作者：fyupeng
技术专栏：☞ https://github.com/fyupeng
项目地址：☞ https://github.com/fyupeng/rpc-netty-framework

---

留给读者

一、介绍

文件下载在浏览器可以根据响应头设置纯下载和直接打开两种方式。

二、代码

@RequestMapping("/downloadPdf")@ResponseBodypublic void downloadSignPdf(HttpServletRequest request, HttpServletResponse response) {OutputStream out = null;try {byte[] bytes = docService.downLoadPdf(gid, type, isHs);if (bytes == null) {// 构造错误信息的 JSON 格式字符串String errorMsg = "{\"msg\": \"文件不存在\", \"gid\": \""+gid+"\", \"type\": \""+type+"\", \"isHs\": \""+isHs+"\" }";// 设置响应的 Content-Type 和字符编码response.setContentType("application/json;charset=UTF-8");// 将错误信息写入响应输出流PrintWriter pw = response.getWriter();pw.print(errorMsg);pw.flush();return;}response.reset(); // 非常重要// 纯下载方式//response.setContentType("text/html; charset=UTF-8");//response.setHeader("Content-Disposition", "attachment;fileName=" + gid + ".pdf");// 直接打开response.setContentType("application/pdf"); // 设置返回的文件类型response.addHeader("Content-Length", String.valueOf(bytes.length));  //文件大小out = response.getOutputStream();out.write(bytes);out.flush();} catch (Exception e) {e.printStackTrace();logger.error("下载电子签名后的pdf失败，gid={}, type={}, isHs={}", gid, type, isHs);} finally {if (out != null) {try {out.close();} catch (Exception e) {e.printStackTrace();}}}}

三、总结

简洁、高效、易用！