NoMessageBodyWriterFoundFailure with resteasy

[sverker.sverker.abrahamsson.com]

I'm trying to do a resteasy service but I keep getting this error:

Failed executing GET /log/search
org.jboss.resteasy.core.NoMessageBodyWriterFoundFailure: Could not find MessageBodyWriter for response object of type: java.util.ArrayList of media type: application/xml

I've found several forum posts on similar problems but no answers that gives a clue on how to solve it. My service class is a stateless ejb and seam component, so I've put the resteasy annotations on the interface, the method is annotated with @Produces({MediaType.APPLICATION_XML}).

I've tried various variants, like returning the List directly and via a Response object like this:

return Response.ok(PushLog.findByMsisdn(em, msisdn, startDate, endDate)).build();

Both give the same error.

The ejb is in a jar which is packed together with the war to an ear. All the libs are in the ear with classpath reference from war manifest.

Any suggestions? Feels like I would be missing some jar but this is the resteasy related jar's I have:

jboss-seam-resteasy-2.2.0.GA.jar
resteasy-atom-provider-1.2.1.GA.jar
resteasy-jaxb-provider-1.2.1.GA.jar
resteasy-jaxrs-1.2.1.GA.jar

[lvdberg]

Hi,

It looks like if you're trying to return a List with objects, and RestEasy is not able to process the ArrayList (because it is not a default object for XML.marshalling).

You can do the following:

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name = "YourObjectView")
public class YourObjectView {

   @XmlElement(required = true) 
   protected List<YOURCLASSES> objects = new ArrayList<YOURCLASS>();

   ... setter 

}

You add you objects to this List and return it as. The JAXB support will take care of marshalling it in the correct format.

Leo

[jharting]

Are you using EAR deployment? If so, are you putting the jars into the ${ear}/lib folder?

[sverker.sverker.abrahamsson.com]

Jozef: Yes, all jars are in ${ear}/lib folder and they are referenced by classpath in manifest of war file.

Leo: I'll try that variant to see if it works.

[sverker.sverker.abrahamsson.com]

Ok, found it. I did like this:

GenericEntity<List<PushLog>> entity = new GenericEntity<List<PushLog>>(PushLog.findAll(em)) {};
return Response.ok(entity).build();

I.e. wrapping my list in a GenericEntity, I believe this is kind of the same as the view object Leo suggests above. It removes the ArrayList type and leaves just List, which can be serialized to xml.

[lvdberg]

Hi,

This is the way to do it. Be aware that you can do this without the annotations, but if you want to have more control of the output, you can add annotation on the bean attributes (or getters) and you change. An important one is XMLTransient, which excludes stuff from the process, neceassary when you have a complex object graph.

Success !

Leo

[sverker.sverker.abrahamsson.com]

Yes, I noticed that I had to use XmlTransient on a relation to prevent it to cause a LazyInitializationException from Hibernate.