public DefaultTableModel getData()
    {
        DefaultTableModel table=new DefaultTableModel();
        table.addColumn("ID");
        table.addColumn("Login");
        table.addColumn("Haslo");

        try {
            ResultSet result = stat.executeQuery("SELECT * FROM Users");
            int id_user;
            String login,password;
            while(result.next()) {
                id_user=result.getInt("id_user");
                login = result.getString("login");
                password = result.getString("password");
                table.addRow(new String[]{"1", login, password});
            }
        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }
        return table;
    }