继续优化错误场景的处理

lib/data/repositories/message/upload_start_handler.dart

@@ -85,6 +85,10 @@ class UploadStartHandler extends MessageHandler {
     } on ParamErrorException {
       debugPrint('====================>上传失败：参数错误');
       throw Exception('参数错误');
+    } on ChunkSigException {
+      debugPrint('====================>上传失败：签名错误');
+      // 确保发送了 uploadEnd 指令
+      _webCubit?.sendUploadEnd(_cmdUnique, _cmdUploadId, '', errMsg: '网络错误，签名失败');
     } on ChunkUploadFailedException {
       debugPrint('====================>上传失败：网络错误');
       // 确保发送了 uploadEnd 指令
@@ -331,9 +335,13 @@ class UploadStartHandler extends MessageHandler {
 
   /// 初始化，请求后端获取签名信息和上传任务ID
   Future<Map<String, dynamic>> _init(ApiService bxeApiService, String objectKey, String bucket) async {
+    try {
       var endpoint = '$_signatureNewUrl?objectKey=$objectKey&bucket=$bucket';
       final resp = await bxeApiService.get(endpoint);
       return resp.data;
+    } catch (e) {
+      throw ChunkSigException('初始化上传任务失败: $e');
+    }
   }
 
   /// 每次上传前，请求后端获取签名信息
@@ -344,9 +352,13 @@ class UploadStartHandler extends MessageHandler {
     String uploadId,
     int partNum,
   ) async {
+    try {
       var endpoint = '$_signatureNextUrl?objectKey=$objectKey&bucket=$bucket&uploadId=$uploadId&partNum=$partNum';
       final resp = await bxeApiService.get(endpoint);
       return resp.data;
+    } catch (e) {
+      throw ChunkSigException('获取签名信息失败: $e');
+    }
   }
 
   /// 上传段（带进度回调）
@@ -374,13 +386,13 @@ class UploadStartHandler extends MessageHandler {
           return {'idx': chunkIndex + 1, 'etag': etags[0]};
         } else {
           // throw Exception('Chunk $chunkIndex upload failed: ${resp.statusCode}');
-          throw Exception('Chunk upload failed');
+          throw ChunkUploadFailedException('Chunk upload failed');
         }
       } catch (e) {
         debugPrint('====================> 分片$chunkIndex 第${attempt + 1}次， 上传失败：${e.toString()}');
         if (attempt == maxRetries) {
           // throw Exception('Chunk $chunkIndex upload failed after $maxRetries attempts: $e');
-          throw Exception('Chunk upload failed');
+          throw ChunkUploadFailedException('Chunk upload failed');
         }
         // 等待后重试
         await Future.delayed(Duration(seconds: 2 * (attempt + 1)));
@@ -440,7 +452,7 @@ class UploadStartHandler extends MessageHandler {
       return response;
     } catch (e) {
       // throw Exception('Chunk upload failed: $e');
-      throw Exception('Chunk upload failed');
+      throw ChunkUploadFailedException('Chunk upload failed');
     }
   }
 
@@ -452,6 +464,7 @@ class UploadStartHandler extends MessageHandler {
     String uploadId,
     Map<int, String> tagsMap,
   ) async {
+    try {
       final parts = [];
       for (int i = 1; i <= tagsMap.length; i++) {
         parts.add({'partNumber': i, 'etag': tagsMap[i]});
@@ -465,10 +478,16 @@ class UploadStartHandler extends MessageHandler {
       });
 
       if (response.statusCode != 200) {
-      throw Exception('合并文件失败');
+        throw ChunkSigException('合并文件失败');
       }
 
       return response.data["location"];
+    } catch (e) {
+      if (e is ChunkSigException) {
+        rethrow;
+      }
+      throw ChunkSigException('合并文件失败: $e');
+    }
   }
 
   String _getLoginPrefix(String busi, String subBusi) {

lib/exception/exceptions.dart

@@ -7,6 +7,15 @@ class ParamErrorException implements Exception {
   String toString() => 'ParamErrorException: $message';
 }
 
+class ChunkSigException implements Exception {
+  final String message;
+
+  ChunkSigException([this.message = '签名失败']);
+
+  @override
+  String toString() => 'ChunkSigException: $message';
+}
+
 class ChunkUploadFailedException implements Exception {
   final String message;