在Node.js中获取request.body值未定义？

Question

my front end code:

    console.log('In front end ', UserDetails.fname);
    $.ajax({
        type: 'POST',
        data: UserDetails.fname,
        url: 'http://localhost:3000',
        success: function(data){
            console.log('Success!!');
        },
        error: function(error){
            console.log('Error!!');
        }
    })

In first console line the UserDetails.fname printing correctly. But when I send it to the back end, the back end shows it as undefined .

my back end code

var express = require('express');
var mysql = require('mysql');
var bodyParser = require('body-parser');
var userId = 1;
var conn = mysql.createConnection({
    host: 'localhost',
    user: 'root',
    password: '',
    database: 'facebook'
});

conn.connect(function(err){
    if(!err){
        console.log('Database connection success...');
    } else {
        console.log('Failed to connect to database...')
    }

});
var app = express();
// Add headers
app.use(function (req, res, next) {
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');
    res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');
    res.setHeader('Access-Control-Allow-Credentials', true);
    next();
});

app.use(bodyParser.json({ type: 'application/*+json' }));
app.use(bodyParser.raw({ type: 'application/vnd.custom-type' }));
app.use(bodyParser.text({ type: 'text/html' }));

app.post("/", function(req, res){
    console.log(req.headers);
    console.log('body: ' + JSON.stringify(req.body));
    res.send(req.body);
});
app.listen(3000);

I have updated my code. But still I have the same probelm.

Answer 1

Make sure to put your body-parser code above all the routes

var bodyParser = require('body-parser');

var app = express();
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

Answer 2

Did you setup a body parser in express ?

https://github.com/expressjs/body-parser#user-content-change-accepted-type-for-parsers