java获取服务器真实外网IP

package com.xiaoma.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import java.net.URL;
import java.net.URLConnection;

import org.jsoup.Connection;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Element;
import org.junit.Test;

public class GetPublicIP {

public GetPublicIP(){}

public static String getPublicIp(){
//此方法需要引入Jsoup.jar包
//您的IP是：[218.18.123.160] 来自：广东省深圳市 电信
String ip="";
org.jsoup.nodes.Document doc = null;
Connection con = null;
con = Jsoup.connect("http://20140507.ip138.com/ic.asp").timeout(10000);

try {
doc = con.get();
//获取包含本机ip的文本串
org.jsoup.select.Elements els = doc.body().select("center");
for(Element el:els){
ip=el.text();
}
//ip = ip.replaceAll("[^0-9.]", "");

} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return ip;
}

return ip;
}

public static String getPublicIp2() throws IOException{
//218.18.123.160
String ip="";
URL url = new URL("http://20140507.ip138.com/ic.asp");
URLConnection conn = url.openConnection();
conn.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.15) Gecko/20110303 Firefox/3.6.15");
conn.setRequestProperty("Content-Type", "text/html");
conn.setRequestProperty("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
InputStream is = conn.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(is, "GB2312"));
String line = null;
while ((line = br.readLine()) != null) {
if (line.contains("您的IP是")) {
// System.out.println(line);
int start = line.indexOf('[') + 1;
int end = line.indexOf(']');
ip = line.substring(start, end);
}
}
br.close();
return ip;
}
@Test
public void testsss() throws IOException{

System.out.println(GetPublicIP.getPublicIp());
System.out.println(GetPublicIP.getPublicIp2());
}

}