Hi Gabriel
ok. here's what to be done in case you decide to try to it later on :
1. Here's how you can register a stax writer using a jaxrs filter :
http://svn.apache.org/repos/asf/cxf/trunk/systests/src/test/java/org/apache/cxf/systest/jaxrs/XmlStreamWriterProvider.java
In your case you would also need to check if it's GET and extract an actual
class method name :
ori.getMethodToInvoke().getName() and pass it to a custom writer
2. Here's a custom writer
http://svn.apache.org/repos/asf/cxf/trunk/systests/src/test/java/org/apache/cxf/systest/jaxrs/CustomXmlStreamWriter.java
so you only override writeStartElement/endElement, and you write a boilerplate
code, using the name of the operation, etc
JAXBProvider will use the custom writer to write to.
I think it is all that needs to be done. Similarly a stax Reader can be created
if needed from a RequestHandler filter.
IMHO it's quite straighforward, but I appreciate it may not be that easy to do
in the actual production env.
Let me know if you have any questions in case you decide to experiment a bit
with this approach.
Cheers, Sergey
----- Original Message -----
From: "Gabriel Guardincerri" <[email protected]>
To: <[email protected]>
Sent: Wednesday, June 17, 2009 3:59 PM
Subject: RE: How to migrate REST HTTP-binding to JAX-RS and keep the xml
messages format?
Hi Sergey,
Thank you for your detailed post. It seems to be really hard to have the
same XML format. For now, I'll wait for a patch to HTTP-binging, I'm also
debuging it myself trying to see if I find the problem. But we will probably
need to think on the alternative of breaking backward compatibility and to
migrate all to standard JAXRS for future releases.
Thank you,
Gabriel
Sergey Beryozkin-2 wrote:
Hi,
I think a response like
<ns1:getUserByUsernameResponse
xmlns:ns1="http://jivesoftware.com/clearspace/webservices";>
<return>
[email protected]
<ID>2001</ID>
<name>user1 user1</name>
<username>user1</username>
</return>
</ns1:getUserByUsernameResponse>
indicates that a response being formatted/wrapped according to soap rules,
so it is unlikely the JAXRS runtime will be capable of formatting the same
way. Now, I'm planning to support CXF Data Bindings wrapped as JAXRS
message providers but I'm not sure it will help in this case.
So with JAX-RS/JAXB you'll have something like
<user xmlns="somenamespace">
[email protected]
<ID>2001</ID>
<name>user1 user1</name>
<username>user1</username>
</user>
I don't see what can be done at the JAXRS level to ensure that the
HTTP-Binding like response is returned. You may want just to move to
JAX-RS right now rather than postponing it and register an XMLStreamWriter
from a JAXRS ResponseHandler filter which upon encountering a root element
would replace it with a boilerplate xml like
<ns1:getUserByUsernameResponse
xmlns:ns1="http://jivesoftware.com/clearspace/webservices";>
<return>
and then after letting the document out finish it with
</return>
</ns1:getUserByUsernameResponse>
I'm presuming the name of the operation is "getUserByUsername", you can
get it from an input message which you can pass into your custom stax
writer upon creating it in the filter.
If your legacy clients were distinguishable somehow from the newer ones
(say they have some unique header, etc) then you can do it for old clients
only.
It is just difficult for us to continue working with the HTTP Binding
given that JAX-RS is a much richer spec. I'd vote for dropping it
completely for 2.3 given that various new contributions are expected
though still maintaining it in 2.2 fixes.
Now about the list response :
<ns1:getUsersResponse
xmlns:ns1="http://jivesoftware.com/clearspace/webservices";>
<return>
[email protected]
<ID>2003</ID>
<name>User Test One</name>
<username>userTest1</username>
</return>
<return>
[email protected]
<ID>2002</ID>
<name>user2 user2</name>
<username>user2</username>
</return>
</ns1:getUsersResponse>
May be we should do in JAX-RS something like
<users xmlns="namespace used by user or package name derived">
<user>
[email protected]
<ID>2003</ID>
<name>User Test One</name>
<username>userTest1</username>
</user>
<user>
[email protected]
<ID>2002</ID>
<name>user2 user2</name>
<username>user2</username>
</user>
</users>
And also introduce some annotations which will give a hint to the runtime
on how to customize the wrapping of the list
Cheers, Sergey
-----Original Message-----
From: Gabriel Guardincerri [mailto:[email protected]]
Sent: 16 June 2009 19:37
To: [email protected]
Subject: Re: How to migrate REST HTTP-binding to JAX-RS and keep the xml
messages format?
Hi Sergey,
So what difference in formats is there when you try to switch to JAX-RS
(with JAXB 2.1 being the default provider) ? When you switch, do you
issues with all the XML samples you posted or is it with PUT only ?
When I switch to JAX-RS with it's default provider I have problems
with all the methods that are in the XML samples. But for PUT or POST
I'm getting a java error, so it may be the qualified namespace that
Daniel mention, I trying to fix and test it again.
On the other side there are differences with GET requests.
For the service "Get User", I get:
Request:
GET http://localhost:8080/rpc/rest/userService/users/user1
Responses:
With HTTP-binding in 2.0.x:
<ns1:getUserByUsernameResponse
xmlns:ns1="http://jivesoftware.com/clearspace/webservices";>
<return>
[email protected]
<ID>2001</ID>
<name>user1 user1</name>
<username>user1</username>
</return>
</ns1:getUserByUsernameResponse>
With JAX-RS with its default provider in 2.2.2:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<User>
[email protected]
<ID>2001</ID>
<name>user1 user1</name>
<username>user1</username>
</User>
And for service "Get Users"
Request
GET http://localhost:8080/rpc/rest/userService/users
Responses:
With HTTP-binding in 2.0.x:
<ns1:getUsersResponse
xmlns:ns1="http://jivesoftware.com/clearspace/webservices";>
<return>
[email protected]
<ID>2003</ID>
<name>User Test One</name>
<username>userTest1</username>
</return>
<return>
[email protected]
<ID>2002</ID>
<name>user2 user2</name>
<username>user2</username>
</return>
</ns1:getUsersResponse>
With JAX-RS with its default provider in 2.2.2:
".No message body writer found for response class : ArrayList."
As Dan said, you can register a Stax XmlStreamReader or Writer (in CXF
interceptors or JAX-RS filters). For ex, you can check if it's PUT and no
namespace is there and adapt as needed - let us know please if/when you
decide to go this route to make a smoother migration, we can provide some
code samples...
Well, PUT services aren't working right now with JAX-RS in 2.2.2, but
they work with HTTP-binding in that version. If we couldn't find a
solution for GET with HTTP-binding in 2.2.2 then yes, I'll need to go
this route and I'll appreciate code samples :). But for now I just
prefer to see how HTTP-binding fix goes before going this way that
will imply code migration and a fix to the xml messages format issue.
Thank you,
Gabriel
-----Original Message-----
From: Gabriel Guardincerri [mailto:[email protected]]
Sent: 15 June 2009 20:16
To: [email protected]
Subject: Re: How to migrate REST HTTP-binding to JAX-RS and keep the xml
messages format?
Hi Dan and Sergey,
The main change between them that MAY affect the XML binding is going
from
JAXB 2.0.x to JAXB 2.1.x. The generated code from xjc can be quite
different and could potentially change things.
Dan, it may be that change. Our code works on 2.0.7, but it doesn't
work on 2.1.5 nor 2.2.2. If there is a way to fix that I'll really
appreciate it. We want to use the latest version 2.2.2 and JAX-RS for
some new web services that we need to build. But we need to keep
backward compatibility with the old web services that we have. So the
best, meaning less effort, option is to have a fix for HTTP-binding in
version 2.2.2. We are planning to migrate this old services, but not
now.
The problem is only with URL params. All our GET and DELETE services
that use some URL param don't work, they always get null values.
For example
For this service
@WebMethod
@Get
@HttpResource(location = "/users/{username}")
WSUser getUserByUsername(@WebParam(name = "username")String username)
throws UserNotFoundException;
Using this request
GET http://localhost:8080/rpc/rest/userService/users/user1
It doesn't work. The username param has a null value. Is there a way
to get a patch for that?
It is interesting. It would be helpful if Gabriel could post two sample
XML
instances, one showing what the clients are currently getting and what
they
would get if CXF 2.2.2 were used, we can proceed from there...
Sergey, actually when using HTTP-binding with CXF 2.2.2 we get the
same XML, the problem is what I mention above, that some methods don't
get params. So we were thinking on migrating them to JAX-RS to make it
work, but we need to configure it to use the same XML messages format
that we have for HTTP-binding. I'm attaching some xml samples
request/response and the interface with the annotations. Sorry that my
first post wasn't a clear.
Anyway, we prefer to just apply a patch to CXF 2.2.2 to make it work,
instead of migrating our old stuff. We are planning to migrate them
since it was deprecated, but if possible not for our next version, we
are short of time for this release and this problem was unexpected.
Thanks in advance,
Gabriel
On Mon, Jun 15, 2009 at 1:12 PM, Sergey Beryozkin<[email protected]>
wrote:
Hi Dan,
Sergey,
I know a bug was fixed in the HTTP binding for 2.2.2 in regards to the
root element things. I'm wondering if that may have affected this or
not.
possibly...
thanks, Sergey
Dan
On Sun June 14 2009 3:47:26 pm Sergey Beryozkin wrote:
Hi,
As far as I'm aware no significant changes have been made to the HTTP
binding recently, I haven't done any work with it for sure. Perhaps
there've been some cosmetic changes but I'm not aware of them.
We've agreed to deprecate the HTTP binding as all the focus now is on
enhancing the JAX-RS runtime.
> The problem is that we need to keep the same XML messages format for
backward compatibility.
Can you please post a sample class annotated with HTTPBinding
annotations and XML message which is expected by current clients ?
Thanks, Sergey
-----Original Message-----
From: Gabriel Guardincerri [mailto:[email protected]]
Sent: 12 June 2009 20:08
To: [email protected]
Subject: How to migrate REST HTTP-binding to JAX-RS and keep the xml
messages format?
Hi,
We have a lot of WS that were implemented using HTTP-binding of CXF
2.0.11,
but when we tried to migrate CXF to 2.2.2 we found out that
HTTP-binding
do
not pass params correctly. So we were trying to migrate those services
to
JAX-RS. The problem is that we need to keep the same XML messages
format
for
backward compatibility. We tried with the three data binding providers
that
are in the jaxrs package XMLBeansElementProvider, JAXBElementProvider
and
AegisElementProvider, but none of them have the same XML format for
messages
that HTTP-binding has.
Is there a way to do so? I mean, to implement services with JAX-RS and
use
the same XML data binding that has HTTP-binding? Or a way to build the
same
XML messages?
Of course, if there is a way to make HTTP-binding work in version
2.2.2
or
2.1.5, it will be the best solution.
Thanks,
Gabriel
--
Daniel Kulp
[email protected]
http://www.dankulp.com/blog
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