使用JFileChooser？按钮&限制文件类型

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.filechooser.FileNameExtensionFilter;

public class FileChooserExample {
    public static void main(String[] args) {
        JFrame frame = new JFrame("File Chooser Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JButton button = new JButton("Open File Chooser");
        button.addActionListener(e -> {
            JFileChooser fileChooser = new JFileChooser();
            FileNameExtensionFilter filter = new FileNameExtensionFilter("Text Files", "txt");
            fileChooser.setFileFilter(filter);

            int result = fileChooser.showOpenDialog(frame);
            if (result == JFileChooser.APPROVE_OPTION) {
                String selectedFilePath = fileChooser.getSelectedFile().getAbsolutePath();
                System.out.println("Selected file: " + selectedFilePath);
            }
        });

        frame.getContentPane().add(button);
        frame.pack();
        frame.setVisible(true);
    }
}