff --git a/src/main/java/com/vibevault/dto/CopyPlaylistRequest.java b/src/main/java/com/vibevault/dto/CopyPlaylistRequest.java
new file mode 100644
index 0000000..4d9ec01
--- /dev/null
+++ b/src/main/java/com/vibevault/dto/CopyPlaylistRequest.java
@@ -0,0 +1,16 @@
+package com.vibevault.dto;
+
+/**
+ * 复制歌单请求DTO
+ */
+public class CopyPlaylistRequest {
+    private String newName;
+
+    public String getNewName() {
+        return newName;
+    }
+
+    public void setNewName(String newName) {
+        this.newName = newName;
+    }
+}
diff --git a/src/main/java/com/vibevault/exception/ErrorResponse.java b/src/main/java/com/vibevault/exception/ErrorResponse.java
new file mode 100644
index 0000000..c78bca5
--- /dev/null
+++ b/src/main/java/com/vibevault/exception/ErrorResponse.java
@@ -0,0 +1,41 @@
+package com.vibevault.exception;
+
+/**
+ * 统一错误响应类
+ * 用于封装API错误响应的结构
+ */
+public class ErrorResponse {
+    private int status;
+    private String error;
+    private String message;
+
+    public ErrorResponse(int status, String error, String message) {
+        this.status = status;
+        this.error = error;
+        this.message = message;
+    }
+
+    public int getStatus() {
+        return status;
+    }
+
+    public void setStatus(int status) {
+        this.status = status;
+    }
+
+    public String getError() {
+        return error;
+    }
+
+    public void setError(String error) {
+        this.error = error;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+
+    public void setMessage(String message) {
+        this.message = message;
+    }
+}
diff --git a/src/main/java/com/vibevault/exception/GlobalExceptionHandler.java b/src/main/java/com/vibevault/exception/GlobalExceptionHandler.java
index 344bcc1..7804b63 100644
--- a/src/main/java/com/vibevault/exception/GlobalExceptionHandler.java
+++ b/src/main/java/com/vibevault/exception/GlobalExceptionHandler.java
@@ -6,10 +6,6 @@ import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.RestControllerAdvice;
 import org.springframework.web.server.ResponseStatusException;
 
-import java.time.LocalDateTime;
-import java.util.HashMap;
-import java.util.Map;
-
 /**
  * 全局异常处理器
  * 
@@ -28,14 +24,8 @@ public class GlobalExceptionHandler {
      * @return 包含错误信息的 ResponseEntity
      */
     @ExceptionHandler(ResourceNotFoundException.class)
-    public ResponseEntity<Map<String, Object>> handleResourceNotFoundException(ResourceNotFoundException ex) {
-        Map<String, Object> body = new HashMap<>();
-        body.put("timestamp", LocalDateTime.now());
-        body.put("status", HttpStatus.NOT_FOUND.value());
-        body.put("error", "Not Found");
-        body.put("message", ex.getMessage());
-        
-        return new ResponseEntity<>(body, HttpStatus.NOT_FOUND);
+    public ResponseEntity<ErrorResponse> handleResourceNotFoundException(ResourceNotFoundException ex) {
+        return buildErrorResponse(HttpStatus.NOT_FOUND.value(), "Not Found", ex.getMessage());
     }
 
     /**
@@ -44,14 +34,18 @@ public class GlobalExceptionHandler {
      * @return 包含错误信息的 ResponseEntity
      */
     @ExceptionHandler(UnauthorizedAccessException.class)
-    public ResponseEntity<Map<String, Object>> handleUnauthorizedAccessException(UnauthorizedAccessException ex) {
-        Map<String, Object> body = new HashMap<>();
-        body.put("timestamp", LocalDateTime.now());
-        body.put("status", HttpStatus.FORBIDDEN.value());
-        body.put("error", "Forbidden");
-        body.put("message", ex.getMessage());
-        
-        return new ResponseEntity<>(body, HttpStatus.FORBIDDEN);
+    public ResponseEntity<ErrorResponse> handleUnauthorizedAccessException(UnauthorizedAccessException ex) {
+        return buildErrorResponse(HttpStatus.FORBIDDEN.value(), "Forbidden", ex.getMessage());
+    }
+    
+    /**
+     * 处理 UnauthorizedException 异常
+     * @param ex 异常对象
+     * @return 包含错误信息的 ResponseEntity
+     */
+    @ExceptionHandler(UnauthorizedException.class)
+    public ResponseEntity<ErrorResponse> handleUnauthorizedException(UnauthorizedException ex) {
+        return buildErrorResponse(HttpStatus.FORBIDDEN.value(), "Forbidden", ex.getMessage());
     }
 
     /**
@@ -60,14 +54,8 @@ public class GlobalExceptionHandler {
      * @return 包含错误信息的 ResponseEntity
      */
     @ExceptionHandler(ResponseStatusException.class)
-    public ResponseEntity<Map<String, Object>> handleResponseStatusException(ResponseStatusException ex) {
-        Map<String, Object> body = new HashMap<>();
-        body.put("timestamp", LocalDateTime.now());
-        body.put("status", ex.getStatusCode().value());
-        body.put("error", ex.getStatusCode().toString());
-        body.put("message", ex.getMessage());
-        
-        return new ResponseEntity<>(body, ex.getStatusCode());
+    public ResponseEntity<ErrorResponse> handleResponseStatusException(ResponseStatusException ex) {
+        return buildErrorResponse(ex.getStatusCode().value(), ex.getStatusCode().toString(), ex.getMessage());
     }
 
     /**
@@ -76,16 +64,19 @@ public class GlobalExceptionHandler {
      * @return 包含错误信息的 ResponseEntity
      */
     @ExceptionHandler(Exception.class)
-    public ResponseEntity<Map<String, Object>> handleGeneralException(Exception ex) {
-        Map<String, Object> body = new HashMap<>();
-        body.put("timestamp", LocalDateTime.now());
-        body.put("status", HttpStatus.INTERNAL_SERVER_ERROR.value());
-        body.put("error", "Internal Server Error");
-        body.put("message", "An unexpected error occurred");
-        
-        // 在开发环境中可以添加异常堆栈信息
-        // body.put("stackTrace", Arrays.toString(ex.getStackTrace()));
-        
-        return new ResponseEntity<>(body, HttpStatus.INTERNAL_SERVER_ERROR);
+    public ResponseEntity<ErrorResponse> handleGeneralException(Exception ex) {
+        return buildErrorResponse(HttpStatus.INTERNAL_SERVER_ERROR.value(), "Internal Server Error", "An unexpected error occurred");
+    }
+    
+    /**
+     * 构建统一的错误响应格式
+     * @param status 响应状态码
+     * @param error 错误类型
+     * @param message 错误消息
+     * @return 包含错误信息的 ResponseEntity
+     */
+    private ResponseEntity<ErrorResponse> buildErrorResponse(int statusCode, String error, String message) {
+        ErrorResponse errorResponse = new ErrorResponse(statusCode, error, message);
+        return ResponseEntity.status(statusCode).body(errorResponse);
     }
 }
diff --git a/src/main/java/com/vibevault/model/Playlist.java b/src/main/java/com/vibevault/model/Playlist.java
index 20bf1b8..c7bf16a 100644
--- a/src/main/java/com/vibevault/model/Playlist.java
+++ b/src/main/java/com/vibevault/model/Playlist.java
@@ -1,9 +1,12 @@
 package com.vibevault.model;
 
+import java.time.LocalDateTime;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
+import org.hibernate.annotations.CreationTimestamp;
+
 import jakarta.persistence.CascadeType;
 import jakarta.persistence.Column;
 import jakarta.persistence.Entity;
@@ -44,6 +47,10 @@ public class Playlist {
     @OneToMany(mappedBy = "playlist", cascade = CascadeType.ALL, orphanRemoval = true)
     private List<Song> songs = new ArrayList<>();
 
+    @Column(nullable = false, updatable = false)
+    @CreationTimestamp
+    private LocalDateTime createdAt;
+
     public Playlist() {
     }
 
@@ -71,10 +78,14 @@ public class Playlist {
     public void setOwner(User owner) {
         this.owner = owner;
     }
-
+    
     public List<Song> getSongs() {
         return Collections.unmodifiableList(songs);
     }
+    
+    public LocalDateTime getCreatedAt() {
+        return createdAt;
+    }
 
     /**
      * 向歌单添加歌曲
diff --git a/src/main/java/com/vibevault/model/Song.java b/src/main/java/com/vibevault/model/Song.java
index f00437d..988ca46 100644
--- a/src/main/java/com/vibevault/model/Song.java
+++ b/src/main/java/com/vibevault/model/Song.java
@@ -1,6 +1,17 @@
 package com.vibevault.model;
 
-import jakarta.persistence.*;
+import java.time.LocalDateTime;
+
+import org.hibernate.annotations.CreationTimestamp;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
 
 /**
  * 歌曲实体类
@@ -31,6 +42,10 @@ public class Song {
     @JoinColumn(name = "playlist_id")
     private Playlist playlist;
 
+    @Column(nullable = false, updatable = false)
+    @CreationTimestamp
+    private LocalDateTime createdAt;
+
     public Song() {
     }
 
@@ -75,4 +90,8 @@ public class Song {
     public void setDurationInSeconds(int durationInSeconds) {
         this.durationInSeconds = durationInSeconds;
     }
+
+    public LocalDateTime getCreatedAt() {
+        return createdAt;
+    }
 }
diff --git a/src/main/java/com/vibevault/repository/PlaylistRepository.java b/src/main/java/com/vibevault/repository/PlaylistRepository.java
index 8268d7e..640b954 100644
--- a/src/main/java/com/vibevault/repository/PlaylistRepository.java
+++ b/src/main/java/com/vibevault/repository/PlaylistRepository.java
@@ -1,11 +1,12 @@
 package com.vibevault.repository;
 
-import com.vibevault.model.Playlist;
-import com.vibevault.model.User;
+import java.util.List;
+
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.stereotype.Repository;
 
-import java.util.List;
+import com.vibevault.model.Playlist;
+import com.vibevault.model.User;
 
 /**
  * 歌单仓库接口
@@ -21,6 +22,36 @@ public interface PlaylistRepository extends JpaRepository<Playlist, Long> {
     // 按所有者查询歌单
     List<Playlist> findByOwner(User owner);
     
+    // 按所有者查询歌单并按名称排序（升序）
+    List<Playlist> findByOwnerOrderByNameAsc(User owner);
+    
+    // 按所有者查询歌单并按名称排序（降序）
+    List<Playlist> findByOwnerOrderByNameDesc(User owner);
+    
+    // 按所有者查询歌单并按创建时间排序（升序）
+    List<Playlist> findByOwnerOrderByCreatedAtAsc(User owner);
+    
+    // 按所有者查询歌单并按创建时间排序（降序）
+    List<Playlist> findByOwnerOrderByCreatedAtDesc(User owner);
+    
     // [Advanced]: 按名称模糊搜索歌单
     List<Playlist> findByNameContainingIgnoreCase(String keyword);
+    
+    // 按名称模糊搜索歌单并按名称排序
+    List<Playlist> findByNameContainingIgnoreCaseOrderByNameAsc(String keyword);
+    
+    // 按所有者和名称模糊搜索歌单
+    List<Playlist> findByOwnerAndNameContainingIgnoreCase(User owner, String keyword);
+    
+    // 按所有者和名称模糊搜索歌单并按创建时间排序（升序）
+    List<Playlist> findByOwnerAndNameContainingIgnoreCaseOrderByCreatedAtAsc(User owner, String keyword);
+    
+    // 按所有者和名称模糊搜索歌单并按创建时间排序（降序）
+    List<Playlist> findByOwnerAndNameContainingIgnoreCaseOrderByCreatedAtDesc(User owner, String keyword);
+    
+    // 按所有者和名称模糊搜索歌单并按名称排序（升序）
+    List<Playlist> findByOwnerAndNameContainingIgnoreCaseOrderByNameAsc(User owner, String keyword);
+    
+    // 按所有者和名称模糊搜索歌单并按名称排序（降序）
+    List<Playlist> findByOwnerAndNameContainingIgnoreCaseOrderByNameDesc(User owner, String keyword);
 }
diff --git a/src/main/java/com/vibevault/repository/SongRepository.java b/src/main/java/com/vibevault/repository/SongRepository.java
index 95c266a..f998a94 100644
--- a/src/main/java/com/vibevault/repository/SongRepository.java
+++ b/src/main/java/com/vibevault/repository/SongRepository.java
@@ -1,15 +1,35 @@
 package com.vibevault.repository;
 
-import com.vibevault.model.Song;
+import java.util.List;
+
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.stereotype.Repository;
 
+import com.vibevault.model.Song;
+
 /**
  * 歌曲仓库接口
  * 
  * 基础功能由 JpaRepository 提供
+ * 
+ * [Advanced] 已添加：
+ * - 按标题关键字模糊搜索歌曲
+ * - 按创建时间排序返回结果
  */
 @Repository
 public interface SongRepository extends JpaRepository<Song, Long> {
-    // 这里可以根据需要添加自定义查询方法
+    // 按标题关键字模糊搜索歌曲
+    List<Song> findByTitleContainingIgnoreCase(String keyword);
+    
+    // 按标题关键字模糊搜索歌曲并按标题排序
+    List<Song> findByTitleContainingIgnoreCaseOrderByTitleAsc(String keyword);
+    
+    // 按歌单ID查询歌曲
+    List<Song> findByPlaylistId(Long playlistId);
+    
+    // 按歌单ID查询歌曲并按创建时间排序
+    List<Song> findByPlaylistIdOrderByCreatedAtAsc(Long playlistId);
+    
+    // 按歌单ID查询歌曲并按标题排序
+    List<Song> findByPlaylistIdOrderByTitleAsc(Long playlistId);
 }
\ No newline at end of file
diff --git a/src/main/java/com/vibevault/service/PlaylistService.java b/src/main/java/com/vibevault/service/PlaylistService.java
index 226d083..43b3416 100644
--- a/src/main/java/com/vibevault/service/PlaylistService.java
+++ b/src/main/java/com/vibevault/service/PlaylistService.java
@@ -1,10 +1,10 @@
 package com.vibevault.service;
 
+import java.util.List;
+
 import com.vibevault.dto.PlaylistDTO;
 import com.vibevault.dto.SongCreateDTO;
 
-import java.util.List;
-
 /**
  * 歌单服务接口
  * 定义歌单相关的业务操作
@@ -45,6 +45,14 @@ public interface PlaylistService {
      */
     void removeSongFromPlaylist(Long playlistId, Long songId, String username);
 
+    /**
+     * 批量向歌单添加歌曲
+     * @param playlistId 歌单 ID
+     * @param songs 歌曲列表
+     * @param username 当前用户名（用于权限检查）
+     */
+    PlaylistDTO addSongsToPlaylist(Long playlistId, List<SongCreateDTO> songs, String username);
+
     /**
      * 删除歌单
      * @param playlistId 歌单 ID
@@ -60,7 +68,24 @@ public interface PlaylistService {
     List<PlaylistDTO> searchPlaylists(String keyword);
 
     /**
-     * [Advanced] 复制歌单
+     * [Advanced] 复制一个歌单为新的歌单
+     * 
+     * @param playlistId 要复制的歌单ID
+     * @param newName 新歌单名称
+     * @param username 当前用户名
+     * @return 新创建的歌单DTO
      */
     PlaylistDTO copyPlaylist(Long playlistId, String newName, String username);
+    
+    /**
+     * [Advanced] 按条件筛选歌单
+     * 
+     * @param username 用户名
+     * @param ownerName 歌单拥有者名称（可选）
+     * @param nameKeyword 歌单名称关键词（可选）
+     * @param sortBy 排序字段（name或createdAt）
+     * @param sortDirection 排序方向（asc或desc）
+     * @return 筛选后的歌单列表
+     */
+    List<PlaylistDTO> filterPlaylists(String username, String ownerName, String nameKeyword, String sortBy, String sortDirection);
 }
diff --git a/src/main/java/com/vibevault/service/impl/PlaylistServiceImpl.java b/src/main/java/com/vibevault/service/impl/PlaylistServiceImpl.java
index 4d3e577..e900490 100644
--- a/src/main/java/com/vibevault/service/impl/PlaylistServiceImpl.java
+++ b/src/main/java/com/vibevault/service/impl/PlaylistServiceImpl.java
@@ -91,6 +91,23 @@ public class PlaylistServiceImpl implements PlaylistService {
         playlistRepository.save(playlist);
     }
 
+    @Override
+    @Transactional
+    public PlaylistDTO addSongsToPlaylist(Long playlistId, List<SongCreateDTO> songDTOs, String username) {
+        Playlist playlist = getPlaylistWithOwnershipCheck(playlistId, username);
+
+        for (SongCreateDTO songDTO : songDTOs) {
+            Song song = new Song();
+            song.setTitle(songDTO.title());
+            song.setArtist(songDTO.artist());
+            song.setDurationInSeconds(songDTO.durationInSeconds());
+            playlist.addSong(song);
+        }
+
+        Playlist savedPlaylist = playlistRepository.save(playlist);
+        return convertToDTO(savedPlaylist);
+    }
+
     @Override
     @Transactional
     public void deletePlaylist(Long playlistId, String username) {
@@ -110,27 +127,133 @@ public class PlaylistServiceImpl implements PlaylistService {
     @Override
     @Transactional
     public PlaylistDTO copyPlaylist(Long playlistId, String newName, String username) {
-        Playlist originalPlaylist = playlistRepository.findById(playlistId)
-                .orElseThrow(() -> new ResourceNotFoundException("Playlist not found with id: " + playlistId));
-
-        User newOwner = userRepository.findByUsername(username)
+        // 验证原歌单存在且用户有权限访问
+        Playlist originalPlaylist = getPlaylistWithOwnershipCheck(playlistId, username);
+        
+        // 获取当前用户
+        User user = userRepository.findByUsername(username)
                 .orElseThrow(() -> new ResourceNotFoundException("User not found with username: " + username));
-
-        Playlist copiedPlaylist = new Playlist();
-        copiedPlaylist.setName(newName);
-        copiedPlaylist.setOwner(newOwner);
-
-        // 复制歌曲
-        for (Song originalSong : originalPlaylist.getSongs()) {
-            Song copiedSong = new Song();
-            copiedSong.setTitle(originalSong.getTitle());
-            copiedSong.setArtist(originalSong.getArtist());
-            copiedSong.setDurationInSeconds(originalSong.getDurationInSeconds());
-            copiedPlaylist.addSong(copiedSong);
+        
+        // 创建新歌单
+        Playlist newPlaylist = new Playlist();
+        newPlaylist.setName(newName);
+        newPlaylist.setOwner(user);
+        
+        // 保存新歌单
+        Playlist savedPlaylist = playlistRepository.save(newPlaylist);
+        
+        // 复制原歌单的所有歌曲
+        List<Song> originalSongs = songRepository.findByPlaylistId(originalPlaylist.getId());
+        for (Song originalSong : originalSongs) {
+            Song newSong = new Song();
+            newSong.setTitle(originalSong.getTitle());
+            newSong.setArtist(originalSong.getArtist());
+            newSong.setDurationInSeconds(originalSong.getDurationInSeconds());
+            newSong.setPlaylist(savedPlaylist);
+            songRepository.save(newSong);
         }
-
-        Playlist savedPlaylist = playlistRepository.save(copiedPlaylist);
-        return convertToDTO(savedPlaylist);
+        
+        // 重新加载新歌单以包含所有歌曲
+        Playlist updatedPlaylist = playlistRepository.findById(savedPlaylist.getId())
+                .orElseThrow(() -> new ResourceNotFoundException("Playlist not found with id: " + savedPlaylist.getId()));
+        
+        return convertToDTO(updatedPlaylist);
+    }
+    
+    @Override
+    public List<PlaylistDTO> filterPlaylists(String username, String ownerName, String nameKeyword, String sortBy, String sortDirection) {
+        List<Playlist> playlists;
+        User user = userRepository.findByUsername(username)
+                .orElseThrow(() -> new ResourceNotFoundException("User not found with username: " + username));
+        
+        // 如果提供了ownerName，则筛选特定用户的歌单
+        if (ownerName != null) {
+            User owner = userRepository.findByUsername(ownerName)
+                    .orElseThrow(() -> new ResourceNotFoundException("User not found with username: " + ownerName));
+            
+            // 根据是否提供关键词和排序条件选择不同的查询方法
+            if (nameKeyword != null) {
+                if (sortBy != null && sortBy.equals("createdAt")) {
+                    if (sortDirection != null && sortDirection.equals("desc")) {
+                        // 按名称关键词筛选并按创建时间降序排序
+                        playlists = playlistRepository.findByOwnerAndNameContainingIgnoreCaseOrderByCreatedAtDesc(owner, nameKeyword);
+                    } else {
+                        // 按名称关键词筛选并按创建时间升序排序
+                        playlists = playlistRepository.findByOwnerAndNameContainingIgnoreCaseOrderByCreatedAtAsc(owner, nameKeyword);
+                    }
+                } else {
+                    if (sortDirection != null && sortDirection.equals("desc")) {
+                        // 按名称关键词筛选并按名称降序排序
+                        playlists = playlistRepository.findByOwnerAndNameContainingIgnoreCaseOrderByNameDesc(owner, nameKeyword);
+                    } else {
+                        // 按名称关键词筛选并按名称升序排序
+                        playlists = playlistRepository.findByOwnerAndNameContainingIgnoreCaseOrderByNameAsc(owner, nameKeyword);
+                    }
+                }
+            } else {
+                if (sortBy != null && sortBy.equals("createdAt")) {
+                    if (sortDirection != null && sortDirection.equals("desc")) {
+                        // 按创建时间降序排序
+                        playlists = playlistRepository.findByOwnerOrderByCreatedAtDesc(owner);
+                    } else {
+                        // 按创建时间升序排序
+                        playlists = playlistRepository.findByOwnerOrderByCreatedAtAsc(owner);
+                    }
+                } else {
+                    if (sortDirection != null && sortDirection.equals("desc")) {
+                        // 按名称降序排序
+                        playlists = playlistRepository.findByOwnerOrderByNameDesc(owner);
+                    } else {
+                        // 按名称升序排序
+                        playlists = playlistRepository.findByOwnerOrderByNameAsc(owner);
+                    }
+                }
+            }
+        } else {
+            // 未提供ownerName，则筛选当前用户的歌单
+            if (nameKeyword != null) {
+                if (sortBy != null && sortBy.equals("createdAt")) {
+                    if (sortDirection != null && sortDirection.equals("desc")) {
+                        // 按名称关键词筛选并按创建时间降序排序
+                        playlists = playlistRepository.findByOwnerAndNameContainingIgnoreCaseOrderByCreatedAtDesc(user, nameKeyword);
+                    } else {
+                        // 按名称关键词筛选并按创建时间升序排序
+                        playlists = playlistRepository.findByOwnerAndNameContainingIgnoreCaseOrderByCreatedAtAsc(user, nameKeyword);
+                    }
+                } else {
+                    if (sortDirection != null && sortDirection.equals("desc")) {
+                        // 按名称关键词筛选并按名称降序排序
+                        playlists = playlistRepository.findByOwnerAndNameContainingIgnoreCaseOrderByNameDesc(user, nameKeyword);
+                    } else {
+                        // 按名称关键词筛选并按名称升序排序
+                        playlists = playlistRepository.findByOwnerAndNameContainingIgnoreCaseOrderByNameAsc(user, nameKeyword);
+                    }
+                }
+            } else {
+                if (sortBy != null && sortBy.equals("createdAt")) {
+                    if (sortDirection != null && sortDirection.equals("desc")) {
+                        // 按创建时间降序排序
+                        playlists = playlistRepository.findByOwnerOrderByCreatedAtDesc(user);
+                    } else {
+                        // 按创建时间升序排序
+                        playlists = playlistRepository.findByOwnerOrderByCreatedAtAsc(user);
+                    }
+                } else {
+                    if (sortDirection != null && sortDirection.equals("desc")) {
+                        // 按名称降序排序
+                        playlists = playlistRepository.findByOwnerOrderByNameDesc(user);
+                    } else {
+                        // 按名称升序排序
+                        playlists = playlistRepository.findByOwnerOrderByNameAsc(user);
+                    }
+                }
+            }
+        }
+        
+        // 转换为DTO并返回
+        return playlists.stream()
+                .map(this::convertToDTO)
+                .collect(Collectors.toList());
     }
 
     // 辅助方法：检查歌单所有权