apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/spi/springsecurity/SpringSecurityUserService.java/SpringSecurityUserService/findByUserIds
class SpringSecurityUserService:  @Override
  public List<UserInfo> findByUserIds(List<String> userIds) {
    List<UserPO> users = userRepository.findByUsernameIn(userIds);

    if (CollectionUtils.isEmpty(users)) {
      return Collections.emptyList();
    }

    return users.stream().map(UserPO::toUserInfo).collect(Collectors.toList());
  }