JpaRelationDao.java 文件源码

private Specification<RelationEntity> getEntityFieldsSpec(EntityId from, String relationType,
    RelationTypeGroup typeGroup, ThingType childType) {
  return new Specification<RelationEntity>() {
    @Override
    public Predicate toPredicate(Root<RelationEntity> root, CriteriaQuery<?> criteriaQuery,
        CriteriaBuilder criteriaBuilder) {
      List<Predicate> predicates = new ArrayList<>();
      if (from != null) {
        Predicate fromIdPredicate = criteriaBuilder.equal(root.get("fromId"),
            UUIDConverter.fromTimeUUID(from.getId()));
        predicates.add(fromIdPredicate);
        Predicate fromEntityTypePredicate = criteriaBuilder.equal(root.get("fromType"), from.getEntityType().name());
        predicates.add(fromEntityTypePredicate);
      }
      if (relationType != null) {
        Predicate relationTypePredicate = criteriaBuilder.equal(root.get("relationType"), relationType);
        predicates.add(relationTypePredicate);
      }
      if (typeGroup != null) {
        Predicate typeGroupPredicate = criteriaBuilder.equal(root.get("relationTypeGroup"), typeGroup.name());
        predicates.add(typeGroupPredicate);
      }
      if (childType != null) {
        Predicate childTypePredicate = criteriaBuilder.equal(root.get("toType"), childType.name());
        predicates.add(childTypePredicate);
      }
      return criteriaBuilder.and(predicates.toArray(new Predicate[0]));
    }
  };
}