为什么我得到未定义的对象，以及如何使用NodeJ解析json数据？

Question

My architecture is as follow:

• The server side is NodeJs

• The client side is HTML & JavaScript & JSON

I'm trying to send some data from client to server, but the server always get invalid data.

Server:

app.post('/process_post', urlencodedParser, function (req, res) {   
   console.log("Got POST (RES): " + res);
   console.log("Got POST (RES-BODT): " + res.body);
   res.sendFile( __dirname + "/" + "MyWeb.html" );
})

Client:

function onSubmit() {

    var xmlhttp;
    var result = '{"Q1":1,"Q2":3,"Q3":9}'                   
    xmlhttp=new XMLHttpRequest();
    xmlhttp.open("POST","~/process_post",true);
    xmlhttp.send(JSON.stringify(result));

    // same result when sending the next data:
    //xmlhttp.send("XYZ");
    return true;
}

but at the server side I'm always getting:

Got POST (RES): [object Object]
Got POST (RES-BODT): undefined

1. What am I missing ?
2. How can I get the parsed json data (Q1, Q2, Q3) at the server side ?

Thanks

Answer 1

Use express body-parser, if you use express: https://github.com/expressjs/body-parser

Add limit 50mb - for sending more date: app.use(bodyParser.json({limit: '50mb'})); app.use(bodyParser.urlencoded({limit: '50mb', extended: true})); app.use(bodyParser.json({limit: '50mb'})); app.use(bodyParser.urlencoded({limit: '50mb', extended: true}));