public static Integer getPort(String address) {
        Matcher matcher = HOST_PORT_PATTERN.matcher(address);
        return matcher.matches() ? Integer.parseInt(matcher.group(2)) : null;
    }
Extracts the port number from a "host:port" address string.
@param address address string to parse
@return port number or null if the given address is incorrect
clients/src/main/java/org/apache/kafka/common/utils/Utils.java