req.body是空的，我无法弄清楚为什么

Question

I'm new to express and node and I'm trying to make an axios post to my server but the req.body is coming up empty when I console.log in node. Anyone know what I'm doing wrong? I'm console logging and sending to postman.

Here is server.js

const app = require('express')()
const bodyParser = require('body-parser');



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

app.get('/', (req, res) => {

  res.send('hello')
})

const port = 4444;

app.post('/send', (req, res) => {
      console.log('body: ', req.body)
      res.status(200).send(req.body)
});



app.listen(port, () => {
  console.log('We are live on port 4444');
});

My axios call

export default class Form extends Component {
     constructor(props) {
         super(props) 
         this.state = {
            name: 'kaleb',
            message: '',
            email: '',
            number: '',
            sent: false
         }




     }

     handleChange = (e) => {
        this.setState({
            [e.target.name]: e.target.value
        })

     }

     handleSubmit = () => {
         axios.post("/send", {name: this.state.name}).then(() => {
             console.log(this.state.name)
         })


     }

Answer 1

try this In server.js:

    app.use(bodyParser.json());
    app.use(bodyParser.json({type: 'application/*+json'}));
    app.use(bodyParser.urlencoded({extended: false}));//or true whatever you need

axios call:

    axios({method:'post',url:'/send',data:{name:this.state.name}})
      .then(console.log(this.state.name));

Answer 2

Try putting the url as http://localhost:4444/send in your axios call:

 handleSubmit = () => {
         axios.post("http://localhost:4444/send", {name: this.state.name}).then(() => {
             console.log(this.state.name)
         })

Answer 3

Ok, Here's what I think after read all of the above comments.

1. You said, when you send the request via postman it's console.log an empty req.body. So there's no problem with your URL. It's heading to correct router. Postman have 3 content types. Just select "X-www-form-urlencoded" & send the request again. It should work.
2. In your component, You said nothing happen after submit. Most probably the problem should be with your URL. Your backend server runs on PORT 4444 & usually react app run on PORT 3000. So when you call axios.post('/send') it's actually sent to localhost:3000/server instead of localhost:4444/server . Now it will not work. You need to set up a proxy to avoid this problem. Here's the way https://facebook.github.io/create-react-app/docs/proxying-api-requests-in-development . Or you can just use axios.post('http://localhost:4444/server')

Note: if you use axios.post('http://localhost:4444/server') , you will face to the cors issue. Use this to eliminate that issue https://www.npmjs.com/package/cors

Answer 4

这通常是通过将urlencoded扩展名设置为true引起的，请尝试以下操作：

app.use(bodyParser.urlencoded({ extended: false }))