How to get computer's WAN IP address in Java?

Question

How do i get the Wide Area Network of my computer with Java? I try with this:

ServerSocket ss = new ServerSocket(port);
System.out.println(ss.getInetAddress().getHostAddress());
//wich return 0.0.0.0

then i try with this:

System.out.println(InetAddress.getLocalHost().toString());
//which return keenan-a658368c/192.168.1.100 < yes it is connected to router

like the function said, it return my local IP address

How do i get the WAN IP Address? such as 118.137.43.219

Answer 1

You can get it from http://whatismyip.com/automation/n09230945.asp. You can open an HttpURLConnection to this site and parse output.

This Program should be helpful :

import java.net.HttpURLConnection;

public class GetExternalIp {

    public static void main(String args[]) {
        try {

            java.net.URL url = new java.net.URL(
                    "http://whatismyip.com/automation/n09230945.asp");

            java.net.HttpURLConnection con = (HttpURLConnection) url
                    .openConnection();

            java.io.InputStream stream = con.getInputStream();

            java.io.InputStreamReader reader = new java.io.InputStreamReader(
                    stream);

            java.io.BufferedReader bReader = new java.io.BufferedReader(reader);

            System.out.print("Your IP address is " + bReader.readLine());

        } catch (Exception e) {
            e.printStackTrace();
        }

    }

}

Referenced from :

http://www.daniweb.com/forums/thread192872.html

http://www.coderanch.com/t/411356/java/java/Public-IP-Address-time-limit