Spring Integration. Gateway reply error on outbound exception - spring

Question

I have the next configuration:
Inbound
<int:gateway id="inGateway" service-interface="XXX"
error-channel="errorChannel"
default-request-channel="requestChannel"
default-reply-channel="replyChannel" />
Outbound:
<ws:outbound-gateway id="ws-outbound-gateway"
request-channel="inbound" reply-channel="outbound" uri="XXX" />
Chain 1:
<int:chain input-channel="requestChannel" output-channel="inbound">
XXX </int:chain>
Chain 2:
<int:chain input-channel="outbound" output-channel="replyChannel"> XXX
</int:chain>
Error:
<int:chain input-channel="errorChannel" output-channel="replyChannel">
<int:transformer ref="logicTransformers" method="errorTransformerMethod"></int:transformer>
</int:chain>
</beans>
Java Transformer:
final GenericError errorCatalog = errorCatalog(errorMessage);
LOGGER.warn("Transformed error from catalog: {}", errorCatalog);
final MessageBuilder<Document> builder =
MessageBuilder.withPayload(XmlUtil.parseToDocument(errorCatalog)).copyHeaders(errorMessage.getHeaders()).copyHeadersIfAbsent(errorMessage.getHeaders());
When the webservice of outbound is down the error go into errorChannel transformer but to reponse we have the next error:
o.s.m.c.GenericMessagingTemplate$TemporaryReplyChannel#242 Reply
message received but the receiving thread has exited due to an
exception while sending the request message:GenericMessage
[payload=[#document: null], headers={spanTraceId=8bf90ea9ff4266c8,
spanId=598680bae5f913d5, spanParentSpanId=8bf90ea9ff4266c8,
replyChannel=org.springframework.messaging.core.GenericMessagingTemplate$TemporaryReplyChannel#76c751de,
functionalId=PRUEBASOA12,
errorChannel=org.springframework.messaging.core.GenericMessagingTemplate$TemporaryReplyChannel#76c751de,
messageSent=true, id=2108386f-99db-98b9-3d30-3bcf45335424,
spanSampled=1, spanName=message:requestChannel}]
We don't understand... because we have the same flow with

Answer 1

In case of error on the service level the original message is wrapped to the MessagingException and the ErrorMessage with that payload is sent to the errorChannel. Even if you use replyChannel explicitly, you still have to ensure the replyChannel header, which is populated by the inbound gateway. And exactly this header plays the main role in the request-reply behavior in that gateway.
That replyHeader is still present in your error flow, but it is already a part of the failedMessage in the MessagingException payload.
So, your logicTransformers.errorTransformerMethod should extract that replyChannel header for the real reply from this method to be sent to the explicit replyChannel. Or you can omit this replyChannel at all because any way the real sendAndReceive is based on the replyChannel header.
Please, read more info in the Reference Manual:
https://docs.spring.io/spring-integration/docs/4.3.11.RELEASE/reference/html/messaging-endpoints-chapter.html#gateway
https://docs.spring.io/spring-integration/docs/4.3.11.RELEASE/reference/html/configuration.html#namespace-errorhandler