Node Js 学习笔记

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hello world

console.log("hello world");

node first.js

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事件

var events = require("events") eventEmitter = new events.EventEmitter();

eventEmitter.on('test',function(){}); eventEmitter.emit("test"); eventEmitter.emit('error');

• on
• emit
• addListener
• removeListener
• listeners
• setMaxListeners
• once
• removeAllListeners

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Buffer

var b = new Buffer(10); b.write("this is a test"); b.toJSON()

• new Buffer(size)
• new Buffer(buffer)
• new Buffer(str,[,encoding])
• buf.length
• buf.write(string)
• buf.toString()
• buf.toJSON()
• buf[index]
• buf.equals(otherBuffer)
• buf.compare(otherBuffer)
• buf.copy(targetBuffer)
• buf.slice()
• buf.fill()

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Stream

• Readable
• Writable
• Duplex
• Transform

事件

• data
  • end
  • error
  • finish

var fs = require('fs') var reader = fs.createReadStream('input.txt') var write = fs.createWriteStream('output.txt') reader.pipe(write)

fs.createReadStream('input.txt') .pipe(zlib.createGzip()) .pipe(fs.createWriteStream('input.txt.gz'));

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一个简单的http server

var http = require("http")

function onRequest(request,response) {
    response.writeHead(200,{"Content-Type":"text/plain"});
    response.write("Hello World");
    response.end();

}

http.createServer(onRequest).listen(8888);

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一个可以解析请求参数的http server

function route(pathname) {
  console.log("About to route a request for " + pathname);
}

exports.route = route;

var http = require("http");
var url = require("url");

function start(route) {
  function onRequest(request, response) {
    var pathname = url.parse(request.url).pathname;
    console.log("Request for " + pathname + " received.");

    route(pathname);

    response.writeHead(200, {"Content-Type": "text/plain"});
    response.write("Hello World");
    response.end();
  }

  http.createServer(onRequest).listen(8888);
  console.log("Server has started.");
}

exports.start = start;

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全局变量

• __filename
• __dirname
• setTimeout
• clearTimeout
• setInterval
• console
• process

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常用的工具

util.inherits

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 = 1991; 
    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); 

util.inspect

util.inspect(object,[showHidden],[depth],[colors])是一个将任意对象转换 为字符串的方法，通常用于调试和错误输出。它至少接受一个参数 object，即要转换的对象。

• util.isArray(object)
• util.isRegExp(object)
• util.isDate(object)
• util.isError(object)

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文件系统

var fs=require("fs")

• fs.readFile()
• fs.readFileSync()
• fs.stat
• fs.writeFile()
• fs.read
• fs.close
• fs.unlink
• fs.mkdir
• fs.readdir
• fs.rmdir
• fs