ElementCollection with nested Embeddable

Trying to find out if what I’m doing is legal according to spec or some sort of bug.

I’m using Quarkus 2.13.3 and Hibernate 5.6.12 via quarkus-hibernate-orm extension.

This class hierarchy fails:

public class Foo implements Serializable {

    String id;

    Set<Bar> bars;
public class Bar {

    Baz baz;
class Baz {

    String property;

I get the error:

2022-10-25 16:01:06,124 ERROR [io.qua.run.Application] (Quarkus Main Thread) Failed to start application (with profile dev): java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0
	at org.hibernate.persister.collection.AbstractCollectionPersister.generateSelectSizeString(AbstractCollectionPersister.java:1048)
	at org.hibernate.persister.collection.AbstractCollectionPersister.<init>(AbstractCollectionPersister.java:522)
	at org.hibernate.persister.collection.BasicCollectionPersister.<init>(BasicCollectionPersister.java:59)
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499)
	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:480)
	at org.hibernate.persister.internal.PersisterFactoryImpl.createCollectionPersister(PersisterFactoryImpl.java:152)
	at org.hibernate.persister.internal.PersisterFactoryImpl.createCollectionPersister(PersisterFactoryImpl.java:140)
	at org.hibernate.metamodel.internal.MetamodelImpl.initialize(MetamodelImpl.java:226)
	at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:319)
	at io.quarkus.hibernate.orm.runtime.boot.FastBootEntityManagerFactoryBuilder.build(FastBootEntityManagerFactoryBuilder.java:74)
	at io.quarkus.hibernate.orm.runtime.FastBootHibernatePersistenceProvider.createEntityManagerFactory(FastBootHibernatePersistenceProvider.java:72)
	at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:80)
	at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:55)
	at io.quarkus.hibernate.orm.runtime.JPAConfig$LazyPersistenceUnit.get(JPAConfig.java:165)
	at io.quarkus.hibernate.orm.runtime.JPAConfig$1.run(JPAConfig.java:66)
	at java.base/java.lang.Thread.run(Thread.java:833)

I don’t know if it helps but earlier in the process there’s this:

2022-10-25 16:01:05,544 DEBUG [org.hib.cfg.CollectionSecondPass] (Quarkus Main Thread) Second pass for collection: com.example.Foo.bars
2022-10-25 16:01:05,544 DEBUG [org.hib.cfg.ann.CollectionBinder] (Quarkus Main Thread) Binding a collection of element: com.example.Foo.bars
2022-10-25 16:01:05,547 DEBUG [org.hib.cfg.Ejb3Column] (Quarkus Main Thread) Binding column: Ejb3Column{table=org.hibernate.mapping.Table(Foo_bars), mappingColumn=baz, insertable=true, updatable=true, unique=false}
2022-10-25 16:01:05,547 DEBUG [org.hib.cfg.ann.PropertyBinder] (Quarkus Main Thread) Building property baz
2022-10-25 16:01:05,548 DEBUG [org.hib.map.PrimaryKey] (Quarkus Main Thread) Forcing column [foo_id] to be non-null as it is part of the primary key for table [foo_bars]
2022-10-25 16:01:05,548 DEBUG [org.hib.cfg.CollectionSecondPass] (Quarkus Main Thread) Mapped collection key: Foo_id, element: 

If try to embed a single Bar (and Baz…) into Foo directly, it works fine, I end up with a column “property” in the foo table, so nested Embeddables work there.
If I try to embed a Set of Baz (which just has basic fields), it works fine.

What isn’t working is an ElementCollection of Embeddable that has any Embedded properties. Is it supposed to?

On logicbig (JPA + Hibernate - Persisting Collections of embeddable type by using @ElementCollection), it implies it should, but I haven’t really found anything else saying yes or no:

Note that all cases of @Embeddable class are applied here: we can use an embeddable class within another one, the embeddable can have entity relationship and/or we can also use multiple instances of same embeddable type collection in our entity.

As far as I can tell from the JPA spec section 2.6, this should be legal. So please create a bug report in the Hibernate issue tracker for this.

Thanks, for looking into it a little bit. I created [HHH-15630] - Hibernate JIRA.

1 Like

I looked over the hibernate-test-case-templates and I checked that out and just made a simple test that will throw the exception to show the problem. I also found The best way to write a Hibernate ORM issue test case - In Relation To where Vlad recommends making a pull request directly into hibernate-orm. Is there a preferred method?

Yes, that is the preferred method :slight_smile: