Android获取外网IP地址

//var returnCitySN = {"cip": "14.152.40.255", "cid": "440000", "cname": "广东省"};
InputStream inStream;
try {
    URL infoUrl = new URL("http://pv.sohu.com/cityjson?ie=utf-8");
    URLConnection connection = infoUrl.openConnection();
    HttpURLConnection httpConnection = (HttpURLConnection) connection;
    int responseCode = httpConnection.getResponseCode();
    if (responseCode == HttpURLConnection.HTTP_OK) {
        inStream = httpConnection.getInputStream();
        BufferedReader reader = new BufferedReader(new InputStreamReader(inStream, "utf-8"));
        StringBuilder strber = new StringBuilder();
        String line;
        while ((line = reader.readLine()) != null) {
            strber.append(line).append("\n");
        }
        inStream.close();
        int start = strber.indexOf("{");
        int end = strber.indexOf("}");
        JSONObject jsonObject = new JSONObject(strber.substring(start, end + 1));
        mNetIpAddress = jsonObject.optString("cip", "");
    }
} catch (Throwable e) {}