spring mvc 上传下载

//下载
@RequestMapping("/attachmentDownload")
    @ResponseBody
    public ResponseEntity<byte[]> attachmentDownload(HttpServletRequest request, HttpServletResponse response,
        HttpSession session, String attachmentId) {
        logger.info("下载附件信息");
        Map<String, Object> params = new HashMap<String, Object>();
        // 附件id
        AttachmentEntity attachmentEntity = attachmentService.selectByID(attachmentId);
        // 附件名称
        String attachmentName = attachmentEntity.getAttachmentName();
        // 附件路径
        String attachmentPath = attachmentEntity.getAttachmentUuid();
        String filePath = "";
        ....................................
        File sourcefile = new File(filePath + File.separator + attachmentPath);
        try {
            if (sourcefile.exists()) {
                HttpHeaders headers = new HttpHeaders();
                String fileName = new String(attachmentName.getBytes("UTF-8"), "iso-8859-1");
                headers.setContentDispositionFormData("attachment", fileName);
                headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
                return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(sourcefile), headers,
                    HttpStatus.CREATED);
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            logger.error("附件下载异常!" + e.getMessage());
            e.printStackTrace();
        }
        return new ResponseEntity<>(HttpStatus.NO_CONTENT);
    }


//预览
    @RequestMapping("/attachmentView")
    @ResponseBody
    public void attachmentView(HttpServletRequest request, HttpServletResponse response, HttpSession session,
        String attachmentId) {
        logger.info("文件预览");
        response.setCharacterEncoding("gbk");
        // 查询附件信息
        AttachmentEntity attachmentEntity = attachmentService.selectByID(attachmentId);
        // 文件路径
        String filePath =
            PropertiesUtil.getRootPath(DataUtil.FILEPATH) + File.separator + getUserCompanyNo(request) + File.separator
                + attachmentEntity.getLoanContractNo();
        String fileTruePath = filePath + File.separator + attachmentEntity.getAttachmentUuid();
        if (new File(fileTruePath).exists()) {
            FileInputStream fis = null;
            OutputStream os = null;
            try {
                fis = new FileInputStream(fileTruePath);
                os = response.getOutputStream();
                int count = 0;
                byte[] buffer = new byte[1024 * 8];
                while ((count = fis.read(buffer)) != -1) {
                    os.write(buffer, 0, count);
                    os.flush();
                }
            } catch (Exception e) {
                e.printStackTrace();
                logger.error(e.getMessage());
            } finally {
                try {
                    fis.close();
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }


  private void writeFile(MultipartFile files, AttachmentEntity attachment, JSONObject json, String araNo)
        throws Exception {
        // TODO Auto-generated method stub
        logger.info("写入文件信息");
        String filePath =
            PropertiesUtil.getRootPath(DataUtil.FILEPATH) + File.separator + araNo + File.separator
                + attachment.getLoanContractNo();
        String originalFilename = files.getOriginalFilename();
        File rootFile = new File(filePath);
        String suffix = files.getOriginalFilename().substring(files.getOriginalFilename().lastIndexOf("."));
        String fileName = CommonUtils.getUuid() + suffix;
        File targetFile = new File(filePath + File.separator + fileName);
        if (!rootFile.exists()) {
            rootFile.mkdirs();
        }
        files.transferTo(targetFile);
        // 处理附件信息
        attachementSave(attachment, files, fileName);
    }

/异常捕获/
@ExceptionHandler
    @ResponseBody
    public JSONObject hanlerException(Exception ex, HttpServletRequest request, HttpServletResponse response)
        throws Exception {
        response.setContentType("text/html;charset=utf-8");
        JSONObject json = new JSONObject();
        json.put("status", "0");
        json.put("message", "操作成功!");
        if (ex instanceof MaxUploadSizeExceededException) {
            long maxSize = ((MaxUploadSizeExceededException)ex).getMaxUploadSize();
            json.put("message", "上传文件太大，不能超过" + maxSize / 1024 / 1024 + "M");
            json.put("status", "1");
        } else {
            json.put("message", "上传失败");
            json.put("status", "1");
        }

        return json;
    }