标签：node   node.js   核心模块   学习笔记   陈小道   

第4章 Node.js核心模块

4.1、全局对象

4.2、常用工具util

util.inherits(constructor，superConstructor)是一个实现对象间原型继承的函数。

var util = require('util');

function Base() {
	this.name = 'base';
	this.base = 1989;

	this.sayHello = function() {
		console.log('Hello ' + this.name);
	};
}

Base.prototype.showName = function() {
	console.log(this.name);
};

function Sub() {
	this.name = 'sub';
}

util.inherits(Sub, Base);

var objBase = new Base();
objBase.showName();
objBase.sayHello();
console.log(objBase);

var objSub = new Sub();
objSub.showName();
//objSub.sayHello();
console.log(objSub);

/*
运行结果：
base
Hello base
{ name: 'base', base: 1991, sayHello: [Function] }
sub
{ name: 'sub' }
 */

var util = require('util');

function Person() {
	this.name = 'ichenxiaodao';
	this.toString = function() {
		return this.name;
	};
}

var obj = new Person();

console.log(util.inspect(obj));
console.log(util.inspect(obj, true));

/*
运行结果：
{ name: 'ichenxiaodao', toString: [Function] }
{ name: 'ichenxiaodao',
  toString:
   { [Function]
     [length]: 0,
     [name]: '',
     [arguments]: null,
     [caller]: null,
     [prototype]: { [constructor]: [Circular] } } }
 */

除了以上我们介绍的几个函数之外，util还提供了util.isArray()、util.isRegExp()、util.isDate()、util.isError()四个类型测试工具，以及util.format()、util.debug()等工具。有兴趣的读者可以访问http://nodejs.org/api/util.html了解详细内容。

4.3、事件驱动events

var events = require('events');

var emitter = new events.EventEmitter();

//注册事件
//指定事件注册一个监听器,接受一个字符串event和一个回调函数listener。
emitter.on("someEvent", function(arg1, arg2) {
	console.log("listener1", arg1, arg2);
});

//注册事件
emitter.on("someEvent", function(arg1, arg2) {
	console.log("listener2", arg1, arg2);
});

//发射事件
//发射event事件,传递若干可选参数到事件监听器的参数表。
emitter.emit("someEvent", "ichenxiaodao", 1989);

/*
运行结果：
listener1 ichenxiaodao 1989
listener2 ichenxiaodao 1989
 */

var events = require('events');

var emitter = new events.EventEmitter();

emitter.emit('error');

/*
运行结果：
events.js:74
        throw TypeError('Uncaught, unspecified "error" event.');
              ^
TypeError: Uncaught, unspecified "error" event.
    at TypeError (<anonymous>)
    at EventEmitter.emit (events.js:74:15)
    at Object.<anonymous> (/Users/cdz/workspace/my-node/NodeJS_Dev_Guide_Book/4/error.js:5:9)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:906:3
 */

4.4、文件系统fs

4.5、HTTP服务器与客户端

var http = require('http');

http.createServer(function(req, res) {
	res.writeHead(200, {
		'Content-Type': 'text/html'
	});
	res.write('<h1>Node.js</h1>');
	res.end('<p>Hello World</p>');
}).listen(3000);

console.log("HTTP server is listening at port 3000.");

var http = require('http');

var server = new http.Server();

server.on('request', function(req, res) {
	res.writeHead(200, {
		'Content-Type': 'text/html'
	});
	res.write('<h1>Node.js</h1>');
	res.end('<p>Hello World</p>');
});

server.listen(3000);

console.log("HTTP server is listening at port 3000.");

var http = require('http');
var url = require('url');
var util = require('util');

http.createServer(function(req, res) {
	res.writeHead(200, {
		'Content-Type': 'text/plain'
	});
	res.end(util.inspect(url.parse(req.url, true)));
}).listen(3000);

/*
访问：
http://127.0.0.1:3000/user?name=ichenxiaodao&email=ichenxiaodao@gmail.com
返回：
{ protocol: null,
  slashes: null,
  auth: null,
  host: null,
  port: null,
  hostname: null,
  hash: null,
  search: '?name=ichenxiaodao&email=ichenxiaodao@gmail.com',
  query: { name: 'ichenxiaodao', email: 'ichenxiaodao@gmail.com' },
  pathname: '/user',
  path: '/user?name=ichenxiaodao&email=ichenxiaodao@gmail.com',
  href: '/user?name=ichenxiaodao&email=ichenxiaodao@gmail.com' 
}

*/

var http = require('http');
var querystring = require('querystring');
var util = require('util');

http.createServer(function(req, res) {
	var post = '';

	req.on('data', function(chunk) {
		post += chunk;
	});

	req.on('end', function(chunk) {
		post = querystring.parse(post);
		res.end(util.inspect(post));
	});
}).listen(3000);

var http = require('http');
var querystring = require('querystring');

var contents = querystring.stringify({
	name: "ichenxiaodao",
	email: "ichenxiaodao@gmail.com",
	address: "Shanghai"
});

var options = {
	host: "www.byvoid.com",
	path: "/application/node/post.php",
	method: "POST",
	headers: {
		"Content-Type": "application/x-www-form-urlencoded",
		"Content-Length": contents.length
	}
};

var req = http.request(options, function(res) {
	res.setEncoding('utf-8');
	res.on('data', function(data) {
		console.log(data);
	});
});

req.write(contents);
req.end();

拓展阅读：http://nodejs.org/api/index.html

文档信息

• 版权声明：自由转载-非商用-非衍生-保持署名 | Creative Commons BY-NC-ND 3.0

• 原文网址：http://blog.csdn.net/cdztop/article/details/33473299

• 最后修改时间：2014年06月23日 01:04

Node.js【5】核心模块,布布扣,bubuko.com

Node.js【5】核心模块

标签：node   node.js   核心模块   学习笔记   陈小道   

原文地址：http://blog.csdn.net/cdztop/article/details/33473299