Vous pouvez propager des modifications d'entités enfants vers des entités parent. Cela vous oblige à propager le verrou OPTIMISTIC_FORCE_INCREMENT chaque fois que l'entité enfant est modifiée.
This article explique en détail comment vous devriez implémenter un tel cas d'utilisation.
En bref, vous devez avoir toutes vos entités mettre en œuvre une interface RootAware
:
public interface RootAware<T> {
T root();
}
@Entity(name = "Post")
@Table(name = "post")
public class Post {
@Id
private Long id;
private String title;
@Version
private int version;
//Getters and setters omitted for brevity
}
@Entity(name = "PostComment")
@Table(name = "post_comment")
public class PostComment
implements RootAware<Post> {
@Id
private Long id;
@ManyToOne(fetch = FetchType.LAZY)
private Post post;
private String review;
//Getters and setters omitted for brevity
@Override
public Post root() {
return post;
}
}
@Entity(name = "PostCommentDetails")
@Table(name = "post_comment_details")
public class PostCommentDetails
implements RootAware<Post> {
@Id
private Long id;
@ManyToOne(fetch = FetchType.LAZY)
@MapsId
private PostComment comment;
private int votes;
//Getters and setters omitted for brevity
@Override
public Post root() {
return comment.getPost();
}
}
Ensuite, vous avez besoin de deux écouteurs d'événements:
public static class RootAwareInsertEventListener
implements PersistEventListener {
private static final Logger LOGGER =
LoggerFactory.getLogger(RootAwareInsertEventListener.class);
public static final RootAwareInsertEventListener INSTANCE =
new RootAwareInsertEventListener();
@Override
public void onPersist(PersistEvent event) throws HibernateException {
final Object entity = event.getObject();
if(entity instanceof RootAware) {
RootAware rootAware = (RootAware) entity;
Object root = rootAware.root();
event.getSession().lock(root, LockMode.OPTIMISTIC_FORCE_INCREMENT);
LOGGER.info("Incrementing {} entity version because a {} child entity has been inserted", root, entity);
}
}
@Override
public void onPersist(PersistEvent event, Map createdAlready)
throws HibernateException {
onPersist(event);
}
}
et
public static class RootAwareInsertEventListener
implements PersistEventListener {
private static final Logger LOGGER =
LoggerFactory.getLogger(RootAwareInsertEventListener.class);
public static final RootAwareInsertEventListener INSTANCE =
new RootAwareInsertEventListener();
@Override
public void onPersist(PersistEvent event) throws HibernateException {
final Object entity = event.getObject();
if(entity instanceof RootAware) {
RootAware rootAware = (RootAware) entity;
Object root = rootAware.root();
event.getSession().lock(root, LockMode.OPTIMISTIC_FORCE_INCREMENT);
LOGGER.info("Incrementing {} entity version because a {} child entity has been inserted", root, entity);
}
}
@Override
public void onPersist(PersistEvent event, Map createdAlready)
throws HibernateException {
onPersist(event);
}
}
qui vous pouvez vous inscrire comme suit:
public class RootAwareEventListenerIntegrator
implements org.hibernate.integrator.spi.Integrator {
public static final RootAwareEventListenerIntegrator INSTANCE =
new RootAwareEventListenerIntegrator();
@Override
public void integrate(
Metadata metadata,
SessionFactoryImplementor sessionFactory,
SessionFactoryServiceRegistry serviceRegistry) {
final EventListenerRegistry eventListenerRegistry =
serviceRegistry.getService(EventListenerRegistry.class);
eventListenerRegistry.appendListeners(EventType.PERSIST, RootAwareInsertEventListener.INSTANCE);
eventListenerRegistry.appendListeners(EventType.FLUSH_ENTITY, RootAwareUpdateAndDeleteEventListener.INSTANCE);
}
@Override
public void disintegrate(
SessionFactoryImplementor sessionFactory,
SessionFactoryServiceRegistry serviceRegistry) {
//Do nothing
}
}
puis fournissent la RootAwareFlushEntityEventListenerIntegrator
via une propriété de configuration Hibernate:
configuration.put(
"hibernate.integrator_provider",
(IntegratorProvider)() -> Collections.singletonList(
RootAwareEventListenerIntegrator.INSTANCE
)
);
Maintenant, lorsque vous modifiez une entité PostCommentDetails
:
PostCommentDetails postCommentDetails = entityManager.createQuery(
"select pcd " +
"from PostCommentDetails pcd " +
"join fetch pcd.comment pc " +
"join fetch pc.post p " +
"where pcd.id = :id", PostCommentDetails.class)
.setParameter("id", 2L)
.getSingleResult();
postCommentDetails.setVotes(15);
La version de l'entité mère Post
est modifiée ainsi:
SELECT pcd.comment_id AS comment_2_2_0_ ,
pc.id AS id1_1_1_ ,
p.id AS id1_0_2_ ,
pcd.votes AS votes1_2_0_ ,
pc.post_id AS post_id3_1_1_ ,
pc.review AS review2_1_1_ ,
p.title AS title2_0_2_ ,
p.version AS version3_0_2_
FROM post_comment_details pcd
INNER JOIN post_comment pc ON pcd.comment_id = pc.id
INNER JOIN post p ON pc.post_id = p.id
WHERE pcd.comment_id = 2
UPDATE post_comment_details
SET votes = 15
WHERE comment_id = 2
UPDATE post
SET version = 1
where id = 1 AND version = 0
Vous aimeriez peut-être répondre à votre propre question dans ce cas. Quelqu'un pourrait venir voter pour vous. Ou même mieux, cela pourrait aider quelqu'un qui cherche la même chose. –