public String getGenre(Integer idCat) throws GenreException {

    try {
      Context ctx = new InitialContext();
      DataSource source = (DataSource) ctx.lookup("jdbc/MusicStore");
      connexion = source.getConnection();

      String requeteSQL = "SELECT LABEL FROM GENRE WHERE GENRE.IDGENRE = ?";
      PreparedStatement prepStat = connexion.prepareStatement(requeteSQL);
      prepStat.setInt(1, idCat);
      ResultSet donnees = prepStat.executeQuery();
      String genre = "";
      if (donnees.next()) {
        genre = donnees.getString(1);
      } else {
        throw new GenreException("errorGenre");
      }

      return genre;
    } catch (SQLException e) {
      throw new GenreException("sqlConnexionError");
    } catch (NamingException e) {
      throw new GenreException("errorNaming");
    } catch (GenreException ex) {
      throw new GenreException(ex.toString());
    } finally {
      try {
        connexion.close();
      } catch (SQLException e) {
        throw new GenreException("sqlConnexionError");
      }
    }
  }
  public ArrayList<Categorie> getCategories() throws GenreException {
    try {
      ArrayList<Categorie> arrCat = new ArrayList<Categorie>();
      Context ctx = new InitialContext();
      DataSource source = (DataSource) ctx.lookup("jdbc/MusicStore");
      connexion = source.getConnection();

      String requeteSQL = "SELECT * FROM GENRE";

      PreparedStatement prepStat = connexion.prepareStatement(requeteSQL);
      ResultSet donnees = prepStat.executeQuery();

      while (donnees.next()) {
        Categorie newCat = new Categorie();
        newCat.setIdCategorie(donnees.getInt(1));
        newCat.setLibelle(donnees.getString(2));
        arrCat.add(newCat);
      }
      if (arrCat.isEmpty()) {
        throw new GenreException("errorGenreNotExist");
      }
      return arrCat;
    } catch (SQLException ex) {
      throw new GenreException("sqlException");
    } catch (NamingException ex) {
      throw new GenreException("errorNaming");
    } catch (GenreException ex) {
      throw new GenreException(ex.toString());
    } finally {
      try {
        connexion.close();
      } catch (SQLException ex) {
        throw new GenreException("sqlException");
      }
    }
  }