如何在JAVA Swing中拥有下载文件选项？

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.URL;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import javax.swing.*;

public class DownloadFileExample {
    public static void main(String[] args) {
        JFrame frame = new JFrame("下载文件选项");
        JButton downloadButton = new JButton("下载文件");
        JTextField textField = new JTextField(20);

        downloadButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    URL url = new URL("要下载的文件的URL");
                    ReadableByteChannel rbc = Channels.newChannel(url.openStream());
                    FileOutputStream fos = new FileOutputStream("保存文件的路径");
                    fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
            }
        });

        frame.add(downloadButton);
        frame.add(textField);
        frame.setSize(400, 300);
        frame.setVisible(true);
    }
}