Add payload conversion to SQS listener

[chrylis]

When an SQS message arrives, the payload is always of type String, but SQS usually does not carry a contentType header. This means that the standard Jackson converter in Spring Integration is unable to handle the payload, and the flow .convert(PayloadType.class) fails due to not having a matching converter.

It appears from the linked issue that the underlying SQS message listener has its own Jackson converter that operates in non-strict mode, permitting parsing of string values. It would be helpful to be able to say

var sqs = new SqsMessageDrivenChannelAdapter(sqsClient, "my-queue");
sqs.setPayloadType(PayloadType.class);

IntegrationFlows.from(sqs)
  ...

If that is not practical, then guidance on how to make conversion happen without requiring a contentType in the original SNS message would be appreciated.

Spring Integration: 5.5.15
Spring Integration AWS: 2.5.2

[artembilan]

The SqsMessageDrivenChannelAdapter does not deal with those HandlerMethodArgumentResolvers.
It has its own internal private class IntegrationQueueMessageHandler extends QueueMessageHandler { with just plain override:

protected void handleMessageInternal(Message<?> message, String lookupDestination) {
   ...
   sendMessage(messageToSend);
}

So, the conversion you mention is really out of this channel adapter scope.

The convert() you mention is not going to work out-of-the-box because there is no simple org.springframework.core.convert.converter.Converter implementation for JSON.

However the solution for you is like this:

.transform(Transformers.fromJson(PayloadType.class))

Closing as Works as Designed