code: public static String requestUrl(final String url, final String method, final Properties header, final String body) {
  		try {
  			final URL siteUrl = new URL(url);
  			final HttpURLConnection connection = (HttpURLConnection) siteUrl.openConnection();
  			connection.setRequestMethod(method);
  			final Enumeration<?> keys = header.keys();
  			while (keys.hasMoreElements()) {
  				final String key = (String) keys.nextElement();
  				connection.addRequestProperty(key, header.getProperty(key));
  			}
  			connection.setDoOutput(true);
  
  			final OutputStream out = connection.getOutputStream();
  			out.write(body.getBytes());
  
  			connection.connect();
  
  			final int errorCode = connection.getResponseCode();
  			if (errorCode != HttpURLConnection.HTTP_OK) {
  				throw new JKHttpException(connection.getResponseMessage(), errorCode);
  			}
  			final String response = JKIOUtil.convertToString(connection.getInputStream());
  			return response;
  		} catch (IOException e) {
  			throw new JKHttpException(e);
  		}
  	}
docs: Send http request.
  
  @param url    the url
  @param method the method
  @param header the header
  @param body   the body
  @return the string