Get external IP address.

NetUtils.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;

public class NetUtils {

  public static String getExternalIpAddress() throws IOException {
		URL whatismyip = new URL("http://checkip.amazonaws.com/");
		BufferedReader in = new BufferedReader(new InputStreamReader(
				whatismyip.openStream()));
		String ip = in.readLine(); // you get the IP as a String
		in.close();
		return ip;
	}

}