如何在没有临时文件的情况下强制zip下载？

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class DownloadServlet extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // 创建一个字节数组输出流，用于存储zip文件内容
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        
        // 创建一个ZipOutputStream对象，将文件内容写入字节数组输出流
        try (ZipOutputStream zos = new ZipOutputStream(baos)) {
            // 添加需要下载的文件到zip压缩包中
            // 示例：添加名为"example.txt"的文件
            ZipEntry entry = new ZipEntry("example.txt");
            zos.putNextEntry(entry);
            zos.write("This is an example file.".getBytes());
            zos.closeEntry();
        }
        
        // 设置HTTP响应头
        response.setContentType("application/zip");
        response.setHeader("Content-Disposition", "attachment; filename=\"example.zip\"");
        
        // 将zip文件内容写入HTTP响应的输出流
        response.getOutputStream().write(baos.toByteArray());
    }
}