JTextField从左到右的数字顺序

我正在尝试制作计算器,我对JTextField有一个问题。当我单击数字(JButtons)如1,2,3,4,5时,它们会出现在JTextField上,如54321。那么,我如何将其更改为显示12345而不是54321?

public void actionPerformed(ActionEvent e) {

    JButton clickedButton = (JButton) e.getSource();


    String displayValue = parent.getDisplayValue();

    String clickedBtnValue = clickedButton.getText();

    parent.setDisplayValue(clickedBtnValue + displayValue); 

contentPane = new JPanel();
    textField = new JTextField(30);
    textField.setAlignmentX(Component.LEFT_ALIGNMENT);
    contentPane.add(textField);
    textField.setHorizontalAlignment(JTextField.RIGHT);
    textField.setBounds(10, 11, 152, 32);
    textField.setColumns(1);
    textField.setComponentOrientation(ComponentOrientation.LEFT_TO_RIGHT);
    textField.addActionListener(eng);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 184, 312);

    contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    setContentPane(contentPane);
    contentPane.setLayout(null);