最近想私下做些项目充实下自己空余时间，闲逛github发现node.js很火闲来没事参合一下。

##node.js简介 Node.js is a platform built on Chrome’s JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.

##安装node.js

git clone https://github.com/joyent/node.git
//不一定是稳定版

稳定版如下方式:

wget http://nodejs.org/dist/v0.10.5/node-v0.10.5.tar.gz
tar -zxvf node-v0.10.5.tar.gz

cd node-v0.10.5
./configure
make
make install

##hello world vim hello.js:

console.log("Hello World");

通过node.js来执行

node hello.js

正常的话，就会在终端输出Hello World

##安装模块

npm install <package>

在下面的应用中会用到formidable

npm install formidable

##一个完整的基于Node.js的web应用

####index.js:

var server = require("./server");
var router = require("./router");
var requestHandlers = require("./requestHandlers");

var handle = {};
handle["/"] = requestHandlenpm install <package.json folder>rs.start;
handle["/start"] = requestHandlers.start;
handle["/upload"] = requestHandlers.upload;
handle["/show"] = requestHandlers.show;

server.start(router.route, handle);

####server.js:

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

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

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

exports.start = start;

####router.js:

function route(handle, pathname, response, request) {
	//console.log("About to route a request for" + pathname);
	if (typeof handle[pathname] === 'function') {
		handle[pathname](response, request);
	} else {
		//console.log("No request handler found for " + pathname);
		response.writeHead(404, {"Content-Type": "text/plain"});
		response.write("404 Not found"); 
		response.end();
	}
}

exports.route = route;

####requestHandlers.js:

var querystring = require("querystring");
var fs = require("fs");
var formidable = require("formidable");

function start(response, request) {
	console.log("Request handler 'start' was called");
	var content = "empty";

	var body = '<html>'+     
		'<head>'+
		'<meta http-equiv="Content-Type" content="text/html;charset=UTF-8" />'+     
		'</head>'+     
		'<body>'+      
		'<form action="/upload" enctype="multipart/form-data" method="post">'+      
		/*'<textarea name="text"></textarea>'+*/ 
		'<input type="file" name="upload">'+    
		'<input type="submit" value="Upload file" />'+  
		'</form>'+     
		'</body>'+     
		'</html>'; 

	response.writeHead(200, {"Content-Type": "text/html"});
	response.write(body);
	response.end();
}


function upload(response, request) {
	console.log("Request handler 'upload' was called");

	var form = new formidable.IncomingForm();
	console.log("about to parse");
	form.parse(request, function(error, fields, files) {     
		console.log("parsing done");      
		fs.renameSync(files.upload.path, "/tmp/test.png");      
		response.writeHead(200, {"Content-Type": "text/html"});     
		response.write("received image:<br/>");     
		response.write("<img src='/show' />");     
		response.end();   
	});node-js-demo.tar.gz
}

function show(response, request) {    
	console.log("Request handler 'show' was called.");    
	fs.readFile("/tmp/test.png", "binary", function(error, data) {     
		if(error) { 
			console.log("readFile error"); 
			response.writeHead(500, {"Content-Type": "text/plain"});       
			response.write(error + "\n");       
			response.end();     
		} else {
			response.writeHead(200, {
				"Content-Type": "image/png",
				"Content-Length": data.length,
			});       
			response.write(data,"binary");       
			response.end();     
		}  
	}); 
} 

exports.start = start;
exports.upload = upload;
exports.show = show;

参考资料

1.名词王国的死刑

资源打包下载

node-js-demo.tar.gz