Error : getaddrinfo ENOTFOUND in node.js

在学习《Node.js In Action》时，第三章Node programming fundamentals中有讲如何处理serial flow的方法，将例子敲到电脑上却发现会报错，例子如下：

var fs = require('fs');var request = require('request');var htmlparser = require('htmlparser');var configFilename = './rss_feeds.txt';function checkForRSSFile () {  fs.exists(configFilename, function(exists) {    if (!exists) {      return next(new Error('Missing RSS file: ' + configFilename));    }    console.log(exists);    next(null, configFilename);  });}function readRSSFile(configFilename) {  fs.readFile(configFilename, function(err, feedList) {    if (err) return next(err);    feedList = feedList              .toString()              .replace(/^\s+|\s+$/g, '')              .split("\n");    var random = Math.floor(Math.random()*feedList.length);    console.log(feedList[random]);    next(null, feedList[random]);  });}function downloadRSSFeed(feedUrl) {  request({uri: feedUrl}, function(err, res, body) {    if (err) return next(err);    if (res.statusCode != 200) {      return next(new Error('Abnormal response status code'));    }    console.log(body);    next(null, body);  });}function parseRSSFeed (rss) {  var handler = new htmlparser.RssHandler();  var parser = new htmlparser.Parser(handler);  parser.parseComplete(rss);  if (!handler.dom.items.length) {    return next(new Error('No RSS items found'));  }  var item = handler.dom.items.shift();  console.log(item.title);  console.log(item.link);}var tasks = [ downloadRSSFeed,              parseRSSFeed ];function next(err, result){  if (err) throw err;  var currentTask = tasks.shift();  if(currentTask) {    currentTask(result);  }}next();

它总是会报：

Error: getaddrinfo ENOTFOUND    at errnoException (dns.js:37:11)    at Object.onanswer [as oncomplete] (dns.js:124:16)

在查阅https://github.com/mikeal/request时看到

Super simple to use

Request is designed to be the simplest way possible to make http calls. It supports HTTPS and follows redirects by default.

var request = require('request');request('http://www.google.com', function (error, response, body) {  if (!error && response.statusCode == 200) {    console.log(body) // Print the google web page.  }})

还是会报错，在网上查了好久都没有找到解决方法，暂时记录在此。