Convert a String to InetAddress without DNS lookup

Question

I have a local IP address in dotted decimal notation in a String. I want to convert it to an InetAddress to feed it to Socket, but I need to do it without doing a DNS lookup (because this might cause lengthy timeouts).

Is there a ready method for that, or do I need to split the String and create the InetAddress from its bytes?

Update The factory methods InetAddress.getByName() and InetAddress.getByAddress() don't seem to be a good fit, as they both also accept hostnames such as java.sun.com. There is no saying if they will try to contact a DNS server in their implementation.

Answer 1

Do like this

InetAddress inetAddress = InetAddress.getByName("192.168.0.105"); 

If a literal IP address is supplied, only the validity of the address format is checked.

java source code

// if host is an IP address, we won't do further lookup     if (Character.digit(host.charAt(0), 16) != -1 || (host.charAt(0) == ':')) {  } 

Answer 2

You can use Guava's InetAddresses#forString() which is specifically documented for your use case:

Returns the InetAddress having the given string representation.
This deliberately avoids all nameservice lookups (e.g. no DNS).

(emphasis added)