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File uploads are a common feature in many web applications, but handling them efficiently and securely can be challenging. In this article, we will explore how to implement efficient file uploads using Node.js, Express.js, and MongoDB. We will cover the entire process, from setting up the server to storing files in MongoDB GridFS, ensuring that your application can handle large files without sacrificing performance.
Handling file uploads efficiently involves several challenges:
We will use the following stack to address these challenges:
multipart/form-data
, which is used for uploading files.First, let’s create a new Node.js project and install the necessary dependencies.
mkdir file-upload-app
cd file-upload-app
npm init -y
npm install express multer mongoose gridfs-stream
Next, we will set up a basic Express server.
// server.js
const express = require('express');
const mongoose = require('mongoose');
const multer = require('multer');
const { GridFsStorage } = require('multer-gridfs-storage');
const Grid = require('gridfs-stream');
const methodOverride = require('method-override');
const bodyParser = require('body-parser');
const crypto = require('crypto');
const path = require('path');
const app = express();
// Middleware
app.use(bodyParser.json());
app.use(methodOverride('_method'));
app.set('view engine', 'ejs');
// Mongo URI
const mongoURI = 'mongodb://localhost:27017/fileupload';
// Create mongo connection
const conn = mongoose.createConnection(mongoURI, { useNewUrlParser: true, useUnifiedTopology: true });
// Init gfs
let gfs;
conn.once('open', () => {
// Init stream
gfs = Grid(conn.db, mongoose.mongo);
gfs.collection('uploads');
});
// Create storage engine
const storage = new GridFsStorage({
url: mongoURI,
file: (req, file) => {
return new Promise((resolve, reject) => {
crypto.randomBytes(16, (err, buf) => {
if (err) {
return reject(err);
}
const filename = buf.toString('hex') + path.extname(file.originalname);
const fileInfo = {
filename: filename,
bucketName: 'uploads'
};
resolve(fileInfo);
});
});
}
});
const upload = multer({ storage });
// @route POST /upload
// @desc Uploads file to DB
app.post('/upload', upload.single('file'), (req, res) => {
res.json({ file: req.file });
});
// @route GET /files
// @desc Display all files in JSON
app.get('/files', (req, res) => {
gfs.files.find().toArray((err, files) => {
// Check if files
if (!files || files.length === 0) {
return res.status(404).json({
err: 'No files exist'
});
}
// Files exist
return res.json(files);
});
});
// @route GET /files/:filename
// @desc Display single file object
app.get('/files/:filename', (req, res) => {
gfs.files.findOne({ filename: req.params.filename }, (err, file) => {
if (!file || file.length === 0) {
return res.status(404).json({
err: 'No file exists'
});
}
return res.json(file);
});
});
// @route GET /image/:filename
// @desc Display Image
app.get('/image/:filename', (req, res) => {
gfs.files.findOne({ filename: req.params.filename }, (err, file) => {
if (!file || file.length === 0) {
return res.status(404).json({
err: 'No file exists'
});
}
// Check if image
if (file.contentType === 'image/jpeg' || file.contentType === 'image/png') {
// Read output to browser
const readstream = gfs.createReadStream(file.filename);
readstream.pipe(res);
} else {
res.status(404).json({
err: 'Not an image'
});
}
});
});
// @route DELETE /files/:id
// @desc Delete file
app.delete('/files/:id', (req, res) => {
gfs.remove({ _id: req.params.id, root: 'uploads' }, (err, gridStore) => {
if (err) {
return res.status(404).json({ err: err });
}
res.redirect('/');
});
});
const port = 5000;
app.listen(port, () => console.log(`Server started on port ${port}`));
We can test our implementation using tools like Postman.
http://localhost:5000/upload
with form data containing the file.http://localhost:5000/files
to get the list of all files.http://localhost:5000/files/:filename
to get a specific file’s details.http://localhost:5000/image/:filename
to view the image in the browser.http://localhost:5000/files/:id
to delete a file.In this article, I demonstrated how to handle file uploads efficiently using Node.js, Express.js, and MongoDB. By leveraging GridFS, we can store and manage large files seamlessly, ensuring scalability, security, and performance. This approach can be further customized and expanded based on specific application requirements, making it a versatile solution for file management in modern web applications.