我使用 MERN Stack 创建了一个 Whatsapp 克隆。面对后端错误

Question

我在 Whatsapp 克隆的后端创建了 WhatsApp 克隆，但我面临以下错误。 当我运行yarn start 时，我在控制台中遇到以下错误。

        yarn start
yarn run v1.23.0-20200615.1913



  $ node server.js
(node:4316) [MONGODB DRIVER] Warning: the options [useUnifedTopology] is not supported
(Use `node --trace-warnings ...` to show where the warning was created)
listen on local host 6000

（节点：4316）[MONGODB DRIVER] 警告：当前服务器发现和监控引擎已弃用，并将在未来版本中删除。要使用新的服务器发现和监控引擎，请将选项 { useUnifiedTopology: true } 传递给 MongoClient 构造函数。

E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\topologies\server.js:441
          new MongoNetworkError(
          ^

MongoNetworkError: failed to connect to server [cluster0-shard-00-01.ngclm.mongodb.net:27017] on first connect [MongoError: bad auth : Authentication failed.
    at Connection.messageHandler (E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\connection\connection.js:362:19)
    at Connection.emit (node:events:390:28)
    at processMessage (E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\connection\connection.js:454:10)
    at TLSSocket.<anonymous> (E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\connection\connection.js:623:15)
    at TLSSocket.emit (node:events:390:28)
    at addChunk (node:internal/streams/readable:315:12)
    at readableAddChunk (node:internal/streams/readable:289:9)
    at TLSSocket.Readable.push (node:internal/streams/readable:228:10)
    at TLSWrap.onStreamRead (node:internal/stream_base_commons:199:23) {
  ok: 0,
  code: 8000,
  codeName: 'AtlasError'
}]
    at Pool.<anonymous> (E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\topologies\server.js:441:11)
    at Pool.emit (node:events:390:28)
    at E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\connection\pool.js:564:14
    at E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\connection\pool.js:1013:9
    at callback (E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\connection\connect.js:75:5)
    at E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\connection\connect.js:147:27
    at E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\auth\scram.js:109:14
    at _callback (E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\connection\connection.js:331:7)
    at Connection.messageHandler (E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\connection\connection.js:362:9)
    at Connection.emit (node:events:390:28)
    at processMessage (E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\connection\connection.js:454:10)
    at TLSSocket.<anonymous> (E:\Whatapp clone\whatsapp-backend\node_modules\mongodb\lib\core\connection\connection.js:623:15)
    at TLSSocket.emit (node:events:390:28)
    at addChunk (node:internal/streams/readable:315:12)
    at readableAddChunk (node:internal/streams/readable:289:9)
    at TLSSocket.Readable.push (node:internal/streams/readable:228:10)

我的主文件 Server.js （这是主文件）

// Import

import express from "express";
import mongoose from "mongoose";
import Messages from './dbMessages.js';
import Pusher from "pusher";
import cors from "cors";

import axios from "axios";

// app config
const app = express();
const port = process.env.PORT || 6000;

// Pusher code
const pusher = new Pusher({
    appId: "1366318",
    key: "eb9c7412499f6e7b4c5f",
    secret: "6903a1ffa86fcb2c3ddd",
    cluster: "ap2",
    useTLS: true
  });
  
// middle ware
app.use(express.json());
app.use(cors());
app.use((req,res, next ) => {
    res.setHeader("Access-Control-Allow-Origin" ,"*");
    res.setHeader( "Access-Control-Allow-Origin" ,"*");
    next();
});
// DB Config
const connection_url='mongodb+srv://whatsapp:[email protected]/whatsapp?retryWrites=true&w=majority';

mongoose.connect(connection_url,{
    useCreateIndex: true,
    useNewUrlParser: true,
    useUnifedTopology: true
})

// ?????
const db = mongoose.connection;

db.once("open",()=>{
    console.log("db connected");
    // message contents is from mongodb database
    const msgCollection = msgCollection('whatsapp'); //collection name in mongodb messagecontents
    // messagecontents changing to whatsapp
    const changeStream = msgCollection.watch();
    // Change Stream  function
    changeStream.on("change", (change) => 
    {
        // this is when we troggling pusher
        console.log('A changed is occur',change);

        if (change.operationType === 'insert'){
            const messageDetails = change.fullDocument;
            pusher.trigger('message', 'insert', {
                name:messageDetails.user,
                message: messageDetails.message,
                timeStamp: messageDetails.timeStamp,
                received: messageDetails.received
            });
        } else {
            console.log('Error Troggling pusher');
        }
    });
});
// api router
app.get('/',(req,res) => {
    res.status(200).send("Hello World");
});

// api to get all the data from database
app.get('/messages/sync' , (req,res) => {
//    Messsages.find() to get back all the messages
   Messages.find((err,data) => {
        if (err) {
            res.status(500).send(err)
        }
         else {
             res.status(200).send(data)
         }
    });
});


app.post('/api/messages/new', (res,req) => {
    const dbMessage = req.body 
    message.create(dbMessage, (err,data)=>{
        if (err){
            res.status(500).send(err)
        }
        else {
            res.status(201).send(`new number created: \n ${data}`)
        }

    });
});
// listen
app.listen(port, () => console.log(`listen on local host ${port}`));

我的架构 (dbMessages.js)

import mongoose from "mongoose";

const whatsappSchema = mongoose.Schema({
    message:String,
    name:String,
    timestamp:String
});

export default mongoose.model('whatsapp', whatsappSchema);

我的 Package.Json

{
  "name": "whatsapp-backend",
  "version": "1.0.0",
  "discription": "",
  "main": "server.js",
  "type": "module",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "node server.js",
    "nodemon":"nodemon --experimental-modules --es-module-specifier-resolution=node "
  },
  "keywords": [],
  "author": "zain",
  "license": "ISC",
  "dependencies": {
    "cors": "^2.8.5",
    "express": "^4.17.3",
    "express_js": "^1.0.0",
    "mongoose": "^6.2.5",
    "nodemon": "^2.0.15",
    "pusher": "^5.0.1",
    "pusher-js": "^7.0.6"
  }
}

Answer 1

删除此行并运行：

import react from 'react';

Answer 2

从 Server.js 文件中删除 import React from 'react'; 因为服务器端不知道 React 是什么。