diff --git a/backend/demo/src/main/java/com/example/demo/config/SecurityConfig.java b/backend/demo/src/main/java/com/example/demo/config/SecurityConfig.java
index b3e7f91..0c3672b 100644
--- a/backend/demo/src/main/java/com/example/demo/config/SecurityConfig.java
+++ b/backend/demo/src/main/java/com/example/demo/config/SecurityConfig.java
@@ -12,6 +12,9 @@
 import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.security.web.SecurityFilterChain;
 import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;
+import org.springframework.web.cors.CorsConfiguration; // 导入 CorsConfiguration
+import org.springframework.web.cors.UrlBasedCorsConfigurationSource; // 导入 UrlBasedCorsConfigurationSource
+import org.springframework.web.filter.CorsFilter; // 导入 CorsFilter
 
 import com.example.demo.security.JwtAuthenticationFilter;
 
@@ -41,6 +44,22 @@
     }
 
     /**
+     * 配置 CORS 过滤器。
+     * 允许前端应用 (http://localhost:5173) 访问后端 API。
+     */
+    @Bean
+    public CorsFilter corsFilter() {
+        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
+        CorsConfiguration config = new CorsConfiguration();
+        config.setAllowCredentials(true); // 允许发送 Cookie
+        config.addAllowedOrigin("http://localhost:5173"); // 允许的前端源
+        config.addAllowedHeader("*"); // 允许所有请求头
+        config.addAllowedMethod("*"); // 允许所有 HTTP 方法 (GET, POST, PUT, DELETE等)
+        source.registerCorsConfiguration("/**", config); // 对所有路径应用 CORS 配置
+        return new CorsFilter(source);
+    }
+
+    /**
      * 核心安全策略配置。
      * 配置内容包括：禁用 CSRF、禁用 Session 管理（使用 JWT 无状态）、
      * 配置请求的授权规则，并将自定义的 JWT 认证过滤器添加到过滤器链中。
@@ -55,6 +74,15 @@
                                            JwtAuthenticationFilter jwtFilter // 直接注入 JwtAuthenticationFilter Bean
                                            ) throws Exception {
         http
+            // 添加 CORS 过滤器到 Spring Security 过滤器链的开头
+            .cors(cors -> cors.configurationSource(request -> {
+                CorsConfiguration config = new CorsConfiguration();
+                config.setAllowCredentials(true);
+                config.addAllowedOrigin("http://localhost:5173");
+                config.addAllowedHeader("*");
+                config.addAllowedMethod("*");
+                return config;
+            }))
             // 禁用 CSRF (跨站请求伪造) 保护，因为 JWT 是无状态的，不需要 CSRF 保护
             .csrf(AbstractHttpConfigurer::disable)
             // 配置 Session 管理策略为无状态，不使用 Session
@@ -62,7 +90,7 @@
             // 配置请求的授权规则
             .authorizeHttpRequests(auth -> auth
                 // 允许对 /auth/** 路径下的所有请求进行匿名访问 (例如登录、注册接口)
-                .requestMatchers("/auth/**").permitAll()
+                .requestMatchers("/api/auth/**").permitAll() // 确保这里的路径与您的 AuthController 匹配
                 // 其他所有请求都需要进行身份认证
                 .anyRequest().authenticated()
             )
diff --git a/backend/demo/src/main/java/com/example/demo/config/WebConfig.java b/backend/demo/src/main/java/com/example/demo/config/WebConfig.java
new file mode 100644
index 0000000..839dce2
--- /dev/null
+++ b/backend/demo/src/main/java/com/example/demo/config/WebConfig.java
@@ -0,0 +1,19 @@
+package com.example.demo.config;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.CorsRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+@Configuration
+public class WebConfig implements WebMvcConfigurer {
+
+   // @Override
+     public void addCorsMappings(CorsRegistry registry) {
+        registry.addMapping("/api/**") // Apply to your API path
+                .allowedOrigins("http://localhost:5173") // URL of your React app
+                .allowedMethods("GET", "POST", "PUT", "DELETE", "OPTIONS")
+                .allowedHeaders("*")
+                .allowCredentials(true);
+    }
+
+}
\ No newline at end of file
diff --git a/backend/demo/src/main/java/com/example/demo/controller/AuthController.java b/backend/demo/src/main/java/com/example/demo/controller/AuthController.java
index d7dfe50..18f3105 100644
--- a/backend/demo/src/main/java/com/example/demo/controller/AuthController.java
+++ b/backend/demo/src/main/java/com/example/demo/controller/AuthController.java
@@ -1,17 +1,13 @@
 package com.example.demo.controller;
 
-import java.time.Instant;
-import java.util.List;
-import java.util.Map;
-
 import org.springframework.http.ResponseEntity;
-import org.springframework.security.authentication.AuthenticationManager; // 导入 AuthenticationManager
-import org.springframework.security.authentication.UsernamePasswordAuthenticationToken; // 导入 UsernamePasswordAuthenticationToken
-import org.springframework.security.core.Authentication; // 导入 Authentication
-import org.springframework.security.core.context.SecurityContextHolder; // 导入 SecurityContextHolder
-import org.springframework.security.crypto.password.PasswordEncoder;
-import org.springframework.validation.BindingResult;
-import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.security.authentication.AuthenticationManager;
+import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.context.SecurityContextHolder; // 导入 AuthenticationManager
+import org.springframework.security.crypto.password.PasswordEncoder; // 导入 UsernamePasswordAuthenticationToken
+import org.springframework.validation.BindingResult; // 导入 Authentication
+import org.springframework.web.bind.annotation.PostMapping; // 导入 SecurityContextHolder
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
@@ -45,64 +41,45 @@
     }
 
     @PostMapping("/login")
-    public ResponseEntity<?> login(
-            @Valid @RequestBody LoginRequestDTO loginRequest,
-            BindingResult bindingResult) {
+public ResponseEntity<?> login(
+        @Valid @RequestBody LoginRequestDTO loginRequest,
+        BindingResult bindingResult) {
 
-        if (bindingResult.hasErrors()) {
-            String errMsg = bindingResult.getFieldErrors().stream()
-                    .map(fe -> fe.getField() + ": " + fe.getDefaultMessage())
-                    .reduce((a, b) -> a + "; " + b)
-                    .orElse("Invalid parameters");
-            return ResponseEntity.badRequest().body(Map.of("error", errMsg));
-        }
+    if (bindingResult.hasErrors()) {
+        // … 参数校验错误的处理，这里不会走到
+    }
 
-        try {
-            // 使用 AuthenticationManager 进行认证
-            // 这会触发 UserServiceImpl 中的 loadUserByUsername 方法的调用，并比较密码
-            Authentication authentication = authenticationManager.authenticate(
-                    new UsernamePasswordAuthenticationToken(
-                            loginRequest.getUsername(),
-                            loginRequest.getPassword()
-                    )
-            );
-            // 将认证信息设置到 Spring Security 的上下文中
-            SecurityContextHolder.getContext().setAuthentication(authentication);
+    try {
+        System.out.println("login(): 开始调用 authenticationManager.authenticate");
+        Authentication authentication = authenticationManager.authenticate(
+                new UsernamePasswordAuthenticationToken(
+                        loginRequest.getUsername(),
+                        loginRequest.getPassword()
+                )
+        );
+        System.out.println("login(): authenticate 成功，principal = " 
+                           + authentication.getPrincipal());
 
-            // 获取认证后的用户详情（假设 User 实体实现了 UserDetails 接口）
-            User userDetails = (User) authentication.getPrincipal();
+        // 设置到上下文
+        SecurityContextHolder.getContext().setAuthentication(authentication);
+        System.out.println("login(): SecurityContext 设置完成");
 
-            // 调用 UserService 方法生成登录响应（包括 JWT Token）
-            LoginResponseDTO response = userService.generateLoginResponse(userDetails);
+        // 强转 principal 为 用户实体
+        User userDetails = (User) authentication.getPrincipal();
+        System.out.println("login(): 拿到 userDetails，username = " + userDetails.getUsername());
 
-            return ResponseEntity.ok(response);
-
-        } catch (Exception e) {
-            // 认证失败（用户名不存在或密码错误），抛出自定义认证异常
-            // GlobalExceptionHandler 会捕获 AuthException 并返回 401
-            throw new AuthException("用户名或密码错误", e);
-        }
-
-        // 移除原有的手动查找用户和密码比对逻辑
-        /*
-        User user = userService.lambdaQuery()
-                .eq(User::getUsername, loginRequest.getUsername())
-                .one();
-
-        if (user == null || !passwordEncoder.matches(loginRequest.getPassword(), user.getPassword())) {
-            throw new AuthException("用户名或密码错误");
-        }
-
-        String token = jwtTokenUtil.generateToken(user.getId(), user.getUsername(), user.getRole());
-
-        LoginResponseDTO response = new LoginResponseDTO();
-        response.setToken(token);
-        response.setExpiresAt(Instant.now().plusMillis(jwtTokenUtil.getExpiration()));
-        response.setUserId(user.getId());
-        response.setUsername(user.getUsername());
-        response.setRoles(List.of(user.getRole()));
+        // 调用生成 JWT 的方法
+        System.out.println("login(): 调用 userService.generateLoginResponse");
+        LoginResponseDTO response = userService.generateLoginResponse(userDetails);
+        System.out.println("login(): generateLoginResponse 返回 token = " + response.getToken());
 
         return ResponseEntity.ok(response);
-        */
+
+    } catch (Exception e) {
+        System.out.println("login(): 捕获到异常: " + e.getClass().getSimpleName() + " - " + e.getMessage());
+        e.printStackTrace();
+        throw new AuthException("用户名或密码错误", e);
     }
+}
+
 }
\ No newline at end of file
diff --git a/backend/demo/src/main/java/com/example/demo/controller/TorrentController.java b/backend/demo/src/main/java/com/example/demo/controller/TorrentController.java
index 0bd501a..6a91d27 100644
--- a/backend/demo/src/main/java/com/example/demo/controller/TorrentController.java
+++ b/backend/demo/src/main/java/com/example/demo/controller/TorrentController.java
@@ -1,16 +1,17 @@
 // src/main/java/com/example/demo/controller/TorrentController.java
 package com.example.demo.controller;
 
-import java.io.IOException; // 导入 DTO
-import java.nio.file.Path; // 导入服务接口
-import java.nio.file.Paths; // 导入 ttorrent 的异常
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 
-import org.springframework.beans.factory.annotation.Value; // 导入 @Value 用于读取配置
-import org.springframework.core.io.Resource; // 导入 Resource
-import org.springframework.core.io.UrlResource; // 导入 UrlResource
-import org.springframework.http.HttpHeaders; // 导入 HttpHeaders
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.core.io.Resource;
+import org.springframework.core.io.UrlResource;
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
-import org.springframework.http.MediaType; // 导入 MediaType
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -27,38 +28,37 @@
 /**
  * 处理 .torrent 文件上传和下载的 RESTful 控制器。
  */
-@RestController // 组合了 @Controller 和 @ResponseBody，表示这是一个 RESTful 控制器
-@RequestMapping("/api") // 定义所有处理方法的根路径
+@RestController
+@RequestMapping("/api")
 public class TorrentController {
 
     private final TorrentService torrentService;
 
-    @Value("${file.upload-dir}") // 从 application.properties 中注入文件上传目录
+    @Value("${file.upload-dir}")
     private String uploadDir;
 
-    // 通过构造函数注入 TorrentService
     public TorrentController(TorrentService torrentService) {
         this.torrentService = torrentService;
     }
 
     /**
-     * 处理 .torrent 文件的上传请求。
+     * 上传 .torrent 文件并处理其元信息。
      *
-     * @param file 上传的 MultipartFile 对象，通过 @RequestParam("file") 绑定。
-     * @return 包含 TorrentInfoDTO 的 ResponseEntity，表示操作结果。
+     * @param file  上传的 .torrent 文件
+     * @param title 用户指定的标题
+     * @return 处理结果
      */
-    @PostMapping("/torrents") // 映射到 /api/torrents 的 POST 请求
-    public ResponseEntity<TorrentInfoDTO> uploadTorrent(@RequestParam("file") MultipartFile file) {
-        // 1. 接收 HTTP 请求 (通过 @PostMapping 和 @RequestParam)
+    @PostMapping("/torrents/upload")
+    public ResponseEntity<TorrentInfoDTO> uploadTorrent(
+            @RequestParam("file") MultipartFile file,
+            @RequestParam("title") String title) {
 
-        // 2. 校验参数
         if (file.isEmpty()) {
             TorrentInfoDTO errorDto = new TorrentInfoDTO();
             errorDto.setMessage("上传文件不能为空。");
             return new ResponseEntity<>(errorDto, HttpStatus.BAD_REQUEST);
         }
 
-        // 校验文件类型 (可选，但推荐)
         if (!file.getOriginalFilename().toLowerCase().endsWith(".torrent")) {
             TorrentInfoDTO errorDto = new TorrentInfoDTO();
             errorDto.setMessage("只允许上传 .torrent 文件。");
@@ -66,65 +66,66 @@
         }
 
         try {
-            // 3. 调用 Service 层处理业务逻辑
-            TorrentInfoDTO result = torrentService.handleUpload(file);
-
-            // 4. 返回 TorrentInfoDTO 给前端
+            TorrentInfoDTO result = torrentService.handleUpload(file, title);
             return new ResponseEntity<>(result, HttpStatus.OK);
         } catch (InvalidBEncodingException e) {
-            // 捕获 .torrent 文件解析错误
             TorrentInfoDTO errorDto = new TorrentInfoDTO();
             errorDto.setMessage("文件解析失败，请确保它是有效的 .torrent 文件: " + e.getMessage());
             return new ResponseEntity<>(errorDto, HttpStatus.BAD_REQUEST);
         } catch (IllegalArgumentException e) {
-            // 捕获服务层抛出的非法参数异常 (如文件为空)
             TorrentInfoDTO errorDto = new TorrentInfoDTO();
             errorDto.setMessage("处理文件时发生错误: " + e.getMessage());
             return new ResponseEntity<>(errorDto, HttpStatus.BAD_REQUEST);
         } catch (IOException e) {
-            // 捕获文件读写或保存失败的异常
             TorrentInfoDTO errorDto = new TorrentInfoDTO();
             errorDto.setMessage("文件上传或保存失败: " + e.getMessage());
             return new ResponseEntity<>(errorDto, HttpStatus.INTERNAL_SERVER_ERROR);
         } catch (Exception e) {
-            // 捕获其他未知异常
             TorrentInfoDTO errorDto = new TorrentInfoDTO();
             errorDto.setMessage("文件上传过程中发生未知错误: " + e.getMessage());
-            e.printStackTrace(); // 打印堆栈跟踪以便调试
+            e.printStackTrace();
             return new ResponseEntity<>(errorDto, HttpStatus.INTERNAL_SERVER_ERROR);
         }
     }
 
     /**
-     * 实现 .torrent 文件的下载功能。
-     * 根据 infoHash 找到对应的 .torrent 文件并提供下载。
+     * 下载已上传的 .torrent 文件。
      *
-     * @param infoHash 洪流的 info hash，用于查找服务器上的文件。
-     * @param fileName 原始文件名 (用于设置下载时的文件名，实际查找文件仍依赖 infoHash)。
-     * @return 包含 .torrent 文件内容的 ResponseEntity。
+     * @param infoHash  该文件的 info hash，用于定位文件
+     * @param fileName  用户下载时看到的文件名
+     * @return ResponseEntity 包含下载资源
      */
-   // 修正后的 downloadTorrent 方法片段
-@GetMapping("/downloads/{infoHash}/{fileName}")
-public ResponseEntity<Resource> downloadTorrent(@PathVariable String infoHash, @PathVariable String fileName) {
-    try {
-        Path fileStorageLocation = Paths.get(uploadDir).toAbsolutePath().normalize();
-        Path filePath = fileStorageLocation.resolve(infoHash + ".torrent").normalize();
-        Resource resource = new UrlResource(filePath.toUri()); // 这一行不会抛出 MalformedURLException
-
-        if (resource.exists() && resource.isReadable()) {
-            String contentType = "application/x-bittorrent";
-            String headerValue = "attachment; filename=\"" + fileName + "\"";
-
-            return ResponseEntity.ok()
-                    .contentType(MediaType.parseMediaType(contentType))
-                    .header(HttpHeaders.CONTENT_DISPOSITION, headerValue)
-                    .body(resource);
-        } else {
-            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+     // —— 2. 启动下载 —— //
+    @PostMapping("/download")
+    public ResponseEntity<Void> download(@RequestParam("infoHash") String infoHash) {
+        try {
+            torrentService.startDownload(infoHash);
+            return ResponseEntity.accepted().build();
+        } catch (Exception e) {
+            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).build();
         }
-    } catch (IOException e) { // 只保留 IOException
-        return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
     }
-    // MalformedURLException 相关的 catch 块已移除
+
+    // —— 3. 查询下载进度 —— //
+    @GetMapping("/download/status/{infoHash}")
+    public ResponseEntity<Float> status(@PathVariable String infoHash) {
+        float progress = torrentService.getDownloadProgress(infoHash);
+        return ResponseEntity.ok(progress);
+    }
+
+    // —— 4. 获取下载后的文件路径 —— //
+    // 如果你想让浏览器直接触发下载，也可以重定向或返回文件流
+    @GetMapping("/download/file/{infoHash}")
+    public ResponseEntity<Resource> file(@PathVariable String infoHash) throws MalformedURLException {
+        String path = torrentService.getDownloadedFilePath(infoHash);
+        if (path == null) {
+            return ResponseEntity.notFound().build();
+        }
+        UrlResource resource = new UrlResource("file:" + path);
+        return ResponseEntity.ok()
+            .header(HttpHeaders.CONTENT_DISPOSITION,
+                    "attachment; filename=\"" + Paths.get(path).getFileName() + "\"")
+            .body(resource);
+    }
+    
 }
-}
\ No newline at end of file
diff --git a/backend/demo/src/main/java/com/example/demo/result.txt b/backend/demo/src/main/java/com/example/demo/result.txt
index bd1dd30..d7cdef4 100644
--- a/backend/demo/src/main/java/com/example/demo/result.txt
+++ b/backend/demo/src/main/java/com/example/demo/result.txt
@@ -110,6 +110,9 @@
 import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.security.web.SecurityFilterChain;
 import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;
+import org.springframework.web.cors.CorsConfiguration; // 导入 CorsConfiguration
+import org.springframework.web.cors.UrlBasedCorsConfigurationSource; // 导入 UrlBasedCorsConfigurationSource
+import org.springframework.web.filter.CorsFilter; // 导入 CorsFilter
 
 import com.example.demo.security.JwtAuthenticationFilter;
 
@@ -139,6 +142,22 @@
     }
 
     /**
+     * 配置 CORS 过滤器。
+     * 允许前端应用 (http://localhost:5173) 访问后端 API。
+     */
+    @Bean
+    public CorsFilter corsFilter() {
+        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
+        CorsConfiguration config = new CorsConfiguration();
+        config.setAllowCredentials(true); // 允许发送 Cookie
+        config.addAllowedOrigin("http://localhost:5173"); // 允许的前端源
+        config.addAllowedHeader("*"); // 允许所有请求头
+        config.addAllowedMethod("*"); // 允许所有 HTTP 方法 (GET, POST, PUT, DELETE等)
+        source.registerCorsConfiguration("/**", config); // 对所有路径应用 CORS 配置
+        return new CorsFilter(source);
+    }
+
+    /**
      * 核心安全策略配置。
      * 配置内容包括：禁用 CSRF、禁用 Session 管理（使用 JWT 无状态）、
      * 配置请求的授权规则，并将自定义的 JWT 认证过滤器添加到过滤器链中。
@@ -153,6 +172,15 @@
                                            JwtAuthenticationFilter jwtFilter // 直接注入 JwtAuthenticationFilter Bean
                                            ) throws Exception {
         http
+            // 添加 CORS 过滤器到 Spring Security 过滤器链的开头
+            .cors(cors -> cors.configurationSource(request -> {
+                CorsConfiguration config = new CorsConfiguration();
+                config.setAllowCredentials(true);
+                config.addAllowedOrigin("http://localhost:5173");
+                config.addAllowedHeader("*");
+                config.addAllowedMethod("*");
+                return config;
+            }))
             // 禁用 CSRF (跨站请求伪造) 保护，因为 JWT 是无状态的，不需要 CSRF 保护
             .csrf(AbstractHttpConfigurer::disable)
             // 配置 Session 管理策略为无状态，不使用 Session
@@ -160,7 +188,7 @@
             // 配置请求的授权规则
             .authorizeHttpRequests(auth -> auth
                 // 允许对 /auth/** 路径下的所有请求进行匿名访问 (例如登录、注册接口)
-                .requestMatchers("/auth/**").permitAll()
+                .requestMatchers("/api/auth/**").permitAll() // 确保这里的路径与您的 AuthController 匹配
                 // 其他所有请求都需要进行身份认证
                 .anyRequest().authenticated()
             )
@@ -185,18 +213,14 @@
 --- Content of: ./controller/AuthController.java ---
 package com.example.demo.controller;
 
-import java.time.Instant;
-import java.util.List;
-import java.util.Map;
-
 import org.springframework.http.ResponseEntity;
-import org.springframework.security.authentication.AuthenticationManager; // 导入 AuthenticationManager
-import org.springframework.security.authentication.UsernamePasswordAuthenticationToken; // 导入 UsernamePasswordAuthenticationToken
-import org.springframework.security.core.Authentication; // 导入 Authentication
-import org.springframework.security.core.context.SecurityContextHolder; // 导入 SecurityContextHolder
-import org.springframework.security.crypto.password.PasswordEncoder;
-import org.springframework.validation.BindingResult;
-import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.security.authentication.AuthenticationManager;
+import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.context.SecurityContextHolder; // 导入 AuthenticationManager
+import org.springframework.security.crypto.password.PasswordEncoder; // 导入 UsernamePasswordAuthenticationToken
+import org.springframework.validation.BindingResult; // 导入 Authentication
+import org.springframework.web.bind.annotation.PostMapping; // 导入 SecurityContextHolder
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
@@ -230,68 +254,175 @@
     }
 
     @PostMapping("/login")
-    public ResponseEntity<?> login(
-            @Valid @RequestBody LoginRequestDTO loginRequest,
-            BindingResult bindingResult) {
+public ResponseEntity<?> login(
+        @Valid @RequestBody LoginRequestDTO loginRequest,
+        BindingResult bindingResult) {
 
-        if (bindingResult.hasErrors()) {
-            String errMsg = bindingResult.getFieldErrors().stream()
-                    .map(fe -> fe.getField() + ": " + fe.getDefaultMessage())
-                    .reduce((a, b) -> a + "; " + b)
-                    .orElse("Invalid parameters");
-            return ResponseEntity.badRequest().body(Map.of("error", errMsg));
+    if (bindingResult.hasErrors()) {
+        // … 参数校验错误的处理，这里不会走到
+    }
+
+    try {
+        System.out.println("login(): 开始调用 authenticationManager.authenticate");
+        Authentication authentication = authenticationManager.authenticate(
+                new UsernamePasswordAuthenticationToken(
+                        loginRequest.getUsername(),
+                        loginRequest.getPassword()
+                )
+        );
+        System.out.println("login(): authenticate 成功，principal = " 
+                           + authentication.getPrincipal());
+
+        // 设置到上下文
+        SecurityContextHolder.getContext().setAuthentication(authentication);
+        System.out.println("login(): SecurityContext 设置完成");
+
+        // 强转 principal 为 用户实体
+        User userDetails = (User) authentication.getPrincipal();
+        System.out.println("login(): 拿到 userDetails，username = " + userDetails.getUsername());
+
+        // 调用生成 JWT 的方法
+        System.out.println("login(): 调用 userService.generateLoginResponse");
+        LoginResponseDTO response = userService.generateLoginResponse(userDetails);
+        System.out.println("login(): generateLoginResponse 返回 token = " + response.getToken());
+
+        return ResponseEntity.ok(response);
+
+    } catch (Exception e) {
+        System.out.println("login(): 捕获到异常: " + e.getClass().getSimpleName() + " - " + e.getMessage());
+        e.printStackTrace();
+        throw new AuthException("用户名或密码错误", e);
+    }
+}
+
+}
+--- End of: ./controller/AuthController.java ---
+
+--- Content of: ./controller/TorrentController.java ---
+// src/main/java/com/example/demo/controller/TorrentController.java
+package com.example.demo.controller;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.core.io.Resource;
+import org.springframework.core.io.UrlResource;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.multipart.MultipartFile;
+
+import com.example.demo.dto.TorrentInfoDTO;
+import com.example.demo.service.TorrentService;
+import com.turn.ttorrent.bcodec.InvalidBEncodingException;
+
+/**
+ * 处理 .torrent 文件上传和下载的 RESTful 控制器。
+ */
+@RestController
+@RequestMapping("/api")
+public class TorrentController {
+
+    private final TorrentService torrentService;
+
+    @Value("${file.upload-dir}")
+    private String uploadDir;
+
+    public TorrentController(TorrentService torrentService) {
+        this.torrentService = torrentService;
+    }
+
+    /**
+     * 上传 .torrent 文件并处理其元信息。
+     *
+     * @param file  上传的 .torrent 文件
+     * @param title 用户指定的标题
+     * @return 处理结果
+     */
+    @PostMapping("/torrents/upload")
+    public ResponseEntity<TorrentInfoDTO> uploadTorrent(
+            @RequestParam("file") MultipartFile file,
+            @RequestParam("title") String title) {
+
+        if (file.isEmpty()) {
+            TorrentInfoDTO errorDto = new TorrentInfoDTO();
+            errorDto.setMessage("上传文件不能为空。");
+            return new ResponseEntity<>(errorDto, HttpStatus.BAD_REQUEST);
+        }
+
+        if (!file.getOriginalFilename().toLowerCase().endsWith(".torrent")) {
+            TorrentInfoDTO errorDto = new TorrentInfoDTO();
+            errorDto.setMessage("只允许上传 .torrent 文件。");
+            return new ResponseEntity<>(errorDto, HttpStatus.UNSUPPORTED_MEDIA_TYPE);
         }
 
         try {
-            // 使用 AuthenticationManager 进行认证
-            // 这会触发 UserServiceImpl 中的 loadUserByUsername 方法的调用，并比较密码
-            Authentication authentication = authenticationManager.authenticate(
-                    new UsernamePasswordAuthenticationToken(
-                            loginRequest.getUsername(),
-                            loginRequest.getPassword()
-                    )
-            );
-            // 将认证信息设置到 Spring Security 的上下文中
-            SecurityContextHolder.getContext().setAuthentication(authentication);
-
-            // 获取认证后的用户详情（假设 User 实体实现了 UserDetails 接口）
-            User userDetails = (User) authentication.getPrincipal();
-
-            // 调用 UserService 方法生成登录响应（包括 JWT Token）
-            LoginResponseDTO response = userService.generateLoginResponse(userDetails);
-
-            return ResponseEntity.ok(response);
-
+            TorrentInfoDTO result = torrentService.handleUpload(file, title);
+            return new ResponseEntity<>(result, HttpStatus.OK);
+        } catch (InvalidBEncodingException e) {
+            TorrentInfoDTO errorDto = new TorrentInfoDTO();
+            errorDto.setMessage("文件解析失败，请确保它是有效的 .torrent 文件: " + e.getMessage());
+            return new ResponseEntity<>(errorDto, HttpStatus.BAD_REQUEST);
+        } catch (IllegalArgumentException e) {
+            TorrentInfoDTO errorDto = new TorrentInfoDTO();
+            errorDto.setMessage("处理文件时发生错误: " + e.getMessage());
+            return new ResponseEntity<>(errorDto, HttpStatus.BAD_REQUEST);
+        } catch (IOException e) {
+            TorrentInfoDTO errorDto = new TorrentInfoDTO();
+            errorDto.setMessage("文件上传或保存失败: " + e.getMessage());
+            return new ResponseEntity<>(errorDto, HttpStatus.INTERNAL_SERVER_ERROR);
         } catch (Exception e) {
-            // 认证失败（用户名不存在或密码错误），抛出自定义认证异常
-            // GlobalExceptionHandler 会捕获 AuthException 并返回 401
-            throw new AuthException("用户名或密码错误", e);
+            TorrentInfoDTO errorDto = new TorrentInfoDTO();
+            errorDto.setMessage("文件上传过程中发生未知错误: " + e.getMessage());
+            e.printStackTrace();
+            return new ResponseEntity<>(errorDto, HttpStatus.INTERNAL_SERVER_ERROR);
         }
+    }
 
-        // 移除原有的手动查找用户和密码比对逻辑
-        /*
-        User user = userService.lambdaQuery()
-                .eq(User::getUsername, loginRequest.getUsername())
-                .one();
+    /**
+     * 下载已上传的 .torrent 文件。
+     *
+     * @param infoHash  该文件的 info hash，用于定位文件
+     * @param fileName  用户下载时看到的文件名
+     * @return ResponseEntity 包含下载资源
+     */
+    @GetMapping("/downloads/{infoHash}/{fileName}")
+    public ResponseEntity<Resource> downloadTorrent(
+            @PathVariable String infoHash,
+            @PathVariable String fileName) {
 
-        if (user == null || !passwordEncoder.matches(loginRequest.getPassword(), user.getPassword())) {
-            throw new AuthException("用户名或密码错误");
+        try {
+            Path fileStorageLocation = Paths.get(uploadDir).toAbsolutePath().normalize();
+            Path filePath = fileStorageLocation.resolve(infoHash + ".torrent").normalize();
+            Resource resource = new UrlResource(filePath.toUri());
+
+            if (resource.exists() && resource.isReadable()) {
+                String contentType = "application/x-bittorrent";
+                String headerValue = "attachment; filename=\"" + fileName + "\"";
+
+                return ResponseEntity.ok()
+                        .contentType(MediaType.parseMediaType(contentType))
+                        .header(HttpHeaders.CONTENT_DISPOSITION, headerValue)
+                        .body(resource);
+            } else {
+                return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+            }
+        } catch (IOException e) {
+            return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
         }
-
-        String token = jwtTokenUtil.generateToken(user.getId(), user.getUsername(), user.getRole());
-
-        LoginResponseDTO response = new LoginResponseDTO();
-        response.setToken(token);
-        response.setExpiresAt(Instant.now().plusMillis(jwtTokenUtil.getExpiration()));
-        response.setUserId(user.getId());
-        response.setUsername(user.getUsername());
-        response.setRoles(List.of(user.getRole()));
-
-        return ResponseEntity.ok(response);
-        */
     }
 }
---- End of: ./controller/AuthController.java ---
+
+--- End of: ./controller/TorrentController.java ---
 
 --- Content of: ./DemoApplication.java ---
 package com.example.demo;
@@ -414,6 +545,96 @@
 
 --- End of: ./dto/LoginResponseDTO.java ---
 
+--- Content of: ./dto/TorrentInfoDTO.java ---
+// src/main/java/com/example/demo/dto/TorrentInfoDTO.java
+package com.example.demo.dto;
+
+import java.io.Serializable;
+
+public class TorrentInfoDTO implements Serializable {
+    private String fileName;
+    private long fileSize;
+    private String infoHash;
+    private String magnetUri;
+    private String downloadUrl;
+    private String message; // For success or error messages
+
+    // Constructors
+    public TorrentInfoDTO() {
+    }
+
+    public TorrentInfoDTO(String fileName, long fileSize, String infoHash, String magnetUri, String downloadUrl, String message) {
+        this.fileName = fileName;
+        this.fileSize = fileSize;
+        this.infoHash = infoHash;
+        this.magnetUri = magnetUri;
+        this.downloadUrl = downloadUrl;
+        this.message = message;
+    }
+
+    // Getters and Setters
+    public String getFileName() {
+        return fileName;
+    }
+
+    public void setFileName(String fileName) {
+        this.fileName = fileName;
+    }
+
+    public long getFileSize() {
+        return fileSize;
+    }
+
+    public void setFileSize(long fileSize) {
+        this.fileSize = fileSize;
+    }
+
+    public String getInfoHash() {
+        return infoHash;
+    }
+
+    public void setInfoHash(String infoHash) {
+        this.infoHash = infoHash;
+    }
+
+    public String getMagnetUri() {
+        return magnetUri;
+    }
+
+    public void setMagnetUri(String magnetUri) {
+        this.magnetUri = magnetUri;
+    }
+
+    public String getDownloadUrl() {
+        return downloadUrl;
+    }
+
+    public void setDownloadUrl(String downloadUrl) {
+        this.downloadUrl = downloadUrl;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+
+    public void setMessage(String message) {
+        this.message = message;
+    }
+
+    @Override
+    public String toString() {
+        return "TorrentInfoDTO{" +
+               "fileName='" + fileName + '\'' +
+               ", fileSize=" + fileSize +
+               ", infoHash='" + infoHash + '\'' +
+               ", magnetUri='" + magnetUri + '\'' +
+               ", downloadUrl='" + downloadUrl + '\'' +
+               ", message='" + message + '\'' +
+               '}';
+    }
+}
+--- End of: ./dto/TorrentInfoDTO.java ---
+
 --- Content of: ./entity/User.java ---
 package com.example.demo.entity;
 
@@ -579,6 +800,127 @@
 
 --- End of: ./entity/User.java ---
 
+--- Content of: ./entity/TorrentInfo.java ---
+// src/main/java/com/example/demo/entity/TorrentInfo.java
+package com.example.demo.entity;
+
+import java.time.LocalDateTime;
+
+import com.baomidou.mybatisplus.annotation.IdType;
+import com.baomidou.mybatisplus.annotation.TableField;
+import com.baomidou.mybatisplus.annotation.TableId;
+import com.baomidou.mybatisplus.annotation.TableName;
+
+@TableName("torrent_info") // 映射到数据库中的 torrent_info 表
+public class TorrentInfo {
+
+    @TableId(value = "id", type = IdType.AUTO) // 标记为主键，并设置为数据库自增
+    private Long id;
+
+    @TableField("info_hash") // 映射到数据库中的 info_hash 列
+    private String infoHash; // 洪流的唯一标识符（信息哈希）
+
+    @TableField("file_name") // 映射到数据库中的 file_name 列
+    private String fileName; // 原始文件名
+
+    @TableField("file_size") // 映射到数据库中的 file_size 列
+    private Long fileSize; // 文件大小（字节）
+
+    @TableField("magnet_uri") // 映射到数据库中的 magnet_uri 列
+    private String magnetUri; // 生成的磁力链接
+
+    @TableField("download_url") // 映射到数据库中的 download_url 列
+    private String downloadUrl; // .torrent 文件的下载 URL
+
+    @TableField("upload_time") // 映射到数据库中的 upload_time 列
+    private LocalDateTime uploadTime; // 上传时间
+
+    // 默认构造函数，MyBatis-Plus 需要
+    public TorrentInfo() {
+    }
+
+    // 带有所有字段的构造函数（不包含 ID 和 uploadTime，因为它们是自动生成的）
+    public TorrentInfo(String infoHash, String fileName, Long fileSize, String magnetUri, String downloadUrl) {
+        this.infoHash = infoHash;
+        this.fileName = fileName;
+        this.fileSize = fileSize;
+        this.magnetUri = magnetUri;
+        this.downloadUrl = downloadUrl;
+        this.uploadTime = LocalDateTime.now(); // 设置当前上传时间
+    }
+
+    // Getters and Setters
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getInfoHash() {
+        return infoHash;
+    }
+
+    public void setInfoHash(String infoHash) {
+        this.infoHash = infoHash;
+    }
+
+    public String getFileName() {
+        return fileName;
+    }
+
+    public void setFileName(String fileName) {
+        this.fileName = fileName;
+    }
+
+    public Long getFileSize() {
+        return fileSize;
+    }
+
+    public void setFileSize(Long fileSize) {
+        this.fileSize = fileSize;
+    }
+
+    public String getMagnetUri() {
+        return magnetUri;
+    }
+
+    public void setMagnetUri(String magnetUri) {
+        this.magnetUri = magnetUri;
+    }
+
+    public String getDownloadUrl() {
+        return downloadUrl;
+    }
+
+    public void setDownloadUrl(String downloadUrl) {
+        this.downloadUrl = downloadUrl;
+    }
+
+    public LocalDateTime getUploadTime() {
+        return uploadTime;
+    }
+
+    public void setUploadTime(LocalDateTime uploadTime) {
+        this.uploadTime = uploadTime;
+    }
+
+    @Override
+    public String toString() {
+        return "TorrentInfo{" +
+               "id=" + id +
+               ", infoHash='" + infoHash + '\'' +
+               ", fileName='" + fileName + '\'' +
+               ", fileSize=" + fileSize +
+               ", magnetUri='" + magnetUri + '\'' +
+               ", downloadUrl='" + downloadUrl + '\'' +
+               ", uploadTime=" + uploadTime +
+               '}';
+    }
+}
+--- End of: ./entity/TorrentInfo.java ---
+
 --- Content of: ./exception/AuthException.java ---
 package com.example.demo.exception;
 
@@ -666,15 +1008,31 @@
 
 --- End of: ./mapper/UserMapper.java ---
 
+--- Content of: ./mapper/TorrentInfoMapper.java ---
+// src/main/java/com/example/demo/mapper/TorrentInfoMapper.java
+package com.example.demo.mapper;
+
+import org.apache.ibatis.annotations.Mapper;
+
+import com.baomidou.mybatisplus.core.mapper.BaseMapper;
+import com.example.demo.entity.TorrentInfo; // MyBatis 的 Mapper 注解
+
+@Mapper // 标记这是一个 MyBatis Mapper 接口
+public interface TorrentInfoMapper extends BaseMapper<TorrentInfo> {
+    // BaseMapper 提供了基本的 CRUD 操作，例如 insert(), selectById(), selectList(), deleteById() 等。
+    // 无需编写任何实现代码。
+}
+--- End of: ./mapper/TorrentInfoMapper.java ---
+
 --- Content of: ./security/JwtAuthenticationFilter.java ---
 package com.example.demo.security;
 
 import java.io.IOException;
-import java.util.List;
 
 import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
-import org.springframework.security.core.authority.SimpleGrantedAuthority;
 import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.security.core.userdetails.UserDetails;
+import org.springframework.security.core.userdetails.UserDetailsService;
 import org.springframework.stereotype.Component;
 import org.springframework.util.StringUtils;
 import org.springframework.web.filter.OncePerRequestFilter;
@@ -682,20 +1040,23 @@
 import com.example.demo.config.JWTProperties;
 import com.example.demo.exception.AuthException;
 
-import io.jsonwebtoken.Claims;
 import jakarta.servlet.FilterChain;
 import jakarta.servlet.ServletException;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
-@Component 
+@Component
 public class JwtAuthenticationFilter extends OncePerRequestFilter {
 
     private final JwtTokenUtil tokenUtil;
     private final JWTProperties props;
+    private final UserDetailsService userDetailsService; // ✅ 注入接口
 
-    public JwtAuthenticationFilter(JwtTokenUtil tokenUtil, JWTProperties props) {
+    public JwtAuthenticationFilter(JwtTokenUtil tokenUtil,
+                                   JWTProperties props,
+                                   UserDetailsService userDetailsService) {
         this.tokenUtil = tokenUtil;
         this.props = props;
+        this.userDetailsService = userDetailsService;
     }
 
     @Override
@@ -715,16 +1076,16 @@
             throw new AuthException("Invalid or expired JWT token");
         }
 
-        Claims claims = tokenUtil.parseClaims(token);
-        String username =tokenUtil.getUsername(token);
-        Long userId = tokenUtil.getUserId(token);
-        String role = tokenUtil.getRole(token);
+        String username = tokenUtil.getUsername(token);
+
+        // ✅ 使用 UserServiceImpl 加载完整的用户对象（包括权限信息）
+        UserDetails userDetails = userDetailsService.loadUserByUsername(username);
 
         UsernamePasswordAuthenticationToken auth =
             new UsernamePasswordAuthenticationToken(
-                userId, 
-                null, 
-                List.of(new SimpleGrantedAuthority(role))
+                userDetails, // ✅ 设置完整的用户对象
+                null,
+                userDetails.getAuthorities()
             );
         SecurityContextHolder.getContext().setAuthentication(auth);
 
@@ -875,26 +1236,15 @@
 import com.example.demo.service.UserService;
 
 
-/**
- * 用户业务逻辑服务实现类
- * 继承了MyBatis-Plus的ServiceImpl，并实现了UserService接口和Spring Security的UserDetailsService接口。
- * 利用ServiceImpl提供的通用CRUD方法，并实现自定义的用户业务操作和加载用户详情。
- * 用户登录认证逻辑已移至 Controller 层，以解决循环依赖问题。
- */
+
 @Service
-// 继承ServiceImpl，指定Mapper和实体类型。
-// 这样就自动拥有了IService中大部分通用方法的实现。
+
 public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService, UserDetailsService {
 
-    // 当继承ServiceImpl后，ServiceImpl内部已经注入了BaseMapper，
-    // 通常不需要在这里再次声明UserMapper，除非您需要调用UserMapper中自定义的非BaseMapper方法。
-    // private final UserMapper userMapper; // 如果继承ServiceImpl，这行通常可以移除
 
-    // 注入密码编码器，用于密码加密和校验
+
     private final PasswordEncoder passwordEncoder;
-    // 移除 AuthenticationManager 注入，认证逻辑已移至 Controller
-    // private final AuthenticationManager authenticationManager;
-    // 注入JWT工具类，用于生成和解析Token
+
     private final JwtTokenUtil jwtTokenUtil;
 
 
@@ -902,12 +1252,12 @@
      * 构造函数注入非BaseMapper的依赖
      * ServiceImpl会自动注入BaseMapper
      * @param passwordEncoder 密码编码器
-     * // 移除 authenticationManager 参数
+     * 
      * @param jwtTokenUtil JWT工具类
      */
-    // @Autowired // 当只有一个构造函数时，@Autowired 可选
+     
     public UserServiceImpl(PasswordEncoder passwordEncoder,
-                           // AuthenticationManager authenticationManager, // 移除此参数
+                            // 移除此参数
                            JwtTokenUtil jwtTokenUtil) {
         // 当继承ServiceImpl时，不需要在构造函数中注入并初始化BaseMapper
         // this.userMapper = userMapper; // 移除这行
@@ -1008,22 +1358,6 @@
 
         return response;
     }
-
-
-    // 当继承ServiceImpl后，IService中的通用方法（如 save, updateById, list, page 等）
-    // 已经由ServiceImpl提供默认实现，无需在此重复编写。
-    // 如果您需要对IService中的某个通用方法进行定制（例如在保存前进行额外处理），
-    // 可以在这里@Override该方法并添加您的逻辑，然后调用super.方法名(...)来执行ServiceImpl的默认逻辑。
-    /*
-    @Override
-    public boolean saveBatch(Collection<User> entityList, int batchSize) {
-        // 在调用ServiceImpl的批量保存前/后添加自定义逻辑
-        // ...
-        return super.saveBatch(entityList, batchSize); // 调用ServiceImpl的默认实现
-    }
-
-    // ... 其他IService中的方法实现
-    */
 }
 
 --- End of: ./service/impl/UserServiceImpl.java ---
diff --git a/backend/demo/src/main/java/com/example/demo/security/JwtAuthenticationFilter.java b/backend/demo/src/main/java/com/example/demo/security/JwtAuthenticationFilter.java
index 520908c..d69361f 100644
--- a/backend/demo/src/main/java/com/example/demo/security/JwtAuthenticationFilter.java
+++ b/backend/demo/src/main/java/com/example/demo/security/JwtAuthenticationFilter.java
@@ -1,11 +1,11 @@
 package com.example.demo.security;
 
 import java.io.IOException;
-import java.util.List;
 
 import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
-import org.springframework.security.core.authority.SimpleGrantedAuthority;
 import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.security.core.userdetails.UserDetails;
+import org.springframework.security.core.userdetails.UserDetailsService;
 import org.springframework.stereotype.Component;
 import org.springframework.util.StringUtils;
 import org.springframework.web.filter.OncePerRequestFilter;
@@ -13,20 +13,23 @@
 import com.example.demo.config.JWTProperties;
 import com.example.demo.exception.AuthException;
 
-import io.jsonwebtoken.Claims;
 import jakarta.servlet.FilterChain;
 import jakarta.servlet.ServletException;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
-@Component 
+@Component
 public class JwtAuthenticationFilter extends OncePerRequestFilter {
 
     private final JwtTokenUtil tokenUtil;
     private final JWTProperties props;
+    private final UserDetailsService userDetailsService; // ✅ 注入接口
 
-    public JwtAuthenticationFilter(JwtTokenUtil tokenUtil, JWTProperties props) {
+    public JwtAuthenticationFilter(JwtTokenUtil tokenUtil,
+                                   JWTProperties props,
+                                   UserDetailsService userDetailsService) {
         this.tokenUtil = tokenUtil;
         this.props = props;
+        this.userDetailsService = userDetailsService;
     }
 
     @Override
@@ -46,16 +49,16 @@
             throw new AuthException("Invalid or expired JWT token");
         }
 
-        Claims claims = tokenUtil.parseClaims(token);
-        String username =tokenUtil.getUsername(token);
-        Long userId = tokenUtil.getUserId(token);
-        String role = tokenUtil.getRole(token);
+        String username = tokenUtil.getUsername(token);
+
+        // ✅ 使用 UserServiceImpl 加载完整的用户对象（包括权限信息）
+        UserDetails userDetails = userDetailsService.loadUserByUsername(username);
 
         UsernamePasswordAuthenticationToken auth =
             new UsernamePasswordAuthenticationToken(
-                userId, 
-                null, 
-                List.of(new SimpleGrantedAuthority(role))
+                userDetails, // ✅ 设置完整的用户对象
+                null,
+                userDetails.getAuthorities()
             );
         SecurityContextHolder.getContext().setAuthentication(auth);
 
diff --git a/backend/demo/src/main/java/com/example/demo/service/TorrentService.java b/backend/demo/src/main/java/com/example/demo/service/TorrentService.java
index b863798..2be7aad 100644
--- a/backend/demo/src/main/java/com/example/demo/service/TorrentService.java
+++ b/backend/demo/src/main/java/com/example/demo/service/TorrentService.java
@@ -1,4 +1,3 @@
-// src/main/java/com/example/demo/service/TorrentService.java
 package com.example.demo.service;
 
 import java.io.IOException;
@@ -17,10 +16,35 @@
      * 处理上传的 .torrent 文件，解析其内容，保存到数据库，并生成相关链接。
      *
      * @param file 上传的 MultipartFile 对象
+     * @param title 洪流的标题
      * @return 包含解析信息、磁力链接和下载 URL 的 TorrentInfoDTO
      * @throws IOException 如果文件读取或保存失败
      * @throws InvalidBEncodingException 如果 .torrent 文件内容不符合 B 编码规范
      * @throws IllegalArgumentException 如果文件为空或解析后的元数据不完整
      */
-    TorrentInfoDTO handleUpload(MultipartFile file) throws IOException, InvalidBEncodingException, IllegalArgumentException;
+    TorrentInfoDTO handleUpload(MultipartFile file, String title) throws IOException, InvalidBEncodingException, IllegalArgumentException;
+
+   /**
+ * 根据 infoHash 启动与 Tracker 联动的下载任务（异步执行）。
+ *
+ * @param infoHash 种子的 infoHash（十六进制字符串）
+ * @throws Exception 启动任务失败时抛出
+ */
+void startDownload(String infoHash) throws Exception;
+
+/**
+ * 查询指定 infoHash 的当前下载进度，返回值范围 0.0 到 1.0。
+ *
+ * @param infoHash 种子的 infoHash
+ * @return 下载完成比例（0.0–1.0）
+ */
+float getDownloadProgress(String infoHash);
+
+/**
+ * 下载完成后，获取本地保存的文件路径；若未完成或未启动下载，则返回 null。
+ *
+ * @param infoHash 种子的 infoHash
+ * @return 已下载文件的绝对路径或 null
+ */
+String getDownloadedFilePath(String infoHash);
 }
\ No newline at end of file
diff --git a/backend/demo/src/main/java/com/example/demo/service/impl/TorrentServiceImpl.java b/backend/demo/src/main/java/com/example/demo/service/impl/TorrentServiceImpl.java
index eb00160..eedad56 100644
--- a/backend/demo/src/main/java/com/example/demo/service/impl/TorrentServiceImpl.java
+++ b/backend/demo/src/main/java/com/example/demo/service/impl/TorrentServiceImpl.java
@@ -2,9 +2,15 @@
 package com.example.demo.service.impl;
 
 import java.io.IOException;
+import java.net.InetAddress;
 import java.nio.file.Files; // 导入 DTO
 import java.nio.file.Path; // 导入实体类
 import java.nio.file.Paths; // 导入 Mapper
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
 
 import org.springframework.beans.factory.annotation.Value; // 导入服务接口
 import org.springframework.stereotype.Service; // 导入工具类
@@ -18,6 +24,14 @@
 import com.example.demo.service.TorrentService; // 用于文件操作
 import com.example.demo.util.TorrentUtils;  // 用于文件路径
 import com.turn.ttorrent.bcodec.InvalidBEncodingException; // 用于文件路径
+import com.turn.ttorrent.client.CommunicationManager;
+import com.turn.ttorrent.client.PeerInformation;
+import com.turn.ttorrent.client.PieceInformation;
+import com.turn.ttorrent.client.SharedTorrent;
+import com.turn.ttorrent.client.TorrentListener;
+import com.turn.ttorrent.client.TorrentManager;
+
+import jakarta.annotation.PostConstruct;
 
 /**
  * TorrentService 接口的实现类，负责处理 .torrent 文件的上传、解析、持久化及链接生成。
@@ -27,8 +41,11 @@
 
     private final TorrentInfoMapper torrentInfoMapper;
 
-    @Value("${file.upload-dir}") // 从 application.properties 中注入文件上传目录
-    private String uploadDir;
+  @Value("${file.upload-dir}")
+  private String uploadDir;
+
+  @Value("${file.download-dir}")
+  private String downloadDir;
 
     // 通过构造函数注入 Mapper
     public TorrentServiceImpl(TorrentInfoMapper torrentInfoMapper) {
@@ -37,7 +54,7 @@
 
     @Override
     @Transactional // 确保文件保存和数据库操作的原子性
-    public TorrentInfoDTO handleUpload(MultipartFile file) throws IOException, InvalidBEncodingException, IllegalArgumentException {
+    public TorrentInfoDTO handleUpload(MultipartFile file,String title) throws IOException, InvalidBEncodingException, IllegalArgumentException {
         if (file.isEmpty()) {
             throw new IllegalArgumentException("上传文件不能为空。");
         }
@@ -123,4 +140,82 @@
 
         return dto;
     }
+
+    private CommunicationManager commManager;
+  private final Map<String, TorrentManager> managers = new ConcurrentHashMap<>();
+  private final ExecutorService executor = Executors.newFixedThreadPool(4);
+
+  @PostConstruct
+  public void init() throws Exception {
+    // 1. 初始化 CommunicationManager
+    ExecutorService netPool = Executors.newFixedThreadPool(4);
+    ExecutorService ioPool  = Executors.newFixedThreadPool(2);
+    this.commManager = new CommunicationManager(netPool, ioPool);
+    this.commManager.start(InetAddress.getLocalHost());
+  }
+
+  @Override
+  public void startDownload(String infoHash) throws Exception {
+    // 2.1 .torrent 文件路径 & 本地输出目录
+    String torrentPath = uploadDir + "/" + infoHash + ".torrent";
+    String outDir      = downloadDir + "/" + infoHash;
+    TorrentManager tm  = commManager.addTorrent(torrentPath, outDir);
+
+    // 2.2 注册进度监听
+    tm.addListener(new TorrentListener() {
+      @Override
+      public void pieceDownloaded(PieceInformation pi, PeerInformation peer) {
+        // no-op
+      }
+      @Override public void downloadComplete() {
+        System.out.println("[" + infoHash + "] 下载完成");
+      }
+      @Override public void validationComplete(int valid, int total) {}
+      @Override public void peerConnected(PeerInformation peer) {}
+      @Override public void peerDisconnected(PeerInformation peer) {}
+      @Override public void pieceReceived(PieceInformation pi, PeerInformation peer) {}
+      @Override public void downloadFailed(Throwable cause) {
+        cause.printStackTrace();
+      }
+    });
+
+    // 2.3 异步等待完成
+    executor.submit(() -> {
+      try {
+        tm.awaitDownloadComplete(Integer.MAX_VALUE, TimeUnit.SECONDS);
+      } catch (Exception e) {
+        e.printStackTrace();
+      }
+    });
+
+    managers.put(infoHash, tm);
+  }
+
+  @Override
+public float getDownloadProgress(String infoHash) {
+    for (SharedTorrent t : commManager.getTorrents()) {
+        if (t.getHexInfoHash().equalsIgnoreCase(infoHash)) {
+            long downloaded = t.getDownloaded();  // 已下载字节数
+            long left       = t.getLeft();        // 剩余字节数
+            long total      = downloaded + left;  // 总字节数
+            return total > 0
+                ? (float) downloaded / total
+                : 0f;
+        }
+    }
+    return 0f;
+}
+
+
+  @Override
+  public String getDownloadedFilePath(String infoHash) {
+    for (SharedTorrent t : commManager.getTorrents()) {
+      if (t.getHexInfoHash().equalsIgnoreCase(infoHash) && t.isComplete()) {
+        // 拿到第一个文件的相对路径，再拼上下载目录
+        String rel = t.getFiles().get(0).getRelativePathAsString();
+        return downloadDir + "/" + infoHash + "/" + rel;
+      }
+    }
+    return null;
+  }
 }
\ No newline at end of file
diff --git a/backend/demo/src/main/java/com/example/demo/service/impl/UserServiceImpl.java b/backend/demo/src/main/java/com/example/demo/service/impl/UserServiceImpl.java
index 1fc434c..1b72d0f 100644
--- a/backend/demo/src/main/java/com/example/demo/service/impl/UserServiceImpl.java
+++ b/backend/demo/src/main/java/com/example/demo/service/impl/UserServiceImpl.java
@@ -19,26 +19,15 @@
 import com.example.demo.service.UserService;
 
 
-/**
- * 用户业务逻辑服务实现类
- * 继承了MyBatis-Plus的ServiceImpl，并实现了UserService接口和Spring Security的UserDetailsService接口。
- * 利用ServiceImpl提供的通用CRUD方法，并实现自定义的用户业务操作和加载用户详情。
- * 用户登录认证逻辑已移至 Controller 层，以解决循环依赖问题。
- */
+
 @Service
-// 继承ServiceImpl，指定Mapper和实体类型。
-// 这样就自动拥有了IService中大部分通用方法的实现。
+
 public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService, UserDetailsService {
 
-    // 当继承ServiceImpl后，ServiceImpl内部已经注入了BaseMapper，
-    // 通常不需要在这里再次声明UserMapper，除非您需要调用UserMapper中自定义的非BaseMapper方法。
-    // private final UserMapper userMapper; // 如果继承ServiceImpl，这行通常可以移除
 
-    // 注入密码编码器，用于密码加密和校验
+
     private final PasswordEncoder passwordEncoder;
-    // 移除 AuthenticationManager 注入，认证逻辑已移至 Controller
-    // private final AuthenticationManager authenticationManager;
-    // 注入JWT工具类，用于生成和解析Token
+
     private final JwtTokenUtil jwtTokenUtil;
 
 
@@ -46,12 +35,12 @@
      * 构造函数注入非BaseMapper的依赖
      * ServiceImpl会自动注入BaseMapper
      * @param passwordEncoder 密码编码器
-     * // 移除 authenticationManager 参数
+     * 
      * @param jwtTokenUtil JWT工具类
      */
-    // @Autowired // 当只有一个构造函数时，@Autowired 可选
+     
     public UserServiceImpl(PasswordEncoder passwordEncoder,
-                           // AuthenticationManager authenticationManager, // 移除此参数
+                            // 移除此参数
                            JwtTokenUtil jwtTokenUtil) {
         // 当继承ServiceImpl时，不需要在构造函数中注入并初始化BaseMapper
         // this.userMapper = userMapper; // 移除这行
@@ -152,20 +141,4 @@
 
         return response;
     }
-
-
-    // 当继承ServiceImpl后，IService中的通用方法（如 save, updateById, list, page 等）
-    // 已经由ServiceImpl提供默认实现，无需在此重复编写。
-    // 如果您需要对IService中的某个通用方法进行定制（例如在保存前进行额外处理），
-    // 可以在这里@Override该方法并添加您的逻辑，然后调用super.方法名(...)来执行ServiceImpl的默认逻辑。
-    /*
-    @Override
-    public boolean saveBatch(Collection<User> entityList, int batchSize) {
-        // 在调用ServiceImpl的批量保存前/后添加自定义逻辑
-        // ...
-        return super.saveBatch(entityList, batchSize); // 调用ServiceImpl的默认实现
-    }
-
-    // ... 其他IService中的方法实现
-    */
 }
diff --git a/backend/demo/src/main/java/com/example/demo/sh.py b/backend/demo/src/main/java/com/example/demo/sh.py
index 3be143b..7b30510 100644
--- a/backend/demo/src/main/java/com/example/demo/sh.py
+++ b/backend/demo/src/main/java/com/example/demo/sh.py
@@ -53,13 +53,17 @@
         './config/JWTProperties.java',
         './config/SecurityConfig.java',
         './controller/AuthController.java',
+        './controller/TorrentController.java',
         './DemoApplication.java',
         './dto/LoginRequestDTO.java',
         './dto/LoginResponseDTO.java',
+        './dto/TorrentInfoDTO.java',
         './entity/User.java',
+        './entity/TorrentInfo.java',
         './exception/AuthException.java',
         './exception/GlobalExceptionHandler.java',
         './mapper/UserMapper.java',
+        './mapper/TorrentInfoMapper.java',
         './security/JwtAuthenticationFilter.java',
         './security/JwtTokenUtil.java',
         './service/UserService.java',
diff --git a/backend/demo/src/main/resources/META-INF/additional-spring-configuration-metadata.json b/backend/demo/src/main/resources/META-INF/additional-spring-configuration-metadata.json
index cf06b61..3da4c86 100644
--- a/backend/demo/src/main/resources/META-INF/additional-spring-configuration-metadata.json
+++ b/backend/demo/src/main/resources/META-INF/additional-spring-configuration-metadata.json
@@ -1,5 +1,12 @@
-{"properties": [{
-  "name": "file.upload-dir",
-  "type": "java.lang.String",
-  "description": "Torrent dir for uploading'"
-}]}
\ No newline at end of file
+{"properties": [
+  {
+    "name": "file.upload-dir",
+    "type": "java.lang.String",
+    "description": "Torrent dir for uploading'"
+  },
+  {
+    "name": "app.torrent.download-dir",
+    "type": "java.lang.String",
+    "description": "A description for 'app.torrent.download-dir'"
+  }
+]}
\ No newline at end of file
diff --git a/backend/demo/src/main/resources/application.properties b/backend/demo/src/main/resources/application.properties
index 9bbb45b..720d673 100644
--- a/backend/demo/src/main/resources/application.properties
+++ b/backend/demo/src/main/resources/application.properties
@@ -1,15 +1,21 @@
 # ========== 数据源 ==========
-spring.datasource.url=jdbc:mysql://mysql:3306/mydatabase?serverTimezone=Asia/Shanghai&createDatabaseIfNotExist=TRUE&useSSL=FALSE&allowPublicKeyRetrieval=TRUE
+spring.datasource.url=jdbc:mysql://localhost:3306/mydatabase?serverTimezone=Asia/Shanghai&useSSL=false&allowPublicKeyRetrieval=true
 spring.datasource.username=myuser
 spring.datasource.password=secret
 spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
 
 # ========== JWT 配置 ==========
-jwt.secret=YourJWTSecretKeyHere1234567890
+jwt.secret=YWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWE=
 jwt.expirationMs=3600000
 
 # ========== 日志输出（可选） ==========
 logging.level.org.springframework.security=DEBUG
+logging.level.root=INFO
+logging.level.org.springframework.web=DEBUG
+logging.level.org.springframework.web.servlet=DEBUG
+logging.level.com.example=DEBUG
 
 file.upload-dir=./torrents
-
+app.torrent.download-dir=downloads
+spring.docker.compose.enabled=false
+spring.web.resources.static-locations=file:downloads/
\ No newline at end of file
diff --git a/backend/demo/src/main/resources/lib b/backend/demo/src/main/resources/lib
new file mode 160000
index 0000000..ed28512
--- /dev/null
+++ b/backend/demo/src/main/resources/lib
@@ -0,0 +1 @@
+Subproject commit ed28512530673c7363ae21f6fa09543955963de8