java获取本地外网ip

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

public class Listip {


// public static void main(String[] args) {
//  // TODO Auto-generated method stub 
//  System.out.println("本机的外网IP是："+Listip.getWebIp("http://www.ip138.com/ip2city.asp"));
// }

public static String getWebIp(String strUrl) {
  try {

   URL url = new URL(strUrl);

   BufferedReader br = new BufferedReader(new InputStreamReader(url

   .openStream()));

   String s = "";

   StringBuffer sb = new StringBuffer("");
  
   String webContent = "";

   while ((s = br.readLine()) != null) {
    sb.append(s + "\r\n");

   }

   br.close();
   webContent = sb.toString();
   int start = webContent.indexOf("[")+1;
   int end = webContent.indexOf("]");
   webContent = webContent.substring(start,end);
  
   return webContent;

  } catch (Exception e) {
   e.printStackTrace();
   return "error open url:" + strUrl;

  }
}
}