private void getConexao(){
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(vendas.class.getName()).log(Level.SEVERE, null, ex);
        }
        try {
            con = DriverManager.getConnection("jdbc:mysql:=//localhost:3306/vendas", "root", "");
        } catch (SQLException ex) {
            Logger.getLogger(vendas.class.getName()).log(Level.SEVERE, null, ex);
        }

    }