Rest service + generic type List

[allouli_raf]

hello,

i've a problem with returning List<Address> using rest service in Gatein, my Class Address is a PUJO, i have this error " Not found writer for class java.util.ArrayList and MIME type application/xml" 

import javax.ws.rs.*;
import org.exoplatform.services.rest.resource.ResourceContainer;  
public class AddressBook implements ResourceContainer{ 
@GET
    @Path("/list")
    @Produces({MediaType.APPLICATION_XML,MediaType.APPLICATION_JSON})
    public List<Address>  getAdressList() {
        List<Address> addresses = new ArrayList<Address>();
        addresses.add(new Address("Shanghai", "Long Hua Street"));
        addresses.add(new Address("Shanghai", "Dong Quan Street"));
        //return contacts;

        return addresses;
        }
}

when i return a string that's work, i mean addresses.toString().

and in web navigator i have this error : "

HTTP ETAT 500

javax.servlet.ServletException: javax.ws.rs.WebApplicationException

org.exoplatform.services.rest.servlet.RestServlet.onService(RestServlet.java:100)

org.exoplatform.container.web.AbstractHttpServlet.service(AbstractHttpServlet.java:116)

javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

org.exoplatform.services.rest.servlet.RestEncodingFilter.doFilter(RestEncodingFilter.java:58)

org.exoplatform.frameworks.jcr.web.ThreadLocalSessionProviderInitializedFilter.doFilter(ThreadLocalSessionProviderInitializedFilter.java:116)

org.exoplatform.services.security.web.SetCurrentIdentityFilter.doFilter(SetCurrentIdentityFilter.java:76)

org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

in gateIn log erro

" Not found writer for class java.util.ArrayList and MIME type application/xml" 

i try this and i still have the same error message

  public Response getContactArray(){
        List<Address> addresses = new ArrayList<Address>();
        addresses.add(new Address("Shanghai", "Long Hua Street"));
        addresses.add(new Address("Shanghai", "Dong Quan Street"));
        GenericEntity entity = new GenericEntity<List<Address>>(addresses) {};
        return Response.ok(entity).build();
    }

any help please

[nscavell]

The framework has no way of knowing how to write your object to XML.  Please have a look at http://jsr311.java.net/nonav/releases/1.0/javax/ws/rs/ext/MessageBodyWriter.html to give you an idea.  Implement this interface and add it to the container.  You should end up with something like

@Provider
@Produces(MediaType.APPLICATION_XML)
public class AddressBookMessageBodyWriter implements MessageBodyWriter {
....

[nscavell]

Also I'm not sure if adding the above implementation of the MessageBodyWriter would actually register it propely.  I would recommend adding a java.ws.Application implementation to the container and following JAX-RS conventations on registering resources and providers.  This removes any dependencies on the actual rest implementation framework.

For example:

public class RestApplication extends Application {
   @Override
   public Set<Object> getSingletons()
   {
      Set<Object> singletons = new HashSet<Object>();
      singletons.add(new AddressBookMessageBodyWriter());
      return singletons;
   }
   @Override
   public Set<Class<?>> getClasses()
   {
      Set<Class<?>> classes = new HashSet<Class<?>>();
      classes.add(AddressBook.class);
      return classes;
   }
}

[allouli_raf]

hello, i try this but i still have the same problem

javax.ws.rs.ext.Provider

@javax.ws.rs.Produces("application/xml")

public class AddressBookWriter implements MessageBodyWriter<ArrayList<Address>>

{

      public boolean isWriteable(Class<?> type,

                                 Type genericType,

                                 Annotation[] annotations,

                                 MediaType mt)

      {

        return Source.class.isAssignableFrom(type);

      }

      public void writeTo(ArrayList<Address> list,

                          Class<?> clazz,

                          Type genericType,

                          Annotation[] annotations,

                          MediaType mediatype,

                          MultivaluedMap<String, Object> httpHeaders,

                          OutputStream os)

      throws IOException,WebApplicationException

      {

          GenericEntity<ArrayList<Address>> entity = new GenericEntity<ArrayList<Address>>(list) {};

          Response response = Response.ok(entity).build();

      }

      public long getSize(ArrayList<Address> list,

                          Class<?> type,

                          Type genericType,

                          Annotation[] annotations,

                          MediaType mt)

      {

        return -1;

      }

    }

with this

import java.util.HashSet;

import java.util.Set;

public class MyApplicatio extends javax.ws.rs.core.Application {

    public Set<Class<?>> getClasses() {

        Set<Class<?>> classes = new HashSet<Class<?>>();

        classes.add(AddressBookWriter.class);

        return classes;

    }

}

any help please

[kien_nguyen]

  You can use simple REST as example:

   @GET

   @Path("hello/{name}")

   @Produces({MediaType.APPLICATION_XML})

   public String hello(@PathParam("name") String name) {

     return "<hello>" + name + "</hello>";

   }

You need to build yourself XML String from List<Address>.

Other solution, you can use a auto-mapping annotation such as javax.xml.bind.annotation.XmlRootElement to map class to XML.

[allouli_raf]

hello,

i found the solution, indeed, we need a wrapper for collection so,  JSON-bean framework can serialize it to json like this:

public class AdresseList {

    private Collection<Address> address;

    public AdresseList() {

    }

    public AdresseList(Collection<Address> address) {

        this.address = address;

    }

    public Collection<Address> getAddress() {

        return address;

    }

    public void setAddress(Collection<Address> address) {

        this.address = address;

    }

and

public Response getContactArray(){

        List<Address> addresses = new ArrayList<Address>();

        addresses.add(new Address("Shanghai", "Long Hua Street"));

        addresses.add(new Address("Shanghai", "Dong Quan Street"));

        AdresseList listAd = new AdresseList(addresses);

        return Response.ok(listAd, "application/json").cacheControl(cc).build();

    }

i will make a complete example in the wiki, thanks for your help