如何从右到左（在JOptionPane内部）设置JTextArea的方向

scrollPane.setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);

textArea.setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.event.*;

public class Test
{
    public static void main(String args[]) throws Exception
    {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JTextArea textArea = new JTextArea(4, 20);
                JScrollPane scrollPane = new JScrollPane( textArea );
                JPanel panel = new JPanel();
                panel.add( scrollPane );

                scrollPane.addAncestorListener( new AncestorListener()
                {
                    public void ancestorAdded(AncestorEvent e)
                    {
                        JScrollPane scrollPane = (JScrollPane)e.getComponent();
                        scrollPane.applyComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);
                    }

                    public void ancestorMoved(AncestorEvent e) {}
                    public void ancestorRemoved(AncestorEvent e) {}
                });

                JOptionPane.showMessageDialog(null, panel);
            }
        });
    }
}

import java.awt.ComponentOrientation;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.util.Locale;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;

/** @see http://stackoverflow.com/questions/6475320 */
public class RTLTextArea extends JPanel {

    private static final String s = \"مرحبا العالم\";
    private JTextArea jta = new JTextArea(7, 5);
    private Locale arabic = new Locale(\"ar\", \"KW\");
    private ComponentOrientation arabicOrientation =
        ComponentOrientation.getOrientation(arabic);

    public RTLTextArea() {
        this.setLayout(new GridLayout());
        this.add(new JScrollPane(jta));
        this.applyComponentOrientation(arabicOrientation);
        for (int i = 0; i < 8; i++) {
            jta.append(s + \"\\n\");
        }
    }

    private void display() {
        JFrame f = new JFrame(\"RTLTextAre\");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(this);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new RTLTextArea().display();
            }
        });
    }
}

jTextArea1.setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);
jTextArea1.setText(<text>);

setComponentOrientation()

TextArea

setText()

TextArea

ComponentOrientation

RIGHT_TO_LEFT

repaint()