解决空指针问题

tenant/organization/src/main/java/com/jzg/organization/utils/IncomeInvoiceLinkUtil.java

@@ -7,6 +7,7 @@ import java.time.ZoneId;
 import java.util.*;
 import java.util.stream.Collectors;
 
+import cn.hutool.core.map.MapUtil;
 import com.jzg.commons.entity.finance.po.InsPlyIncomeInvoiceLink;
 import com.jzg.commons.entity.finance.po.InsPlyIncomeInvoiceSettlement;
 import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
@@ -29,12 +30,12 @@ public class IncomeInvoiceLinkUtil {
                                                                           InsPlyIncomeInvoiceLinkMapper linkMapper,
                                                                           InsPlyIncomeInvoiceSettlementMapper settlementMapper) {
         if (CollUtil.isEmpty(incomeIdList)) {
-            return null;
+            return MapUtil.empty();
         }
 
         List<InsPlyIncomeInvoiceLink> invoiceLinkList = getInvoiceLinkList(incomeIdList, linkMapper);
         if (CollUtil.isEmpty(invoiceLinkList)) {
-            return null;
+            return MapUtil.empty();
         }
 
         // 2、拿到所有invoiceId
@@ -73,12 +74,13 @@ public class IncomeInvoiceLinkUtil {
 
         List<InsPlyIncomeInvoiceLink> invoiceLinkList = getInvoiceLinkList(incomeIdList, linkMapper);
         if (CollUtil.isEmpty(invoiceLinkList)) {
-            return null;
+            return MapUtil.empty();
         }
 
         // 按incomeId分组，一个income可能多条link
-        return invoiceLinkList.stream()
+        Map<String, List<InsPlyIncomeInvoiceLink>> invoiceLinkMap = invoiceLinkList.stream()
                 .collect(Collectors.groupingBy(InsPlyIncomeInvoiceLink::getIncomeId));
+        return invoiceLinkMap;
     }