Support @SqsHandler routing for Message<T> parameters

[dbouclier]

Type: Bug

Component:
"SQS"

Describe the bug
When using @SqsListener with multiple @SqsHandler methods, if a handler method is Message<'Pojo'> instead of just 'Pojo', routing always falls through to the default handler.

Sample

Using Spring boot 3.x and spring cloud aws 4.0.0

// This WORKS — Pojo parameter
 @SqsListener(queueNames = "myQueue")
 public class WorkingListener {

     @SqsHandler
     public void onCreated(MyPojo event) {
         // Correctly routed
     }

     @SqsHandler
     public void onUpdated(MyOtherPojo event) {
         // Correctly routed
     }

     @SqsHandler(isDefault = true)
     public void onDefault(Event event) {
         // Only receives truly unmatched events
     }
 }

 // This FAILS — Message<Pojo> parameter
 @SqsListener(queueNames = "myQueue")
 public class BrokenListener {

     @SqsHandler
     public void onCreated(Message<Pojo> message) {
         // Never reached — falls through to default
     }

     @SqsHandler
     public void onUpdated(Message<MyOtherPojo> message) {
         // Never reached — falls through to default
     }

     @SqsHandler(isDefault = true)
     public void onDefault(Event event) {
         // ALL events end up here
     }
 }

Workaround

Add the POJO as the first parameter for routing, and Message as a second parameter:

 @SqsHandler
 public void onCreated(Pojo pojo, Message<Pojo> message) {
     // 'pojo' enables correct routing with access to message metadata
 }

``

[MatejNedic]

Hey @dbouclier , this is expected.

In class -> CompositeInvocableHandler during invoke following is called:

		Class<?> payloadClass = message.getPayload().getClass();
		InvocableHandlerMethod handler = getHandlerForPayload(payloadClass);

Since paylodClass type will be MyOtherPojo or Pojo it will not match, since it will try to match it with Srpings Message
class.

If you need headers this should work if I am not wrong:

    @SqsHandler
     public void onUpdated(MyOtherPojo message, MessageHeaders headers) {
         // Never reached — falls through to default
     }

cc @tomazfernandes if you have anything to add or any proposals please share.

[tomazfernandes]

Hey @dbouclier, thanks for bringing this up, and @MatejNedic for the context.

Being able to route Message<Pojo> to the proper @SqsHandler would be a useful enhancement to the feature.

One way to support that would be for handler matching to consider the generic argument of Message<T>, something along these lines:

private boolean isPayloadAssignable(MethodParameter methodParameter, Class<?> payloadClass) {
    Class<?> parameterType = methodParameter.getParameterType();
    if (Message.class.isAssignableFrom(parameterType)) {
        ResolvableType resolvableType = ResolvableType.forMethodParameter(methodParameter);
        Class<?> genericType = resolvableType.getGeneric(0).resolve();
        return genericType != null && genericType.isAssignableFrom(payloadClass);
    }
    return parameterType.isAssignableFrom(payloadClass);
}

Happy to review a PR for this.