文件上传前生成目标路径 - multer

Question

在将文件上传到其中之前尝试创建一个文件夹。但是，如果我在尝试再次下载文件时不更新节点上的服务器，则会出现问题，它会添加到已创建的文件夹中。如果我更新服务器，它会创建一个新文件夹并根据需要上传。请看代码，我该如何改进？

const db = require('../db');
const fs = require('fs');
const path = require('path');
const uuidv1 = require('uuid/v1');
const multer = require('multer');

console.log(uuidv1())
let storage = multer.diskStorage({
  destination: `./uploads/${uuidv1()}`,
  filename: (req, file, cb) => {
    cb(null, 'test1' + '-' + Date.now() + '.' + path.extname(file.originalname));
  }
});

let upload = multer({storage});

module.exports = (router) => {

  router.get('/get', (req, res) => {
    db.connect.query('SELECT * FROM habalka',
      {type: db.sequelize.QueryTypes.SELECT}
    ).then(result => {
      res.json(result);
    })
  });

  router.post('/post', upload.any(), (req, res) => {
    res.json('test');


  });

  return router;
};

Answer 1

您的问题是当您启动您的应用时，它生成新的uuid（一次- 在应用程序启动时）并作为字符串传递给 diskStorage 方法。

但是您希望每次上传文件时都生成该路径。

所以这里是解决方案：

Multer 具有功能动态生成两个 目标路径 和 文件名.

所以你必须传递一个函数，它将生成路径并return它在回调.

阅读后的示例this manual：

let storage = multer.diskStorage({

  // pass function that will generate destination path
  destination: (req, file, cb) => {

    // initial upload path
    let destination = path.join(__dirname, 'uploads'); // ./uploads/

    // if user logged in and You store user object in session
    if (req.session && req.session.user && req.session.user.id) {
      destination = path.join(destination, 'users', req.session.user.id, uuidv1()); // ./uploads/users/8/generated-uuid-here/
    }
    else {
      destination = path.join(destination, 'files', uuidv1()); // ./uploads/files/generated-uuid-here/
    }

    cb(
      null, 
      destination
    );
  },

  // pass function that may generate unique filename if needed
  filename: (req, file, cb) => {
    cb(
      null, 
      Date.now() + '.' + path.extname(file.originalname)
    );
  }

});

Answer 2

我的最终代码在这里并且有效！谢谢

const db = require('../db');
const fs = require('fs');
const uuid = require('uuid');
const path = require('path');
const multer = require('multer');
const shell = require('shelljs');


console.log(uuid())

let storage = multer.diskStorage({

  // pass function that will generate destination path
  destination: (req, file, cb) => {
    // initial upload path
    let destination = path.join(__dirname, '../uploads'); // ./uploads/

    let id = uuid();
    shell.mkdir('-p', './uploads/' + id);
    destination = path.join(destination, '', id); // ./uploads/files/generated-uuid-here/
    console.log('dest', destination)

    cb(
      null,
      destination
    );
  },

  // pass function that may generate unique filename if needed
  filename: (req, file, cb) => {
   let ext = file.originalname.substring(file.originalname.lastIndexOf('.'), file.originalname.length);
  callback(null,file.originalname.split('.').slice(0,-1).join('.') + '-'+Date.now() +ext);
  }

});

var upload = multer({storage: storage})

module.exports = (router) => {

  router.get('/get', (req, res) => {
    db.connect.query('SELECT * FROM habalka',
      {type: db.sequelize.QueryTypes.SELECT}
    ).then(result => {
      res.json(result);
    })
  });

 app.post('/uploads', function (req, res) {
upload(req, res, function (err) {
  if (err) {
    console.log(err);
    return res.end("Something went wrong!");
  }else{
    
  let ext = req.file.originalname.substring(req.file.originalname.lastIndexOf('.'), req.file.originalname.length);
    var files='./uploads/'+req.file.originalname.split('.').slice(0 ,-1).join('.')+'-'+Date.now()+ext
    console.log(req.file.originalname);
    collection.insertOne({files},function(err,result){
      if(err){
           console.log("Something is Wrong");
      }else{
        
        res.json(result._id);
        console.log(result);
      }
    })
   }
});

})

  return router;
};

文件上传前生成目标路径 - multer

Generate destination path before file upload - multer

uuid

node.js

multer