code: @RequestMapping(produces = MediaType.APPLICATION_JSON_VALUE, value = "/parse", method = RequestMethod.GET)
    public String parse(@RequestParam("sentence") String sentence, HttpServletRequest request) {
      if (sentence == null || sentence.trim().isEmpty()) {
        return StringUtils.EMPTY;
      }
  
      sentence = sentence.trim();
      LOGGER.info("Parse [" + sentence + "]");
      DTree tree = PARSER.parse(sentence);
  
      DTreeEntity parseTreeEntity = new DTreeEntity(tree, "SAMPLE_AUTHOR");
      dNodeEntityRepository.save(parseTreeEntity.dNodeEntities);
      dTreeEntityRepository.save(parseTreeEntity);
  
      return "[" + toJSON(tree.get(0)) + "]";
    }
docs: Parse sentence.
  
  @param sentence sentence.
  @param request  http servlet request.
  @return parse tree JSON.