node工具--connect

HTTP構建一個網站：

var http = require('http');
var fs = require('fs');
var server = http.createServer(function(req, res) {
	if('GET' === req.method && '/img' === req.url.substr(0,4) && '.jpg' === req.url.substr(-4)) {
		fs.stat(__dirname + req.url, function(err, stat) { //檢查文件是否存在
			if(err || !stat.isFile()) {
				res.writeHead(404);
				res.end('Not Found');
				return;
			}
			serve(__dirname + req.url, 'image/png');  //'application/jpg'：會下載圖片
		});
	} else if('GET' === req.method && '/' === req.url) {
		serve(__dirname + '/index.html','text/html');
	} else {
		res.writeHead(400);
		res.end('Not Found');
	}
	function serve(path, type) {
		res.writeHead(200, {'Content-Type': type});
		fs.createReadStream(path).pipe(res); //將文件系統流接到HTTP響應流中;
	}

});
server.listen(3000);

經過connect實現一個網站：

• 建立package.json:

  {
  	"name": "my-website",
  	"version": "0.0.1",
  	"dependencies": {
  		"connect": "1.8.7"
  	},
  	"description": "an connect website"
  }

• 安裝依賴：npm install;
• 代碼例子：

  //用connect修改http構建的網站；
  var connect = require('connect');
  var server = connect.createServer();  //能夠簡化 server = connect();
  server.use(function(req, res, next) {
  	console.log(' %s: %s ', req.method, req.url);   
  	next();       //下一個中間件;
  });
  server.use(function(req, res, next) {
  	if('GET' === req.method && '/img' === req.url.substr(0,4)) {
  		console.log('img');
  	} else {
  		next();
  	}
  });
  server.use(function(req, res, next) {
  	if('GET' === req.method && '/' === req.url) {
  		console.log('index');
  	} else {
  		console.log('other');
  		next();
  	}
  });
  server.use(function(req, res, next) {
  	res.writeHead(404);
  	res.end('Not Found');
  });
  
  server.listen(3000);
  

 

中間件：//中間件由函數組成，它除了處理req,res對象外還接受　一個next函數作流控制；

//sample.js
/*
請求超時
*/
module.exports = function(opts) {
	var time = opts.time || 100;
	return function(req, res, next) {
		console.log(1);
		var timer = setTimeout(function() {
			console.log('\033[90m%s %s\033[91mis taking too long!\033[39m', req.method, req.url);
		}, time);
	    var end = res.end;
	    res.end = function(chunk, encoding) {
	    	res.end = end;
	    	res.end(chunk, encoding);
	    	clearTimeout();
	    }	
	    next();
   }
}




//main.js
var connect = require('connect');
var time = require('./3.2');
var server = connect.createServer();
/*
記錄請求狀況
*/
server.use(connect.logger('dev'));
/*
實現時間中間件
*/
server.use(time({time: 500}));
/*
快速響應
*/
server.use(function(req, res, next) {
	if('/a' === req.url) {
		res.writeHead(200);
		res.end('Fast!');
	} else {
		next();
	}
});
/*
慢速響應
*/
server.use(function(req, res, next) {
	if('/b' === req.url) {
		setTimeout(function() {
			res.writeHead(200);
			res.end('slow');	
		}, 1000);
	} else {
		next();
	}
});

server.listen(3000);

• static中間件：
  • 掛載:將任意一個URL匹配到文件系統中任意一個目錄

    server.use('/my-images', connect.static(__dirname + '/website/img'));

  • maxAge:設置一個資源客戶端緩存的時間

    server.use('/js', connect.static(__dirname, {maxAge:10000}));

  • hidden:設置爲true的話，connect也會託管文件系統中的隱藏文件

    server.use(connect.static(__dirname, {hidden:true}));

• query中間件：獲取查詢字符串  //query中間件在express中默認是啓用的；

  server.use(connect.query())
  server.use(function (req, res) {
      console.log(req.query.name);	   //req.query對象格式返回，如訪問xxx?name = jinks;返回{name:'jinks'}
  })

• logger中間件：診斷工具；將發送進來的請求信息和發送出去的響應信息打印在終端
  • server.use(connect.logger('dev'));

      

• • server.use(connect.logger('default'));

      

• • server.use(connect.logger('short'));

      

• • server.use(connect.logger('tiny'));

      

• • server.use(connect.logger(':method :remote-addr'  :res[Content-Length]));  //自定義格式輸出; 查看完整的token
• bodyParser中間層：
  • 與http模塊中使用qs模塊解析post請求消息體同樣，bodyParser中間層也具備這樣功能；

    server.use(connect.bodyParser());
    server.use(function(req, res, next) {
       //req.body;    
    }

  • 其另外一個功能就是處理用戶上傳的文件；

    var connect = require('connect');
    var fs = require('fs');
    var server = connect(connect.logger('dev'),connect.static('static'),connect.bodyParser());  //簡化加載中間件
    //設置默認url：'/'爲文件系統中static文件夾，若是有Index.html，就加載此項；
    server.use(function(req, res, next) {
    	if('POST' === req.method ) {
    		fs.readFile(req.files.files.path, 'utf8', function(err, data) {
    			if(err) {
    				res.writeHead(500);
    				res.end('Error!');
    				return;
    			}
    		res.writeHead(200, {'Content-Type': 'text/html'});
    		res.end([
    			'<h3>File: ' + req.files.files.name + '</h3>',
    			'<h4>Type: ' + req.files.files.type + '</h4>',
    			'<h1>Contents:</h4><pre>' + data + '</pre>'
    			].join(''));	
    		});
    	} else {
    		next();
    	}
    })
    
    server.listen(3000);

• cookieParser中間件; //讀寫cookie數據

  server.use(connect.cookieParser());
  
  server.use(function(req, res ,next) {
  	//req.cookies  //對象形式返回
  })；
  

• session中間件；

  • 出於安全考慮，在初始化session中間件的時候須要提供secret選項

    connect.session({secret: 'my app secret'})

  • 使用req.sesstion記錄數據：    req.session.logged_in； req.session.name

建立會話：

--------------users.json----------------------------------
//當只要對外暴露數據時，不須要module.exports而直接把數據文件以JSON形式暴露出來           
{
	"jinks": {
		"password" : "ferret",
		"name": "jinks"
	}
}

--------------app.js------------------------------------
var connect = require('connect');
var users = require('./users');

var server = connect(
	connect.logger('dev'),
	connect.bodyParser(),
	connect.cookieParser(),
	connect.session({secret: 'my app secret'}),
    function(req, res, next) {
    	console.log(req.session.logged_in);
		if('/' === req.url && req.session.logged_in) {
			res.writeHead(200, {'Content-Type': 'text/html'});
			res.end('welcome back, <b>' + req.session.name + '</b>. '
				+ '<a href="/logout">Logout</a>');
		} else {
			next();
		}
   },
	function(req, res, next) {
		if('/' === req.url && 'GET' === req.method) {
			res.writeHead(200, {'Content-Type': 'text/html'});
			res.end([
				'<form action="/login" method="post"'
			   +'<fieldset>'
			   +'<legend>Please log in</legend>'
			   +'<p>User: <input type="text" name="user"/></p>'
			   +'<p>Password: <input type="password" name="password"/></p>'
			   +'<button>Submit</button>'
			   +'</fieldset>'
			   +'</form>'].join(''));
		} else {
			next();
		}
	},
	function(req, res, next) {
		if('/login' === req.url && 'POST' === req.method) {
			res.writeHead(200);
			if(!users[req.body.user] || req.body.password != users[req.body.user].password) {
				res.end('Bad username/password');
			} else {
				req.session.logged_in = true;
				req.session.name = users[req.body.user].name;
				res.end('Authenticated!');
			}
		} else {
			next();
		}
	},
	function(req, res, next) {
		if('/logout' === req.url) {
			req.session.logged_in = false;
			res.writeHead(200);
			res.end('Logged out!');
		} else {
			next();
		}
	});

server.listen(3000);