OnJava8-Examples/strings/ThreatAnalyzer.java

// strings/ThreatAnalyzer.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
import java.util.regex.*;
import java.util.*;

public class ThreatAnalyzer {
  static String threatData =
    "58.27.82.161@08/10/2015\n" +
    "204.45.234.40@08/11/2015\n" +
    "58.27.82.161@08/11/2015\n" +
    "58.27.82.161@08/12/2015\n" +
    "58.27.82.161@08/12/2015\n" +
    "[Next log section with different data format]";
  public static void main(String[] args) {
    Scanner scanner = new Scanner(threatData);
    String pattern = "(\\d+[.]\\d+[.]\\d+[.]\\d+)@" +
      "(\\d{2}/\\d{2}/\\d{4})";
    while(scanner.hasNext(pattern)) {
      scanner.next(pattern);
      MatchResult match = scanner.match();
      String ip = match.group(1);
      String date = match.group(2);
      System.out.format(
        "Threat on %s from %s%n", date,ip);
    }
  }
}
/* Output:
Threat on 08/10/2015 from 58.27.82.161
Threat on 08/11/2015 from 204.45.234.40
Threat on 08/11/2015 from 58.27.82.161
Threat on 08/12/2015 from 58.27.82.161
Threat on 08/12/2015 from 58.27.82.161
*/