使用InputStream下载大文件

import java.io.BufferedInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.URL;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;

public class FileDownloader {

    public static void main(String[] args) {
        String fileUrl = "https://example.com/largefile.zip";
        String destinationFile = "downloaded_largefile.zip";

        try {
            downloadFile(fileUrl, destinationFile);
            System.out.println("文件下载完成！");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void downloadFile(String fileUrl, String destinationFile) throws Exception {
        URL url = new URL(fileUrl);
        InputStream inputStream = null;
        FileOutputStream fileOutputStream = null;
        ReadableByteChannel readableByteChannel = null;

        try {
            inputStream = new BufferedInputStream(url.openStream());
            fileOutputStream = new FileOutputStream(destinationFile);
            readableByteChannel = Channels.newChannel(inputStream);

            byte[] buffer = new byte[4096];
            int bytesRead;

            while ((bytesRead = readableByteChannel.read(buffer)) != -1) {
                fileOutputStream.write(buffer, 0, bytesRead);
            }
        } finally {
            if (readableByteChannel != null) {
                try {
                    readableByteChannel.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (fileOutputStream != null) {
                try {
                    fileOutputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}