无法将 axios post 发送到节点 js 服务器 - net::ERR_CONNECTION_REFUSED 在本地主机上

Question

我正在尝试从我的 localhost:3000 上的 react/node/axios 网站和本地主机上的 node/nodemailer 服务器运行发送表单：4000，当提交form/axios.post 需要几秒钟然后我在 clg 上收到此错误：

Error: Network Error at createError (createError.js:16) at XMLHttpRequest.handleError 
(xhr.js:84) xhr.js:177 POST http://localhost:4000/send_mail net::ERR_CONNECTION_REFUSED

我在代码和我的机器上尝试了很多东西，比如禁用 firewall/protections... 没有任何效果。

这是我正在使用的 React 组件：

import React from 'react';
import { Link } from 'react-router-dom';
import ReCAPTCHA from 'react-google-recaptcha';
import axios from 'axios';

import './style.css';

const ContactForms = () => {
    const [isWork, setIsWork] = React.useState(false);

    const [name, setName] = React.useState('');
    const [telephone, setTelephone] = React.useState('');
    const [email, setEmail] = React.useState('');
    const [file, setFile] = React.useState();
    const [message, setMessage] = React.useState('');

    const [sent, setSent] = React.useState(false);
    const [msg, setMsg] = React.useState('');
    const recaptchaRef = React.createRef();

    console.log(sent);
    console.log(name);

    const handleSand = async (e) => {
        e.preventDefault();

        const token = await recaptchaRef.current.executeAsync();

        // const formData = new FormData();
        // formData.append('name', name);
        // formData.append('telephone', telephone);
        // formData.append('email', email);
        // formData.append('token', token);
        // formData.append('file', file);
        // formData.append('message', message);

        axios
            .post('http://localhost:4000/send_mail', {
                name,
                telephone,
                email,
                token,
                file,
            })
            .then((r) => {
                setSent(true);
                setMsg(r.data.message);
            })
            .catch((e) => {
                console.log(e);
            });
    };

    console.log(file);

    if (sent) return <div>{msg}</div>;
    return (
        <>
            {!sent ? (
                <section className="faleConosco" id="forms">
                    <div className="faleConosco__background"></div>
                    <div className="faleConosco__formulario">
                        <div className="faleConosco__buttons">
                            <button
                                className="button--amarelo amarelo"
                                onClick={() => setIsWork(false)}
                            >
                                Fale conosco
                            </button>
                        </div>
                        <div className="faleConosco__info">
                            <h2 className="faleConosco__title title--style">
                                Faça parte do nosso time
                            </h2>
                            <span className="faleConosco__subtitle">
                                E transforme a gestão de telecom com a gente
                            </span>

                            <form className="formularioContato" onSubmit={handleSand}>
                                <input
                                    type="text"
                                    placeholder="Nome completo"
                                    value={name}
                                    onChange={(e) => setName(e.target.value)}
                                    required
                                />
                                <button type="submit" className="button--azul">
                                    Enviar
                                </button>

                                <label>
                                    <input type="checkbox" required />
                                    Eu li, estou ciente das condições de tratamento dos meus dados
                                    pessoais e dou meu consentimento, quando aplicável, conforme
                                    descrito nesta política de privacidade
                                </label>

                                <ReCAPTCHA
                                    sitekey="6Lf3EpAaAAAAAOaWFeNFGhqaQk0Fab4gMfDclxx0"
                                    size="invisible"
                                    ref={recaptchaRef}
                                />
                            </form>
                        </div>
                    </div>
                </section>
            ) : (
                <section className="faleConosco" id="forms">
                    <div className="faleConosco__background"></div>
                    <div className="faleConosco__formulario">
                        <h1>enviado</h1>
                    </div>
                </section>
            )}
        </>
    );
};

export default ContactForms;

这是我的服务器代码：

const express = require('express');
const app = express();

require('dotenv').config();

const bodyParser = require('body-parser');
const cors = require('cors');
const nodemailer = require('nodemailer');

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

app.use(cors());

app.post('/send_mail', cors(), async (req, res) => {
    let { text } = req.body;
    const transport = nodemailer.createTransport({
        service: process.env.MAIL_SERVICE,
        auth: {
            user: process.env.MAIL_USER,
            pass: process.env.MAIL_PASS,
        },
        tls: {
            rejectUnauthorized: false,
        },
    });

    await transport.sendMail({
        from: `Leads Tel&Com <${process.env.MAIL_USER}>`,
        to: `${process.env.MAIL_USER}`,
        subject: 'teste',
        text: 'teste',
    });
});

app.listen(
    (process.env.PORT || 4000,
    () => {
        console.log('Server is listening on port 4000');
    })
);

Answer 1

我注意到您正在使用 cors() 作为中间件，那么您为什么要在后端的 post 路由中再次发送 cors()。对后端的任何请求最终都会通过 app.use(cors())，无需在 post 路由中再次发送 cors。

同时检查您的前端，您很可能遇到了 cors 错误。可能是因为上面提到的问题。

Answer 2

我认为你的后端应用不是运行，你有额外的括号 app.listen((....)) 和 app.listen

旧代码

app.listen(
    (process.env.PORT || 4000,
    () => {
        console.log('Server is listening on port 4000');
    })
);

新密码

app.listen(process.env.PORT || 4000, () => {
    console.log('Server is listening on port 4000');
});

无法将 axios post 发送到节点 js 服务器 - net::ERR_CONNECTION_REFUSED 在本地主机上

Not able to send an axios post to a node js server - net::ERR_CONNECTION_REFUSED on localhost

node.js

nodemailer

reactjs

axios