JAVA Physical Address가져오기

import java.io.*;
import java.net.*;
import java.util.*;
import java.util.regex.*;

public class GetMac {
public static void main(String[] args) throws IOException {
  String address = new GetMac().getMacAddress();
  System.out.println(address);
}

public String getMacAddress() throws IOException {
  String macAddress = null;
  String command = "ipconfig /all";
  Process pid = Runtime.getRuntime().exec(command);
  BufferedReader in = new BufferedReader(new InputStreamReader(pid.getInputStream()));
  while (true) {
      String line = in.readLine();
      if (line == null)
      break;
     
      Pattern p = Pattern.compile(".*Physical Address.*: (.*)");
      Matcher m = p.matcher(line);
      if (m.matches()) {
          macAddress = m.group(1);
          break;
      }
  }
  in.close();
  return macAddress;
  }
}