nodejs ,, some basic operations

1. Chinese garbled solve the problem:

the require HTTP = const ( 'HTTP' ) 

const Server = http.createServer ((REQ, RES) => {
     // set the character encoding - parsed form of the text 
    // 200 represents this request is successful 
    // text / html ---- resolution tag output 
    // text / plain ---- ---- escape tag output is outputted 
    // nodejs server default text / HTML 
    res.writeHead (200 is , {
         'the Type-the Content': 'text / Plain; charset = UTF-. 8 ' 
    }) 
    res.write ( ' <h1 of> Hello World </ h1 of> ' ) 
    res.write ( ' Hello <H2> </ H2> ') // if there is Chinese characters, The default setting will be garbled ---- character encoding 
    res.end () 
}) 

server.listen ( 3000 ) 

console.log ('Runing with your Server IS AT HTTP: // localhost: 3000' ) 

// ???? open the console - "NETWORK, refresh the page, I found two request is a request to --- ---- not filter 2 requests required.

2. Parse the URL (the URL of your set)

// HTTP 
// parse URL url 
/ * * 
 * parse the full URL address field 
┌────────────────────────────── ────────────────────────────────────────────────── ────────────────┐ 
│ │ href 
├──────────┬──┬─────────────── ──────┬────────────────────────┬────────────────── ─────────┬───────┤ 
│ │ │ protocol Host auth │ │ path hash │ │ 
│ │ │ ├─────────────── agreement │ ──┬──────┼──────────┬────────────────┤ 
│ │ │ │ │ pathname hostname Port │ │ Search │ │
│ │ │ │ │ domain routing port │ │ ├─┬──────────────┤ 
│ │ │ │ │ │ │ │ │ │ Query 
"HTTPS: // the User: Pass @ Sub. example.com:? 8080 / the p-/ A / t / H = Query String #hash " 
│ │ │ │ │ │ │ Port hostname │ │ │ 
│ │ │ │ ├───────────── ────┴──────┤ │ │ parameter hash value │ 
│ │ │ Protocol username password │ │ │ │ │ │ Host 
├──────────┴──┼─── ───────┴──────────┼────────────────────────┤ │ │ │
Origin │ │ Origin │ │ │ Search pathname hash │ │
├─────────────┴─────────────────────┴────────────────────────┴──────────┴────────────────┴───────┤
Href │ │ 
└────────────────────────────────────────────── ────────────────────────────────────────────────── ┘ 
 * 
  
  Protocol: 'HTTP:' // protocol* / 
const url = the require ( 'url' ) 

const urlStr = "HTTP: // localhost:? 3000 / wudaxun the Login username & password = 123456 =" // url.parse (urlStr [, boolean]) character --- conversion of the URL string type objects into 
const obj = url.parse (urlStr, to true ) // the console.log (obj) / * * 
 * the Url { 
  host: 'localhost: 3000' // domain name + port 
  port: '3000', // port







  slashes: to true, 
  auth: null, // Author 
  hostname: 'localhost', // domain 
  hash: null, // hash value 
  search: '? username = wudaxun & password = 123456', // + parameters? Query: 'username = wudaxun & password = 123456 ', // string type argument 
  pathname:' / login ', // routing 
  path:' / login username = wudaxun & password = 123456 ', // routing +?? + Parameters 
  href: 'http: // localhost: ? 3000 / login username = wudaxun & password = 123456' // complete address 
} 
 
 * / 

 console.log (obj.query)   // username & password = 123456 = wudaxun

　console.log(obj.query.username) //wudaxun
　console.log(obj.query.password) //123456

3.querystrng converted into a string parameter type of object type

/ * * 
 * QueryString 
 * converted into a string parameter type of object type 
 * 
 * & wudaxun username = password = 123456   
 * 
 * ===> 
 *   
 * {username: wudaxun, password: 123456} 
 * / 
const QueryString = the require ( 'QueryString' ) 

const queryStr = 'username = password = 123456 & wudaxun & Age = 18 is' // querystring.parse (queryStr) * ---- to convert the object into a string type argument 
const obj = querystring.parse (queryStr) 
the console.log (obj) / * ** 
 * { 
  username: 'wudaxun', 
  password: '123456', 
  Age: '18 is' 
} 
summary:







    The actual development process does not require the use querystring, recommended url.parse (str, true) 

    second argument url.parse () is true to turn the object, the principle is querystring.parse ()
  * / 


 // ?? ? known pages string can get, so if the user enters the URL of it?

4. resolve URL (the URL of the server to obtain)

const http = require('http')
const url = require('url')

const server = http.createServer((req, res) => {
    if (req.url !== '/favicon.ico') {
        res.writeHead(200, {
            'Content-Type': 'text/html;charset=utf-8'
        })

        const urlStr = req.url // /login?username=wudaxun&password=123456

        const obj = url.parse(urlStr, true).query // { username: 'wudaxun', password: '123456' }

        const { username, password } = obj

        res.write ( `user name: $ {username}`) 
        res.write ( `Password: $ {password}`) 

        res.end () 

    } 
}) 

server.listen ( 3000 ) 

// Login & Registration Form Do not use - - loss of data 


/ * * 
 * If the user enters / home then the output Home 
 * If the user input / kind then output classification 
 * If the user input / cart shopping cart then output 
 * If the user input / user then the output of individual centers 
 * /

fs（file-system）

/ * * 
 * FS File System ---- 
 * flag rear language: 
 * write files 
 * / 

 // read the file 
 // fs.readFile (path, 'UTF-. 8', (ERR, Data) => {}) 

 const FS = the require ( 'FS' ) 

 fs.readFile ( './01node introduced .html', 'UTF-. 8', (ERR, Data) => {
     IF (ERR) { 
        the console.log ( ERR) 
    } the else { 
        the console.log (Data) 
    } 
 })
 

Open another web page on the server:

the require HTTP = const ( 'HTTP' ) 
const FS = the require ( 'FS' ) 
const Server = http.createServer ((REQ, RES) => {
     IF (req.url! == '/favicon.ico' ) { 
        RES .writeHead ( 200 is , {
             'the Type-the Content': 'text / HTML; charset = UTF-. 8' 
        }) 

        fs.readFile ( './12test.html', 'UTF-. 8', (ERR, Data) => {
             IF (ERR) the throw ERR // encounters an error, an exception is thrown, code is no longer continue 
            res.write (the Data) 
            res.end () 
        }) 
    } 
}) 

Server.listen(3000) 


/ * * 
 * If the user enters / home then the output Home .html 
 * If the user input / kind classify the output .html 
 * If the user input / cart shopping cart then output .html 
 * If the user input / user then the output of individual centers .html 
 * /