连接 ECONNREFUSED 127.0.0.1:27017'

Question

新手上路，请多包涵

我有那个代码：

 var express = require('express'),
    stylus = require('stylus'),
    logger = require('morgan'),
    bodyParser = require('body-parser'),
    mongoose = require('mongoose');

var env = process.env.NODE_ENV = process.env.NODE_ENV || 'development';

var app = express();

function compile(str, path){
    return stylus(str).set('filename', path);
}

app.set('views', __dirname + '/server/views');
app.set('view engine', 'jade');
app.use(logger('dev'));
app.use(bodyParser.urlencoded({ extended: true }));
app.use(stylus.middleware(
        {
            src: __dirname + '/public',
            compile: compile
        }
    ));
app.use(express.static(__dirname + '/public'));

mongoose.connect('mongodb://localhost/multivision');
var db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error..'));
db.once('open', function callback(){
    console.log('multivision db opened');
});

app.get('/partials/:partialPath', function(req, res){
    res.render('partials/' + req.params.partialPath);
});

app.get('*', function(req, res) {
  res.render('index');
});

var port = 3131;
app.listen(port);
console.log('Listening on port ' + port + '...');

但是当我尝试 nodemon server.js 它会引发错误：