code: package helpers;
  
  import static spark.Spark.post;
  
  public class HelperServer {
      public static void main(String[] args) {
          CoreNLPFeaturizer f = new CoreNLPFeaturizer();
          PolarityAnnoation nd = new PolarityAnnoation();
          post("/", "application/json", (req,res) -> {
              String requestType=req.queryParams("type");
              String sentence = req.queryParams("sentence");
              String is_raw = req.queryParams("is_raw");
              if (requestType.equals("featurize")){
                  if (is_raw.toLowerCase().equals("true"))
                      return f.featurizer.extractFeatures(sentence, "raw");
                  else
                      return  f.featurizer.extractFeatures(sentence, "conll");
              }
              else if(requestType.equals("negation"))
                  return nd.get_polarityAnnotation(sentence, is_raw.toLowerCase().equals("true"));
              else
                  return null;
          });
      }
  }