Question

我有一个客户端角度应用程序，它向节点js服务器发送POST请求。

order(market: string, price: string, side: string, size: string): Observable<any> {
        var payload = { market: market, order: { price: price, side: side, size: size } };
        return this.http.post<any>('http://localhost:3000' + "/orders", JSON.stringify(payload))
            .pipe(
                tap((res: any) => {
                   console.log(res);
                }),
                retry(3), // retry a failed request up to 3 times
                catchError(this.handleError) // then handle the error
            );
    }

带有express-generator的nodejs：

var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');
var cors = require('cors');
var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'pug');

app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
var corsOptions = {
    origin: 'http://localhost:4200',
    optionsSuccessStatus: 200 // some legacy browsers (IE11, various SmartTVs) choke on 204 
  }

app.use(cors(corsOptions))

app.use('/', indexRouter);
app.use('/users', usersRouter);

app.post('/orders', (req, res) => {
    console.log(req.body)   
});

// catch 404 and forward to error handler
app.use(function (req, res, next) {
    next(createError(404));
});

// error handler
app.use(function (err, req, res, next) {
    // set locals, only providing error in development
    res.locals.message = err.message;
    res.locals.error = req.app.get('env') === 'development' ? err : {};

    // render the error page
    res.status(err.status || 500);
    res.render('error');
});

module.exports = app;

角度应用可以访问nodejs应用中的方法

app.post('/orders', (req, res) => {
    console.log(req.body)
});

但req.body未定义。我在这里做错什么了吗？

Answer 1

您的后端代码对我来说看起来不错。我相信问题是由前端代码引起的。特别是这一行：

this.http.post<any>('http://localhost:3000' + "/orders", JSON.stringify(payload))

请勿对要发送到后端的数据进行字符串化处理。像这样更改它：

this.http.post<any>('http://localhost:3000' + "/orders", payload)

Answer 2

您需要使用body-parser，它是ExpressJS中间件，可让您解析POST请求。这是一个有据可查的问题，您也可以找到类似的S / O问题here

nodejs请求主体未定义

2 个答案: