AuthorBuilder.java 文件源码

/**
   * gets an author from the database by determining the type of the provided id. if no author is present it builds one from the id.
   * @param id the author identifier
   * @return the author retrieved from the database or build with the identifier
* @throws JDOMException thrown upon parsing the source response
* @throws IOException thrown upon reading profiles from disc
* @throws SAXException thrown when parsing the files from disc
 */
  public PublicationAuthor retrieveAuthor(String id) throws JDOMException, IOException, SAXException {
      typeOfID = determineID(id);
      LOGGER.info("given ID: " + id + " is of type " + typeOfID);
      EntityManagerFactory emf = Persistence.createEntityManagerFactory("publicationAuthors");
      EntityManager em = emf.createEntityManager();
      CriteriaBuilder cb = em.getCriteriaBuilder();
      CriteriaQuery<PublicationAuthor> q = cb.createQuery(PublicationAuthor.class);
      Root<PublicationAuthor> c = q.from(PublicationAuthor.class);
      List<Predicate> predicates = new ArrayList<>();
      if (typeOfID.equals("surname")) {
          if (id.contains(",")) {
              predicates.add(cb.equal(c.get("surname"),id.substring(0,id.indexOf(","))));
              predicates.add(cb.equal(c.get("firstname"),id.substring(id.indexOf(",")+1)));
              LOGGER.info("retriving surname, firstname from database for " + id);
          } else if (id.contains(" ")) {
              predicates.add(cb.equal(c.get("firstname"),id.substring(0,id.indexOf(" "))));
              predicates.add(cb.equal(c.get("surname"),id.substring(id.indexOf(" ")+1)));
              LOGGER.info("retrieving firstname surname from database for " + id);
          } else {
              predicates.add(cb.equal(c.get("surname"), id));
              LOGGER.info("retrieving surname from database for " + id);
          }
      }
      predicates.add(cb.equal(c.get(typeOfID), id));
      q.select(c).where(cb.equal(c.get(typeOfID), id));
      TypedQuery<PublicationAuthor> query = em.createQuery(q);
      List<PublicationAuthor> authors = query.getResultList();
      em.close();
      if (authors.size() == 1) {
          LOGGER.info("found author in database");
          this.author = authors.get(0);
          return author;
      }
      LOGGER.info("no match in database");
      return buildAuthor(id);
  }