diff --git a/bms-back/bms-admin/src/main/java/com/bms/web/controller/ar/ArBankAccountController.java b/bms-back/bms-admin/src/main/java/com/bms/web/controller/ar/ArBankAccountController.java
index 568545a2..afda6589 100644
--- a/bms-back/bms-admin/src/main/java/com/bms/web/controller/ar/ArBankAccountController.java
+++ b/bms-back/bms-admin/src/main/java/com/bms/web/controller/ar/ArBankAccountController.java
@@ -8,7 +8,7 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 import com.bms.ar.domain.ArBankAccount;
-import com.bms.ar.mapper.ArBankAccountMapper;
+import com.bms.ar.service.IArBillService;
 import com.bms.common.core.controller.BaseController;
 import com.bms.common.core.domain.AjaxResult;
 
@@ -20,14 +20,14 @@ import com.bms.common.core.domain.AjaxResult;
 public class ArBankAccountController extends BaseController {
 
     @Autowired
-    private ArBankAccountMapper arBankAccountMapper;
+    private IArBillService billService;
 
     /**
      * 启用账户列表；可按币种过滤，默认账户优先。
      */
     @GetMapping("/options")
     public AjaxResult options(@RequestParam(value = "currency", required = false) String currency) {
-        List<ArBankAccount> list = arBankAccountMapper.selectEnabledList(currency);
+        List<ArBankAccount> list = billService.selectEnabledBankAccounts(currency);
         return AjaxResult.success(list);
     }
 }
diff --git a/bms-back/bms-system/src/main/java/com/bms/ar/service/IArBillService.java b/bms-back/bms-system/src/main/java/com/bms/ar/service/IArBillService.java
index cfcecb94..35e3b5b7 100644
--- a/bms-back/bms-system/src/main/java/com/bms/ar/service/IArBillService.java
+++ b/bms-back/bms-system/src/main/java/com/bms/ar/service/IArBillService.java
@@ -33,6 +33,8 @@ public interface IArBillService
 
     ArBankAccount getDefaultBankAccount(String currency);
 
+    List<ArBankAccount> selectEnabledBankAccounts(String currency);
+
     List<PrcOrderBill> previewBill(ArBillGenerateQuery query);
 
     BigDecimal sumPreviewBill(ArBillGenerateQuery query);
diff --git a/bms-back/bms-system/src/main/java/com/bms/ar/service/impl/ArBillServiceImpl.java b/bms-back/bms-system/src/main/java/com/bms/ar/service/impl/ArBillServiceImpl.java
index 1e30f324..63fe9b5a 100644
--- a/bms-back/bms-system/src/main/java/com/bms/ar/service/impl/ArBillServiceImpl.java
+++ b/bms-back/bms-system/src/main/java/com/bms/ar/service/impl/ArBillServiceImpl.java
@@ -168,10 +168,14 @@ public class ArBillServiceImpl implements IArBillService {
      */
     @Override
     public List<ArBill> selectArBillList(ArBillQuery query) {
+        long startedAt = System.nanoTime();
         List<ArBill> bills = billMapper.selectArBillList(query);
         for (ArBill bill : bills) {
             bill.setBankAccountNo(maskAccount(bill.getBankAccountNo()));
         }
+        log.debug("应收账单列表查询完成，billNo={}, customerId={}, status={}, resultCount={}, costMs={}",
+                safeLogValue(query.getBillNo()), query.getCustomerId(), safeLogValue(query.getStatus()),
+                bills.size(), elapsedMillis(startedAt));
         return bills;
     }
 
@@ -180,12 +184,16 @@ public class ArBillServiceImpl implements IArBillService {
      */
     @Override
     public ArBill selectArBillById(Long arBillId) {
+        long startedAt = System.nanoTime();
         ArBill bill = billMapper.selectArBillById(arBillId);
         if (bill == null) {
             throw new ServiceException("应收账单不存在");
         }
         bill.setBankAccountNo(maskAccount(bill.getBankAccountNo()));
         bill.setExports(exportMapper.selectByBillId(arBillId));
+        log.debug("应收账单详情查询完成，arBillId={}, status={}, exportCount={}, costMs={}",
+                arBillId, bill.getStatus(), bill.getExports() == null ? 0 : bill.getExports().size(),
+                elapsedMillis(startedAt));
         return bill;
     }
 
@@ -194,7 +202,11 @@ public class ArBillServiceImpl implements IArBillService {
      */
     @Override
     public List<ArBillDetail> selectArBillDetails(Long arBillId) {
-        return detailMapper.selectByBillId(arBillId);
+        long startedAt = System.nanoTime();
+        List<ArBillDetail> details = detailMapper.selectByBillId(arBillId);
+        log.debug("应收账单明细查询完成，arBillId={}, resultCount={}, costMs={}",
+                arBillId, details.size(), elapsedMillis(startedAt));
+        return details;
     }
 
     /**
@@ -202,7 +214,11 @@ public class ArBillServiceImpl implements IArBillService {
      */
     @Override
     public List<ArBillDetailFee> selectArBillDetailFees(Long arBillId, Long detailId) {
-        return detailFeeMapper.selectByBillIdAndDetailId(arBillId, detailId);
+        long startedAt = System.nanoTime();
+        List<ArBillDetailFee> fees = detailFeeMapper.selectByBillIdAndDetailId(arBillId, detailId);
+        log.debug("应收账单费用明细查询完成，arBillId={}, detailId={}, resultCount={}, costMs={}",
+                arBillId, detailId, fees.size(), elapsedMillis(startedAt));
+        return fees;
     }
 
     /**
@@ -210,26 +226,45 @@ public class ArBillServiceImpl implements IArBillService {
      */
     @Override
     public ArBankAccount getDefaultBankAccount(String currency) {
+        long startedAt = System.nanoTime();
         ArBankAccount account = bankAccountMapper.selectDefaultByCurrency(
                 StringUtils.isEmpty(currency) ? "CNY" : currency);
         if (account != null) {
             account.setAccountNo(maskAccount(account.getAccountNo()));
         }
+        log.debug("应收默认收款账户查询完成，currency={}, found={}, costMs={}",
+                safeLogValue(StringUtils.isEmpty(currency) ? "CNY" : currency), account != null,
+                elapsedMillis(startedAt));
         return account;
     }
 
+    /** 查询启用的收款账户选项，账户号和账户名称不写入日志。 */
+    @Override
+    public List<ArBankAccount> selectEnabledBankAccounts(String currency) {
+        long startedAt = System.nanoTime();
+        List<ArBankAccount> accounts = bankAccountMapper.selectEnabledList(currency);
+        log.debug("应收收款账户选项查询完成，currency={}, resultCount={}, costMs={}",
+                safeLogValue(currency), accounts.size(), elapsedMillis(startedAt));
+        return accounts;
+    }
+
     /**
      * 分页预览可生成订单；多个订单号、运单号或转单号按 OR 条件精确匹配。
      */
     @Override
     public List<PrcOrderBill> previewBill(ArBillGenerateQuery query) {
+        long startedAt = System.nanoTime();
         validatePreviewQuery(query);
         List<String> orderIdentifiers = normalizeOrderIdentifiers(query.getOrderOrTrackingNo());
         List<String> excludeOrderIdentifiers = normalizeOrderIdentifiers(query.getExcludeOrderOrTrackingNo());
-        return sourceBillMapper.selectPrcOrderBillByCustomerPeriod(query.getCustomerId(),
+        List<PrcOrderBill> result = sourceBillMapper.selectPrcOrderBillByCustomerPeriod(query.getCustomerId(),
                 query.getCustomerCode(), orderIdentifiers,
                 excludeOrderIdentifiers, query.getBillPeriodEnd(), query.getCurrency(),
                 eligibleOrderBillStatuses(), ArIncomeBillFeeStatus.UNBILLED.getCode(), null);
+        log.debug("应收账单生成范围预览查询完成，customerId={}, billPeriodEnd={}, currency={}, resultCount={}, costMs={}",
+                query.getCustomerId(), query.getBillPeriodEnd(), safeLogValue(query.getCurrency()),
+                result.size(), elapsedMillis(startedAt));
+        return result;
     }
 
     /**
@@ -237,13 +272,18 @@ public class ArBillServiceImpl implements IArBillService {
      */
     @Override
     public BigDecimal sumPreviewBill(ArBillGenerateQuery query) {
+        long startedAt = System.nanoTime();
         validatePreviewQuery(query);
         List<String> orderIdentifiers = normalizeOrderIdentifiers(query.getOrderOrTrackingNo());
         List<String> excludeOrderIdentifiers = normalizeOrderIdentifiers(query.getExcludeOrderOrTrackingNo());
-        return nvl(sourceBillMapper.sumPrcOrderBillIncomeByCustomerPeriod(query.getCustomerId(),
+        BigDecimal total = nvl(sourceBillMapper.sumPrcOrderBillIncomeByCustomerPeriod(query.getCustomerId(),
                 query.getCustomerCode(), orderIdentifiers,
                 excludeOrderIdentifiers, query.getBillPeriodEnd(), query.getCurrency(),
                 eligibleOrderBillStatuses(), ArIncomeBillFeeStatus.UNBILLED.getCode()));
+        log.debug("应收账单生成范围金额汇总完成，customerId={}, billPeriodEnd={}, currency={}, costMs={}",
+                query.getCustomerId(), query.getBillPeriodEnd(), safeLogValue(query.getCurrency()),
+                elapsedMillis(startedAt));
+        return total;
     }
 
     /**
@@ -254,9 +294,13 @@ public class ArBillServiceImpl implements IArBillService {
     @Override
     @Transactional(rollbackFor = Exception.class)
     public ArBillGenerateTask generateBill(ArBillGenerateRequest request, String operator, String requestId) {
+        long startedAt = System.nanoTime();
         validatePeriod(request);
         ArBillGenerateTask existed = generateTaskMapper.selectByRequestToken(requestId);
         if (existed != null) {
+            log.info("应收账单生成请求命中幂等记录，operator={}, requestId={}, taskId={}, status={}, costMs={}",
+                    safeLogValue(operator), safeLogValue(requestId), existed.getTaskId(), existed.getStatus(),
+                    elapsedMillis(startedAt));
             return existed;
         }
 
@@ -341,6 +385,10 @@ public class ArBillServiceImpl implements IArBillService {
         task.setCreateBy(operator);
         generateTaskMapper.insert(task);
         eventPublisher.publishEvent(new ArBillGenerateTaskEvent(task.getTaskId()));
+        log.info("应收账单生成任务已创建，operator={}, requestId={}, customerId={}, billPeriodEnd={}, selectionMode={}, selectedCount={}, excludedCount={}, taskId={}, status={}, costMs={}",
+                safeLogValue(operator), safeLogValue(requestId), request.getCustomerId(), request.getBillPeriodEnd(),
+                safeLogValue(selectionMode), sourceBillIds.size(), excludedSourceBillIds.size(),
+                task.getTaskId(), task.getStatus(), elapsedMillis(startedAt));
         return task;
     }
 
@@ -349,10 +397,13 @@ public class ArBillServiceImpl implements IArBillService {
      */
     @Override
     public ArBillGenerateTask selectGenerateTask(Long taskId) {
+        long startedAt = System.nanoTime();
         ArBillGenerateTask task = generateTaskMapper.selectById(taskId);
         if (task == null) {
             throw new ServiceException("账单生成任务不存在");
         }
+        log.debug("应收账单生成任务状态查询，taskId={}, status={}, processedCount={}, totalCount={}, costMs={}",
+                taskId, task.getStatus(), task.getProcessedCount(), task.getTotalCount(), elapsedMillis(startedAt));
         return task;
     }
 
@@ -361,7 +412,11 @@ public class ArBillServiceImpl implements IArBillService {
      */
     @Override
     public List<ArBillGenerateTask> selectActiveGenerateTasks(String operator) {
-        return generateTaskMapper.selectActiveByCreateBy(operator);
+        long startedAt = System.nanoTime();
+        List<ArBillGenerateTask> tasks = generateTaskMapper.selectActiveByCreateBy(operator);
+        log.debug("当前用户应收账单生成任务查询，operator={}, taskCount={}, costMs={}",
+                safeLogValue(operator), tasks.size(), elapsedMillis(startedAt));
+        return tasks;
     }
 
     /**
@@ -370,6 +425,7 @@ public class ArBillServiceImpl implements IArBillService {
     @Override
     @Transactional(rollbackFor = Exception.class)
     public ArBillGenerateTask cancelGenerateTask(Long taskId, String operator, String requestId) {
+        long startedAt = System.nanoTime();
         ArBillGenerateTask task = selectGenerateTask(taskId);
         if (!operator.equals(task.getCreateBy())) {
             throw new ServiceException("只能取消自己创建的账单生成任务");
@@ -377,6 +433,8 @@ public class ArBillServiceImpl implements IArBillService {
         if (ArBillGenerateTaskStatus.SUCCESS.equals(task.getStatus())
                 || ArBillGenerateTaskStatus.FAILED.equals(task.getStatus())
                 || ArBillGenerateTaskStatus.CANCELED.equals(task.getStatus())) {
+            log.info("应收账单生成任务取消请求已处理，operator={}, requestId={}, taskId={}, status={}, costMs={}",
+                    safeLogValue(operator), safeLogValue(requestId), taskId, task.getStatus(), elapsedMillis(startedAt));
             return task;
         }
         if (ArBillGenerateTaskStatus.WAITING.equals(task.getStatus())) {
@@ -384,7 +442,10 @@ public class ArBillServiceImpl implements IArBillService {
         } else {
             generateTaskMapper.markCancelRequested(taskId);
         }
-        return selectGenerateTask(taskId);
+        ArBillGenerateTask result = selectGenerateTask(taskId);
+        log.info("应收账单生成任务取消请求已处理，operator={}, requestId={}, taskId={}, status={}, costMs={}",
+                safeLogValue(operator), safeLogValue(requestId), taskId, result.getStatus(), elapsedMillis(startedAt));
+        return result;
     }
 
     /**
@@ -393,6 +454,7 @@ public class ArBillServiceImpl implements IArBillService {
     @Override
     @Transactional(rollbackFor = Exception.class)
     public ArBillGenerateTask retryGenerateTask(Long taskId, String operator, String requestId) {
+        long startedAt = System.nanoTime();
         ArBillGenerateTask task = selectGenerateTask(taskId);
         if (!operator.equals(task.getCreateBy())) {
             throw new ServiceException("只能重新生成自己创建的账单任务");
@@ -402,7 +464,11 @@ public class ArBillServiceImpl implements IArBillService {
         }
         ArBillGenerateRequest request = JSON.parseObject(task.getRequestPayload(), ArBillGenerateRequest.class);
         request.setRequestId(requestId);
-        return generateBill(request, operator, requestId);
+        ArBillGenerateTask retried = generateBill(request, operator, requestId);
+        log.info("应收账单生成任务重试请求已处理，operator={}, requestId={}, sourceTaskId={}, newTaskId={}, status={}, costMs={}",
+                safeLogValue(operator), safeLogValue(requestId), taskId, retried.getTaskId(), retried.getStatus(),
+                elapsedMillis(startedAt));
+        return retried;
     }
 
     /**
@@ -757,6 +823,7 @@ public class ArBillServiceImpl implements IArBillService {
     @Override
     @Transactional(rollbackFor = Exception.class)
     public ArBill confirmBill(Long arBillId, ArBillActionRequest request, String operator, String requestId) {
+        long startedAt = System.nanoTime();
         ArBill bill = billMapper.selectArBillByIdForUpdate(arBillId);
         if (bill == null) {
             throw failure(arBillId, ArLogObjectType.BILL, String.valueOf(arBillId), ArLogOperationType.CONFIRM,
@@ -787,7 +854,10 @@ public class ArBillServiceImpl implements IArBillService {
         // 应收账单只负责形成应收，不参与客户余额或授信额度变更。
         recordSuccess(bill, ArLogObjectType.BILL, ArLogOperationType.CONFIRM,
                 "确认应收账单", ArBillStatus.DRAFT.getCode(), ArBillStatus.CONFIRMED.getCode(), requestId, operator);
-        return selectArBillById(arBillId);
+        ArBill result = selectArBillById(arBillId);
+        log.info("应收账单确认处理完成，operator={}, requestId={}, arBillId={}, status={}, costMs={}",
+                safeLogValue(operator), safeLogValue(requestId), arBillId, result.getStatus(), elapsedMillis(startedAt));
+        return result;
     }
 
     /**
@@ -796,6 +866,7 @@ public class ArBillServiceImpl implements IArBillService {
     @Override
     @Transactional(rollbackFor = Exception.class)
     public ArBill voidBill(Long arBillId, ArBillActionRequest request, String operator, String requestId) {
+        long startedAt = System.nanoTime();
         String remark = request == null ? null : request.getRemark();
         if (StringUtils.isEmpty(remark)) {
             throw failure(arBillId, ArLogObjectType.BILL, String.valueOf(arBillId), ArLogOperationType.VOID,
@@ -826,7 +897,10 @@ public class ArBillServiceImpl implements IArBillService {
         sourceBillMapper.refreshArBillStatusByArBillId(arBillId);
         recordSuccess(bill, ArLogObjectType.BILL, ArLogOperationType.VOID,
                 "作废应收账单：" + remark, bill.getStatus(), ArBillStatus.VOID.getCode(), requestId, operator);
-        return selectArBillById(arBillId);
+        ArBill result = selectArBillById(arBillId);
+        log.info("应收账单作废处理完成，operator={}, requestId={}, arBillId={}, status={}, costMs={}",
+                safeLogValue(operator), safeLogValue(requestId), arBillId, result.getStatus(), elapsedMillis(startedAt));
+        return result;
     }
 
     /**
@@ -835,11 +909,15 @@ public class ArBillServiceImpl implements IArBillService {
     @Override
     @Transactional(rollbackFor = Exception.class)
     public ArBillExport exportBill(Long arBillId, String operator, String requestId) {
+        long startedAt = System.nanoTime();
         ArBillLog previous = logMapper.selectSuccessByRequestId(requestId, ArLogObjectType.EXPORT.getCode(),
                 ArLogResult.SUCCESS.getCode());
         if (previous != null && isNumber(previous.getObjectId())) {
             ArBillExport previousExport = exportMapper.selectById(Long.valueOf(previous.getObjectId()));
             if (previousExport != null) {
+                log.info("应收账单导出请求命中幂等记录，operator={}, requestId={}, arBillId={}, exportId={}, status={}, costMs={}",
+                        safeLogValue(operator), safeLogValue(requestId), arBillId, previousExport.getExportId(),
+                        previousExport.getExportStatus(), elapsedMillis(startedAt));
                 return previousExport;
             }
         }
@@ -859,6 +937,9 @@ public class ArBillServiceImpl implements IArBillService {
         }
         ArBillExport processing = exportMapper.selectProcessingByBillId(arBillId);
         if (processing != null) {
+            log.info("应收账单导出任务已存在，operator={}, requestId={}, arBillId={}, exportId={}, status={}, costMs={}",
+                    safeLogValue(operator), safeLogValue(requestId), arBillId, processing.getExportId(),
+                    processing.getExportStatus(), elapsedMillis(startedAt));
             return processing;
         }
         ArExportTemplate template = exportTemplateMapper.selectDefaultEnabled(EXPORT_TEMPLATE_BUSINESS_TYPE,
@@ -887,6 +968,9 @@ public class ArBillServiceImpl implements IArBillService {
         recordSuccess(bill, ArLogObjectType.EXPORT, ArLogOperationType.EXPORT,
                 "已提交账单导出任务", bill.getStatus(), bill.getStatus(), requestId, operator, export.getExportId());
         eventPublisher.publishEvent(new ArBillExportTaskEvent(export.getExportId()));
+        log.info("应收账单导出任务已创建，operator={}, requestId={}, arBillId={}, exportId={}, status={}, costMs={}",
+                safeLogValue(operator), safeLogValue(requestId), arBillId, export.getExportId(),
+                export.getExportStatus(), elapsedMillis(startedAt));
         return export;
     }
 
@@ -895,10 +979,13 @@ public class ArBillServiceImpl implements IArBillService {
      */
     @Override
     public ArBillExport selectExport(Long exportId) {
+        long startedAt = System.nanoTime();
         ArBillExport export = exportMapper.selectById(exportId);
         if (export == null) {
             throw new ServiceException("导出任务不存在");
         }
+        log.debug("应收账单导出任务状态查询，exportId={}, status={}, costMs={}",
+                exportId, export.getExportStatus(), elapsedMillis(startedAt));
         return export;
     }
 
@@ -909,9 +996,13 @@ public class ArBillServiceImpl implements IArBillService {
     public void processExportTask(Long exportId) {
         ArBillExport export = exportMapper.selectById(exportId);
         if (export == null || !ArExportStatus.PROCESSING.getCode().equals(export.getExportStatus())) {
+            log.debug("应收账单导出任务跳过，exportId={}, status={}",
+                    exportId, export == null ? null : export.getExportStatus());
             return;
         }
 
+        long startedAt = System.nanoTime();
+        log.info("开始执行应收账单导出任务，exportId={}, arBillId={}", exportId, export.getArBillId());
         ArBill bill = null;
         try {
             bill = billMapper.selectArBillById(export.getArBillId());
@@ -940,11 +1031,20 @@ public class ArBillServiceImpl implements IArBillService {
             export.setStorageKey(FileUploadUtils.getPathFileName(downloadDir, relative));
             export.setFileSize(Files.size(target));
             export.setFileHash(sha256(target));
-            if (exportMapper.markSuccess(export) == 0) {
+            int updated = exportMapper.markSuccess(export);
+            if (updated == 0) {
                 Files.deleteIfExists(target);
+                log.warn("应收账单导出文件已生成但任务状态未更新，exportId={}, arBillId={}",
+                        exportId, export.getArBillId());
+            } else {
+                log.info("应收账单导出任务执行完成，exportId={}, arBillId={}, rowCount={}, fileSize={}, costMs={}",
+                        exportId, export.getArBillId(), export.getRowCount(), export.getFileSize(),
+                        elapsedMillis(startedAt));
             }
         } catch (Exception e) {
             String message = exportFailureMessage(e);
+            log.error("应收账单导出任务执行失败，exportId={}, arBillId={}, message={}, costMs={}",
+                    exportId, export.getArBillId(), safeLogValue(message), elapsedMillis(startedAt), e);
             if (exportMapper.markFailed(exportId, message) > 0) {
                 logService.recordFailure(export.getArBillId(), ArLogObjectType.EXPORT, String.valueOf(exportId),
                         ArLogOperationType.EXPORT, bill == null ? null : bill.getStatus(), message, export.getExportBy(), null);
@@ -964,11 +1064,16 @@ public class ArBillServiceImpl implements IArBillService {
 
     @Override
     public List<ArBillExport> selectExports(Long arBillId) {
-        return exportMapper.selectByBillId(arBillId);
+        long startedAt = System.nanoTime();
+        List<ArBillExport> exports = exportMapper.selectByBillId(arBillId);
+        log.debug("应收账单导出记录查询，arBillId={}, exportCount={}, costMs={}",
+                arBillId, exports.size(), elapsedMillis(startedAt));
+        return exports;
     }
 
     @Override
     public void downloadExport(Long exportId, HttpServletResponse response) throws Exception {
+        long startedAt = System.nanoTime();
         ArBillExport export = exportMapper.selectById(exportId);
         if (export == null || !ArExportStatus.SUCCESS.getCode().equals(export.getExportStatus()) || StringUtils.isEmpty(export.getStorageKey())) {
             throw new ServiceException("导出文件不存在或尚未生成成功");
@@ -980,11 +1085,18 @@ public class ArBillServiceImpl implements IArBillService {
         response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
         FileUtils.setAttachmentResponseHeader(response, export.getFileName());
         FileUtils.writeBytes(BmsConfig.getProfile() + FileUtils.stripPrefix(resource), response.getOutputStream());
+        log.debug("应收账单导出文件下载完成，exportId={}, fileSize={}, costMs={}",
+                exportId, export.getFileSize(), elapsedMillis(startedAt));
     }
 
     @Override
     public List<ArBillLog> selectLogList(ArBillLog query) {
-        return logService.selectLogList(query);
+        long startedAt = System.nanoTime();
+        List<ArBillLog> logs = logService.selectLogList(query);
+        log.debug("应收账单操作日志查询完成，arBillId={}, objectType={}, operationType={}, resultCount={}, costMs={}",
+                query.getArBillId(), safeLogValue(query.getObjectType()), safeLogValue(query.getOperationType()),
+                logs.size(), elapsedMillis(startedAt));
+        return logs;
     }
 
     private String exportFailureMessage(Exception e) {
@@ -1738,4 +1850,17 @@ public class ArBillServiceImpl implements IArBillService {
         }
         return new ArrayList<>(uniqueIdentifiers);
     }
+
+    private long elapsedMillis(long startedAt) {
+        return (System.nanoTime() - startedAt) / 1_000_000L;
+    }
+
+    /** 防止请求参数中的换行控制字符伪造多行日志，并限制日志字段长度。 */
+    private String safeLogValue(String value) {
+        if (StringUtils.isEmpty(value)) {
+            return value;
+        }
+        String sanitized = value.replaceAll("[\\p{Cntrl}]", "_");
+        return sanitized.length() > 128 ? sanitized.substring(0, 128) : sanitized;
+    }
 }