打包下载成.zip文件项目背景
公司使用vue + SpringBoot实现批量下载功能
今天在调试批量下载这个功能。打包成.zip
文件时,在返回给前端浏览器出现报错信息:
后端报错:
ERROR c.c.p.c.e.BusinessExceptionHandler – java.io.IOException: 你的主机中的软件中止了一个已建立的连接。
org.apache.catalina.connector.ClientAbortException: java.io.IOException: 你的主机中的软件中止了一个已建立的连接。
找了好久的错,发现浏览器的控制台有报错信息
Access to XMLHttpRequest at ‘http://…:8097/pcsms-admin/batchExport/pdf?vids=1e7ed541bdd6b9f5614cca14623f8681,8dfda9f7151745ad5aa5f0abc2c55d5c’ from origin ‘http://..:8001’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource.
于是在后端中设置响应体,如 HttpServletResponse response :
response.setHeader("Access-Control-Allow-Origin","*");
紧接着又出现如下的报错信息:
Access to XMLHttpRequest at ‘http://…:8097/batchExport/pdf?vids=1e7ed541bdd6b9f5614cca14623f8681,8dfda9f7151745ad5aa5f0abc2c55d5c’ from origin ‘http://…:8001’ has been blocked by CORS policy: The value of the ‘Access-Control-Allow-Origin’ header in the response must not be the wildcard ‘*’ when the request’s credentials mode is ‘include’. The credentials mode of requests initiated by the XMLHttpRequest is controlled by the withCredentials attribute.
在面向百度编程中,找到一个帖子有详细的解释–axios设置withCredentials导致“跨域”的解决方案。检查前端配置果然有:
axios.defaults.withCredentials = true;
(一) 当前端配置withCredentials=true时, 后端配置Access-Control-Allow-Origin不能为*, 必须是相应地址
(二) 当配置withCredentials=true时, 后端需配置Access-Control-Allow-Credentials
(三) 当前端配置请求头时, 后端需要配置Access-Control-Allow-Headers为对应的请求头集合
于是我们可以采取方法一:axios.defaults.withCredentials = false;
在找其他解决方法时,找到一个可以不更改前端配置的方法二–Jquery Ajax设置withCredentials解决跨域请求,在response里加上以下两个header
response.addHeader("Access-Control-Allow-Origin", request.getHeader("Origin"));// response.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");response.addHeader("Access-Control-Allow-Credentials","true");
最后,终于问题成功解决。
后端代码:
- TestController
@RequestMapping(value = "/batchExport/pdf", method = RequestMethod.POST)public void batchExportPdf(HttpServletRequest request, HttpServletResponse response, @RequestParam("vids") String vids) throws Exception { //获取uavFileId,不进行xss过滤// HttpServletRequest orgRequest = XssHttpServletRequestWrapper.getOrgRequest(request);// String ids = orgRequest.getParameter("vids"); String[] vid = vids.split(","); byte[] data = sopService.batchExportPdf(vid); String fileName = URLEncoder.encode("批量下载PDF" + DateUtils.format(new Date(), "yyyyMMddHHmmss") + ".zip", "UTF-8"); response.reset(); // 当前端配置withCredentials=true时, 后端配置Access-Control-Allow-Origin不能为*, 必须是相应地址 response.addHeader("Access-Control-Allow-Origin", request.getHeader("Origin")); // 这个若不起作用,使用下面的"FileName"的// response.addHeader("Access-Control-Expose-Headers","*"); response.addHeader("Access-Control-Allow-Methods", "GET,POST,PUT,DELETE"); // 设置在下载框默认显示的文件名 response.setHeader("Content-disposition", "attachment;filename=" + fileName + ";" + "filename*=utf-8''" + fileName); response.setHeader("FileName", fileName); // 让axios放行指定的响应头 https://blog.csdn.net/u012586326/article/details/125790079 response.addHeader("Access-Control-Expose-Headers","FileName"); // 写明文件大小 response.addHeader("Content-Length", "" + data.length); // 指明response的返回对象是文件流 response.setContentType("application/octet-stream; charset=UTF-8"); response.setCharacterEncoding("UTF-8"); // 当前端配置withCredentials=true时, 后端需配置Access-Control-Allow-Credentials response.addHeader("Access-Control-Allow-Credentials","true"); IOUtils.write(data, response.getOutputStream()); }
- TestService
/** * 批量下载pdf * @param vids * @return */ byte[] batchExportPdf(String[] vids) throws Exception;
- TestServiceImpl
@Override public byte[] batchExportPdf(String[] vids) { ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); // 用于将数据压缩成Zip文件格式 ZipOutputStream zipOut = new ZipOutputStream(outputStream); FileInputStream inputStream = null; List deletePdf = new ArrayList(); List in = new ArrayList(); try { for (String vid : vids) { // 下载到本地 // PdfDTO包含:pdfPath(本地PDF路径)、fileName(下载后的文件名(不含文件后缀.pdf)) PdfDTO dto = exportPdfByVid(vid); if (!ObjectUtils.isEmpty(dto)) { zipOut.putNextEntry(new ZipEntry((Objects.requireNonNull(dto.getFileName())) + ".pdf")); inputStream = new FileInputStream(new File(dto.getPdfPath())); int len; byte[] bytes = new byte[1024]; while ((len = inputStream.read(bytes)) != -1) { zipOut.write(bytes, 0, len); } //关闭该zip文件中打开的项 zipOut.closeEntry(); deletePdf.add(dto.getPdfPath()); in.add(inputStream); } } } catch (Exception e) { log.error("批量下载时出现错误:" + e.toString()); throw new BusinessException("批量下载时出现错误:" + e.getMessage()); } finally { try { for (FileInputStream stream : in) { stream.close(); } // 关流 IOUtils.closeQuietly(zipOut); } catch (IOException e) { log.error("批量下载时流关闭异常:" + e.toString()); } // 删除源文件(我这里是因为从数据服务器下载了文件到本地,所以删掉本地的) File file = null; for (String s : deletePdf) { file = new File(s); file.delete(); } } return outputStream.toByteArray(); }
参考:
https://blog.csdn.net/cckevincyh/article/details/81140443
https://developer.mozilla.org/zh-CN/docs/Web/HTTP/Headers/Access-Control-Allow-Origin
https://blog.csdn.net/baidu_28068985/article/details/105558280
https://blog.csdn.net/HermitSun/article/details/100797223