fix(pdf): 优化PDF文本提取服务异常处理

- 添加FeignException专门处理逻辑
- 实现详细的Feign异常日志记录功能
- 新增响应体解析和根因链构建方法
- 添加异常消息规范化处理
- 改进错误日志的可读性和调试信息完整度

backend/services/data-management-service/src/main/java/com/datamate/datamanagement/application/PdfTextExtractAsyncService.java

@@ -4,6 +4,8 @@ import com.datamate.common.infrastructure.common.Response;
 import com.datamate.datamanagement.infrastructure.client.PdfTextExtractClient;
 import com.datamate.datamanagement.infrastructure.client.dto.PdfTextExtractRequest;
 import com.datamate.datamanagement.infrastructure.client.dto.PdfTextExtractResponse;
+import feign.FeignException;
+import feign.Request;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.scheduling.annotation.Async;
@@ -47,8 +49,71 @@ public class PdfTextExtractAsyncService {
             } else {
                 log.info("PdfTextExtract succeeded, datasetId={}, fileId={}", datasetId, fileId);
             }
+        } catch (FeignException feignException) {
+            logFeignException(datasetId, fileId, feignException);
         } catch (Exception e) {
             log.error("PdfTextExtract call failed, datasetId={}, fileId={}", datasetId, fileId, e);
         }
     }
+
+    private void logFeignException(String datasetId, String fileId, FeignException feignException) {
+        Request request = feignException.request();
+        String httpMethod = request == null || request.httpMethod() == null
+            ? "UNKNOWN"
+            : request.httpMethod().name();
+        String requestUrl = request == null || request.url() == null
+            ? "UNKNOWN"
+            : request.url();
+        String responseBody = resolveFeignResponseBody(feignException);
+        String rootCauseChain = buildCauseChain(feignException, 12);
+        log.error(
+            "PdfTextExtract call failed with FeignException, datasetId={}, fileId={}, status={}, method={}, url={}, responseBody=\n{}\nrootCauseChain={}",
+            datasetId,
+            fileId,
+            feignException.status(),
+            httpMethod,
+            requestUrl,
+            responseBody,
+            rootCauseChain,
+            feignException
+        );
+    }
+
+    private String resolveFeignResponseBody(FeignException feignException) {
+        String responseBody = feignException.contentUTF8();
+        if (responseBody == null || responseBody.isBlank()) {
+            responseBody = feignException.getMessage();
+        }
+        if (responseBody == null || responseBody.isBlank()) {
+            return "EMPTY_RESPONSE_BODY";
+        }
+        return responseBody;
+    }
+
+    private String buildCauseChain(Throwable throwable, int maxDepth) {
+        StringBuilder causeChain = new StringBuilder();
+        Throwable current = throwable;
+        int depth = 0;
+        while (current != null && depth < maxDepth) {
+            if (causeChain.length() > 0) {
+                causeChain.append(" <- ");
+            }
+            causeChain.append(current.getClass().getSimpleName())
+                .append(": ")
+                .append(normalizeCauseMessage(current.getMessage()));
+            current = current.getCause();
+            depth++;
+        }
+        if (current != null) {
+            causeChain.append(" <- ...");
+        }
+        return causeChain.toString();
+    }
+
+    private String normalizeCauseMessage(String message) {
+        if (message == null || message.isBlank()) {
+            return "EMPTY_MESSAGE";
+        }
+        return message.replace("\r", " ").replace("\n", " ").trim();
+    }
 }