得到一个回圈NIF。

/** 
来 自 
时   代    Java - nowjava.com
**/


//package com.nowjava;

import java.net.NetworkInterface;

import java.net.SocketException;

import java.util.Enumeration;


public class Main {

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

        System.out.println(getLoopbackNIF());

    }


    /**

     * Get a loopback NIF.

     * @return a loopback NIF, <code>null</code> if not found.

     */

    // TODO support case with multiple loopback NIFs

    public static NetworkInterface getLoopbackNIF() {/*来自 nowjava*/


        Enumeration<NetworkInterface> nets;

        try {

            nets = NetworkInterface.getNetworkInterfaces();

        } catch (SocketException se) {

            return null;

        }


        while (nets.hasMoreElements()) {

            NetworkInterface net = nets.nextElement();

            try {

                if (net.isUp() && net.isLoopback())

                    return net;

            } catch