Re: Cannot obtain UriInfo in isWriteable() for custom providers

[Sergey Beryozkin]

Hi Tao
On 25/11/11 21:53, Lin, Tao wrote:

Hi Sergey,

Thank you for the quick response. It would be greatly appreciated if you could 
fix the problem.

There is another minor problem related to this one. The list returned from 
UriInfo.getMatchedResources() is not in the correct order according to the 
JAX-RS spec.

 From the Java Doc for UriInfo.getMatchedResources():

"Get a read-only list of the currently matched resource class instances. Each entry 
is a resource class instance that matched the request URI either directly or via a 
sub-resource method or a sub-resource locator. Entries are ordered according to reverse 
request URI matching order, with the current resource first."

In my testing, the entries are NOT ordered according to reverse request URI 
matching order. The current resource is actually at the end.

Both issues have been fixed, thanks for reporting them

Cheers, Sergey

Thanks,

Tao

-----Original Message-----
From: Sergey Beryozkin [mailto:sberyoz...@gmail.com]
Sent: Friday, November 25, 2011 1:20 PM
To: users@cxf.apache.org
Subject: Re: Cannot obtain UriInfo in isWriteable() for custom providers

Hi
On 25/11/11 18:21, Lin, Tao wrote:

Hi,

I would like to write a custom provider, which extends a default provider in 
CXF. I would also like to make the custom provider only handles the resources 
my application exposes. It should be possible since the requested resource can 
be obtained through UriInfo object (UriInfo.getMatchedResources()), which is 
injected into the provider directly or indirectly .

However, UriInfo is only available in writeTo() but not in isWriteable(). Here 
is the sample code to demonstrate the problem:

~~
@Produces("application/json")
@Consumes("application/json")
@Provider
public class MyJSONProvider extends JSONProvider
{
      @Context MessageContext context;

      @Override
      public boolean isWriteable(Class<?>   type, Type genericType, 
Annotation[] annotations, MediaType mt)
      {
          UriInfo uriInfo = context.getUriInfo();
          List<Object>   resources = uriInfo.getMatchedResources(); // throw 
null pointer at this line

          return Customer.class.isAssignableFrom(type);
      }

      @Override
      public void writeTo(Object obj, Class<?>   cls, Type genericType, Annotation[] 
anns, MediaType m, MultivaluedMap<String, Object>   headers, OutputStream os)
              throws IOException
      {
          UriInfo uriInfo = context.getUriInfo();
          List<Object>   resources = uriInfo.getMatchedResources();

          super.writeTo(obj, cls, genericType, anns, m, headers, os);
      }
}
~~

In the writeTo() method, uriInfo contains the information I need while in the 
isWriteable(), uriInfo is null. But what I really want is the uriInfo available 
in isWriteable().

Here is my question:

is this by design or simply a bug?

To me, this is a bug.

I'll probably agree; I've been aware of it, the reason I've never done
it that all the the injection is kind of not cheap so I thought I'd only
get the code injecting contexts only for the chosen provider.
I'll investigate a bit more, and get back on this issue

Cheers, Sergey

Thanks,

Tao

--
Sergey Beryozkin

Talend Community Coders
http://coders.talend.com/

Blog: http://sberyozkin.blogspot.com