Date start = new Date();
try {
FileInputStream fin = new FileInputStream(args[0]);
Reader in = new InputStreamReader(fin);
SafeBufferedReader bin = new SafeBufferedReader(in);
String entry = null;
while ((entry = bin.readLine()) != null) {
// separate out the IP address
int index = entry.indexOf(' ", 0);
String ip = entry.substring(0, index);
String theRest = entry.substring(index, entry.length());
// find the hostname and print it out
try {
InetAddress address = InetAddress.getByName(ip);
System.out.println(address.getHostName() + theRest);
}
catch (UnknownHostException ex) {
System.out.println(entry);
}
} // end while
}
catch (IOException ex) {
System.out.println("Exception: " + ex);
}
Date end = new Date();
long elapsedTime = (end.getTime()-start.getTime())/1000;
System.out.println("Elapsed time: " + elapsedTime + " seconds");
