import java.net.*; import java.io.*; class weblog { public static void main(String args[]) { String thisLine; String thisIP; String theRest; int index; InetAddress thisAddress; byte[] address; try { FileInputStream fin = new FileInputStream(args[0]); DataInputStream myInput = new DataInputStream(fin); while ((thisLine = myInput.readLine()) != null) { index = thisLine.indexOf(" ", 0); thisIP = thisLine.substring(0, index); theRest = thisLine.substring(index, thisLine.length()); try { thisAddress = InetAddress.getByName(thisIP); address = thisAddress.getAddress(); System.out.println(InetAddressFactory.newInetAddress(address).getHostName() + theRest); } catch (UnknownHostException e) { System.out.println(thisLine); } } // while loop ends here } catch (IOException e) { System.out.println("Exception: " + e); } } // end main }