hibernateblaze-persistence

Collection type re-mapping with Blaze Persistence

I'm using the Entity View Module of Blaze Persistence for mapping the following Hibernate entities to DTOs.

@Entity
@Table(name = "configuration")
public class ConfigurationEntity {

  @Id
  private UUID institution;

  @OneToMany(mappedBy = "configuration", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
  private List<DescriptionEntity> descriptions;
}

@Entity
@Table(name = "description")
public class DescriptionEntity {
  @EmbeddedId
  private Identifier identifier;

  private String name;

  @ManyToOne(fetch = FetchType.LAZY)
  @MapsId("identifier_institution")
  @JoinColumn(name = "identifier_institution")
  private InstitutionConfigurationEntity configuration;
}

@Embeddable
public class Identifier implements Serializable {

  private UUID institution;
  private String language;
}

Using an entity view where all child entities are stored as a list works without problems. However, instead I want to create a Map<String, DescriptionView> where the key refers to DescriptionEntity.Identifier.language and values are views of DescriptionEntity.

According to documentation (https://persistence.blazebit.com/documentation/1.5/entity-view/manual/en_US/#collection-type-re-mapping) the @MappingIndex should be used for that. But even for the simplified case when using DescriptionEntity.name instead of the composite key, the library always throws java.lang.IllegalArgumentException: Attribute 'name' not found on type 'ConfigurationEntity'.

@EntityView(ConfigurationEntity.class)
public interface InstitutionView {
  @IdMapping(value = "institution")
  UUID getIdentifier();

  List<DescriptionView> getDescriptions(); // this works

  @MappingIndex("name") // Attribute 'name' not found on type 'ConfigurationEntity'
  Map<String, DescriptionView> getDescriptions(); // this doesn't
}

I'm having a hard time understanding why blaze would think the name attribute would be in ConfigurationEntity instead of DescriptionEntity. This has led me to believe that the entity relations are not defined properly, but I have reviewed them over and over again and couldn't find anything (I'm using hibernate-orm.implicit-naming-strategy=component-path by the way, meaning that the composite key columns are named identifier_institution and identifier_language).

I would be glad for any recommendations on how to solve this!

Solution

  • I believe this is a bug in the type validation code related to the fact that your one-to-many mapping uses mappedBy. I think it tries to find the attribute for the mapping index in the type that the mappedBy path refers to, which is ConfigurationEntity, but the resulting query would still be correct.

    I just ran a quick test and was able to reproduce your issue, and now also created a GitHub issue for this: https://github.com/Blazebit/blaze-persistence/issues/1695

    You have two ways to workaround this until this bug is fixed: