Problema com EJB 3.0 / Persistencia

Assuntos Gerais
#1

Ola Pessoal!!

Estou fazendo um exemplo para entender EJB / Persistencia porem esta me dando o erro abaixo e nao consegui resolver, se alguem puder me dar uma ajuda:

[quote]type Exception report

message

descriptionThe server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: #{EntityJSFBackBean.addCustomer}: javax.ejb.EJBException: Transaction aborted; nested exception is: javax.transaction.RollbackException: Transaction marked for rollback.
root cause

javax.faces.FacesException: #{EntityJSFBackBean.addCustomer}: javax.ejb.EJBException: Transaction aborted; nested exception is: javax.transaction.RollbackException: Transaction marked for rollback.
root cause

javax.faces.el.EvaluationException: javax.ejb.EJBException: Transaction aborted; nested exception is: javax.transaction.RollbackException: Transaction marked for rollback.
root cause

javax.ejb.EJBException: Transaction aborted; nested exception is: javax.transaction.RollbackException: Transaction marked for rollback.
note The full stack traces of the exception and its root causes are available in the Sun Java System Application Server 9.1_01 logs.
[/quote]

Sessao

[code]@PersistenceContext
EntityManager em;

public Customer addNewCustomer(final Customer customer) {

    em.persist(customer);
    
    return customer;
}[/code]

BackBean

[code]@EJB
private MyEntitySessionLocal myEntitySessionLocal;
private Customer customer = new Customer();

/** Creates a new instance of EntityJSFBackBean */
public EntityJSFBackBean() {
}

public String addCustomer() {
    myEntitySessionLocal.addNewCustomer(customer);
    return "gotoHome";
}

public List<Customer> getCustumers() {

    return getMyEntitySessionLocal().getCustomers();
}

public MyEntitySessionLocal getMyEntitySessionLocal() {
    return myEntitySessionLocal;
}

public void setMyEntitySessionLocal(MyEntitySessionLocal myEntitySessionLocal) {
    this.myEntitySessionLocal = myEntitySessionLocal;
}

public Customer getCustomer() {
    return customer;
}

public void setCustomer(Customer customer) {
    this.customer = customer;
}

}[/code]

JSP

[code]<f:view>

Adding a Customer


<h:messages/>
<h:form>
Id: <h:inputText value="#{EntityJSFBackBean.customer.customerId}"/>

Name: <h:inputText value="#{EntityJSFBackBean.customer.name}"/>

ZIP : <h:inputText value="#{EntityJSFBackBean.customer.zip}"/>
            <h:commandButton value="Add" action="#{EntityJSFBackBean.addCustomer}"/>
        </h:form>   
        
    </f:view>
[/code]
#2