public static String post(String url, Map<String, String> postData) {
        PrintUtils.soutIfTest("[Post URL] " + url + "\t" + postData);
        HttpPost httpPost = new HttpPost(url);
        List<NameValuePair> params = new ArrayList<NameValuePair>();

        if (postData != null) {
            for (String key : postData.keySet()) {
                params.add(new BasicNameValuePair(key, postData.get(key)));
            }
        }
        try {
            httpPost.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));
            String content = httpclient.execute(httpPost,
                    new BasicResponseHandler());
            return content;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }