hibernate reactive: keep session opened for ontToMany fields-CodePudding

Here my entity:

@NoArgsConstructor
@AllArgsConstructor
@Builder
@Data
@Entity
@Table(name = "GITTBUSUARIS")
public class Usuari {
    
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "USUARIS_ID")
    private Integer id;
    
    @Column(name = "USUARIS_CODI")
    private String codi;

    @Column(name = "USUARIS_NOM")
    private String nom;

    // @OneToMany(cascade = CascadeType.ALL, mappedBy = "id.usuari", fetch = FetchType.EAGER)
    // private Set<PermisUsuari> permisos;
    
}

As you can see, permisos field is commented.

Here my repository:

@RequiredArgsConstructor
public class ReactiveJpaSpecificationExecutorBase<T> implements ReactiveJpaSpecificationExecutor<T> {

    private final Mutiny.SessionFactory sessionFactory;

    @Override
    public Mono<T> findOne(Specification<T> spec) {
        CriteriaQuery<T> criteriaQuery = this.buildQuery(spec, Sort.unsorted());

        return this.sessionFactory
            .withSession(session -> session.createQuery(criteriaQuery).getSingleResultOrNull())
            .convert().with(UniReactorConverters.toMono());
    }

}

Above code works right. However, when I uncomment permisos field, I'm getting this exception message:

Failed to execute statement [select rol0_.ROLS_ID as rols_id1_12_0_, rol0_.ROLS_CODI as rols_cod2_12_0_, rol0_.ROLS_DENOMINACIO as rols_den3_12_0_ from GITTBROLS rol0_ where rol0_.ROLS_ID=@P1]: could not load an entity: [cat.gencat.clt.git.backend.model.persistency.Rol#1]



java.util.concurrent.CompletionException: java.lang.IllegalStateException: Session/EntityManager is closed

I'm reaching my code:

@RestController
@RequestMapping(value = "/qdcf")
@RequiredArgsConstructor
@Timed
public class QdCFController {

    private final QdCFService qdcfService;
    private final UsuariRepository usuariRepository;

    @GetMapping("/user")
    public Mono<Usuari> user() {
        return this.usuariRepository.findOne(UsuariSpecs.hasCodi("11111111A"));
    }
}

How could I keep session opened per thread?

CodePudding user response：

The error happens because the app is trying to load the entity Rol. You are not showing the association with Rol in the question but I assume it's a lazy association.

Hibernate Reactive doesn't load lazy associations on demand like Hibernate ORM. If that's the case, you have two options:

Load the association eagerly with a fetch join in the criteria

Fetch the roles when you have the result. Assuming the association is called roles, it should look something like:

return this.sessionFactory
          .withSession(session -> session
              .createQuery(criteriaQuery).getSingleResultOrNull()
              .onItem().ifNotNull().call( result -> Mutiny.fetch(result.getRoles()) )
          )
          .convert().with(UniReactorConverters.toMono());

I would need to see the mapping of all the entities involved to help you more