RESTEasy Reactive: investigate JSON streaming

[FroMage]

There are several existing competing mime types / RFCs for streaming JSON in requests/responses.

We should investigate them and possibly support one or more.

[FroMage]

@gytis this is what @geoand talked to you about.

[FroMage]

Note that for the "response streaming" part this may depend on #13661

[gytis]

Great! I'm happy to take this one. Feel free to assign me.

[FroMage]

Great!

[FroMage]

Apparently Kubernetes API server (https://kubernetes.io/docs/reference/command-line-tools-reference/kube-apiserver/) uses application/json;stream=watch and streams.

[geoand]

WTF is that stream=watch thing :)

[FroMage]

One option is http://ndjson.org/

[ntrp]

Just to add ndjson is the default streaming method of Spring WebFlux Multi responses

[ntrp]

I could start implementing a solution to support Ndjson on JaxRS endpoints if anybody can point me in the right direction. I have seen the SSE provider in JaxRS core but I think this one can be much simpler. I am still missing all the links to understand fully what is necessary to make it happen. Did a quick and dirty 10 min PoC with a custom provider but the provider receives a list of objects instead of receiving single Multi emits of course.

[geoand]

Currently the JSON handling for SEE can be found in https://github.com/quarkusio/quarkus/blob/main/independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/handlers/PublisherResponseHandler.java

[ntrp]

Ah cool, I did not find that one yet hehe. That's a really good entry point, thanks!