Get real network interface IP-address use JAVA

/* getIPx.java get ethernet ip address */

import java.net.*;
import java.util.*;

public class getIPx {

public static void main(String args[]) throws Exception {

String niname ;
InetAddress ia[] = null ;
String ip = null ;
NetworkInterface ni = null ;
Enumeration e = (Enumeration) ni.getNetworkInterfaces();
ni = (NetworkInterface) e.nextElement() ;
niname = (String) ni.getName();
if (niname!="eth0") {
ni = (NetworkInterface) e.nextElement() ;
niname = (String) ni.getName();
}
System.out.println(niname );
Enumeration e2 = (Enumeration) ni.getInetAddresses(); // get All ipaddresses
/*while (e2.hasMoreElements()) { // if more then one address need do loop
ia[0] = (InetAddress) e2.nextElement();
ip = ia[0].getHostAddress();
} */
System.out.println(e2.nextElement());
} //end of main
} // end of class