CloudEvent deserialization does not work with quarkus-resteasy-reactive

[wojciechkopciewicz]

Describe the bug

When using quarkus-resteasy-reactive (plus quarkus-resteasy-reactive-jackson) CloudEvent class cannot be deserialized on REST endpoints. Everything works fine with quarkus-reasteasy.

Expected behavior

CloudEvent class should be deserialized.

Actual behavior

The following exception is being thrown and 500 Internal Server Error is returned from the server:

ERROR [io.qua.res.rea.jac.run.map.NativeInvalidDefinitionExceptionMapper] (vert.x-eventloop-thread-0) com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of `io.cloudevents.CloudEvent` (no Creators, like default constructor, exist): abstract types either need to be mapped to concrete types, have custom deserializer, or contain additional type information
 at [Source: (ByteArrayInputStream); line: 1, column: 1]

How to Reproduce?

cloudevents-reactive-sample.zip

Output of uname -a or ver

No response

Output of java -version

No response

GraalVM version (if different from Java)

No response

Quarkus version or git rev

2.12.2.Final

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

No response

Additional information

No response

[quarkus-bot]

/cc @FroMage, @geoand, @stuartwdouglas

[geoand]

I'll have a look later on today or tomorrow

[geoand]

It seems to work in Classic RESTEasy because of an undocumented feature there: The extension code scans the classpath for JAX-RS Providers. I am a little weary of adding the same feature to RESTEasy Reactive.

I propose adding the Jandex plugin to the build of io.cloudevents:cloudevents-http-restful-ws.

[wojciechkopciewicz]

@geoand would you be able to provide a working example?

[geoand]

I'm actually rethinking this and it probably does make sense to do what RESTEasy Classic does

[geoand]

#27981 should take care of the issue

[wojciechkopciewicz]

In the meantime I tried to use jandex option using application.properties approach described here: https://quarkus.io/guides/cdi-reference#how-to-generate-a-jandex-index and it works fine.

[geoand]

Yeah, that's the general way to index libraries on the classpath that are not searched by default