Resteasy Reactive Rest Client fails to re-construct large chunks of streamed json (stream+json) and fails deserialization

[fleckware]

Describe the bug

Note: This is related to #30040 in that both result in JsonMappingExceptions, but this is a different issue.

I am trying to use RestMediaType.APPLICATION_STREAM_JSON to stream a Multi that contains a few larger objects (think ~25 kB each) from my reactive java server to a reactive java client, using the rest client.

However, the deserialization of the objects fails with Unexpected end-of-input errors, either at the end of 1943 bytes or 8192 bytes. (For the 1943 case, I think there is potentially header info on the first chunk that is cutting into the 8192 total, since when I try to collect the chunks as Strings instead of reading them as my custom objects, all but the first String are 8192 chars long)

Through my own investigation I have found the workaround is to increase the Vertx HttpClientOptions for DEFAULT_MAX_CHUNK_SIZE and DEFAULT_RECEIVE_BUFFER_SIZE, both of which are defaulted to 8192

Maybe that is the final solution, but I would think that the rest client should be able to use the newline-delimited json to determine when it has received an entire object, and buffer/hold in memory up to that point before attempting to deserialize.

Expected behavior

Rest client can properly receive and deserialize a stream of larger json objects, without having to fiddle with the http client options myself

Actual behavior

Errors in the client:

com.fasterxml.jackson.databind.JsonMappingException: Unexpected end-of-input in field name
 at [Source: (ByteArrayInputStream); line: 1, column: 1943]
...
com.fasterxml.jackson.core.io.JsonEOFException: Unexpected end-of-input in VALUE_STRING
 at [Source: (ByteArrayInputStream); line: 1, column: 8192]

How to Reproduce?

Reproducer: service3 (client) and service4 (server) in https://github.com/fleckware/quarkus-test

1. in one terminal ./gradlew service4:quarkusDev
2. in a separate terminal ./gradlew service3:quarkusDev
3. in a separate terminal curl localhost:8081/service4/test/large > output.json
4. observe that when hitting the streaming endpoint on the server directly, there is no issue
5. now try to hit it using the rest client curl localhost:8080/service3/test/large
6. observe the json mapping error in the service3 terminal

Output of uname -a or ver

No response

Output of java -version

openjdk 11.0.10

GraalVM version (if different from Java)

No response

Quarkus version or git rev

2.15.0

Build tool (ie. output of mvnw --version or gradlew --version)

gradle 7.4.2

Additional information

No response

[quarkus-bot]

/cc @FroMage(resteasy-reactive), @Sgitario(rest-client), @cescoffier(rest-client), @geoand(rest-client,resteasy-reactive), @stuartwdouglas(resteasy-reactive)

[cescoffier]

Thank you for the report and the very nice reproducer.
The problem is the absence of a proper parser for application/stream+json.

#30255 contains the fix.

[fleckware]

Thank you! Will that PR closes #30040 as well ? I notice you used the endpoint from that issue as a unit test