java - How to filter IP from log file in another Rdd -

i fetching ip access log file,tried using pattern not getting correct output.

public class ipcount {     public static void main(string[] args) {      string ipaddress_pattern = "(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)";     pattern pattern = pattern.compile(ipaddress_pattern);     matcher matcher = pattern.matcher(t);      javasparkcontext sc = new javasparkcontext("local", "ipcount");     @suppresswarnings({ "unused", "serial" })     javardd<string> lines = sc.textfile("/home/bhaumik/documents/access_log", 5)             .flatmap(new flatmapfunction<string, string>() {                  @override                 public iterable<string> call(string t) throws exception {                     // todo auto-generated method stub                     return null; //here should can ip filter log file.                 }             });     } } 

here's java method extracting ips javardd<string>, assuming each line might contain zero, one, or more ips:

public javardd<string> getips(javardd<string> rdd) {     final string ipaddress_pattern = "(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)";     final pattern pattern = pattern.compile(ipaddress_pattern);      return rdd.flatmap(new flatmapfunction<string, string>() {         @override         public iterable<string> call(string t) throws exception {             final matcher matcher = pattern.matcher(t);             final linkedlist<string> matches = new linkedlist<>();             while (matcher.find()) {                 matches.add(matcher.group());             }             return matches;         }     }); }