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1. The first nodejs application
n1_hello.js
console.log('hello word!');
Execute the file in the command line cmd (Open the command line at this file):
node n1_hello.js
Return the result from cmd on the command line:
hello word!
2. Basic format of nodejs
//步骤一:引入require模块,require指令载入http模块 var http = require('http'); //步骤二:创建服务器 http.createServer(function (request, response) { // 发送 HTTP 头部 // HTTP 状态值: 200 : OK // 内容类型: text/html response.writeHead(200, {'Content-Type': 'text/html;chaset=utf-8;'}); //步骤三:接受请求与响应请求 if(request.url!=='/favicon.ico'){ ...... // 发送响应数据 response.end('');//必须有,没有则没有协议尾 } }).listen(8000); // 终端打印如下信息 console.log('Server running at http://127.0.0.1:8000/');
3. Nodejs calling function
----------------- Call local function--------------------------------
var http = require('http'); http.createServer(function (request, response) { response.writeHead(200, {'Content-Type': 'text/html;chaset=utf-8;'}); if(request.url!=='/favicon.ico'){ fun1(response); // 发送响应数据 response.end(''); } }).listen(8000); // 终端打印如下信息 console.log('Server running at http://127.0.0.1:8000/'); function fun1(res){ console.log('fun1'); res.write('hello,我是fun1'); }
-----------------Call external functions-----------------------------
Note: External functions must be written in module.exports, exports is the interface exposed by the module
------------(1) Only call one function- ----------
In the main program:
var http = require('http'); var otherfun = require("./models/otherfuns.js");//调用外部页面的fun2 http.createServer(function (request, response) { response.writeHead(200, {'Content-Type': 'text/html;chaset=utf-8;'}); if(request.url!=='/favicon.ico'){ otherfun(response);//支持一个函数时 response.end(''); } }).listen(8000); // 终端打印如下信息 console.log('Server running at http://127.0.0.1:8000/');
otherfuns.js
function fun2(res){ console.log('fun2'); res.write('你好!,我是fun2'); } module.exports = fun2;//只支持一个函数
------------(2) Call multiple functions-----------
Main program Medium:
var http = require('http'); var otherfun = require("./models/otherfuns.js");//调用写函数的外部页面otherfuns.js http.createServer(function (request, response) { response.writeHead(200, {'Content-Type': 'text/html;chaset=utf-8;'}); if(request.url!=='/favicon.ico'){ //todo 以对象.方法名调用 otherfun.fun2(response); otherfun.fun3(response); //todo 以字符串调用对应函数(结果同上) //otherfun['fun2'](response); //otherfun['fun3'](response); response.end(''); } }).listen(8000); // 终端打印如下信息 console.log('Server running at http://127.0.0.1:8000/'); }
otherfuns.js Medium
module.exports={ fun2:function(res){//匿名函数 console.log('fun2'); res.write('你好!,我是fun2');//在页面中输出 }, fun3:function(res){ console.log('fun3'); res.write('你好!,我是fun3'); }, ...... }
4. Preliminary nodejs routing
Main program n4_rout.js:
var http = require('http'); //引入url模块 var url = require('url'); http.createServer(function (request, response) { response.writeHead(200, {'Content-Type': 'text/html;chaset=utf-8;'}); if(request.url!=='/favicon.ico'){ var pathname = url.parse(request.url).pathname; pathname=pathname.replace(/\//,'');//替换掉前面的/ console.log(pathname); response.end(''); } }).listen(8000); // 终端打印如下信息 console.log('Server running at http://127.0.0.1:8000/');
Execute the file in the command line cmd, access: http://localhost:8000/, enter the routing address here, as shown below, and observe Command Line.
5. Nodejs reads files
Main program:
var http = require('http'); var optfile=require('./models/optfile');//导入文件 http.createServer(function (request, response) { // 发送 HTTP 头部 // HTTP 状态值: 200 : OK // 内容类型: text/html response.writeHead(200, {'Content-Type': 'text/html;chaset=utf-8;'}); if(request.url!=='/favicon.ico'){//清除第2次访问 optfile.readfileSync('./views/login.html');//同步调用读取文件readfileSync()方法 //optfile.readfile('./views/login.html',response);//异步步调用读取文件readfile()方法 response.end('ok!!!!!');//todo 不写没有协议尾 console.log('主程序执行完毕!'); } }).listen(8000); // 终端打印如下信息 console.log('Server running at http://127.0.0.1:8000/');
optfile In .js:
var fs=require('fs');//Node 导入文件系统模块(fs)语法 导入fs操作文件的类 module.exports={ readfileSync:function(path){ // 同步读取 var data = fs.readFileSync(path,'utf-8');//以中文读取同步文件路径path console.log("同步方法执行完毕。"); }, readfile:function(path){ // 异步读取 fs.readFile(path,function (err, data) { if (err) { console.error(err); }else{ console.log("异步读取: " + data.toString()); } }); console.log("异步方法执行完毕。"); }, }
Result: In command line cmd
(1) When reading the file synchronously:
(2) When reading files asynchronously: (commonly used)
In the web page: all are:
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