流式传输java servlet中的大型文件

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/download")
public class LargeFileDownloadServlet extends HttpServlet {

    private static final int BUFFER_SIZE = 1024 * 1024; // 1MB

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String filePath = "path/to/large/file.ext";
        File file = new File(filePath);

        response.setContentType("application/octet-stream");
        response.setHeader("Content-Disposition", "attachment; filename=\"" + file.getName() + "\"");
        response.setHeader("Content-Length", String.valueOf(file.length()));

        try (FileInputStream fis = new FileInputStream(file);
             ServletOutputStream os = response.getOutputStream()) {
            byte[] buffer = new byte[BUFFER_SIZE];
            int bytesRead;
            while ((bytesRead = fis.read(buffer)) != -1) {
                os.write(buffer, 0, bytesRead);
                os.flush();
            }
        }
    }
}