Node.js—学习

一、Node.js

1. Hello World

var  http  =  require('http');
http.createServer(function(request,  response)  {
    response.writeHead(200,{'Content-Type':'text/html;charset=utf-8'});
    if(request.url!=="/favicon.ico"){  //清除第2此访问
        console.log('访问');
        response.write('hello,world');
        response.end('hell,世界');//不写则没有http协议尾,但写了会产生两次访问
    }
}).listen(8000);
console.log('Server  running  at  http://127.0.0.1:8000/');  

/*
启动服务
cmd下执行：
node  n1_hello.js
浏览器访问：http://localhost:8000
*/

2. 函数调用

//---服务器node.js---
var http = require('http');
var otherfun = require('./models/otherfuns.js');
http.createServer(function(request,response){
	response.writeHead(200,{'Content-Type':'text/html;charset=utf-8'});
    if(request.url!=="/favicon.ico"){    //清除第2此访问
        fun1(response);
		otherfun.controller(request,response);
        otherfun.call(response);
        //---使用字符串调用对应的函数---
        funcname = "addContent"
        otherfun[funcname](response);
        otherfun['getVisit'](response);
        response.end('');
    }
}).listen(8000);
console.log('Server running at http://127.0.0.1:8000/');
//---普通函数---
function  fun1(res){
    res.write("你好,我是fun1");
}

//---/models/otherfuns.js---
function  controller(req,res){
    res.write("发送");
    call('hello',req,res);
    res.end("");
}
function  call(res){
    console.log('call');
}
module.exports  =  controller;    //只支持一个函数

//只支持多个函数
module.exports={
    getVisit:function(){
    return  visitnum++;
    },
    addContent:function(a,b){
    return  a+b;
    }
}

3. 模块调用

//---node.js---
var http = require('http');
//var User = require('./models/User');
var Teacher = require('./models/Teacher');
http.createServer(function(request,response){
	response.writeHead(200,{'Content-Type':'text/html;charset=utf-8'});
	if(request.url!=="/favicon.ico"){        //清除第2此访问
        //实例化teacher对象
		teacher  =  new  Teacher(1,'李四',30);
		teacher.teach(response);
		response.end('');
	}
}).listen(8000);

//---User.js--
function  User(id,name,age){
    this.id=id;
    this.name=name;
    this.age=age;
    this.enter=function(){
        console.log("进入图书馆");
    }
}
module.exports = User;

//---models/Teacher.js---
var User = require('./User');
function Teacher(id,name,age){
    //没有构造方法，继承父类
	User.apply(this,[id,name,age]);
    this.teach=function(res){
        res.write(this.name+"老师讲课");
    }
}
module.exports = Teacher;

4. 路由

//---node.js---
var http = require('http');
var url = require('url');
var router = require('./router');
http.createServer(function(request,response){
	response.writeHead(200,{'Content-Type':'text/html;charset=utf-8'});
	if(request.url!=="/favicon.ico"){
        //获取url的路径
        var pathname = url.parse(request.url).pathname;
        //替换掉路径前面的 /
        pathname = pathname.replace(/\//,'');
        router[pathname](request,response);
		response.end('');
	}
}).listen(8000);

//---router.js---
module.exports={
	login:function(req,res){
        res.write("我是login方法");
    },
    zhuce:function(req,res){
        res.write("我是注册方法");
    }
}

5. 文件读取

//---node.js---
var http = require("http");
var optfile = require("./models/optfile");
http.createServer(function(request,response){
    response.writeHead(200,{'Content-Type':'text/html';charset=utf-8'});
	if(request.url!=="/favicon.ico"){
        //闭包函数;防止异步操作时，已经end了，再进行write报错
        function recall(data){
            response.write(data);
            response.end('ok')
        }
        optfile.readfile('./views/login.html',recall);
        console.log('主程序执行完毕');
    }
}).listen(8000)

//---/models/optfile---
var fs = require('fs');
module.exports={
    //同步读取
    readfileSync:function(path){
        var data = fs.readFileSync(path,'utf-8');
        console.log("同步方法执行完毕");
        return data;
    },
    //异步读取
    readfile:function(path,recall){
        fs.readFile(path,function(err,data){
            if(err){
                console.log(err);
            }else{
                console.log(data.toString());
                recall(data);
            }
        })
    }
}

//---修改后路由---
//---node.js---
var http = require('http');
var url = require('url');
var router = require('./router');
var optfile = require("./models/optfile");
http.createServer(function(request,response){
    response.writeHead(200,{'Content-Type':'text/html';charset=utf-8'});
	if(request.url!=="/favicon.ico"){
		//获取url的路径
        var pathname = url.parse(request.url).pathname;
        //替换掉路径前面的 /
        pathname = pathname.replace(/\//,'');
        router[pathname](request,response);
        console.log('主程序执行完毕');
    }
}).listen(8000)

//---router.js---
var optfile = require("./models/optfile");
module.exports={
	login:function(req,res){
        function recall(data){
			res.write(data);
        	res.end("");
        }
		optfile.readfile('./views/login.html',recall);
    },
    zhuce:function(req,res){
        function recall(data){
			res.write(data);
        	res.end("");
        }
		optfile.readfile('./views/zhuce.html',recall);
    }
}

6. 文件写入

//---node.js---
var http = require('http');
var url = require('url');
var router = require('./router');
var optfile = require("./models/optfile");
http.createServer(function(request,response){
    response.writeHead(200,{'Content-Type':'text/html';charset=utf-8'});
	if(request.url!=="/favicon.ico"){
		//获取url的路径
        var pathname = url.parse(request.url).pathname;
        //替换掉路径前面的 /
        pathname = pathname.replace(/\//,'');
        router[pathname](request,response);
        console.log('主程序执行完毕');
    }
}).listen(8000)

//---/models/optfile---
var fs = require('fs');
module.exports={
    //同步写入
    writefileSync:function(path,data){
        fs.writeFileSync(path,data);
        console.log("同步方法执行完毕");
    },
    //异步读取
    writefile:function(path,data,recall){
        fs.writeFile(path,data,function(err){
            if(err){
                throw err;
            }else{
				console.log("It is saved!");
                recall('写文件成功')
            }
        })
    }
}

//---router.js---
var optfile = require("./models/optfile");
module.exports={
	login:function(req,res){
        function recall(data){
			res.write(data);
        	res.end("");
        }
		optfile.readfile('./views/login.html');
    },
    writefile:function(req,res){
        function recall(data){
			res.write(data);
        	res.end("");
        }
		optfile.writefile('./views/one.txt','hello world',recall);
    }
}

7. 读取图片

//---node.js---
var http = requrie('http');
var optfile = require('./models/optfile');
http.createServer(function(request,response){
    //读取图片需要时二进制流格式
    response.writeHead(200,{'Content-Type':'image/jpeg'});
    if(request.url!='/favicon.ico'){
        optfile.readImg('./imgs/pig.png',response);
    }
}).listen(8000);

//---/models/optfile---
var fs = require('fs');
module.exports={
    readImg:function(path,res){
        //默认为string，binary是二进制
        fs.readFile(path,'binary',function(err,filedata){
            if(err){
                console.log(err);
                return;
            }else{
                res.write(filedata,'binary');
                res.end();
            }
        })
    }
}

8. 异常处理

//同步捕获异常
pathname = url.parse(request.url).pathname;
pathname = pathname.replace(/\//,'');
try{
    router[pathname](request,response);
}catch(err){
    console.log("error="+err);
    response.writeHead(200,{'Content-Type':'text/html';charset='utf-8'});
    response.write(err.toString());
    response.end('');
}

//---node.js---
var http = require('http');
var url = require('url');
var router = require('./router');
var exception = require('./models/Exception');
http.createServer(function  (request,response){
	if(request.url!=="/favicon.ico"){//清除第2此访问
		pathname=url.parse(request.url).pathname;
		pathname = pathname.replace(/\//,'');//替换掉前面的/
		try{
		//router[pathname](request,response);
			data  =  exception.expfun(0);
			response.write(data);
			response.end('');
		}catch(err){
			console.log('aaaaa='+err);
			response.writeHead(200,{'Content-Type':'text/html;charset=utf-8'});
			response.write(err.toString());
			response.end('');
		}
		console.log("server执行完毕");
	}
}).listen(8000);

//---Exception.js---
module.exports={
    expfun:function(flag){
        if(flag==0){
            //抛出异常
            throw  '我是例外';
        }
        return  "success";
    }
}

9. 参数接收

<form action='./login' method='get'>
    <input type='text' name='email'/>
    <input type='password' name='pwd'/>
    <input type='submit' value='登录'>
</form>

//---node.js---
var http = require('http');
var url = require('url');
var router = require('./router');
http.createServer(function(request,response){
	if(request.url!=="/favicon.ico"){                //清除第2此访问
		pathname=url.parse(request.url).pathname;
		pathname = pathname.replace(/\//,'');//替换掉前面的/
		try{
			router[pathname](request,response);
		}catch(err){
			console.log('出错='+err);
			response.writeHead(200,{'Content-Type':'text/html;charset=utf-8'});
			response.write(err);
			response.end('');
		}
		console.log("server执行完毕");
	}
}).listen(8000);

//---router.js--
var  optfile  =  require('./models/optfile');
var  url  =  require('url');
var  querystring  =  require('querystring');  //post需导入
module.exports={
	login:function(req,res){
        //--------get方式接收参数----------------
        var rdata = url.parse(req.url,true).query;
		console.log(rdata);
        if(rdata['email']!=undefined){
			console.log(rdata['email']);
                                }     

        //-------post方式接收参数----------------
		var  post  =  '';//定义了一个post变量，用于暂存请求体的信息
        //通过req的data事件监听函数，每当接受到请求体的数据，就累加到post变量中
		req.on('data',  function(chunk){
            post  +=  chunk;
        });      

        //-------注意异步-------------
		//在end事件触发后，通过querystring.parse将post解析为真正的POST请求格式，然后向客户端返回。
        req.on('end',  function(){
            post  =  querystring.parse(post);
            console.log('email:'+post['email']+'\n');
			console.log('pwd:'+post['pwd']+'\n');
        });
        //---------------------------------------
        data  =  optfile.readfileSync('./views/login.html');
        res.write(data);
        res.end();
    }
}