public static String post(String url, List<NameValuePair> params) {
		CloseableHttpClient httpclient = HttpClients.createDefault();
		HttpPost httpPost = new HttpPost(url);
		if (params != null) {
			try {
				httpPost.setEntity(new UrlEncodedFormEntity(params,"UTF-8"));
			} catch (UnsupportedEncodingException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		CloseableHttpResponse response = null;
		try {
			response = httpclient.execute(httpPost);
			ResponseHandler<String> handler = new BasicResponseHandler();
			return handler.handleResponse(response);
		} catch (ClientProtocolException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			try {
				response.close();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		return null;
	}