OptionalUtil.ofNullable(user.getTelephoneNumber())
                .filter(StringUtil::isNotBlank)
                .ifPresent(s -> entry.put(new BasicAttribute(fessConfig.getLdapAttrTelephoneNumber(), s)));
        OptionalUtil.ofNullable(user.getHomePhone())
                .filter(StringUtil::isNotBlank)
                .ifPresent(s -> entry.put(new BasicAttribute(fessConfig.getLdapAttrHomePhone(), s)));