Unable to find a MessageBodyReader of content-type text/plain in classic Jaxrs Client

[hantsy]

I used the classic Jaxrs ClientBuilder to create a client and manually shake hands to a simple API that returns a simple long type in literal form and content type is text/plain.

Example Codes: https://github.com/hantsy/quarkus-sandbox/tree/master/restclient-jaxrs

client = ClientBuilder.newBuilder()
        .register(ResteasyJackson2Provider.class)
        .register(StringTextStar.class)
        .executorService(executorService)
        .build();


return client.target(baseUrl + "/posts/count")
        .queryParam("q", q)
        .request().accept(MediaType.TEXT_PLAIN_TYPE)
        .rx()
        .get(Long.class);

But I encountered the following classic error,

RESTEASY003145: Unable to find a MessageBodyReader of content-type text/plain and 
type class java.lang.Long

Which providers I should register in client to fix this?