apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/spi/ldap/LdapUserService.java/LdapUserService/lookupUser
class LdapUserService:  private UserInfo lookupUser(String member, List<String> userIds) {
    return ldapTemplate.lookup(member, (AttributesMapper<UserInfo>) attributes -> {
      UserInfo tmp = new UserInfo();
      Attribute emailAttribute = attributes.get(emailAttrName);
      if (emailAttribute != null && emailAttribute.get() != null) {
        tmp.setEmail(emailAttribute.get().toString());
      }
      Attribute loginIdAttribute = attributes.get(loginIdAttrName);
      if (loginIdAttribute != null && loginIdAttribute.get() != null) {
        tmp.setUserId(loginIdAttribute.get().toString());
      }
      Attribute userDisplayNameAttribute = attributes.get(userDisplayNameAttrName);
      if (userDisplayNameAttribute != null && userDisplayNameAttribute.get() != null) {
        tmp.setName(userDisplayNameAttribute.get().toString());
      }

      if (userIds != null) {
        if (userIds.stream().anyMatch(c -> c.equals(tmp.getUserId()))) {
          return tmp;
        }
        return null;
      }
      return tmp;

    });
  }