public void alterarNotificacao(Notificacao notificacao) {
    PreparedStatement ps = null;

    try {
      conexao = ConexaoFactory.conexaoHeroku();

      String sql = "UPDATE SET  islida  = ? " + " FROM notificacao WHERE cd_notificacao = ? ";

      ps = conexao.prepareStatement(sql);

      ps.setBoolean(1, notificacao.isLida());
      ps.setInt(2, notificacao.getCdNotificacao());

      ps.executeUpdate();

    } catch (Exception e) {
      e.printStackTrace();
    } finally {
      try {
        ps.close();
        conexao.close();
      } catch (SQLException ex) {
        ex.printStackTrace();
      }
    }
  }