JAVA:尝试通过身份验证从URL下载文件

import java.io.BufferedInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.Authenticator;
import java.net.PasswordAuthentication;
import java.net.URL;
import java.net.URLConnection;

public class FileDownloader {
    public static void main(String[] args) {
        try {
            // 设置身份验证信息
            Authenticator.setDefault(new Authenticator() {
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication("username", "password".toCharArray());
                }
            });

            // 创建URL对象
            URL url = new URL("http://example.com/file.txt");

            // 打开连接
            URLConnection connection = url.openConnection();

            // 获取输入流
            BufferedInputStream in = new BufferedInputStream(connection.getInputStream());

            // 创建文件输出流
            FileOutputStream out = new FileOutputStream("file.txt");

            // 下载文件
            byte[] buffer = new byte[1024];
            int bytesRead;
            while ((bytesRead = in.read(buffer)) != -1) {
                out.write(buffer, 0, bytesRead);
            }

            // 关闭流
            in.close();
            out.close();

            System.out.println("文件下载成功！");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}