public void adicionar(Lanche lanche) throws SQLException {
        String sql = "insert into lanches (lan_nome,lan_ingredientes,lan_valor) "
                + "values (?,?,?)";
        try {
            PreparedStatement stmt = this.conexao.prepareStatement(sql);
            stmt.setString(1, lanche.getNome());
            stmt.setString(2, lanche.getIngredientes());
            stmt.setDouble(3, lanche.getValor());
            stmt.execute();
            stmt.close();
        } catch (SQLException ex) {
            JOptionPane.showMessageDialog(null, "Erro: " + ex);
        }
    }