GWT : exception when running incoming RPC call on EclipseLink

I'm writing a project with Eclipse using EclipseLink ,hsqldb and GWT . When I try a do a RPC I always get stuck on this exception :

SEVERE: javax.servlet.ServletContext log: Exception while dispatching incoming RPC call com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract void it.myProject.client.service.EmployeeService.createEmployee()' threw an unexpected exception: javax.persistence.PersistenceException: No persistence providers available for >"myDB" after trying the following discovered implementations: org.datanucleus.api.jpa.PersistenceProviderImpl

This is my main file myProject.java where I execute the RPC:

public class MyProject implements EntryPoint {       private final EmployeeServiceAsync aService = (EmployeeServiceAsync)             GWT.create(EmployeeService.class);       @Override     public void onModuleLoad() {         aService.createEmployee(new AsyncCallback<Void>() {          @Override          public void onFailure(Throwable caught) {              Window.alert("Creation Employees failed!");          }          @Override          public void onSuccess(Void result) {              Window.alert("Creation success!");          }      });

I've specified the name of my Database and the provider in persistence.xml :

 <persistence-unit name="myDB" transaction-type="RESOURCE_LOCAL">  

<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider> 

In my build path I've put: eclipselink.jar ; gwt-servlet.jar ; hsqldb.jar ; javax.persistence_2.0.4.jar ; persistence-api-sources-2.0.jar ; smartgwt.jar

Please give any advices you think and feel free to ask if you need other code or anything.

I'm blocked on this since a week and noone in the web seems to have the same problem .

 

--
You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group.
To unsubscribe from this group and stop receiving emails from it, send an email to google-web-toolkit+unsubscribe@googlegroups.com.
To post to this group, send email to google-web-toolkit@googlegroups.com.
Visit this group at http://groups.google.com/group/google-web-toolkit.
For more options, visit https://groups.google.com/groups/opt_out.