Determine if the REST Client is blocking or non-blocking in a ClientRequestFilter / ClientResponseFilter.

[lmartella1]

Hello,
In my Quarkus application, which exposes REST APIs and makes various REST client calls to external APIs as part of processing incoming requests, I need to apply custom logic in a ClientResponseFilter based on whether the client call is blocking or reactive.

Currently, I determine the client type by checking the return type of the client method as following:

  private boolean isAsyncClientRequest(ClientRequestContext requestContext) {
    Class methodReturnType =
        ((Method)requestContext.getProperty("org.eclipse.microprofile.rest.client.invokedMethod")).getReturnType();
    return methodReturnType.equals(CompletionStage.class)
        || methodReturnType.equals(Uni.class)
        || methodReturnType.equals(Multi.class);
  }

While this method works, I have the impression it relies on internal implementations of the REST Client, which may change in the future and potentially break this approach. Do you have any suggestions for a more robust solution?

Thank you in advance.

[quarkus-bot[bot]]

/cc @cescoffier (rest-client), @geoand (rest-client)

[geoand]

There isn't any API you could use, but what you are doing is generally correct.

[lmartella1]

Thank you for your feedback. Is there any possibility that an official API addressing this purpose will be introduced in a future Quarkus release?

[geoand]

You can always open a feature request :)