Criteria query with JoinType LEFT

MessageRepository.java

List<Message> getAllBy() {
  CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
  
  CriteriaQuery<Message> query = criteriaBuilder.createQuery(Message.class);
  Root<Message> message = query.from(Message.class);
  // Add fetching of the author field
  message.fetch(Message_.author, JoinType.LEFT);
  query.select(message);
  
  TypedQuery<Message> typedQuery = entityManager.createQuery(query);
  return typedQuery.getResultList();
}