Search code examples
javaspringhibernatejpahibernate-mapping

JPA OneToOne relationships returning null

I have this class

public class Hotel implements Serializable {


    @OneToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "FILE_ID")
    private File file;

..
}

and this query

Query query = em.createQuery("SELECT file.hotel FROM File file   where file.id = :id ");

and I would like to know if it is possible to return an empty Hotel object instead of null if the hotel does not exists in the relationship but the file exists

Solution

  • Since you're using JPA, you could make use of a repository. JPA can automatically return a type of Optional<>. Via Optional.isPresent() you can check if the query returned something.

    A repository could look like this:

    public interface FileRepository extends JpaRepository<File, Long> {
    Optional<File> findById(Long id);

}