node工具--connect

HTTP构建一个网站：

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) { //检查文件是否存在
			if(err || !stat.isFile()) {
				res.writeHead(404);
				res.end('Not Found');
				return;
			}
			serve(__dirname + req.url, 'image/png');  //'application/jpg'：会下载图片
		});
	} 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); //将文件系统流接到HTTP响应流中;
	}

});
server.listen(3000);

通过connect实现一个网站：

• 创建package.json:

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

• 安装依赖：npm install;
• 代码例子：

  //用connect修改http构建的网站；
  var connect = require('connect');
  var server = connect.createServer();  //可以简化 server = connect();
  server.use(function(req, res, next) {
  	console.log(' %s: %s ', req.method, req.url);
  	next();       //下一个中间件;
  });
  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);
  

中间件：//中间件由函数组成，它除了处理req,res对象外还接受　一个next函数做流控制；

//sample.js
/*
请求超时
*/
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();
/*
记录请求情况
*/
server.use(connect.logger('dev'));
/*
实现时间中间件
*/
server.use(time({time: 500}));
/*
快速响应
*/
server.use(function(req, res, next) {
	if('/a' === req.url) {
		res.writeHead(200);
		res.end('Fast!');
	} else {
		next();
	}
});
/*
慢速响应
*/
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中间件：
  • 挂载:将任意一个URL匹配到文件系统中任意一个目录

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

  • maxAge:设置一个资源客户端缓存的时间

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

  • hidden:设置为true的话，connect也会托管文件系统中的隐藏文件

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

• query中间件：获取查询字符串  //query中间件在express中默认是启用的；

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

• logger中间件：诊断工具；将发送进来的请求信息和发送出去的响应信息打印在终端
  • 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]));  //自定义格式输出; 查看完整的token
• bodyParser中间层：
  • 与http模块中使用qs模块解析post请求消息体一样，bodyParser中间层也具有这样功能；

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

  • 其另一个功能就是处理用户上传的文件；

    var connect = require('connect');
    var fs = require('fs');
    var server = connect(connect.logger('dev'),connect.static('static'),connect.bodyParser());  //简化加载中间件
    //设置默认url：'/'为文件系统中static文件夹，如果有Index.html，就加载此项；
    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中间件; //读写cookie数据

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

• session中间件；

  • 出于安全考虑，在初始化session中间件的时候需要提供secret选项

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

  • 使用req.sesstion记录数据：    req.session.logged_in； req.session.name

创建会话：

--------------users.json----------------------------------
//当只要对外暴露数据时，不需要module.exports而直接把数据文件以JSON形式暴露出来
{
	"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);