直接傳入地址下載
public static void downloadFile(HttpServletResponse response, String url) {
        response.setCharacterEncoding("UTF-8");
        response.setContentType("application/octet-stream");
        response.setHeader("content-type", "application/octet-stream");
        String fileName = url.substring(url.lastIndexOf("/") + 1);
        response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, StandardCharsets.UTF_8));
        response.setHeader("Access-Control-Expose-Headers", "Content-Disposition");
        InputStream in = null;
        OutputStream out = null;
        try {
            //獲取要下載的文件輸入流
            in = new URL(url).openStream() ;
            int len = 0;
            //創(chuàng)建數(shù)據(jù)緩沖區(qū)
            byte[] buffer = new byte[1024];
            //通過response對象獲取outputStream流
            out = response.getOutputStream();
            //將FileInputStream流寫入到buffer緩沖區(qū)
            while ((len = in.read(buffer)) > 0) {
                //使用OutputStream將緩沖區(qū)的數(shù)據(jù)輸出到瀏覽器
                out.write(buffer, 0, len);
            }
            out.flush();
            in.close();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (out != null) {
                try {
                    out.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

將多個(gè)文件打包成zip流下載
 public static void downloadFile2Zip(HttpServletResponse response, List<String> urls, String zipFileName) {
        if (CollectionUtil.isNotEmpty(urls) && !StringUtils.hasLength(zipFileName)) {
            throw new RuntimeException("數(shù)據(jù)為空");
        }
        String dowwnloadName = zipFileName + ".zip";
        response.setCharacterEncoding("UTF-8");
        response.setContentType("application/octet-stream");
       response.setHeader("content-type", "application/octet-stream");
        response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(dowwnloadName, StandardCharsets.UTF_8));
        response.setHeader("Access-Control-Expose-Headers", "Content-Disposition");
        try (ZipOutputStream zipOut = new ZipOutputStream(response.getOutputStream())) {
            zipOut.setMethod(ZipOutputStream.DEFLATED);
            for (String url : urls) {
                 try (InputStream is = new URL(url).openStream()) {
                    String fileName = url.substring(url.lastIndexOf("/") + 1);
                    if (!fileName.isEmpty()) {
                        zipOut.putNextEntry(new ZipEntry(fileName));
                        final byte[] bytes = new byte[1024];
                        int lenth;
                        while ((lenth = is.read(bytes)) != -1) {
                            zipOut.write(bytes, 0, lenth);
                        }
              } catch (Exception exception) {
                    exception.printStackTrace();
                }
            }
        } catch (Exception exception) {
            exception.printStackTrace();
        }
    }