[jax-rs-spec users] [jsr339-experts] Re: Re: New abstract methods in Response

From: Markus KARG <>
Date: Thu, 25 Oct 2012 23:21:25 +0200

WebDavResponse.multistatus(.) works similar to Response.ok(.): It provides a
convenient way to produce the typical WebDAV response of "207 Multi-Status"
without having to write Response.status(MULTI_STATUS), hence is as essential
to WebDAV as ok() is for vanilla http.


The WebDavResponse class is existing already, but is not found in the public
downloads so far as it was prepared for the next release of WebDAV Support
for JAX-RS, which I intended to ship when migrated to JAX-RS 2.0. So you
would invalidate an already made investment in source code, what I am not
happy about.


Can you please provide a code example how implementing und using
.multistatus() would look like using your proposed delegation solution so I
can see whether it would work and what it actually means to me and my users?


BTW, I wonder why breaking backwards compatibility suddenly is no issue
anymore as I can remember some months back I was near to get lapidated for
proposing breaking backwards compatibility.?! I mean, if there are any users
out there which have existing Response implementations (Who knows? Who has
collected valid statistics?) their application simply will not run anymore.
Ain't that an issue? (Just for curiosity, as apparently you seem to plan to
provide a tailored solution for my case)





From: Marek Potociar []
Sent: Donnerstag, 25. Oktober 2012 22:57
Subject: [jsr339-experts] Re: [jax-rs-spec users] Re: New abstract methods
in Response



On Oct 25, 2012, at 7:53 PM, Markus KARG <> wrote:

I am sorry that I have to object that application classes my not extend
Response anymore, as the WebDAV Support for JAX-RS needs this as an
extension point to provide the possibility to simply write:




What would that do? How would it translate to Response method calls?


So I have to object. It must still be possible for non-JAX-RS-implementors
to extend Response. Or the JAX-RS 2.0 must provide another extension point
for things like WebDAV.


Are you saying you are already extending Response or that someone may want
to extend Response? Would it work for you, if we provided an
AbstractResponseDelegate, that would implement delegation to a wrapped
Response instance and would be available for customization and extension?
That way you would be able to extend the response behavior with new
convenience methods that would call the wrapped Response methods. Would that







From: Marek Potociar [mailto:marek.potociar@ <>]

Sent: Donnerstag, 25. Oktober 2012 14:59
To: <>
Subject: [jsr339-experts] New abstract methods in Response


Hello experts,


As you know we've added quite a lot of new abstract methods to the Response
API. The approach is however somewhat problematic, because Response javadoc
states that:


An application class can extend this class directly or can use one of the
static methods to create an instance using a ResponseBuilder.


So, adding new abstract methods is strictly speaking a BV incompatible
change. Still, we are not aware of any application developer extending the
Response class. Are you?


We thought we would change the javadoc to not support extending Response
anymore and at the same time implement the newly added methods. Yet, as it
turns out, the only practical default implementation would be to throw an
UnsupportedOpperationException in most cases. Otherwise we would have to
bring in a lot of internal utility classes from Jersey into the API and the
implementation would still only work on the server side. Therefore we feel
that it would be best to keep the new methods abstract and only change the
javadoc to state that:


An application class should not extend this class directly. Response class
is reserved for an extension by a JAX-RS implementation providers. An
application should use one of the static methods to create a Response
instance using a ResponseBuilder.


Again, this is a BW-incompatible change. But we don't know any application
that would be really extending the Response class.


Let us know what you think about the proposal. Given the full context, would
you support it even if it is BW-incompatible change?