public static String toURL(String protocol, String host, int port, String path) {
        StringBuilder sb = new StringBuilder();
        sb.append(protocol).append("://");
        sb.append(host).append(':').append(port);
        if (path.charAt(0) != '/')
            sb.append('/');
        sb.append(path);
        return sb.toString();
    }
@param hostName
@return ip address or hostName if UnknownHostException
lts-core/src/main/java/com/github/ltsopensource/core/commons/utils/NetUtils.java