Java传统下载和SpringMVC下载

  /**
      * 传统下载
      * @param filename 文件名称
      */
     @RequestMapping(value="download", method={RequestMethod.GET, RequestMethod.POST})
     public void download(HttpServletRequest request, HttpServletResponse response, String filename) {
         String realpath = request.getServletContext().getRealPath("/");
         // 输出文件路径
         String filepath = realpath + filedir + "/" + filename;
         response.setContentType("application/octet-stream;charset=utf-8");
         response.setHeader("Content-Disposition", "attachment;filename=" + filename);
         response.addHeader("Pragma", "no-cache");
         response.addHeader("Cache-Control", "no-cache");
         try {
             OutputStream os = response.getOutputStream();
             InputStream is = new BufferedInputStream(new FileInputStream(filepath));
             byte[] buffer = new byte[4096];
             int length = 0;
             while((length = is.read(buffer)) > 0) {
                 os.write(buffer, 0, length);
             }
             is.close();
             os.close();
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

     /**
      * SpringMVC下载
      * @return 文件名称
      */
     @RequestMapping(value="graceDownload", method={RequestMethod.GET, RequestMethod.POST})
     public ResponseEntity<byte[]> graceDownload(HttpServletRequest request, String filename) {
         String realpath = request.getServletContext().getRealPath("/");
         // 输出文件路径
         String filepath = realpath + filedir + "/" + filename;
         byte[] byteArray = null;
         try {
             byteArray = FileUtils.readFileToByteArray(new File(filepath));
         } catch(Exception e) {
             e.printStackTrace();
         }
         HttpHeaders headers = new HttpHeaders();
         headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
         headers.setContentDispositionFormData("attachment", filename);
         ResponseEntity<byte[]> responseEntity = new ResponseEntity<byte[]>(byteArray, headers, HttpStatus.CREATED);
         return responseEntity;
     }