método estático que puedes incluir en tus clientes REST

requestWebService.java

public static JSONObject requestWebService(String serviceUrl) {
    disableConnectionReuseIfNecessary();
 
    HttpURLConnection urlConnection = null;
    try {
        // create connection
        URL urlToRequest = new URL(serviceUrl);
        urlConnection = (HttpURLConnection) 
            urlToRequest.openConnection();
        urlConnection.setConnectTimeout(CONNECTION_TIMEOUT);
        urlConnection.setReadTimeout(DATARETRIEVAL_TIMEOUT);
         
        // handle issues
        int statusCode = urlConnection.getResponseCode();
        if (statusCode == HttpURLConnection.HTTP_UNAUTHORIZED) {
            // handle unauthorized (if service requires user login)
        } else if (statusCode != HttpURLConnection.HTTP_OK) {
            // handle any other errors, like 404, 500,..
        }
         
        // create JSON object from content
        InputStream in = new BufferedInputStream(
            urlConnection.getInputStream());
        return new JSONObject(getResponseText(in));
         
    } catch (MalformedURLException e) {
        // URL is invalid
    } catch (SocketTimeoutException e) {
        // data retrieval or connection timed out
    } catch (IOException e) {
        // could not read response body 
        // (could not create input stream)
    } catch (JSONException e) {
        // response body is no valid JSON string
    } finally {
        if (urlConnection != null) {
            urlConnection.disconnect();
        }
    }       
     
    return null;
}