为什么即使在节点服务器和 mongodb 加载后 localhost 也没有加载？

Question

我已经开始学习 MEAN 开发。我已经设置了我的快速服务器以及我的 mongodb 连接。在终端中运行 node server 时，服务器开始运行，mongo 也能够连接，但 localhost:8081/api/videos 没有加载。我清除了缓存和 cookie，但仍然没有解决方案。我附上下面的代码。

server.js

const express = require('express');
const bodyParser = require('body-parser');
const path = require('path');
const api = require('./server/routes/api');

// Port for express server
const port = 8081;

const app = express();

app.use(express.static(path.join(__dirname,'dist/mean')));
app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json);
app.use('/api', api);

app.get('*', (req,res)=> {
    res.sendFile(path.join(__dirname, 'dist/mean/index.html'));
});

app.listen(port, function(){
    console.log('Server running at localhost:' + port);
});

api.js

const express = require('express');
const router = express.Router();
const mongoose = require('mongoose');
const Video = require('../models/video');

// Creating mongo db connection
const db = 'mongodb+srv://<username>:<password>@training-qfjgb.mongodb.net/test?retryWrites=true&w=majority';
mongoose.Promise = global.Promise;
mongoose.connect(db, { useUnifiedTopology: true, useNewUrlParser: true }, err => {
    if(err) {
      console.log('Error: '+err);
    }
    else {
      console.log('Successfully connected to mongodb');
    }
  });

router.get('/videos', function(req, res){
    console.log('Get request for all videos');
    Video.find({}).exec(function(err, videos){
      if(err)
      {console.log('Error retrieving videos');}
      else
      {res.json(videos);}
    });
});

module.exports = router;

video.js（这是用于架构的）

const mongoose = require('mongoose');

const Schema = mongoose.Schema;

// Creating database schema

const videoSchema = new Schema({
    title: String,
    url: String,
    description: String
});

// Creating model of database videoplayer as model and then exporting
module.exports = mongoose.model('video', videoSchema, 'videoplayer');

Answer 1

const db = 'mongodb+srv://username:password@training-qfjgb.mongodb.net/test?retryWrites=true&w=majority';

用户名：密码应该更改。 admin:12345（如你所用）