Java IP Address Get getExternalIp()

Description

get External Ip

License

Open Source License

Declaration

public static InetAddress getExternalIp() throws SocketException 

Method Source Code

//package com.java2s;
/*//ww w .  j  a va 2 s  . c  o m
 * Copyright (c) 2011 - 2012. Elega9t Ltd. All rights reserved.
 * ELEGA9T PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.Copyright (c) 2011 - 2012. Elega9t Ltd. All rights reserved.
 */

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.regex.Pattern;
import static java.net.NetworkInterface.getNetworkInterfaces;

public class Main {
    private static String EXTERNAL_IP_REGEX = "^([0-9]{1,3})\\.([0-9]{1,3})\\.([0-9]{1,3})\\.([0-9]{1,3})$";

    public static InetAddress getExternalIp() throws SocketException {
        List<InetAddress> localInetAddresses = getLocalInetAddresses();
        Pattern pattern = Pattern.compile(EXTERNAL_IP_REGEX);
        for (InetAddress localInetAddress : localInetAddresses) {
            String hostAddress = localInetAddress.getHostAddress();
            if (!hostAddress.startsWith("127.") && pattern.matcher(hostAddress).matches()) {
                return localInetAddress;
            }
        }
        return null;
    }

    public static List<InetAddress> getLocalInetAddresses() throws SocketException {
        List<InetAddress> addrList = new ArrayList<InetAddress>();
        Enumeration<NetworkInterface> networkInterfaces = getNetworkInterfaces();
        while (networkInterfaces.hasMoreElements()) {
            NetworkInterface ifc = networkInterfaces.nextElement();
            if (ifc.isUp()) {
                Enumeration<InetAddress> inetAddresses = ifc.getInetAddresses();
                while (inetAddresses.hasMoreElements()) {
                    InetAddress addr = inetAddresses.nextElement();
                    addrList.add(addr);
                }
            }
        }
        return addrList;
    }
}

Related

1. getAllLocalIPs()
2. getAllLocalIpv4Addresses()
3. getAllMyHostIPV4Adresses()
4. getAllUsableIPAddresses()
5. getExternalIP()
6. getExternalIp()
7. getExternalIp()
8. getExternalIP(String host, String regexPattern)
9. getExternalIPAddress()