Spring3和Hibernate4中的长事务会话

Question

在下面的场景中，我获得了LazyInitializationException到Shop.events集合。

我知道问题可能在调用shop.getEvents之前就关闭了。

我当时正在学习OpenSessionInViewFilter，但我认为在每次调用服务器的过程中，每个事务会话都不是一个好主意。FetchType.EAGER也不太好。

我需要帮助来解决这个问题。提前谢谢你。

@Entity
@Table(name = "shop")
public class Shop implements Serializable {

    // Another class attributes.    

    @OneToMany(mappedBy = "shop", fetch=FetchType.LAZY)
    private Set<Event> events;

    // Getters and setters.

}

@Entity
@Table(name = "event")
public class Event implements Serializable {

    // Another class attributes.

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "shop_id", nullable = false)
    private Shop shop;

    // Getters and setters.

}

持久层实现。

public interface AbstractDao<E, I extends Serializable> {

    E findUniqueByCriteria(Criteria criteria);

}

public interface ShopDao extends AbstractDao<Shop, String>{

    Shop getShopFromId(int shop_id, int manager_id);

}

@Repository("shopDao")
public class ShopDaoImpl extends AbstractDaoImpl<Shop, String> implements ShopDao {

    protected ShopDaoImpl() {

        super(Shop.class);
    }

    @Override
    public Shop getShopFromId(int shop_id, int manager_id) {

        Criteria criteria = this.getCurrentSession().createCriteria(Shop.class)
                .add(Restrictions.and(
                Restrictions.like("active", true),
                Restrictions.like("id", shop_id)))
                .createCriteria("manager").add(
                Restrictions.like("id", manager_id));

        return (Shop) this.findUniqueByCriteria(criteria);
    }

}

public interface ShopService {

    Shop getShopFromId(int shop_id, int manager_id);

}

@Service("shopService")
@Transactional(readOnly = true)
public class ShopServiceImpl implements ShopService {

    @Autowired
    private ShopDao shopDao;

    @Override
    public Shop getShopFromId(int shop_id, int manager_id) {

        return this.shopDao.getShopFromId(shop_id, manager_id);
    }

}

控制器看起来是这样的。

类属性。

@Autowired
private ShopService shopService;

方法控制器

Manager manager = (Manager) request.getSession(false).getAttribute("manager");

Shop shop = (Shop) this.shopService.getShopFromId(shop_id, manager.getId());

Set<Event> events = shop.getEvents();

Answer 1

解决方案是使用@Transactional(传播= Propagation.REQUIRED)的Controller方法。因此，在方法持久性操作中使用相同的事务会话。