【springMVC】从网络上打包下载图片并提供给浏览器下载

    @RequestMapping(value = "/downLoadImage", method = RequestMethod.GET)
    public void downLoadImage(HttpServletResponse response, String id) throws Exception {
        List<String> urls = Lists.newArrayList();
        urls.add("http://a.hiphotos.baidu.com/image/pic/item/b219ebc4b74543a96a58c53112178a82b801148f.jpg");

        Map<String, InputStream> isMap = Maps.newHashMap();
        urls.forEach(urlStr -> {
            String[] fileNameParts = urlStr.split("/");
            String fileName = fileNameParts[fileNameParts.length - 1];
            try {
                URL url = new URL(urlStr);
                URLConnection con = url.openConnection();
                // 设置超时间为3秒
                con.setConnectTimeout(3 * 1000);
                // 防止屏蔽程序抓取而返回403错误
                con.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
                InputStream is = con.getInputStream();
                isMap.put(fileName, is);
            } catch (Exception e) {
                e.printStackTrace();
            }
        });

        response.setContentType("application/octet-stream");
        String filename = URLEncoder.encode("打包图片", "UTF-8");
        response.setHeader("Content-Disposition", "attachment; filename=" + filename + ".zip");
        ZipOutputStream zipOut = new ZipOutputStream(response.getOutputStream());
        isMap.forEach((fileName, is) -> {
            try {
                addToZip(is, zipOut, fileName);
            } catch (Exception e) {
                e.printStackTrace();
            }
        });
        zipOut.flush();
        zipOut.close();
    }

    private void addToZip(InputStream is, ZipOutputStream zipOut, String fileName) throws IOException {
        fileName = URLEncoder.encode(fileName, "UTF-8");
        ZipEntry entry = new ZipEntry(fileName);
        zipOut.putNextEntry(entry);
        int len;
        byte[] buffer = new byte[1024];
        while ((len = is.read(buffer)) > 0) {
            zipOut.write(buffer, 0, len);
        }
        zipOut.closeEntry();
        is.close();
    }

window.location.href = 'path/downLoadImage?id=' + id;