Spring3和Hibernate 4中的Mantain长事务会话

Question

在下面的场景中，我将LazyInitializationException发送到Shop.events Collection。

我知道问题可能是在执行调用shop.getEvents之前关闭了事务会话。

我正在学习OpenSessionInViewFilter，但我认为在对服务器的每次调用中，保持每个事务会话都不是一个好主意。FetchType.EAGER也不好。

我需要帮助来解决这个问题。提前谢谢。

@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);
    }
}

---

控制器看起来像这样。

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

解决方案是用@Transactional（propagation=propagation.REQUIRED）配置Controller方法。因此，在方法持久化操作中使用相同的事务会话。