public static String buildUrl(final String host, final Integer port) {
        return Optional.of(String.join(":", host, String.valueOf(port))).orElse(null);
    }
Build url string.

@param host the host
@param port the port
@return the string
shenyu-admin/src/main/java/org/apache/shenyu/admin/utils/CommonUpstreamUtils.java