Hi everyone,

I am currently developing Java/GWT-application which is hosted on a weblogic application server. I am using EJB3.0 with EclipseLink as persistence layer. Sadly my GWT has problems to deserialize persistent entities.

It might be helpful for you to know, that I

• have the EclipseLink-Library in my classpath (including javax.persistence.Entity)
• am not recieving the persistence objects from a database or persistence-manager - I am creating the objects with standard java code
• use Eclipse IDE for Java EE Developers for development and deploying and I am compiling my GWT code with the GWT-Plugin (GWT 2.1.0) - my source code is split up in several projects
• am pretty sure, that the problems occures on client side, since the HTTP response of my server is the same in my working and in my not working example
• tried to patch javax.persistence.Entity and tried to include several libraries which included javax.persistence.Entity but nothing was helping

In my server provides a list of instances of class SerialClass; the interface looks like this:

public interface GreetingService extends RemoteService {
    List<SerialClass> greetServer();
}

My onModuleLoad()-Method gets those instances and creates a browser-popup with the information:

public void onModuleLoad() {
    GreetingServiceAsync server = (GreetingServiceAsync) GWT.create(GreetingService.class);
    server.greetServer(new AsyncCallback<List<SerialClass>>() {
        public void onFailure(Throwable caught) {
        }

        public void onSuccess(List<SerialClass> result) {

            String resultString = "";
            try {
                for (SerialClass serial : result) {
                    if (serial == null) {
                        resultString += "null ";
                    } else {
                        resultString += ">" + serial.id + "< ";
                    }
                }
            } catch (Throwable t) {
                Window.alert("failed to process");
            }

            Window.alert("success:" + resultString);
        }
    });

}

My server is looking like this:

public class GreetingServiceImpl extends RemoteServiceServlet implements GreetingService {
    public List<SerialClass> greetServer() throws IllegalArgumentException {
        List<SerialClass> list = new ArrayList<SerialClass>();
        for (int i = 0; i < 100; i++) {
            list.add(new SerialClass());
        }
        return list;
    }
}

Case 1 => everything works fine

I am using this SerialClass (either without any annotation, or with any annotation other than Entity - for example javax.persistence.PersistenceContext works fine):

//@Entity
public class SerialClass implements Serializable, IsSerializable {
    public int id = 4711;
}

The popup contains (as expected):

success:>4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711< >4711<

The data sent over HTTP looks like this:

//OK[4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,100,1,["java.util.ArrayList/3821976829","serial.shared.SerialClass/10650133"],0,6]

Case 2 => its not working at all

I am using this SerialClass:

@Entity
public class SerialClass implements Serializable, IsSerializable {
    public int id = 4711;
}

My popup contains (THIS IS MY PROBLEM):

success:>2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null >2< null 

The data sent over HTTP looks like this (exactly the same!):

//OK[4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,4711,2,100,1,["java.util.ArrayList/3821976829","serial.shared.SerialClass/10650133"],0,6]

There is no suspicious logging output - neither on server, nor on client. All HTTP-responses have return code 200.

My current workaround

I am going to try to create transfer objects as a copy of my SerialClass - those transfer objects will look exactly the same, but will not have the @Entity annotation.

Alternatively I could try to use the RequestFactory (thanks to @Hilbrand for the hint).

I really don't know how to solve that problem and I'm really thankful about any suggestions, hints, tips, links, etc.