空指针

src/main/java/com/project/information/domain/service/impl/GetStatisticsKnowledgePointDomainServiceImpl.java

@@ -1,5 +1,6 @@
 package com.project.information.domain.service.impl;
 
+import com.project.base.domain.exception.BusinessErrorException;
 import com.project.base.domain.result.Result;
 import com.project.information.domain.dto.KnowledgePointStatisticsDTO;
 import com.project.information.domain.entity.InformationEntity;
@@ -21,6 +22,9 @@ public class GetStatisticsKnowledgePointDomainServiceImpl implements GetStatisti
     @Override
     public Result<KnowledgePointStatisticsDTO> getStatistics(Long subLineId) throws Exception {
         KnowledgePointStatisticsDTO dto = knowledgePointMapper.selectBySubLineId(subLineId);
+        if(dto==null){
+            throw new BusinessErrorException("子产品线不存在");
+        }
         List<Long> relatedDocumentList = informationBaseService.lambdaQuery().select(InformationEntity::getId)
                 .eq(InformationEntity::getSubLineId, subLineId).list()
                 .stream().map(InformationEntity::getId).toList();