springmvc文件上传下载

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
　　<property name="defaultEncoding" value="UTF-8"></property>
　　<property name="maxUploadSize" value="数字"></property>
</bean>

　　@RequestMapping(value="fileupload",method=RequestMethod.POST)
    public String fileupload(String title,@RequestParam("upfiles") MultipartFile[] upfiles) {
        // 文件上传的代码
        System.out.println(title);
        //空文件不去上传操作
        for(MultipartFile upfile:upfiles) {
            if(upfile.getSize()>0) {
　　　　　　　　　　//文件上传服务器保存路径
                String path="D:\\upload\\";
                //上传文件的文件名
                String filename = upfile.getOriginalFilename();
                System.out.println(filename);
                File  file = new File(path+filename);
                try {
                     //上传文件开始
                    upfile.transferTo(    file);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }        
        return "show";
    }

　　@RequestMapping("download")
    public ResponseEntity<byte[]> download(String file){//创建下载路径
        String filename = file;
        String path = "D:\\upload\\";
        File file = new File(path + filename);

        HttpHeaders httpHeaders = new HttpHeaders();
        //获取文件后缀
        int i1 = filename.lastIndexOf(".");
        String substring = filename.substring(i1);

        //设置下载时文件名
        filename=filename+substring;
　　　　　//将文件名进行url转码
        try {
            filename = URLEncoder.encode(filename,"utf-8");
        } catch (UnsupportedEncodingException e) {
            System.out.println("上传异常");
            e.printStackTrace();
        }
        httpHeaders.setContentDispositionFormData("attachment", filename);
        //设置二进制流方式下载
        httpHeaders.setContentType(MediaType.APPLICATION_OCTET_STREAM);

        try {
            return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file), httpHeaders, HttpStatus.OK);
        } catch (Exception e) {
            session.setAttribute("load","fail");
            e.printStackTrace();
        }

        return null;

    }