简单实现文件的上传下载

最新推荐文章于 2025-06-04 19:18:46 发布

滑头鬼的鬼

最新推荐文章于 2025-06-04 19:18:46 发布

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文章标签： java

本文链接：https://blog.youkuaiyun.com/li15974168626/article/details/107245433

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public HashMap<String, Object> downloadFile( HttpServletResponse response ,Model model,HashMap<String, Object> errorMap,HttpServletRequest request) {
   //待下载文件名
   String fileName = (String) model.asMap().get("downloadName");

       // 文件中文显示乱码
   String userAgent = request.getHeader("user-agent").toLowerCase();
if (userAgent.contains("msie") || userAgent.contains("like gecko") ) {
// win10 ie edge 浏览器和其他系统的ie
fileName = URLEncoder.encode(fileName, "UTF-8");
} else {
// fe
fileName = new String(fileName.getBytes("utf-8"), "iso-8859-1");
}
   //设置为格式的文件
   response.setContentType("application/octet-stream");
   response.setHeader("Content-Disposition", "attachment; filename=" + fileName);
   byte[] buff = new byte[1024];
   //创建缓冲输入流
   BufferedInputStream bis = null;
   OutputStream outputStream = null;
   try {
   outputStream = response.getOutputStream();

   //这个路径为待下载文件的路径
   bis = new BufferedInputStream(new FileInputStream(new File((String) model.asMap().get("newpath"))));
   int read = bis.read(buff);

   //通过while循环写入到指定了的文件夹中
   while (read != -1) {

   并不是每次都能读到1024个字节，用read作为每次读取数据的长度，否则会出现文件损坏的错误
   outputStream.write(buff, 0, read);
   outputStream.flush();
   read = bis.read(buff);
   }
   } catch ( IOException e ) {
   e.printStackTrace();
   //出现异常返回给页面失败的信息

   errorMap.put("errorMap", true);
   } finally {
   if (bis != null) {
   try {
   bis.close();
   } catch (IOException e) {
   e.printStackTrace();
   }
   }
   if (outputStream != null) {
   try {
   outputStream.close();
   } catch (IOException e) {
   e.printStackTrace();
   }
   }
   }

   return errorMap;
   }

   /**
   *
   * @param model
   * @param uploadFile
   * @param errorMap
   * @return
   */
   private HashMap<String, Object> uploadFiles(Model model, MultipartFile uploadFile,
           HashMap<String, Object> errorMap) {
           InputStream inputStream = null;
           OutputStream outputStream = null;
       try {
//path路径均为常量
           String path = new StringBuilder()
                   .append(uploadTemporaryDirectory)
                   .append(File.separator)
                   .append(CommonConstants.STR_TAS_TASK)
                   .append(File.separator)
                   .append(CommonConstants.STR_TAS_TEMPORARY_UPLOAD)
                   .append(File.separator)
                   .toString();
           inputStream = uploadFile.getInputStream();
           String fileName = uploadFile.getOriginalFilename();
           File targetFile = new File(path + fileName);
           if (!targetFile.getParentFile().exists()) {
               targetFile.getParentFile().mkdirs();
           }
           outputStream = new FileOutputStream(targetFile);
           FileCopyUtils.copy(inputStream, outputStream);
       } catch (IOException e) {
           e.printStackTrace();
           errorMap.put("errorMap", true);
           return errorMap;
       } finally {
           if (inputStream != null) {
               try {
                   inputStream.close();
               } catch (IOException e) {
                   e.printStackTrace();
               }
           }
           if (outputStream != null) {
               try {
                   outputStream.close();
               } catch (IOException e) {
                   e.printStackTrace();
               }
           }
       }
       return errorMap;
   }