Hey people, i have a the following map* which is giving me lots of trouble:
Map<MetricSourceInterface, AliasesInterface>
MetricSourceInterface is an entity with simple properties. AliasesInterface is an entity with only an Id and a list of strings.
Hibernate is creating the database schema so theres no problem with changing it whatsoever.
On a side-note, this is a sub problem from trying to map:
Map<MetricSourceInterface, List<String>>
Does anyone know the proper way to solve this?
Theres only one limitation for this, i dont want to create an UserType for AliasesInterface or List
Thx in advance :)
*edited with pstanton's correction :)
As long as AliasesInterface is indeed an entity in Hibernate sense, there's really no problem with mapping this:
@OneToMany(targetEntity=AliasInterface.class)
@MapKeyManyToMany(targetEntity=MetricSourceInterface.class, joinColumns=@JoinColumn(name="metric_source_id"))
private Map<MetricSourceInterface, AliasesInterface> myMap;
Note that the above assumes that both AliasInterface and MetricSourceInterface are entities; if they are indeed interfaces you'll need to refer to their concrete implementations instead.
Keep in mind that @MapKeyManyToMany is Hibernate extesion to JPA. More details / examples on mapping collections are in Hibernate docs.
Update: The same approach using XML mapping files:
<map name="myMap">
<key column="owner_id"/> <!-- FK to owner entity table -->
<map-key-many-to-many column="metric_source_id" class="MetricSourceInterface"/>
<one-to-many class="AliasesInterface"/>
</map>
There are more details here and other examples here.