[Hibernate Search] - Projections in a ManyToOne relation

wrondon · **Posted:** Mon Oct 11, 2010 11:54 pm

Good evening Srs!,

In short, I have this Entities:

PRODUCT

Code:

@Entity
@Indexed 
public class Product {
    @Id
    @DocumentId 
    private Long id;

    @ManyToOne
    @JoinColumn(name="idStore")
    @Field(store=Store.YES,index=Index.UN_TOKENIZED)
    @FieldBridge(impl=BridgeStore.class)
    private Store store;
    //getters and setters
}

STORE

Code:

@Entity
public class Store {
    @Id
    Long idStore;
    String nameStore;
    //getters and setters
}

BRIDGE STORE

Code:

public class BridgeStore implements FieldBridge {
    @Override
    public void set(String name, Object oStore, Document document, LuceneOptions luceneOptions) {
        Store store = (Store) oStore;
        luceneOptions.addFieldToDocument("idStore",store.getIdStore().toString(),document);
        luceneOptions.addFieldToDocument("nameStore",store.getNameStore().toString(),document);
    }

}

And this is my FullTextQuery:

Code:

    FullTextQuery query = fullTextSession.createFullTextQuery(luceneQuery, Product.class); 
    query.setProjection("id", "nameStore"); //I already tried "store.nameStore"

id: That's ok!
nameStore: Always null

I tried implement TwoWayStringBridge, but did not work.

Am I doing something wrong?

Thank you very much.

Att,
Rondon

wrondon · **Posted:** Tue Oct 12, 2010 1:20 pm

Hey guys, I got it!

Instead of use "@Field & @FieldBridge" at the "Store store" attribute, I just put "@IndexedEmbedded" and, in the Store entity, I mapped with "@Field" the "idStore" and "nameStore".

Thanks anyway!

Regards,
Wrondon

sanne.grinovero · **Posted:** Tue Oct 12, 2010 1:42 pm

Hi Wrondon,
yes using IndexedEmbedded seems a better fit for your problem; still to clarify the original issue:
Projection is meant to convert the document fields back in their object form, so to "restore" Store you would need a TwoWayStringBridge and you wouldn't return the properties but the Store sa a single object.

To just return the values from the index, i.e. reading the "idStore" and "nameStore" you defined in your bridge, you could use

Code:

.setProjection(ProjectionConstants.DOCUMENT);

so that the results return Lucene's Document, this has an API similar to a Map and contains the values for both idStore and nameStore.

Cheers,

wrondon · **Posted:** Wed Oct 13, 2010 12:17 pm

Hi Grinovero!

Thank you very much for the reply!

Best Regards