When adding a extension to a builder it is not being serialized to the message

https://github.com/cloudevents/sdk-java/blob/c85c691ea63516bfc7920ad4289ec1b6e267be4e/api/src/main/java/io/cloudevents/impl/DefaultCloudEventImpl.java#L36

When building a cloudEvent like below :

    final DistributedTracingExtension dte = new DistributedTracingExtension();
    dte.setTraceparent("00-0af7651916cd43dd8448eb211c80319c-b7ad6b7169203331-01");
    dte.setTracestate("congo=BleGNlZWRzIHRohbCBwbGVhc3VyZS4");

    return new
        CloudEventBuilder<T>().contentType(ContentType.APPLICATION_JSON.getMimeType())
        .id("123")
        .time(ZonedDateTime.ofInstant(Instant.now(), ZoneOffset.UTC))
        .type("evType")
        .source("a.b.c")
        .data(entity)
        .extension(dte).build();

The extension is not being serialized when creating the json event.

[pajoma]

Any news on this? We need the extensions as well.

[razkevich]

We have found an easy workaround for this. So instead of doing this:

payloadAsString = io.cloudevents.json.Json.encode(cloudEvent);

we do this:

payloadAsString = io.cloudevents.json.Json.MAPPER.writerFor(CloudEvent.class).writeValueAsString(cloudEvent);

For some reason the latter results in a string which has extensions serialized in one of the resulting json fields