java web upload files and download file snippets to share

The example of this article is to share the specific code of java web to upload files and download files for your reference, the specific content is as follows

 /**
  * Purpose : upload documents 
  * 
  * @param req
  * @param fileTitle
  * @param fileType
  * @param fileDesc
  * @return
  */
 @RequestMapping("upload")
 public ModelAndView upload(HttpServletRequest req, String fileType, String fileDesc, String share) {
  UserAllInfo userAll = (UserAllInfo) req.getSession().getAttribute("userAll");
  ModelAndView mav = new ModelAndView();
  //  Gets the size of the file 
  String fileSize = "";
  int length = req.getContentLength();
  // Converted to KB
  double len1 = (double) (Math.round((length / 1024) * 100)) / 100;
  // Converted to MB
  double len2 = (double) (Math.round((len1 / 1024) * 100)) / 100;
  if (len2 > 1) {
   fileSize = String.valueOf(len2) + "MB";
  } else {
   fileSize = String.valueOf(len1) + "KB";
  }
  // Converts the request into a request to process the file 
  MultipartRequest mreq = (MultipartRequest) req;
  // File upload special class 
  MultipartFile mfile = mreq.getFile("uploadFile");

  //  Get the context path 
  String root = req.getSession().getServletContext().getRealPath("/");
  File dir = new File(root);
  //  Gets the filename and file mime type 
  String str = mfile.getOriginalFilename();
  String[] st = str.split("\\.");

  File savedFile = null;
  try {
   // Creates in the specified directory 1 Two new empty files prefixed with the name of the file "upload_"
   savedFile = File.createTempFile("upload_", mfile.getOriginalFilename(), dir);
   // Copies the contents of the buffer to the newly created file 
   FileCopyUtils.copy(mfile.getInputStream(), new FileOutputStream(savedFile));
  } catch (Exception e) {
   e.printStackTrace();
  }
  String path = savedFile.getPath();

  //  Encapsulates information about a file in an object 
  FileInfo file = new FileInfo();
  if (userAll != null) {
   file.setUploadPersonId(userAll.getUser().getUserId());
  } else {
   mav.setViewName("login");
   return mav;
  }
  file.setFileName(st[0]);
  file.setFilePath(path);
  Date date = new Date();
  file.setUploadDate(date);
  file.setFileSize(fileSize);
  file.setFileType(fileType);
  file.setFileForm(st[1]);
  if ("superman".equals(userAll.getUser().getUserNumber())) {
   file.setFileShare("Y");
   file.setCheckFlag("Y");
  } else {
   file.setFileShare(share);
   file.setCheckFlag("N");
  }
  file.setDeleteFlag("N");
  file.setDownloadTimes(0);
  //  Save the file information 
  boolean bool = fileSer.saveFile(file);
  String userNumber = userAll.getUser().getUserNumber();
  // Set jump interface 
  mav.setViewName("jsp/person/upload");
  logSer.saveLog(" The user \"" + userNumber + "\" Upload a file \"" + file.getFileName() + "\"");
  mav.getModel().put("bool", bool);
  return mav;
 }

 /**
  * Purpose : download the document 
  * 
  * @param fileId  file id
  * @return
  */
 @RequestMapping("download")
 public void download(Integer fileId, HttpServletResponse resp) {
  FileInfo file = new FileInfo();
  // Through the file id Get basic information about the file 
  file = fileSer.getFileById(fileId);

  //  Set the file by its suffix name mime type 
  String mime = "application/";
  switch (file.getFileForm()) {
  case "doc":
   mime = mime + "msword";
   break;
  case "docx":
   mime = mime + "msword";
   break;
  case "pdf":
   mime = mime + "pdf";
   break;
  case "xls":
   mime = mime + "vnd.ms-excel";
  case "ppt":
   mime = mime + "vnd.ms-powerpoint";
   break;
  case "txt":
   mime = "text/plain";
   break;
  default:
   break;
  }
  resp.setContentType(mime);
  String fileName = file.getFileName();
  String name = "";
  try {
   //  Use the filename utf-8 Encoding format encoding, so that the Chinese characters can be displayed normally 
   name = URLEncoder.encode(fileName, "utf-8");
  } catch (UnsupportedEncodingException e1) {
   e1.printStackTrace();
  }

  //  Select save path 
  resp.setHeader("content-disposition", "attachment;filename=" + name + "." + file.getFileForm()
    + ";filename*=utf-8''" + name + "." + file.getFileForm());

  String filePath = file.getFilePath();
  InputStream is = null;
  OutputStream os = null;
  try {
   is = new BufferedInputStream(new FileInputStream(filePath));
   os = new BufferedOutputStream(resp.getOutputStream());
   byte[] buff = new byte[1024];
   @SuppressWarnings("unused")
   int count;
   while ((count = is.read(buff)) != -1) {
    os.write(buff);
   }
   // Modify download times 
   fileSer.update(fileId);
  } catch (Exception e) {
   e.printStackTrace();
  } finally {
   // Finally, remember to close the input and output streams 
   if (is != null) {
    try {
     is.close();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
   if (os != null) {
    try {
     os.close();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
  }
 }