An EJB3QL query queries can return tuples of objects if projection is used. Each result tuple is returned as an object array:

Iterator kittensAndMothers = sess.createQuery(
            "select kitten, mother from Cat kitten join kitten.mother mother")
            .getResultList()
            .iterator();

while ( kittensAndMothers.hasNext() ) {
    Object[] tuple = (Object[]) kittensAndMothers.next();
    Cat kitten  = tuple[0];
    Cat mother  = tuple[1];
    ....
}