[Resteasy-users] [resteasy-users][2.0-beta-2] Strange marshalling of Response wrapped in WebApplicationException

[Eoghan G. <eg...@re...>]

Hi Folks,

I'm using a javax.ws.rs.WebApplicationException to trigger a 409
response with a non-empty entity body containing a JAXB-generated Fault
type. Something like:

 throw new WebApplicationException(
     Response.status(Response.Status.CONFLICT)
             .entity(fault)
             .build());

The resource method is decorated with @Consumes & @Produces listing
application/xml, application/yaml and application/json.

The incoming request that causes the 409 condition to fire has both
Content-Type and Accept both set to application/xml.

Now for some reason, the Fault instance in the response is being
marshalled as yaml, but with the Content-Type of the response left
unset, literally as follows:

 HTTP/1.1 409 Conflict
 Content-Length: 122
 Server: Jetty(6.1.23)
 --- !com.redhat.rhevm.api.model.Fault
 detail: "Attempt to set immutable field: id"
 reason: Broken immutability constraint
 
Whereas if I explicitly apply the conneg rules myself, and set the
Content-Type of the response to the type specified in the incoming
Accept header like so:

 throw new WebApplicationException(
     Response.status(Response.Status.CONFLICT)
             .headers("Content-Type", <type from incoming Accept>)
             .entity(fault)
             .build());


then all is well again and the response plays out as follows:

 HTTP/1.1 409 Conflict
 Content-Type: application/xml
 Content-Length: 168
 Server: Jetty(6.1.23)
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
 <fault>
   <reason>Broken immutability constraint</reason>
   <detail>Attempt to set immutable field: id</detail>
 </fault> 

exactly as I expected originally. Does this smell like a bug, as in
shouldn't the appropriate content type be applied automatically?

Cheers,
Eoghan