nodeAPI--HTTP

HTTP:   //超文本协议，是属于TCP上层的协议

• http协议构建在请求和响应概念上，node.js中对应http.ServerRequest,http.ServerResponse;
• 当用户浏览网站，用户代理（浏览器）会创建一个请求，该请求通过TCP发送给web服务器；

流对接：

var http = require('http');
var fs = require('fs');
var stream;

http.createServer(function (req, res) {
	res.writeHead(200,{'Content-Type':'image/png'});
	stream = fs.createReadStream('1.png');
	stream.on('data', function(data) {
		res.write(data);
	});
	stream.on('end', function() {
		res.end();
	});
}).listen(3000);
--------------------------------------------
require('http').createServer(function (req, res) {
	res.writeHead(200,{'Content-Type':'image/png'});
	require('fs').createReadStream('1.png').pipe(res);
}).listen(3000);

一个简单web服务器的例子：

• querystring模块：它能将一个字符串解析成一个对象；

require('querystring').parse('name = guillermo');
//{"name":"guillermo"}

• url和method判断，headers ：req.url ; req.method //返回的是大写; req.headers //返回的是数组
• data和end事件

var http = require('http');
var qs = require('querystring');
http.createServer(function(req, res) {
	if('/' === req.url) {
		res.writeHead(200, {'Content-Type': 'text/html'});
		res.end([
			'<form method="post" action="/url">',
			'<h1>My form</h1>',
			'<fieldset>',
			'<label>Personal information</label>',
			'<p>What is your name?</p>',
			'<input type = "text" name = "name">',
			'<p><button>Submit</button></p>',
			'</form>'
		].join(''));
	} else if('/url' === req.url && 'POST' === req.method) {
		var body = '';
		req.on('data', function(chunk) {
			body += chunk;
		});
		req.on('end', function() {
			res.writeHead(200, {'Content-Type': 'text/html'});
			res.end('<p>Your name is <b>' + qs.parse(body).name + '</b></p>');
		});
	} else {
		res.writeHead(404);
		res.end('Not Found');
	}
}).listen(3000);

client和server通信：

• 简单例子：
  • server:

    var http = require('http');
    var qs = require('querystring');
    http.createServer(function(req, res) {
    	res.writeHead(200);
    	res.end('Hello World');
    }).listen(3000);

  • client:

    var http = require('http');
    http.request({     //初始化一个http.Client Request对象
    	host: '127.0.0.1',
    	port: 3000,
    	url: '/',
    	method: 'get'
    }, function(res) {
    	var body = '';
    	res.setEncoding('utf8');
    	res.on('data', function(chunk) {
    		body += chunk;
    	});
    	res.on('end', function() {
    		console.log('
     We got: 33[96m' + body + '33[39m
    ');
    	});
    }).end();

• 通信：

  • server:

    var qs = require('querystring');
    var http = require('http');
    http.createServer(function(req, res) {
    	var body = '';
    	req.on('data', function(chunk) {
    		body += chunk;
    	});
    	req.on('end', function() {
    		res.writeHead(200);
    		res.end('Done');
    		console.log('
     got name 33[90m' + qs.parse(body).name + '33[39m
    ');
    	});
    }).listen(3000);

  • client:

    var http = require('http');
    var qs = require('querystring');
    
    function send(theName) {
    	http.request({
    		host: '127.0.0.1',
    		port: 3000,
    		url: '/',
    		method: 'POST'
    	}, function(res) {
    		res.setEncoding('utf8');
    	    console.log('
     33[90m request complete!33[39m');
    		process.stdout.write('
     your name: ')
    	
       }).end(qs.stringify({name: theName}));
    }
    process.stdout.write('
     your name: ');
    process.stdin.resume();
    process.stdin.setEncoding('utf-8');
    process.stdin.on('data', function(name) {
    	send(name.replace('
    ',''));
    });