org.hibernate.AnnotationException: @OneToOne or @ManyToOne on xxx references an unknown entity: xxx

Context :

During the process of converting the old hibernate xml heavy structure to the new annotation based structure, the following error was encountered after annotating one of the entity files…

org.hibernate.AnnotationException: @OneToOne or @ManyToOne on com.project.entityone.model.EntityOne.addedBy references an unknown entity: com.project.entitytwo.model.EntityTwo

… seemed like new annnotated entity was not being recognised by hibernate !

Solution :

1) Ensure that the entity has been appropriately referenced in hibernate.cfg.xml

ie

<hibernate-configuration>
    <session-factory>
        ...
        <mapping class="com.project.entitytwo.model.EntityTwo"/>
        ...
    </session-factory>
</hibernate-configuration>

2) Ensure that @Entity has been specified at the class-level ( at the top of the class )

ie.

@Entity
@Table( name="ENTITY_TWO" )
public class EntityTwo extends AbstractPersistanceClass
{
    ...

Wa Allahu ‘Alam