[undertow-dev] re-establish a usable response object after an IOException

Resteasy is processing a REST request that is to produce a JSON object. The generation of the JSON object fails because the users's (class) object is missing a required annotation. This programming error causes an IOException to be thrown by com.fasterxml.jackson.databind.ObjectWriter and the response is tagged as completed in HttpServerExchange. But the user has also defined a custom ExceptionMapper<throwable> for Resteasy to use to report any exceptions. Custom ExceptionMappers in this case are processed after the response has be marked complete. Is there any way to re-establish a usable response object so the user's ExceptionMapper can report the failure to the client?