Axios FormData（）获取空对象

Question

Browser-side code

let data = new FormData();
data.append('file', file);
data.append('userId', userId);


axios.post(`${baseUrl}/uploadFile`, data, {headers: {'Content-Type':'multipart/form-data'}}).then((result) => console.log(result)).catch((err) => cb(err))

Server side code

app.use((req, res, next) => {
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, DELETE, PUT, PATCH, OPTIONS');
    res.setHeader('Access-Control-Allow-Headers', 'Content-Type, api_key, Authorization'); 
    res.setHeader('Access-Control-Expose-Headers', 'Content-Range');
    next();
  }); 

app.use('/', express.static('public'))

app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());

I have tried almost everything but I always get an empty Object.

The file is a pdf

Anyone can help?

Answer 1

You are sending multipart/form-data encoded data.

You have:

 app.use(bodyParser.urlencoded({ extended: true })); app.use(bodyParser.json()); 

ie

• A decoder for URL encoded data
• A decoder for JSON encoded data

You don't have one for Multipart encoded data!

Now, since you are using it, see the documentation for body parser :

This does not handle multipart bodies, due to their complex and typically large nature. For multipart bodies, you may be interested in the following modules:

• busboy and connect-busboy
• multiparty and connect-multiparty
• formidable
• multer