Я работаю над проектом JSF / JPA с базой данных Sakila в MySQL с Hibernate. Когда я хочу объединить объект клиента в БД, это занимает 20 секунд. Я предполагаю, что это связано с отображением моего класса сущности, но я не могу понять, что я сделал не так. Вот мой класс Customer:
@Entity
@Table(name = "customer")
public class Customer implements Serializable, IEntity {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Basic(optional = false)
@Column(name = "customer_id")
private Short customerId;
@Basic(optional = false)
@Column(name = "first_name")
private String firstName;
@Basic(optional = false)
@Column(name = "last_name")
private String lastName;
@Column(name = "email")
private String email;
@Basic(optional = false)
@Column(name = "active")
private boolean active;
@Basic(optional = false)
@Column(name = "create_date")
@Temporal(TemporalType.TIMESTAMP)
private Date createDate;
@Basic(optional = false)
@Column(name = "last_update")
@Temporal(TemporalType.TIMESTAMP)
private Date lastUpdate;
@LazyCollection(LazyCollectionOption.FALSE)
@OneToMany(cascade = CascadeType.ALL, mappedBy = "customerId")
private List<Rental> rentalList;
@LazyCollection(LazyCollectionOption.FALSE)
@OneToMany(cascade = CascadeType.ALL, mappedBy = "customerId")
private List<Payment> paymentList;
@JoinColumn(name = "address_id", referencedColumnName = "address_id")
@ManyToOne(optional = false)
private Address addressId;
@JoinColumn(name = "store_id", referencedColumnName = "store_id")
@ManyToOne(optional = false)
private Store storeId;
//Constructor
//getter_setter
}
И в моем CustomerService ejb я вызываю функцию слияния:
@Named
@Stateless
public class CustomerService {
@PersistenceContext(name = "sakila")
EntityManager em;
public String merge(IEntity entity) {
try {
em.merge(entity);
return "success";
}catch(Exception e){
return "failure";
}
}
}
В журнале я вижу, что спящий режим выполняет 11037 операторов выбора, подобных этому
select
paymentlis0_.customer_id as customer5_11_0_,
paymentlis0_.payment_id as payment_1_11_0_,
paymentlis0_.payment_id as payment_1_11_1_,
paymentlis0_.amount as amount2_11_1_,
paymentlis0_.customer_id as customer5_11_1_,
paymentlis0_.last_update as last_upd3_11_1_,
paymentlis0_.payment_date as payment_4_11_1_,
paymentlis0_.rental_id as rental_i6_11_1_,
paymentlis0_.staff_id as staff_id7_11_1_,
rental1_.rental_id as rental_i1_12_2_,
rental1_.customer_id as customer5_12_2_,
rental1_.inventory_id as inventor6_12_2_,
rental1_.last_update as last_upd2_12_2_,
rental1_.rental_date as rental_d3_12_2_,
rental1_.return_date as return_d4_12_2_,
rental1_.staff_id as staff_id7_12_2_,
customer2_.customer_id as customer1_5_3_,
customer2_.active as active2_5_3_,
customer2_.address_id as address_8_5_3_,
customer2_.create_date as create_d3_5_3_,
customer2_.email as email4_5_3_,
customer2_.first_name as first_na5_5_3_,
customer2_.last_name as last_nam6_5_3_,
customer2_.last_update as last_upd7_5_3_,
customer2_.store_id as store_id9_5_3_,
inventory3_.inventory_id as inventor1_9_4_,
inventory3_.film_id as film_id3_9_4_,
inventory3_.last_update as last_upd2_9_4_,
inventory3_.store_id as store_id4_9_4_,
staff4_.staff_id as staff_id1_13_5_,
staff4_.active as active2_13_5_,
staff4_.address_id as address10_13_5_,
staff4_.email as email3_13_5_,
staff4_.first_name as first_na4_13_5_,
staff4_.last_name as last_nam5_13_5_,
staff4_.last_update as last_upd6_13_5_,
staff4_.password as password7_13_5_,
staff4_.picture as picture8_13_5_,
staff4_.store_id as store_i11_13_5_,
staff4_.username as username9_13_5_,
staff5_.staff_id as staff_id1_13_6_,
staff5_.active as active2_13_6_,
staff5_.address_id as address10_13_6_,
staff5_.email as email3_13_6_,
staff5_.first_name as first_na4_13_6_,
staff5_.last_name as last_nam5_13_6_,
staff5_.last_update as last_upd6_13_6_,
staff5_.password as password7_13_6_,
staff5_.picture as picture8_13_6_,
staff5_.store_id as store_i11_13_6_,
staff5_.username as username9_13_6_,
address6_.address_id as address_1_1_7_,
address6_.address as address2_1_7_,
address6_.address2 as address3_1_7_,
address6_.city_id as city_id8_1_7_,
address6_.district as district4_1_7_,
address6_.last_update as last_upd5_1_7_,
address6_.phone as phone6_1_7_,
address6_.postal_code as postal_c7_1_7_,
store7_.store_id as store_id1_14_8_,
store7_.address_id as address_3_14_8_,
store7_.last_update as last_upd2_14_8_,
store7_.manager_staff_id as manager_4_14_8_,
store8_.store_id as store_id1_14_9_,
store8_.address_id as address_3_14_9_,
store8_.last_update as last_upd2_14_9_,
store8_.manager_staff_id as manager_4_14_9_
from
payment paymentlis0_
left outer join
rental rental1_
on paymentlis0_.rental_id=rental1_.rental_id
left outer join
customer customer2_
on rental1_.customer_id=customer2_.customer_id
left outer join
inventory inventory3_
on rental1_.inventory_id=inventory3_.inventory_id
left outer join
staff staff4_
on rental1_.staff_id=staff4_.staff_id
inner join
staff staff5_
on paymentlis0_.staff_id=staff5_.staff_id
inner join
address address6_
on staff5_.address_id=address6_.address_id
inner join
store store7_
on staff5_.store_id=store7_.store_id
left outer join
store store8_
on staff5_.staff_id=store8_.manager_staff_id
where
paymentlis0_.customer_id=?
Требуется 20 секунд, прежде чем Hibernate наконец отправит запрос на обновление.
Information: Hibernate:
update
customer
set
active=?,
address_id=?,
create_date=?,
email=?,
first_name=?,
last_name=?,
last_update=?,
store_id=?
where
customer_id=?
Я предполагаю, что мое отображение неверно, и клиент настроен на ленивую загрузку. Кто-нибудь может указать на мою ошибку?




Очевидно, что для слияния реализация JPA (здесь Hibernate) должна знать, есть ли какие-либо изменения, внесенные в отсоединенные (или ленивые, еще не извлеченные) объекты, поэтому она проверяет свое состояние с помощью SELECT. Поскольку вы каскадируете (с CascadeType.ALL), ваше слияние со всеми связанными сущностями - обновляется весь график.
Либо не каскадное слияние, либо при гарантированном слиянии используйте обновление JPQL (или CriteriAPI), если вам нужно только обновить родительский объект, игнорируя его дочерние элементы.
Спасибо большое. Это решило мою проблему. Я думаю, что этот статья также может содержать полезную информацию.