node.js - 如何使用 multer 存储具有文件扩展名的文件？

Question

设法将我的文件存储在一个文件夹中，但它们存储时没有文件扩展名。

有谁知道我将如何存储带有文件扩展名的文件？

score 165 · Accepted Answer

我有一个解决方法来添加正确的文件扩展名。如果您使用path节点模块

var multer = require('multer');
var path = require('path')

var storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, 'uploads/')
  },
  filename: function (req, file, cb) {
    cb(null, Date.now() + path.extname(file.originalname)) //Appending extension
  }
})

var upload = multer({ storage: storage });

score 52 · Accepted Answer

来自文档：“Multer 不会为您附加任何文件扩展名，您的函数应返回带有文件扩展名的完整文件名。”

以下是添加扩展的方法：

var multer = require('multer');

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

var upload = multer({ storage: storage });

我建议使用该mimetype属性来确定扩展名。例如：

filename: function (req, file, cb) {
  console.log(file.mimetype); //Will return something like: image/jpeg

更多信息：https ://github.com/expressjs/multer

score 16 · Accepted Answer

我从file.mimetype. 我拆分了 mimetype 并从中获取文件扩展名请尝试以下功能。

let storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, './uploads')
  },
  filename: function (req, file, cb) {
    let extArray = file.mimetype.split("/");
    let extension = extArray[extArray.length - 1];
    cb(null, file.fieldname + '-' + Date.now()+ '.' +extension)
  }
})
const upload = multer({ storage: storage })

score 8 · Accepted Answer

可以这样做：

var storage = multer.diskStorage({
    destination: function (req, file, cb) {
        cb(null, config.DIR)
    },
    filename: function (req, file, cb) {
        let ext = file.originalname.substring(file.originalname.lastIndexOf('.'), file.originalname.length);
        cb(null, Date.now() + ext)
    }
});
const upload = multer({
    storage: storage
}).any();

score 6 · Accepted Answer

import multer from 'multer';
import * as shortid from 'shortid';
import * as mime from 'mime-types';

const storage = multer.diskStorage({
  destination: function (req,file,cb) {
    cb(null, '/path/to/uploads/');
  },
  filename: function (req,file,cb) {
    /* generates a "unique" name - not collision proof but unique enough for small sized applications */
    let id = shortid.generate();
    /* need to use the file's mimetype because the file name may not have an extension at all */
    let ext = mime.extension(file.mimetype);
    cb(null, `${id}.${ext}`);
  }
});

编辑

shortid 已被弃用，您应该使用 nanoid。

import multer from 'multer';
import * as nanoid from 'nanoid';
import * as mime from 'mime-types';

const storage = multer.diskStorage({
  destination: function (req,file,cb) {
    cb(null, '/path/to/uploads/');
  },
  filename: function (req,file,cb) {
    /* generates a "unique" name - not collision proof but unique enough for small sized applications */
    let id = nanoid();
    /* need to use the file's mimetype because the file name may not have an extension at all */
    let ext = mime.extension(file.mimetype);
    cb(null, `${id}.${ext}`);
  }
});

score 4 · Accepted Answer

我使用这个小技巧来获取文件扩展名，并作为一种解决方法来规避当有人上传具有相似文件名的文件两次或服务器中存在的文件时可能出现的问题。

const path = require('path');
const crypto = require('crypto');

let upload = multer({
storage: multer.diskStorage({
    destination: (req, file, cb) => {
        cb(null, path.join(__dirname, '../uploads'))
    },
    filename: (req, file, cb) => {
        // randomBytes function will generate a random name
        let customFileName = crypto.randomBytes(18).toString('hex')
        // get file extension from original file name
        let fileExtension = path.extname(file.originalname).split('.')[1];
        cb(null, customFileName + '.' + fileExtension)
    }
  })
})

score 3 · Accepted Answer

已经回答的代码中可能存在一些问题。

可能有一些文件没有扩展名的情况。
不应该有upload.any()用法。它容易受到攻击者的攻击
上传功能不应该是全局 的。

为了更好的安全性，我编写了以下代码。

var storage = multer.diskStorage({
    destination: function (req, file, cb) {

        cb(null, 'temp/')
    },
    filename: function (req, file, cb) {
        let ext = ''; // set default extension (if any)
        if (file.originalname.split(".").length>1) // checking if there is an extension or not.
            ext = file.originalname.substring(file.originalname.lastIndexOf('.'), file.originalname.length);
        cb(null, Date.now() + ext)
    }
})
var upload = multer({ storage: storage });

使用它进行上传

// using only single file object name (HTML name attribute)
// May use upload.array(["file1","file2"]) for more than one
app.post('/file_upload', upload.single("file"), function (req,res) {
    //console.log(req.body, 'Body');
    console.log(req.file, 'file');
    res.send("cool");
})

score 1 · Accepted Answer

文件扩展名可以是动态的。这是解决方案

const path = require('path'); // path for cut the file extension
const storage = multer.diskStorage({
    destination: function (req, file, cb) {
      cb(null, 'uploads')
    },
    filename: function (req, file, cb) {
      cb(null, 'upload_at_' + Date.now() + path.extname(file.originalname))
    }
  })

score 1 · Accepted Answer

我使用这种方法并且它有效。

我以这种格式存储文件：FieldName+Date+Extension => Profile1621416613594.jpg

var multer = require('multer');
    
var storage = multer.diskStorage({
    destination: function (req,file,cb){
        cb(null, './uploads')
    },
    filename: function (req,file,cb){
        cb(null,file.fieldname+'-'+Date.now()+'.'+file.mimetype.split('/').reverse()[0]);
    },
});

var upload = multer({storage: storage});

score 0 · Accepted Answer

一种面向对象的方式来存储具有唯一名称的图像

// image.service.ts
import { diskStorage, StorageEngine } from "multer";

class ImageStorageService {

    storage: StorageEngine
    constructor() {
        const MIME_TYPE_MAP = {
            'image/png': 'png',
            'image/jpeg': 'jpg',
            'image/jpg': 'jpg'
        }

        this.storage = diskStorage({
            destination: (req, file, callback) => {
                const isValid = MIME_TYPE_MAP[file.mimetype]
                let error = new Error(`Invalid mime type`)
                if (isValid)
                    error = null

                //app.use(express.static(path.join(`${__dirname}/assets`)))
                callback(error, 'assets/images')
            },
            filename: (req, file, callback) => {
                let currentFileName: string = file.originalname.substr(0, file.originalname.lastIndexOf('.'))
                const name = currentFileName.toLowerCase().split(' ').join('-')
                const ext = MIME_TYPE_MAP[file.mimetype]
                callback(null, `${name}-${Date.now()}.${ext}`)
            }
        })
    }
}

export const ImageStorage = new ImageStorageService().storage

然后在您的一条路线中

import { ImageStorage } from "./services/image-storage.service";

this.router.post('/signup', multer({ storage: ImageStorage }).single('image'), async (req, res, next) => {
    let img_url: string
    if (req.file) {
        const url: string = `${req.protocol}:\/\/${req.get('host')}`
        img_url = url + '/images/' + req.file.filename
        //http://localhost:3000/images/penguins-1548339248380.jpg
    }
})

score 0 · Accepted Answer

可以这样做...简单易懂

// validate uploaded files
const FILE_TYPE_MAP = {
  // mime type
  "image/png": "png",
  "image/jpeg": "jpeg",
  "image/jpg": "jpg",
};
const storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, "public/uploads");
  },
  filename: function (req, file, cb) {
    const filename = file.originalname.replace(" ", "-");
    const extension = FILE_TYPE_MAP[file.mimetype]
    cb(null, `${filename}-${Date.now()}.${extension}`);
  },
});

score 0 · Accepted Answer

常量 multer = 要求（'multer'）; 常量 uuid = 要求（'uuid/v1'）;

const MIME_TYPE_MAP = {
  'image/png': 'png',
  'image/jpeg': 'jpeg',
  'image/jpg': 'jpg'
};

const fileUpload = multer({
  limits: 500000,
  storage: multer.diskStorage({
    destination: (req, file, cb) => {
      cb(null, 'uploads/images');
    },
    filename: (req, file, cb) => {
      const ext = MIME_TYPE_MAP[file.mimetype];
      cb(null, uuid() + '.' + ext);
    }
  }),
  fileFilter: (req, file, cb) => {
    const isValid = !!MIME_TYPE_MAP[file.mimetype];
    let error = isValid ? null : new Error('Invalid mime type!');
    cb(error, isValid);
  }
});

module.exports = fileUpload;

score 0 · Accepted Answer

维护 multer 生成的唯一文件名并添加从 mimetype 解析的扩展名的简单帮助函数：

只需传递 multer 返回的对象

const fs = require('fs');

function renameWithExt(file) {
  const ext = file.mimetype.split('/')[1]; // parse the extension type

  fs.rename(`${file.path}`, `${file.path}.${ext}`, () => {
    console.log(`File: ${file.filename} renamed with extension '.${ext}'`);
  });
}

renameWithExt(req.file);

score 0 · Accepted Answer

我喜欢将原始文件名用于 SEO 目的。这需要更多检查是否已存在同名文件。此外，扩展解析通过几个步骤完成，以提供最大的灵活性。

var storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, 'uploads/')
  },
  filename: function (req, file, cb) {
    // try to get extension from original file name
    var lioDot = file.originalname.lastIndexOf('.');
    if (lioDot !== -1) {
      // I like to use original upload filename for SEO but first lets clean it 
      var newName = file.originalname.substring(0, lioDot).replace(/([^a-z0-9]+)/gi, '-');
      var ext = file.originalname.substring(lioDot, file.originalname.length);
    } else {
      var newName = file.originalname.replace(/([^a-z0-9]+)/gi, '-');
      // try to get extension from mime type string
      var extArray = file.mimetype.split("/");
      var ext = extArray[extArray.length - 1];
      // mime type extension resolving by pure string extraction is not accurate for a lot of types
      // https://www.freeformatter.com/mime-types-list.html
      // it's usually fine for ext strings up to 4 characters, png, jpeg, gif, bmp, tiff ..
      if (ext > 4) {
        // other mime types you would like to support
        var mimetypes = { 'vnd.openxmlformats-officedocument.wordprocessingml.document': '.docx' };
        if (mimetypes.hasOwnProperty(ext)) ext = mimetypes[ext];
      }
    }

    var newFullName = newName + ext;
    var i = 0;
    // we need to check if the file with the same name already exists
    // if it exists then we're adding something to make it unique 
    while (fs.existsSync(process.env.PWD + '/uploads/' + newFullName)) {
      newFullName = newName + '-' + ++i + ext;
    }
    cb(null, newFullName);
  }
})

const upload = multer({ storage: storage });

score 0 · Accepted Answer

我正在这样做

var multer  = require('multer');

var storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, './public/uploads/img/')
  },
  filename: function (req, file, cb) {
    let ext = file.originalname.substring(file.originalname.lastIndexOf('.'), file.originalname.length);
    cb(null, Date.now() + ext);
  }
})

var upload = multer({ storage: storage }).single('eventimage');

score -1 · Accepted Answer

const multer = require('multer');
const uuid = require('uuid/v1');

const MIME_TYPE_MAP = {
  'image/png': 'png',
  'image/jpeg': 'jpeg',
  'image/jpg': 'jpg'
};

const fileUpload = multer({
  limits: 500000,
  storage: multer.diskStorage({
    destination: (req, file, cb) => {
      cb(null, 'uploads/images');
    },
    filename: (req, file, cb) => {
      const ext = MIME_TYPE_MAP[file.mimetype];
      cb(null, uuid() + '.' + ext);
    }
  }),
  fileFilter: (req, file, cb) => {
    const isValid = !!MIME_TYPE_MAP[file.mimetype];
    let error = isValid ? null : new Error('Invalid mime type!');
    cb(error, isValid);
  }
});

module.exports = fileUpload;

node.js - 如何使用 multer 存储具有文件扩展名的文件？

16 回答 16

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