private Connection connection;

    public void ucitajDriver() throws Exception {
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException ex) {
            throw new Exception("Neuspesno ucitavanje drivera!", ex);
        }
    }

    public void otvoriKonekciju() throws Exception {
        try {
            connection = DriverManager.getConnection("jdbc:mysql://localhost/poslovnipartneri", "root", "");
            connection.setAutoCommit(false);
            // Zahteva eksplicitnu potvrdu transakcije
        } catch (SQLException ex) {
            throw new Exception("Neuspesno otvaranje konekcije!", ex);
        }
    }

    public void commitTransakcije() throws Exception {
        try {
            connection.commit();
        } catch (SQLException ex) {
            throw new Exception("Neuspesan commit transakcije!", ex);
        }
    }

    public void rollbackTransakcije() throws Exception {
        try {
            connection.rollback();
        } catch (SQLException ex) {
            throw new Exception("Neuspesan rollback transakcije!", ex);
        }
    }

    public void zatvoriKonekciju() throws Exception {
        try {
            connection.close();
        } catch (SQLException ex) {
            throw new Exception("Neuspesno zatvaranje konekcije!", ex);
        }
    }