使用Multer重命名上传的文件不起作用(Express.js)

Question

我正在尝试使用Express.js和Multer从HTML表单上传文件.我已设法将文件保存到所需位置(名为uploads的文件夹).

但是,我想在上传时重命名该文件,因为默认情况下,Multer给它一个奇怪的名字,例如:

5257ee6b035926ca99923297c224a1bb

可能是一个十六进制时间戳左右,但我需要一个更明确的名称,以便稍后调用它上面的脚本.

我按照这里的解释,但它没有做任何更多的事情:上传带有hexa名称的文件.

此外,似乎永远不会触发onFileUploadStart和onFileUploadComplete这两个事件,因为我的控制台中没有记录任何内容.

我正在为服务器和路由使用两个单独的文件:

app.js

/**
 * Dependencies
 */

var express = require('express');
var path = require('path');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

/**
 * Importation of routes
 */
var routes = require('./routes/index');
var recog = require('./routes/recog');

/**
 * Express
 */
var app = express();

app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended: false}));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

// pour contrer les erreurs de cross domain
app.use(function (req, res, next) {

    // Website you wish to allow to connect
    res.setHeader('Access-Control-Allow-Origin', '*');

    // Request methods you wish to allow
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE');

    // Request headers you wish to allow
    res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');

    // Set to true if you need the website to include cookies in the requests sent
    // to the API (e.g. in case you use sessions)
    res.setHeader('Access-Control-Allow-Credentials', true);

    // Pass to next layer of middleware
    next();
});

/**
 * Routes
 */
app.use('/', routes);
app.use('/recog', recog);

module.exports = app;

recog.js

/**
 * Requirements
 */
var express = require('express');
var router = express.Router();
var multer = require('multer');
var uploads = multer({
    dest: 'uploads/',
    rename: function (fieldname, filename) {
        console.log("Rename...");
        return filename + Date.now();
    },
    onFileUploadStart: function () {
        console.log("Upload is starting...");
    },
    onFileUploadComplete: function () {
        console.log("File uploaded");
    }
});

/**
 * Upload d'une image
 */
router.post('/upload', uploads.single('image'), function (req, res, next) {
    console.log("Front-end is calling");
    res.json({status: 'success', data: 'Fichier chargé.\nOrgane sélectionné : ' + req.body.organ});
});

module.exports = router;

我一直在挖掘,但我无法弄清楚问题是什么,因为我对Node.js和JavaScript一般都是新手.

谢谢你的帮助!

Answer 1

Multer的用法已经改变.

目前,Multer构造函数只接受三个选项:

1. DIST /存储
2. 的FileFilter
3. 范围

现在重命名,onFileUploadStart,onFileUploadComplete不起作用.

但是可以使用DiskStorage重命名

var storage = multer.diskStorage({
    destination: function (req, file, cb) {
        cb(null, '/tmp/my-uploads')
    },
    filename: function (req, file, cb) {
        cb(null, file.fieldname + '-' + Date.now())
  }
})

var upload = multer({ storage: storage })

看看这些链接:

• https://github.com/expressjs/multer
• multer回调不起作用？

Answer 2

我知道这篇文章已过时了.我想为那些可能晚些时候到达的人做出贡献.下面是一个功能齐全的服务器脚本,用于处理多个上传的图片,其中包含随机保存的图片名称

var express = require("express");
var multer = require("multer");
var app = express();
var path = require("path");
var uuid = require("uuid");

// Allow cross origin resource sharing (CORS) within our application
app.use(function(req, res, next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
    next();
});

var storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, 'uploadedimages/')
  },
  filename: function (req, file, cb) {
    cb(null, uuid.v4() + path.extname(file.originalname));
  }
})

var upload = multer({ storage: storage })

// "files" should be the same name as what's coming from the field name on the client side.
app.post("/upload", upload.array("files", 12), function(req, res) {
    res.send(req.files);
    console.log("files = ", req.files);
});

var server = app.listen(3000, function() {
    console.log("Listening on port %s...", server.address().port);
});

Answer 3

试试我正在使用的这种方式

  var storage = multer.diskStorage({
    destination: function (req, file, cb) {
      cb(null, 'uploads/')
    },
    filename: function (req, file, cb) {
      console.log(file);
      var fileObj = {
        "image/png": ".png",
        "image/jpeg": ".jpeg",
        "image/jpg": ".jpg"
      };
      if (fileObj[file.mimetype] == undefined) {
        cb(new Error("file format not valid"));
      } else {
        cb(null, file.fieldname + '-' + Date.now() + fileObj[file.mimetype])
      }
    }
  })

  var upload = multer({ storage: storage })