Check if network interface is up in Java

import java.net.NetworkInterface;
import java.util.Enumeration;
/*  www. java2  s .c  om*/
public class Main {
  public static void main(String[] args) throws Exception {
    Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces();
    while (en.hasMoreElements()) {
      NetworkInterface ni = en.nextElement();
      System.out.println(" Is up = " + ni.isUp());
    }
  }
}