BUG修复

themis-business/src/main/java/com/qmth/themis/business/service/impl/TOeExamRecordServiceImpl.java

@@ -1419,8 +1419,8 @@ public class TOeExamRecordServiceImpl extends ServiceImpl<TOeExamRecordMapper, T
                 examStudentCacheBean.getRoomCode(),
                 examStudentCacheBean.getRoomName(),
                 tOeExamRecord.getFinishType(),
-                paperStructJson.toJSONString(),
-                answerJson.toJSONString(),
+                Objects.nonNull(paperStructJson) ? paperStructJson.toJSONString() : null,
+                Objects.nonNull(answerJson) ? answerJson.toJSONString() : null,
                 examStudentAnswerJson);
     }