gistfile1.java

/* what I would like to achieve: */
public interface ItemRepository<T> { 
      @Query("select distinct a from " + TABLE_NAME + " a " + "join ti.tags tt where tt = ?1") 
      public List<T> findByTag(Tag t); }
}

public interface AaaaRepository extends ItemRepository<Aaaa> {
      TABLE_NAME = "Aaaa";
}



/* what we have: */
public interface ItemRepository<T extends Item> extends BaseRepository<T> {

    final static String DISTINCT_ITEM = "select distinct ti from ";

    final static String BY_TAG = "join ti.tags tt where tt = ?1";

    public List<T> findByTag(Tag tag);

}



public interface AaaaRepository extends ItemRepository<Event> {

    final static String ITEM = "Aaaa";



    @Override
    @Query(DISTINCT_ITEM + ITEM + BY_TAG)
    public List<Aaaaa> findByTag(Tag tag); // duplicate
}



public interface BbbbRepository extends ItemRepository<Event> {

    final static String ITEM = "Bbbb";



    @Override
    @Query(DISTINCT_ITEM + ITEM + BY_TAG)
    public List<Bbbb> findByTag(Tag tag); // duplicate
}