Java regex for accepting a valid hostname,IPv4, or IPv6 address
Anyone have a good (preferably tested) regex for accpeting only a valid DNS hostname, IPv4 or IPv6 address? I understand that you may be forced to use a regex. However, if possible it is better to avoid using regexes for this task and use a Java library class to do the validation instead. If you want to do validation and DNS lookup together, then InetAddress.getByName(String) is a good choice. This will cope with DNS, IPv4 and IPv6 in one go, and it returns you a neatly wrapped InetAddress instance that contains both the DNS name (if provided) and the IPv4 or IPv6 address. If you just want to