private static StringBuilder getResponseStr(
			Collection<Parameter> parameters, HttpURLConnection connection)
			throws IOException {
		StringBuilder responseStr = new StringBuilder("");
		
		OutputStream out = connection.getOutputStream();
		if(parameters!=null&&parameters.size()>0){
			try {
				
				out.write(buildParameterStr(parameters).getBytes("UTF-8"));
				out.flush();
			} catch (Exception e) {
				e.printStackTrace();
			} finally {
				if (out != null)
					out.close();
			}
		}

		
		if (connection.getResponseCode() == 200) {
			BufferedReader reader = new BufferedReader(new InputStreamReader(
					connection.getInputStream()));
			try {
				for (String line = reader.readLine(); line != null; line = reader
						.readLine()) {
					responseStr.append(line);
				}
			} catch (Exception e) {
				e.printStackTrace();
			} finally {
				if (reader != null)
					reader.close();
			}
		}
		System.out.println(connection.getResponseMessage());
		return responseStr;
	}