node events.js：136 throw er;未处理的“错误”事件

Question

我正在接受events.js：136 throw er;未处理的'错误'事件不知道如何以及为什么？ 我已经重新安装了nodejs和mongodb，但是抛出了相同的错误。

的package.json

{
"name": "bookstore",
"version": "1.0.0",
"description": "simple bookstore app",
"main": "app.js",
"devDependencies": {},
"scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
},
"dependencies": {
    "express": "*",
    "body-parser": "*",
    "mongoose": "*"
},
"author": "AveesP",
"license": "ISC"

}

App.js代码

var express = require('express');
var app = express();
var bodyParser = require('body-parser');
var mongoose = require('mongoose');
//connect to mongoose
mongoose.connect('mongodb://localhost/bookstore');
var db = mongoose.connection;
app.get('/', function(req, res) {
   res.send('Hello world!');
});
app.listen(3000);
console.log('Running on port 3000...');

Answer 1

尝试使用以下命令扩大激活观察者的处理程序数量（应用程序监听器更改）

sudo sysctl fs.inotify.max_user_watches=524288 sudo sysctl -p --system

Answer 2

我有根本原因..我没有使用mongodb建立任何数据库连接错误..

感谢马克的时间。

Answer 3

端口问题

app.listen(8080);

试试这些代码

  var http = require('http');
 //create a server object:
  http.createServer(function (req, res) {
 res.write('Hello World!'); //write a response to the client
 res.end(); //end the response
}).listen(8080); //the server object listens on port 8080