object references an unsaved transient instance - save the transient instance before flushin

Question

Java 8

Spring 4.3

here class Folder:

@Indexed(index = "Folder")
public class Folder<P extends Folder> extends AbstractEntity  {
}

And it's parent:

@MappedSuperclass
@XmlRootElement
@XmlAccessorType(XmlAccessType.NONE)
public abstract class AbstractEntity implements JsonSerializable, Serializable, Cloneable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue
    @JsonProperty("_id")
    private int id;
    
    protected AbstractEntity() {
    }

Here my publisher:

public class MyPublisher {
    @Override
    public void nextStep() {
        getApplicationEventPublisher().publishEvent(new ProcessEvent());
    }
}

Here event listener

public class MyClass {
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.event.EventListener;

@Autowired
private SomeDao someDao;

  @EventListener
    public void handleProcessEvent(ProcessEvent processEvent) {
        LOGGER.info("handleProcessEvent: processEvent = {}", processEvent);
        List<GatewayDiversityLink> gatewayDiversityLink = someDao.findAll(); // error herer!!!
        LOGGER.info("handleProcessEvent: gatewayDiversityLink = {}", gatewayDiversityLink);
    }

}

But throw exception when call method handleProcessEvent

Error:

 org.springframework.dao.InvalidDataAccessApiUsageException: object references an unsaved transient instance - save the transient instance before flushing: com.myproject.Folder; nested exception is org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.myproject.Folder
        at org.springframework.orm.hibernate4.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:190) ~[spring-orm-4.3.22.RELEASE.jar:4.3.22.RELEASE]
        at org.springframework.orm.hibernate4.HibernateExceptionTranslator.convertHibernateAccessException(HibernateExceptionTranslator.java:57) ~[spring-orm-4.3.22.RELEASE.jar:4.3.22.RELEASE]
        at org.springframework.orm.hibernate4.HibernateExceptionTranslator.translateExceptionIfPossible(HibernateExceptionTranslator.java:44) ~[spring-orm-4.3.22.RELEASE.jar:4.3.22.RELEASE]
        at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:59) ~[spring-tx-4.3.22.RELEASE.jar:4.3.22.RELEASE]
        at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:209) ~[spring-tx-4.3.22.RELEASE.jar:4.3.22.RELEASE]
        at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:147) ~[spring-tx-4.3.22.RELEASE.jar:4.3.22.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.22.RELEASE.jar:4.3.22.RELEASE]
        at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213) ~[spring-aop-4.3.22.RELEASE.jar:4.3.22.RELEASE]
        at com.sun.proxy.$Proxy241.findByElementId(Unknown Source) ~[?:?]