@Override
    public List<ResourceVO> findByParentId(final String id) {
        return resourceMapper.selectByParentId(id)
                .stream()
                .filter(item -> item.getResourceType().equals(AdminResourceEnum.THREE_MENU.getCode()))
                .map(ResourceVO::buildResourceVO)
                .collect(Collectors.toList());
    }
get button by parent id.

@param id resource id
@return {@linkplain List}
shenyu-admin/src/main/java/org/apache/shenyu/admin/service/impl/ResourceServiceImpl.java