JAVA后台实现文件批量下载方式

	/**
     * 本地文件路径
     */
	private static final String FILE_PATH = "F:\\test";
/**
     * 批量下载文件
     *
     * @param list     批量文件集合（前端只传id集合，后端去查数据库拿到文件信息）
     * @param request  request
     * @param response response
     * @param <T>      实体类 extends BaseEntityPoJo 
     */
    public static <T extends BaseEntityPoJo> void batchDownloadFile(List<T> list, HttpServletRequest request, HttpServletResponse response) {
        //设置响应头信息
        response.reset();
        response.setCharacterEncoding("utf-8");
        response.setContentType("multipart/form-data");
        //设置压缩包的名字，date为时间戳
        String date = DateUtil.formatDateTimeSecond(new Date());
        String downloadName = "压缩包" + date + ".zip";
        //返回客户端浏览器的版本号、类型
        String agent = request.getHeader("USER-AGENT");
        try {
            //针对IE或者以IE为内核的浏览器：
            if (agent.contains("MSIE") || agent.contains("Trident")) {
                downloadName = java.net.URLEncoder.encode(downloadName, "UTF-8");
            } else {
                //非IE浏览器的处理：
                downloadName = new String(downloadName.getBytes(StandardCharsets.UTF_8), StandardCharsets.ISO_8859_1);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        response.setHeader("Content-Disposition", "attachment;fileName=\"" + downloadName + "\"");

        //设置压缩流：直接写入response，实现边压缩边下载
        ZipOutputStream zipOs = null;
        //循环将文件写入压缩流
        DataOutputStream os = null;
        //文件
        File file;
        try {
            zipOs = new ZipOutputStream(new BufferedOutputStream(response.getOutputStream()));
            //设置压缩方法
            zipOs.setMethod(ZipOutputStream.DEFLATED);
            //遍历文件信息（主要获取文件名/文件路径等）
            for (T t : list) {
                try {
                    //文件名（包含后缀名，如：测试.pdf）
                    Field field = t.getClass().getDeclaredField("name");
                    field.setAccessible(true);
                    String name = field.get(t).toString();
                    //本地文件路径（绝对路径，包含后缀名，如：F:\\test\\测试.pdf），这里是在windows上测试的，路径是反斜杠
                    String path = FILE_PATH + File.separator + name;
                    log.info("batchDownloadFile:[filePath:{}]", path);
                    file = new File(path);
                    if (!file.exists()) {
                        throw new RuntimeException("文件不存在");
                    }
                    //添加ZipEntry，并将ZipEntry写入文件流
                    zipOs.putNextEntry(new ZipEntry(name));
                    os = new DataOutputStream(zipOs);
                    FileInputStream fs = new FileInputStream(file);
                    byte[] b = new byte[100];
                    int length;
                    //读入需要下载的文件的内容，打包到zip文件
                    while ((length = fs.read(b)) != -1) {
                        os.write(b, 0, length);
                    }
                    //关闭流
                    fs.close();
                    zipOs.closeEntry();
					//==============此处如果是网络文件路径，可按如下方式读取=============
					/*
					//文件名（包含后缀名,如:测试.pdf）
                    Field field = t.getClass().getDeclaredField("name");
                    field.setAccessible(true);
                    String name = field.get(t).toString() + ".pdf";
                    //网络文件路径（浏览器可直接访问的路径，如：http://192.168.0.12/frame-service-gengbao/document/四川省2022第四季度报告.pdf）
                    Field urlField = t.getClass().getDeclaredField("url");
                    urlField.setAccessible(true);
                    URL url = new URL(urlField.get(t).toString());
                    URLConnection connection = url.openConnection();
                    InputStream is = connection.getInputStream();
                    //添加ZipEntry，并将ZipEntry写入文件流
                    zipOs.putNextEntry(new ZipEntry(name));
                    os = new DataOutputStream(zipOs);
                    byte[] b = new byte[100];
                    int length;
                    //读入需要下载的文件的内容，打包到zip文件
                    while ((length = is.read(b)) != -1) {
                        os.write(b, 0, length);
                    }
                    is.close();
                    zipOs.closeEntry();
                    */
                } catch (IllegalAccessException | NoSuchFieldException e) {
                    log.error("下载文件出错![{}]", e.getMessage());
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            //关闭流
            try {
                if (os != null) {
                    os.flush();
                    os.close();
                }
                if (zipOs != null) {
                    zipOs.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    }

	/**
     * 批量下载（测试时可改为GET请求，浏览器直接调用接口）
     *
     * @param ids      用于查询相关表获取文件信息
     * @param request  request
     * @param response response
     */
    @GetMapping("/batchDownloadFile")
    @ApiOperation("批量下载")
    public void batchDownloadFile(@RequestParam("ids") final String ids,
                                  HttpServletRequest request,
                                  HttpServletResponse response) {
        log.info("downloadPlanFile:批量下载[ids:{},request:{},response:{}]", ids, request, response);
        List<Integer> idList = ControllerHelper.splitToLong(ids);
        List<RegulatoryReport> list = service.list(idList);
        FileUtil.batchDownloadFile(list, request, response);
    }

public static List<Integer> splitToLong(final String str) {
        return StringUtils.isEmpty(str) ? Collections.emptyList() : Stream.of(str.split(",")).map(Integer::valueOf).collect(Collectors.toList());
    }

	/**
     * 将日期解析成yyyyMMddHHmmss的字符串
     *
     * @param date the date
     * @return the string
     */
    public static String formatDateTimeSecond(Date date) {
        if (date == null) {
            return "";
        }
        return new SimpleDateFormat(DATETIME_STAMP_SECOND, Locale.CHINA).format(date);
    }

File f = new File(filePath);
String path = (f+“”).replaceAll(“\\”, “/”);