I'm trying to create a Hibernate entity and then read a one-to-many Collection in the same method/transaction and its always returning empty for the get Collection call. I've tried to use an `fetch=FetchType.EAGER` instead of `fetch=FetchType.LAZY` and I've also tried a Hibernate `flush()` after the car insert and before the car read, but the one-to-many Collection is always empty. If I remove the get Collection call (see getCarList() below) and put it in another method, the Collection is not empty but I would like to keep the insert and read in the same method if possible. If I do a flush and refresh then the Collection is populated, but isn't that practice discouraged? Ideas?
Entity: Code:
@Entity
@Table(name = "car")
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "car_type", discriminatorType = DiscriminatorType.STRING)
public class Car {
private Car defaultCar;
private List<Car> carList = new ArrayList<Car>();
@ManyToOne
@JoinColumn(name = "DEFAULT_CAR_ID")
public Car getDefaultCar() {
return defaultCar;
}
public void setDefaultCar(Car defaultCar) {
this.defaultCar = defaultCar;
}
@OneToMany(mappedBy = "defaultCar", fetch=FetchType.LAZY)
public List<Car> getCarList() {
return carList;
}
public void setCarList(List<Car> carList) {
this.carList = carList;
}
@Transient
public void initializeCarList() {
Hibernate.initialize(this.carList);
}
Service Implementation: Code:
public List<Car> saveAndGetDefaultCarList(){
Car car1 = new Car();
carDAO.create(car1);
Car car2 = new Car();
car2.setDefaultCar(car1);
carDAO.create(car2);
List<Car> defaultCarList = car1.getCarList(); //always returning empty List
}
DAO Implementation:Code:
public class CarDAOImpl implements CarDAO {
private DaoFactory daoFactory;
@Override
public Copy create(Car car) {
GenericDao<Car> dao = daoFactory.getDao(Car.class);
return dao.create(car);
}
public void setDaoFactory(DaoFactory daoFactory) {
this.daoFactory = daoFactory;
}
public void setCarDao(CarDAO carDAO) {
this.carDAO = carDAO;
}
}
public class HibernateDaoFactory implements DaoFactory {
private SessionFactory sessionFactory;
private HibernateSessionConfigurer sessionConfigurer;
public <T> GenericDao<T> getDao(Class<T> clazz) {
HibernateDao<T> dao = new HibernateDao<T>(clazz);
dao.setSessionFactory(sessionFactory);
dao.setSessionConfigurer(sessionConfigurer);
return dao;
}
public QueryDao getQueryDao() {
HibernateQueryDao dao = new HibernateQueryDao();
dao.setSessionFactory(sessionFactory);
dao.setSessionConfigurer(sessionConfigurer);
return dao;
}
public void flush() {
sessionFactory.getCurrentSession().flush();
}
public void setSessionFactory(SessionFactory sf) {
this.sessionFactory = sf;
}
public void setSessionConfigurer(HibernateSessionConfigurer cfg) {
this.sessionConfigurer = cfg;
}
}
Library Versions: hibernate-core-4.2.0.final
spring-core-3.2.2.RELEASE.jar
Spring Hibernate Config: Code:
<bean id="txManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory"/>
</bean>
<tx:advice id="txAdvice" transaction-manager="txManager">
<tx:attributes>
<tx:method name="create*" propagation="REQUIRED"/>
</tx:attributes>
</tx:advice>
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