question: public static Collection < InetAddress > toInetAddresses ( Collection < String > addrs , Collection < String > hostNames ) throws IgniteCheckedException { Set < InetAddress > res = new HashSet < > ( addrs . size ( ) ) ; Iterator < String > hostNamesIt = hostNames . iterator ( ) ; for ( String addr : addrs ) { String hostName = hostNamesIt . hasNext ( ) ? hostNamesIt . next ( ) : null ; InetAddress inetAddr = null ; if ( ! F . isEmpty ( hostName ) ) { try { inetAddr = InetAddress . getByName ( hostName ) ; } catch ( UnknownHostException ignored ) { } } if ( inetAddr == null || inetAddr . isLoopbackAddress ( ) ) { try { inetAddr = InetAddress . getByName ( addr ) ; } catch ( UnknownHostException ignored ) { } } if ( inetAddr != null ) res . add ( inetAddr ) ; } if ( res . isEmpty ( ) ) throw new IgniteCheckedException ( "Addresses can not be resolved [addr=" + addrs + ", hostNames=" + hostNames + ']' ) ; return res ; }
target:  Returns tha list of resolved inet addresses. First addresses are resolved by host names, if this attempt fails then the addresses are resolved by ip addresses.