public Conexion Conectar()
    {
        try {

            Class.forName("oracle.jdbc.OracleDriver");
            String bd = "jdbc:oracle:thin:@localhost:1521:XE";
            conexion = DriverManager.getConnection(bd,"inventario","system");

            if(conexion != null){
                System.out.println("conexion exitosa");
            }else{
                System.out.println("conexion fallida");
            }

        } catch (SQLException e) {
            System.out.println("ERROR SQL: "+e.getMessage());
        } catch(Exception ex){
            System.out.println("OTRO ERROR: "+ex.getMessage());
        }

        return this;
    }