RuleChainActorMessageProcessor: onTellNext null pointer fix

application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleChainActorMessageProcessor.java

@@ -250,10 +250,17 @@ public class RuleChainActorMessageProcessor extends ComponentMsgProcessor<RuleCh
             checkActive(msg);
             EntityId entityId = msg.getOriginator();
             TopicPartitionInfo tpi = systemContext.resolve(ServiceType.TB_RULE_ENGINE, msg.getQueueName(), tenantId, entityId);
-            List<RuleNodeRelation> relations = nodeRoutes.get(originatorNodeId).stream()
+
+            List<RuleNodeRelation> ruleNodeRelations = nodeRoutes.get(originatorNodeId);
+            if (ruleNodeRelations == null) { // When unchecked, this will cause NullPointerException when rule node doesn't exist anymore
+                log.warn("[{}][{}][{}] No outbound relations (null). Probably rule node does not exist. Probably old message.", tenantId, entityId, msg.getId());
+                ruleNodeRelations = Collections.emptyList();
+            }
+
+            List<RuleNodeRelation> relationsByTypes = ruleNodeRelations.stream()
                     .filter(r -> contains(relationTypes, r.getType()))
                     .collect(Collectors.toList());
-            int relationsCount = relations.size();
+            int relationsCount = relationsByTypes.size();
             if (relationsCount == 0) {
                 log.trace("[{}][{}][{}] No outbound relations to process", tenantId, entityId, msg.getId());
                 if (relationTypes.contains(TbRelationTypes.FAILURE)) {
@@ -268,14 +275,14 @@ public class RuleChainActorMessageProcessor extends ComponentMsgProcessor<RuleCh
                     msg.getCallback().onSuccess();
                 }
             } else if (relationsCount == 1) {
-                for (RuleNodeRelation relation : relations) {
+                for (RuleNodeRelation relation : relationsByTypes) {
                     log.trace("[{}][{}][{}] Pushing message to single target: [{}]", tenantId, entityId, msg.getId(), relation.getOut());
                     pushToTarget(tpi, msg, relation.getOut(), relation.getType());
                 }
             } else {
                 MultipleTbQueueTbMsgCallbackWrapper callbackWrapper = new MultipleTbQueueTbMsgCallbackWrapper(relationsCount, msg.getCallback());
-                log.trace("[{}][{}][{}] Pushing message to multiple targets: [{}]", tenantId, entityId, msg.getId(), relations);
-                for (RuleNodeRelation relation : relations) {
+                log.trace("[{}][{}][{}] Pushing message to multiple targets: [{}]", tenantId, entityId, msg.getId(), relationsByTypes);
+                for (RuleNodeRelation relation : relationsByTypes) {
                     EntityId target = relation.getOut();
                     putToQueue(tpi, msg, callbackWrapper, target);
                 }