根据时间随机数生成随机文件名 ，SpringMVC 上传文件

 /**
  * 获取当前时间 yyyyMMddHHmmss
  * @return String
  */
 public static String getCurrTime() {
  Date now = new Date();
  SimpleDateFormat outFormat = new SimpleDateFormat("yyyyMMddHHmmss");
  String s = outFormat.format(now);
  return s;
 }

/**
  * 取出一个指定长度大小的随机正整数.
  *
  * @param length
  *            int 设定所取出随机数的长度。length小于11
  * @return int 返回生成的随机数。
  */
 public static int buildRandom(int length) {
  int num = 1;
  double random = Math.random();
  if (random < 0.1) {
   random = random + 0.1;
  }
  for (int i = 0; i < length; i++) {
   num = num * 10;
  }
  return (int) ((random * num));
 } 

-----------------------------------------------------------------SpringMVC上传文件

@RequestMapping(value = "/doAdd", method = RequestMethod.POST)
 public String doAdd(@RequestParam("imgFile") MultipartFile file, HttpServletRequest request, WaterSingle waterSingle) {
  if(null != file){
   if(StringUtils.isEmpty(file.getOriginalFilename())){
    waterSingle.setWaterName("");
   }else{
    String realFileName = file.getOriginalFilename();
    realFileName = Utils.generateRandomFilename() + realFileName.substring(realFileName.lastIndexOf("."));
    String path = GlobalStatic.uploadFilePath5 + realFileName;
    Utils.uploadfile(file, path);
    User user = (User) getSession().getAttribute("currentUser");
    waterSingle.setWaterName(realFileName);
    waterSingle.setUserName("登录名：" + user.getLoginName() + "，真实姓名："+user.getTrueName());
    waterSingle.setUploadTime(new Date());
   }
   waterSingleService.addWaterSingle(waterSingle);
  }
  return "redirect:/watersingle/list";
 }

 

public static boolean  uploadfile(MultipartFile file,String fileFullName){
  try {
   FileOutputStream fileOutputStream=new FileOutputStream(new java.io.File(fileFullName));
   InputStream fis=file.getInputStream();
   byte[] buff=new byte[1024];
   @SuppressWarnings("unused")
   int length=0;
   while((length=fis.read(buff))>0){
    fileOutputStream.write(buff);
   }
   fileOutputStream.flush();
   fileOutputStream.close();
   fis.close();
   return true;
  } catch (FileNotFoundException e) {
   // TODO Auto-generated catch block
   throw new RuntimeException(e);
  } catch (IOException e)
  {
   throw new RuntimeException(e);
  }
  //return false;
  
 }

public static void copyFile(File src, File dst) {
  InputStream in = null;
  OutputStream out = null;

  try {

   in = new BufferedInputStream(new FileInputStream(src), BUFFER_SIZE);

   out = new BufferedOutputStream(new FileOutputStream(dst),

   BUFFER_SIZE);

   byte[] buffer = new byte[BUFFER_SIZE];

   int len = 0;

   while ((len = in.read(buffer)) > 0) {

    out.write(buffer, 0, len);

   }

  } catch (Exception e) {

   e.printStackTrace();

  } finally {

   if (null != in) {

    try {

     in.close();

    } catch (IOException e) {

     e.printStackTrace();

    }

   }

   if (null != out) {

    try {

     out.close();

    } catch (IOException e) {

     e.printStackTrace();

    }

   }

  }

 }