Home > Web Front-end > JS Tutorial > nodejs basic application

nodejs basic application

高洛峰
Release: 2017-02-04 10:35:21
Original
1179 people have browsed it

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/');
Copy after login

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');
}
Copy after login

-----------------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/');
Copy after login

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
Copy after login

------------(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/');
}
Copy after login

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');
 },
   ......
}
Copy after login

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/');
Copy after login

Execute the file in the command line cmd, access: http://localhost:8000/, enter the routing address here, as shown below, and observe Command Line.

nodejs basic application

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/');
Copy after login

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。");
 },
}
Copy after login

Result: In command line cmd

(1) When reading the file synchronously:

nodejs basic application

(2) When reading files asynchronously: (commonly used)

nodejs basic application

In the web page: all are:

nodejs basic application

The above is the entire content of this article. I hope that the content of this article can bring some help to everyone's study or work. I also hope to support the PHP Chinese website!

For more articles related to nodejs basic applications, please pay attention to the PHP Chinese website!

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template