/**
     * Parse the parameters of a connection into a CoreNLP properties file that can be passed into
     * {@link StanfordCoreNLP}, and used in the I/O stages.
     *
     * @param httpExchange The http exchange; effectively, the request information.
     * @return A {@link Properties} object corresponding to a combination of default and passed
     *     properties.
     * @throws UnsupportedEncodingException Thrown if we could not decode the key/value pairs with
     *     UTF-8.
     */
    private Properties getProperties(HttpExchange httpExchange)
        throws UnsupportedEncodingException {
      // Load the default properties
      Properties props = new Properties();
      defaultProps
          .entrySet()
          .stream()
          .forEach(
              entry -> props.setProperty(entry.getKey().toString(), entry.getValue().toString()));

      // Try to get more properties from query string.
      Map<String, String> urlParams = getURLParams(httpExchange.getRequestURI());
      if (urlParams.containsKey("properties")) {
        StringUtils.decodeMap(URLDecoder.decode(urlParams.get("properties"), "UTF-8"))
            .entrySet()
            .forEach(entry -> props.setProperty(entry.getKey(), entry.getValue()));
      } else if (urlParams.containsKey("props")) {
        StringUtils.decodeMap(URLDecoder.decode(urlParams.get("properties"), "UTF-8"))
            .entrySet()
            .forEach(entry -> props.setProperty(entry.getKey(), entry.getValue()));
      }

      // Make sure the properties compile
      props.setProperty(
          "annotators",
          StanfordCoreNLP.ensurePrerequisiteAnnotators(
              props.getProperty("annotators").split("[, \t]+")));

      return props;
    }
 @Override
 public void handle(HttpExchange httpExchange) throws IOException {
   Map<String, String> urlParams = getURLParams(httpExchange.getRequestURI());
   httpExchange.getResponseHeaders().set("Content-Type", "text/plain");
   boolean doExit = false;
   String response = "Invalid shutdown key\n";
   if (urlParams.containsKey("key") && urlParams.get("key").equals(shutdownKey)) {
     response = "Shutdown successful!\n";
     doExit = true;
   }
   httpExchange.sendResponseHeaders(HTTP_OK, response.getBytes().length);
   httpExchange.getResponseBody().write(response.getBytes());
   httpExchange.close();
   if (doExit) {
     System.exit(0);
   }
 }
    @Override
    public void handle(HttpExchange httpExchange) throws IOException {
      // Set common response headers
      httpExchange.getResponseHeaders().add("Access-Control-Allow-Origin", "*");

      Future<String> json =
          corenlpExecutor.submit(
              () -> {
                try {
                  // Get the document
                  Properties props =
                      new Properties() {
                        {
                          setProperty("annotators", "tokenize,ssplit,pos,lemma,ner,depparse");
                        }
                      };
                  Annotation doc = getDocument(props, httpExchange);
                  if (!doc.containsKey(CoreAnnotations.SentencesAnnotation.class)) {
                    StanfordCoreNLP pipeline = mkStanfordCoreNLP(props);
                    pipeline.annotate(doc);
                  }

                  // Construct the matcher
                  Map<String, String> params = getURLParams(httpExchange.getRequestURI());
                  // (get the pattern)
                  if (!params.containsKey("pattern")) {
                    respondError("Missing required parameter 'pattern'", httpExchange);
                    return "";
                  }
                  String pattern = params.get("pattern");
                  // (get whether to filter / find)
                  String filterStr = params.getOrDefault("filter", "false");
                  final boolean filter =
                      filterStr.trim().isEmpty()
                          || "true".equalsIgnoreCase(filterStr.toLowerCase());
                  // (create the matcher)
                  final SemgrexPattern regex = SemgrexPattern.compile(pattern);

                  // Run TokensRegex
                  return JSONOutputter.JSONWriter.objectToJSON(
                      (docWriter) -> {
                        if (filter) {
                          // Case: just filter sentences
                          docWriter.set(
                              "sentences",
                              doc.get(CoreAnnotations.SentencesAnnotation.class)
                                  .stream()
                                  .map(
                                      sentence ->
                                          regex
                                              .matcher(
                                                  sentence.get(
                                                      SemanticGraphCoreAnnotations
                                                          .CollapsedCCProcessedDependenciesAnnotation
                                                          .class))
                                              .matches())
                                  .collect(Collectors.toList()));
                        } else {
                          // Case: find matches
                          docWriter.set(
                              "sentences",
                              doc.get(CoreAnnotations.SentencesAnnotation.class)
                                  .stream()
                                  .map(
                                      sentence ->
                                          (Consumer<JSONOutputter.Writer>)
                                              (JSONOutputter.Writer sentWriter) -> {
                                                SemgrexMatcher matcher =
                                                    regex.matcher(
                                                        sentence.get(
                                                            SemanticGraphCoreAnnotations
                                                                .CollapsedCCProcessedDependenciesAnnotation
                                                                .class));
                                                int i = 0;
                                                while (matcher.find()) {
                                                  sentWriter.set(
                                                      Integer.toString(i),
                                                      (Consumer<JSONOutputter.Writer>)
                                                          (JSONOutputter.Writer matchWriter) -> {
                                                            IndexedWord match = matcher.getMatch();
                                                            matchWriter.set("text", match.word());
                                                            matchWriter.set(
                                                                "begin", match.index() - 1);
                                                            matchWriter.set("end", match.index());
                                                            for (String capture :
                                                                matcher.getNodeNames()) {
                                                              matchWriter.set(
                                                                  "$" + capture,
                                                                  (Consumer<JSONOutputter.Writer>)
                                                                      groupWriter -> {
                                                                        IndexedWord node =
                                                                            matcher.getNode(
                                                                                capture);
                                                                        groupWriter.set(
                                                                            "text", node.word());
                                                                        groupWriter.set(
                                                                            "begin",
                                                                            node.index() - 1);
                                                                        groupWriter.set(
                                                                            "end", node.index());
                                                                      });
                                                            }
                                                          });
                                                  i += 1;
                                                }
                                                sentWriter.set("length", i);
                                              }));
                        }
                      });
                } catch (Exception e) {
                  e.printStackTrace();
                  try {
                    respondError(e.getClass().getName() + ": " + e.getMessage(), httpExchange);
                  } catch (IOException ignored) {
                  }
                }
                return "";
              });

      // Send response
      byte[] response = new byte[0];
      try {
        response = json.get(5, TimeUnit.SECONDS).getBytes();
      } catch (InterruptedException | ExecutionException | TimeoutException e) {
        respondError("Timeout when executing Semgrex query", httpExchange);
      }
      if (response.length > 0) {
        httpExchange.getResponseHeaders().add("Content-Type", "text/json");
        httpExchange.getResponseHeaders().add("Content-Length", Integer.toString(response.length));
        httpExchange.sendResponseHeaders(HTTP_OK, response.length);
        httpExchange.getResponseBody().write(response);
        httpExchange.close();
      }
    }