自动滚动jtextarea仅适用于行

JTextArea textArea = new JTextArea();

JScrollPane scrollPane = new JScrollPane(textArea);

DefaultCaret caret = (DefaultCaret) textArea.getCaret();
caret.setUpdatePolicy(DefaultCaret.ALWAYS_UPDATE);

import javax.swing.*;
import javax.swing.text.DefaultCaret;
import java.awt.*;

public class AutoScrollExample extends JFrame {
    public AutoScrollExample() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setTitle("Auto Scroll JTextArea Example");

        JTextArea textArea = new JTextArea();
        JScrollPane scrollPane = new JScrollPane(textArea);

        // 启用自动滚动
        DefaultCaret caret = (DefaultCaret) textArea.getCaret();
        caret.setUpdatePolicy(DefaultCaret.ALWAYS_UPDATE);

        getContentPane().add(scrollPane, BorderLayout.CENTER);
        setSize(400, 300);
        setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> new AutoScrollExample());
    }
}