update

examcloud-core-print-service/src/main/java/cn/com/qmth/examcloud/core/print/service/impl/StatisticServiceImpl.java

@@ -220,6 +220,10 @@ public class StatisticServiceImpl implements StatisticService {
         GetBasePaperReq req = new GetBasePaperReq();
         req.setPaperId(paperId);
         GetQuestionListResp resp = questionCloudService.getQuestionStructure(req);
+        if (resp == null || resp.getJson() == null) {
+            log.warn("试卷试题结构不存在！ paperId is " + paperId);
+            return null;
+        }
         return new JsonMapper().fromJson(resp.getJson(), ExamQuestionStructureInfo.class);
     }