import java.net.Inet6Address;
import java.net.InetAddress;

public class IPv6Test {

   public static void main(String[] arg) {
      try {
         InetAddress[] addr = InetAddress.getAllByName("josm.openstreetmap.de");
         for(int i = 0; i < addr.length; ++i) {
            InetAddress ip = addr[i];
            System.out.println("Test " + ip);
            if(ip instanceof Inet6Address && ip.isReachable(1000)) {
               System.out.println("IPV6 ok " + ip);
            }
         }
      } catch (Exception e) {
         e.printStackTrace();
      }
   }
}