使用Node.js Express从改造中提取@Field参数

Question

I am trying to make an app in Android and have some problem. I have searched the web but I haven't found an obvious solution.

In my Android app I send a Post request for a login task using Retrofit.

@FormUrlEncoded
@POST("/login")
Call<Boolean> loginUser(@Field("username") String userName, @Field("password") String password);

My server is in Node.js with express and I don't know how to extract the username and password parameters.

my app.js file looks like this:

var http = require('http');
var express = require('express');
var bodyparser = require('body-parser');

var connection = require('./dbConnection');

var app = express();
require('./models')(app);
require('./controllers')(app);
require('./routes')(app);

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

connection.init();

var server = app.listen(3000, function() {
    console.log('Server listening on port ' + server.address().port);
});

And my routes file for login looks like this:

var loginM = require('../models/login');
var loginC = require('../controllers/login');

module.exports = function(app) {

    app.post('/login/', function(req, res, next) {
        loginM.attemptLogin(req.body, res);
    });
}

req.body does not seem to give me the @Field variables, I have tried req.headers and req.params as well with no success. Can someone explain how to extract them?

Much appreciated

Answer 1

On NodeJs side, or better: expressjs app side, you need to use a body-parser middleware, such as https://github.com/expressjs/body-parser

npm install body-parser --save

Since body-parser supports JSON as well as URL encoded input (which retrofit @Field generates) you need to add appropriate middleware functions to app:

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

// parse JSON inputs
app.use(bodyParser.json());

// Also, parse URL encoded inputs
app.use(bodyParser.urlencoded());

// handle requests
app.post('/login/', function(req, res, next) {
   loginM.attemptLogin(req.body, res);
});

Also , remember that you add body-parser middleware Before adding routes/controllers to the app. Because parser middleware should be executed before so that input is parsed by the time request handling logic is executed.

var app = express();

// first
app.use(bodyparser.urlencoded({extended: true}));
app.use(bodyparser.json());

// after
require('./models')(app);
require('./controllers')(app);
require('./routes')(app);