code: public static JsonSimple parse(InputStream input) throws IOException {
          JsonSimple inputData = new JsonSimple(input);
          JsonSimple responseData = new JsonSimple();
  
          // Go through every top level node
          JsonObject object = inputData.getJsonObject();
          for (Object key : object.keySet()) {
              // Ignoring some non-form related nodes
              String strKey = validString(key);
              if (!EXCLUDED_FIELDS.contains(strKey)) {
                  // And parse them into the repsonse
                  String data = validString(object.get(key));
                  parseField(responseData, strKey, data);
              }
          }
          return responseData;
      }
docs: Accept and parse raw JSON data from an InputStream. Field name String
  literals will be broken down into meaningful JSON data structures.
  
  @param input The form data to parse from an InputStream
  @return JsonSimple The parsed form data in JSON
  @throws IOException if there are errors reading/parsing the form data