Spring Data REST now exposes an EntityLookup interface that allows to customize the property of an entity that shall be used to create item resource URIs. By default this mechanism uses the backend identifier and uses the repository's findOne(…) method.
The EntityLookup now exposes one method to return the property value to be used for URI generation as well as one method to obtain the entity instance from the very same raw identifier value. The EntityLookups are registered with both the SelfLinkProvider (for link creation) and the RepositoryInvoker (to obtain the entity instance).
