Question

main.js（仅限相关部分）

var express = require('express');
var app = require('express')(),
    expressSession = require('express-session'),
    cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

// Create application/x-www-form-urlencoded parser
var urlencodedParser = bodyParser.urlencoded({ extended: false })

// Access Middleware
var connect = require('connect');
var http = require('http');
var session = require('express-session');

app.use(express.static('public'));
app.use(expressSession({
    secret: 'SECKEY',
    resave: true,
    saveUninitialized: true
}));

app.post('/process_post', urlencodedParser, function (req, res) {
    // Prepare output in JSON format
    var response = {
        first_name:req.body.first_name,
        last_name:req.body.last_name
    };
    console.log(response);


    var post = req.body;
    if(post.first_name === 'u' && post.last_name === 'p') {
        res.session.user_id = 3;
        res.redirect('/home');
    } else {
        res.send('INVALID');
    }

    res.end(JSON.stringify(response));
});

这是我得到的错误：

TypeError: Cannot set property 'user_id' of undefined
   at D:\Users\Winston\Code\NodeJS Projects\Sample\main.js:43:29
   at Layer.handle [as handle_request] (D:\Users\Winston\Code\NodeJS Projects\Sample\node_modules\express\lib\router\layer.js:95:5)
   at next (D:\Users\Winston\Code\NodeJS Projects\Sample\node_modules\express\lib\router\route.js:131:13)
   at D:\Users\Winston\Code\NodeJS Projects\Sample\node_modules\body-parser\lib\read.js:121:5
   at invokeCallback (D:\Users\Winston\Code\NodeJS Projects\Sample\node_modules\body-parser\node_modules\raw-body\index.js:262:16)
   at done (D:\Users\Winston\Code\NodeJS Projects\Sample\node_modules\body-parser\node_modules\raw-body\index.js:251:7)
   at IncomingMessage.onEnd (D:\Users\Winston\Code\NodeJS Projects\Sample\node_modules\body-parser\node_modules\raw-body\index.js:308:7)
   at IncomingMessage.emit (events.js:104:17)
   at _stream_readable.js:908:16
   at process._tickCallback (node.js:355:11)

req.session没有工作，但我认为我定义了一切。我已经安装了connect和express-session中间件。我怎样才能在将来调试这样的问题？

编辑1：打印出req.session

{ cookie:
   { path: '/',
     _expires: null,
     originalMaxAge: null,
     httpOnly: true } }
{ first_name: 'u', last_name: 'p' }
{ cookie:
   { path: '/',
     _expires: null,
     originalMaxAge: null,
     httpOnly: true } }

Answer 1

您正在呼叫res.session而不是req.session

Answer 2

您在下面更改了代码：

res.session.user_id = 3;

到

req.session.user_id = 3;

Node.js req.session变量未定义

2 个答案: