Android正确获取外网ip的方法。

public static String GetNetIp() {
    String IP = "";
    try {
        String address = "http://ip.taobao.com/service/getIpInfo2.php?ip=myip";
        URL url = new URL(address);

      //  URLConnection htpurl=url.openConnection();

        HttpURLConnection connection = (HttpURLConnection) url
                .openConnection();
        connection.setUseCaches(false);
        connection.setRequestMethod("GET");
        connection.setRequestProperty("user-agent",
                "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.7 Safari/537.36"); //设置浏览器ua 保证不出现503

        if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
            InputStream in = connection.getInputStream();

            // 将流转化为字符串
            BufferedReader reader = new BufferedReader(
                    new InputStreamReader(in));

            String tmpString = "";
            StringBuilder retJSON = new StringBuilder();
            while ((tmpString = reader.readLine()) != null) {
                retJSON.append(tmpString + "\n");
            }

            JSONObject jsonObject = new JSONObject(retJSON.toString());
            String code = jsonObject.getString("code");

            LogUtil.e("提示：" +retJSON.toString());
            if (code.equals("0")) {
                JSONObject data = jsonObject.getJSONObject("data");
                IP = data.getString("ip") + "(" + data.getString("country")
                        + data.getString("area") + "区"
                        + data.getString("region") + data.getString("city")
                        + data.getString("isp") + ")";

                Log.e("提示", "您的IP地址是：" + IP);
            } else {
                IP = "";
                Log.e("提示", "IP接口异常，无法获取IP地址！");
            }
        } else {
            IP = "";
            Log.e("提示", "网络连接异常，无法获取IP地址！");
        }
    } catch (Exception e) {
        IP = "";
        Log.e("提示", "获取IP地址时出现异常，异常信息是：" + e.toString());
    }
    return IP;
}