请求 urlencoded 正文在 express 中为空

Question

I'm trying to get url parameters in express 4.17.3 using the urlencoded middleware but the body is always empty, I reproducted it to a minimal code:

const express = require("express");

(()=>{
    const app  = express();
    app.use(express.urlencoded());
    
    app.get("/", async(req, res)=>{
        console.log(req.body); //always print '{}'
        res.send();
    });
    
    app.listen(83, ()=>{
        console.log("test app listening on port 83");
    })
})();

Here's my request

http://localhost:83/?param1=42

What am I doing wrong?

Answer 1

A few things to break down. To answer your question to get params you can use req.query so your code would be:

app.get('/', async (req, res) => {
  console.log(req.query)
  res.send()
})

Addressing urlencoded it should be changed from:

app.use(express.urlencoded());

to:

app.use(express.urlencoded({ extended: true }))

good habit to not hard code the port so the line of code:

app.listen(83, ()=>{
  console.log("test app listening on port 83");
})

should be:

const PORT = process.env.PORT || 83

app.listen(PORT, () => {
  console.log(`test app listening on port ${PORT}`)
})

full working code example:

const express = require('express')
const app = express()

app.use(express.urlencoded({ extended: true }))

const PORT = process.env.PORT || 83

app.get('/', async (req, res) => {
  console.log(req.query)
  res.send()
})

app.listen(PORT, () => {
  console.log(`test app listening on port ${PORT}`)
})

When using express I also like to implement nodemon and if you add this to your package.json :

"dev": "nodemon node index.js"

then in the terminal you can run:

npm run dev

you wont have to restart your server during development changes.