nodejs笔记二

const fs = require('fs')

fs.readFile('./ajax.png', 'utf-8', (err, content) => {
  console.log(content)
})

function main(argv) {
  console.log(argv)
}

main(process.argv.slice(2))

const http = require("http")

http.createServer((req,res) => {
  res.writeHead(200, {
    "content-type": "text/plain"
  })
  res.write("hello nodejs")
  res.end()
}).listen(3000)

exports.sayHello = function(){ 
  return 'Hello World'; 
}

var x = 0
console.log(x)

var y = 0
console.log(y)
"scripts": {
  "script1": "node script1.js",
  "script2": "node script2.js"
}

// view.js
console.log(process.env.npm_package_name); // foo
console.log(process.env.npm_package_version); // 1.2.5

const path = require('path')
var extname = path.extname('index.html')
console.log(extname)

const name = 'gp19'

const sayName = () => {
  console.log(name)
}

console.log('module 1')

// 接口暴露方法一：
module.exports = {
  say: sayName
}

// 接口暴露方法二：
exports.say = sayName

// 错误！
exports = {
  say: sayName
}

const m1 = require('./m1')
m1.say()

exports.done = false
const b = require('./b.js')
console.log('in a, b.done = %j', b.done)
exports.done = true
console.log('a done')

console.log('b starting')
exports.done = false
const a = require('./a.js')
console.log('in b, a.done = %j', a.done)
exports.done = true
console.log('b done')

console.log('main starting')
const a = require('./a.js')
const b = require('./b.js')
console.log('in main, a.done = %j, b.done = %j', a.done, b.done)

const url = require('url')
const urlString = 'https://www.baidu.com:443/ad/index.html?id=8&name=mouse#tag=110'
const parsedStr = url.parse(urlString)
console.log(parsedStr)

const url = require('url')
const urlObject = {
  protocol: 'https:',
  slashes: true,
  auth: null,
  host: 'www.baidu.com:443',
  port: '443',
  hostname: 'www.baidu.com',
  hash: '#tag=110',
  search: '?id=8&name=mouse',
  query: { id: '8', name: 'mouse' },
  pathname: '/ad/index.html',
  path: '/ad/index.html?id=8&name=mouse',
  href: 'https://www.baidu.com:443/ad/index.html?id=8&name=mouse#tag=110'
}
const parsedObj = url.format(urlObject)
console.log(parsedObj)

const url = require('url')
var a = url.resolve('/one/two/three', 'four')
var b = url.resolve('http://example.com/', '/one')
var c = url.resolve('http://example.com/one', '/two')
console.log(a + "," + b + "," + c)

const querystring = require('querystring')
var qs = 'x=3&y=4'
var parsed = querystring.parse(qs)
console.log(parsed)

const querystring = require('querystring')
var qo = {
  x: 3,
  y: 4
}
var parsed = querystring.stringify(qo)
console.log(parsed)

const querystring = require('querystring')
var str = 'id=3&city=北京&url=https://www.baidu.com'
var escaped = querystring.escape(str)
console.log(escaped)

const querystring = require('querystring')
var str = 'id%3D3%26city%3D%E5%8C%97%E4%BA%AC%26url%3Dhttps%3A%2F%2Fwww.baidu.com'
var unescaped = querystring.unescape(str)
console.log(unescaped)

var http = require('http')
var https = require('https')

// 1、接口 2、跨域
const server = http.createServer((request, response) => {
  var url = request.url.substr(1)

  var data = ''

  response.writeHeader(200, {
    'content-type': 'application/json;charset=utf-8',
    'Access-Control-Allow-Origin': '*'
  })

  https.get(`https://m.lagou.com/listmore.json${url}`, (res) => {

    res.on('data', (chunk) => {
      data += chunk
    })

    res.on('end', () => {
      response.end(JSON.stringify({
        ret: true,
        data
      }))
    })
  })

})

server.listen(8080, () => {
  console.log('localhost:8080')
})

const https = require('https')
const querystring = require('querystring')

const postData = querystring.stringify({
  province: '上海',
  city: '上海',
  district: '宝山区',
  address: '同济支路199号智慧七立方3号楼2-4层',
  latitude: 43.0,
  longitude: 160.0,
  message: '求购一条小鱼',
  contact: '13666666',
  type: 'sell',
  time: 1571217561
})

const options = {
  protocol: 'https:',
  hostname: 'ik9hkddr.qcloud.la',
  method: 'POST',
  port: 443,
  path: '/index.php/trade/add_item',
  headers: {
    'Content-Type': 'application/x-www-form-urlencoded',
    'Content-Length': Buffer.byteLength(postData)
  }
}

function doPost() {
  let data

  let req = https.request(options, (res) => {
    res.on('data', chunk => data += chunk)
    res.on('end', () => {
      console.log(data)
    })
  })

  req.write(postData)
  req.end()
}

// setInterval(() => {
//   doPost()
// }, 1000)

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

const app = http.createServer((req, res) => {
  let urlObj = url.parse(req.url, true)

  switch (urlObj.pathname) {
    case '/api/user':
      res.end(`${urlObj.query.cb}({"name": "gp145"})`)
      break
    default:
      res.end('404.')
      break
  }
})

app.listen(8080, () => {
  console.log('localhost:8080')
})

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

const app = http.createServer((req, res) => {
  let data = ''
  let urlObj = url.parse(req.url, true)

  res.writeHead(200, {
    'content-type': 'application/json;charset=utf-8',
    'Access-Control-Allow-Origin': '*'
  })

  req.on('data', (chunk) => {
    data += chunk
  })

  req.on('end', () => {
    responseResult(querystring.parse(data))
  })

  function responseResult(data) {
    switch (urlObj.pathname) {
      case '/api/login':
        res.end(JSON.stringify({
          message: data
        }))
        break
      default:
        res.end('404.')
        break
    }
  }
})

app.listen(8080, () => {
  console.log('localhost:8080')
})

const http = require('http')
const proxy = require('http-proxy-middleware')

http.createServer((req, res) => {
  let url = req.url

  res.writeHead(200, {
    'Access-Control-Allow-Origin': '*'
  })

  if (/^\/api/.test(url)) {
    let apiProxy = proxy('/api', { 
      target: 'https://m.lagou.com',
      changeOrigin: true,
      pathRewrite: {
        '^/api': ''
      }
    })

    // http-proy-middleware 在Node.js中使用的方法
    apiProxy(req, res)
  } else {
    switch (url) {
      case '/index.html':
        res.end('index.html')
        break
      case '/search.html':
        res.end('search.html')
        break
      default:
        res.end('[404]page not found.')
    }
  }
}).listen(8080)

const https = require('https')
const http = require('http')
const cheerio = require('cheerio')

http.createServer((request, response) => {
  response.writeHead(200, {
    'content-type': 'application/json;charset=utf-8'
  })

  const options = {
    protocol: 'https:',
    hostname: 'maoyan.com',
    port: 443,
    path: '/',
    method: 'GET'
  }

  const req = https.request(options, (res) => {
    let data = ''
    res.on('data', (chunk) => {
      data += chunk
    })

    res.on('end', () => {
      filterData(data)
    })
  })

  function filterData(data) {
    let $ = cheerio.load(data)
    let $movieList = $('.movie-item')
    let movies = []
    $movieList.each((index, value) => {
      movies.push({
        title: $(value).find('.movie-title').attr('title'),
        score: $(value).find('.movie-score i').text(),
      })
    })

    response.end(JSON.stringify(movies))
  }

  req.end()
}).listen(9000)

const EventEmitter = require('events')

class MyEventEmitter extends EventEmitter {}

const event = new MyEventEmitter()

event.on('play', (movie) => {
  console.log(movie)
})

event.emit('play', '我和我的祖国')
event.emit('play', '中国机长')

const fs = require('fs')
const fsP = require('fs').promises

// 创建文件夹
fs.mkdir('./logs', (err) => {
  console.log('done.')
})

// 文件夹改名
fs.rename('./logs', './log', () => {
  console.log('done')
})

// 删除文件夹
fs.rmdir('./log', () => {
  console.log('done.')
})

// 写内容到文件里
fs.writeFile(
  './logs/log1.txt',
  'hello',
  // 错误优先的回调函数
  (err) => {
    if (err) {
      console.log(err.message)
    } else {
      console.log('文件创建成功')
    }
  }
)

// 给文件追加内容
fs.appendFile('./logs/log1.txt', '\nworld', () => {
  console.log('done.')
})

// 读取文件内容
fs.readFile('./logs/log1.txt', 'utf-8', (err, data) => {
  console.log(data)
})

// 删除文件
fs.unlink('./logs/log1.txt', (err) => {
  console.log('done.')
})

// 批量写文件
for (var i = 0; i < 10; i++) {
  fs.writeFile(`./logs/log-${i}.txt`, `log-${i}`, (err) => {
    console.log('done.')
  })
}

// 读取文件/目录信息
fs.readdir('./', (err, data) => {
  data.forEach((value, index) => {
    fs.stat(`./${value}`, (err, stats) => {
      // console.log(value + ':' + stats.size)
      console.log(value + ' is ' + (stats.isDirectory() ? 'directory' : 'file'))
    })
  })
})

// 同步读取文件
try {
  const content = fs.readFileSync('./logs/log-1.txt', 'utf-8')
  console.log(content)
  console.log(0)
} catch (e) {
  console.log(e.message)
}

console.log(1)

// 异步读取文件：方法一
fs.readFile('./logs/log-0.txt', 'utf-8', (err, content) => {
  console.log(content)
  console.log(0)
})
console.log(1)

// 异步读取文件：方法二
fs.readFile('./logs/log-0.txt', 'utf-8').then(result => {
  console.log(result)
})

// 异步读取文件：方法三
function getFile() {
  return new Promise((resolve) => {
    fs.readFile('./logs/log-0.txt', 'utf-8', (err, data) => {
      resolve(data)
    })
  })
}

;(async () => {
  console.log(await getFile())
})()

// 异步读取文件：方法四
const fsp = fsP.readFile('./logs/log-1.txt', 'utf-8').then((result) => {
  console.log(result)
})

console.log(fsP)

// watch 监测文件变化
fs.watch('./logs/log-0.txt', () => {
  console.log(0)
})

const fs = require('fs')

const readstream = fs.createReadStream('./note.txt')
const writestream = fs.createWriteStream('./note2.txt')

writestream.write(readstream)

const fs = require('fs')
const zlib = require('zlib')

const gzip = zlib.createGzip()

const readstream = fs.createReadStream('./note.txt')
const writestream = fs.createWriteStream('./note2.txt')

readstream
  .pipe(gzip)
  .pipe(writestream)

writestream.write(readstream)

const readline = require('readline')

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
})

rl.question('What do you think of Node.js? ', (answer) => {
  // TODO: Log the answer in a database
  console.log(`Thank you for your valuable feedback: ${answer}`)

  rl.close()
})

const crypto = require('crypto')

const secret = 'abcdefg'
const hash = crypto.createHmac('sha256', secret)
                   .update('I love you')
                   .digest('hex')
console.log(hash)

var http = require('http')
var fs = require('fs')

http.createServer( function ( req, res ) {

  switch ( req.url ) {
    case '/home':
      res.write('home')
      res.end()
      break
    case '/mine':
      res.write('mine')
      res.end()
      break
    case '/login': 
      fs.readFile( './static/login.html',function ( error , data ) {
        if ( error ) throw error  
        res.write( data )
        res.end()
      })
      break
    case '/fulian.jpg':
      fs.readFile( './static/fulian.jpg', 'binary', function( error , data ) {
        if( error ) throw error 
        res.write( data, 'binary' )
        res.end()
      })
      break
    default: 
      break
   }

 }).listen( 8000, 'localhost', function () {
   console.log( '服务器运行在： http://localhost:8000' )
 })

// 引入依赖的模块
var path = require('path')
var fs = require('fs')
var mime = require('mime')

function readStaticFile(res, filePathname) {

  var ext = path.parse(filePathname).ext
  var mimeType = mime.getType(ext)

  // 判断路径是否有后缀, 有的话则说明客户端要请求的是一个文件 
  if (ext) {
    // 根据传入的目标文件路径来读取对应文件
    fs.readFile(filePathname, (err, data) => {
    // 错误处理
      if (err) {
        res.writeHead(404, { "Content-Type": "text/plain" })
        res.write("404 - NOT FOUND")
        res.end()
      } else {
        res.writeHead(200, { "Content-Type": mimeType })
        res.write(data)
        res.end()
      }
    });
    // 返回 true 表示, 客户端想要的 是 静态文件
    return true
  } else {
    // 返回 false 表示, 客户端想要的 不是 静态文件
    return false
  }
}

// 导出函数
module.exports = readStaticFile

// 引入相关模块
var http = require('http');
var url = require('url');
var path = require('path');
var readStaticFile = require('./modules/readStaticFile');

// 搭建 HTTP 服务器
var server = http.createServer(function(req, res) {
  var urlObj = url.parse(req.url);
  var urlPathname = urlObj.pathname;
  var filePathname = path.join(__dirname, "/public", urlPathname);

  // 读取静态文件
  readStaticFile(res, filePathname);
});

// 在 3000 端口监听请求
server.listen(3000, function() {
  console.log("服务器运行中.");
  console.log("正在监听 3000 端口:")
})

var express = require('express');
var app = express();

app.get('/', function (req, res) {
  res.send('Hello World!');
});

var server = app.listen(3000, function () {
  var host = server.address().address;
  var port = server.address().port;

  console.log('Example app listening at http://%s:%s', host, port);
});

var express = require('express');
var app = express();

// respond with "hello world" when a GET request is made to the homepage
app.get('/', function(req, res) {
  res.send('hello world');
});

// GET method route
// 对网站首页的访问返回 "Hello World!" 字样
app.get('/', function (req, res) {
  res.send('Hello World!')
})

// 网站首页接受 POST 请求
app.post('/', function (req, res) {
  res.send('Got a POST request')
})

// /user 节点接受 PUT 请求
app.put('/user', function (req, res) {
  res.send('Got a PUT request at /user')
})

// /user 节点接受 DELETE 请求
app.delete('/user', function (req, res) {
  res.send('Got a DELETE request at /user')
})

app.all('/secret', function (req, res, next) {
  console.log('Accessing the secret section ...')
  next(); // pass control to the next handler
})

// 匹配根路径的请求
app.get('/', function (req, res) {
  res.send('root');
});

// 匹配 /about 路径的请求
app.get('/about', function (req, res) {
  res.send('about');
});

// 匹配 /random.text 路径的请求
app.get('/random.text', function (req, res) {
  res.send('random.text');
});

// 匹配 acd 和 abcd
app.get('/ab?cd', function(req, res) {
  res.send('ab?cd');
});

// 匹配 abcd、abbcd、abbbcd等
app.get('/ab+cd', function(req, res) {
  res.send('ab+cd');
});

// 匹配 abcd、abxcd、abRABDOMcd、ab123cd等
app.get('/ab*cd', function(req, res) {
  res.send('ab*cd');
});

// 匹配 /abe 和 /abcde
app.get('/ab(cd)?e', function(req, res) {
 res.send('ab(cd)?e');
});

// 匹配任何路径中含有 a 的路径：
app.get(/a/, function(req, res) {
  res.send('/a/');
});

// 匹配 butterfly、dragonfly，不匹配 butterflyman、dragonfly man等
app.get(/.*fly$/, function(req, res) {
  res.send('/.*fly$/');
});

app.get('/example/a', function (req, res) {
  res.send('Hello from A!');
});

app.get('/example/b', function (req, res, next) {
  console.log('response will be sent by the next function ...');
  next();
}, function (req, res) {
  res.send('Hello from B!');
});

var cb0 = function (req, res, next) {
  console.log('CB0')
  next()
}

var cb1 = function (req, res, next) {
  console.log('CB1')
  next()
}

var cb2 = function (req, res) {
  res.send('Hello from C!')
}

app.get('/example/c', [cb0, cb1, cb2])

var cb0 = function (req, res, next) {
  console.log('CB0')
  next()
}

var cb1 = function (req, res, next) {
  console.log('CB1')
  next()
}

app.get('/example/d', [cb0, cb1], function (req, res, next) {
  console.log('response will be sent by the next function ...')
  next()
}, function (req, res) {
  res.send('Hello from D!')
})

app.route('/book')
  .get(function(req, res) {
    res.send('Get a random book');
  })
  .post(function(req, res) {
    res.send('Add a book');
  })
  .put(function(req, res) {
    res.send('Update the book');
  });

var express = require('express');
var router = express.Router();

// 该路由使用的中间件
router.use(function timeLog(req, res, next) {
  console.log('Time: ', Date.now());
  next();
});
// 定义网站主页的路由
router.get('/', function(req, res) {
  res.send('Birds home page');
});
// 定义 about 页面的路由
router.get('/about', function(req, res) {
  res.send('About birds');
});

module.exports = router;

var birds = require('./birds')
...
app.use('/birds', birds)

app.use(express.static('public'))

http://localhost:3000/images/kitten.jpg
http://localhost:3000/css/style.css
http://localhost:3000/js/app.js
http://localhost:3000/images/bg.png
http://localhost:3000/hello.html

app.use(express.static('public'))
app.use(express.static('files'))

var app = express()

// 没有挂载路径的中间件，应用的每个请求都会执行该中间件
app.use(function (req, res, next) {
  console.log('Time:', Date.now())
  next()
})

// 挂载至 /user/:id 的中间件，任何指向 /user/:id 的请求都会执行它
app.use('/user/:id', function (req, res, next) {
  console.log('Request Type:', req.method)
  next()
})

// 路由和句柄函数(中间件系统)，处理指向 /user/:id 的 GET 请求
app.get('/user/:id', function (req, res, next) {
  res.send('USER')
})

// 一个中间件栈，对任何指向 /user/:id 的 HTTP 请求打印出相关信息
app.use('/user/:id', function(req, res, next) {
  console.log('Request URL:', req.originalUrl)
  next()
}, function (req, res, next) {
  console.log('Request Type:', req.method)
  next()
})

// 一个中间件栈，处理指向 /user/:id 的 GET 请求
app.get('/user/:id', function (req, res, next) {
  console.log('ID:', req.params.id)
  next()
}, function (req, res, next) {
  res.send('User Info')
})

// 处理 /user/:id， 打印出用户 id
app.get('/user/:id', function (req, res, next) {
  res.end(req.params.id)
})

// 一个中间件栈，处理指向 /user/:id 的 GET 请求
app.get('/user/:id', function (req, res, next) {
  // 如果 user id 为 0, 跳到下一个路由
  if (req.params.id == 0) next('route')
  // 否则将控制权交给栈中下一个中间件
  else next() //
}, function (req, res, next) {
  // 渲染常规页面
  res.render('regular')
});

// 处理 /user/:id， 渲染一个特殊页面
app.get('/user/:id', function (req, res, next) {
  res.render('special')
})

var router = express.Router()

var app = express()
var router = express.Router()

// 没有挂载路径的中间件，通过该路由的每个请求都会执行该中间件
router.use(function (req, res, next) {
  console.log('Time:', Date.now())
  next()
})

// 一个中间件栈，显示任何指向 /user/:id 的 HTTP 请求的信息
router.use('/user/:id', function(req, res, next) {
  console.log('Request URL:', req.originalUrl)
  next()
}, function (req, res, next) {
  console.log('Request Type:', req.method)
  next()
})

// 一个中间件栈，处理指向 /user/:id 的 GET 请求
router.get('/user/:id', function (req, res, next) {
  // 如果 user id 为 0, 跳到下一个路由
  if (req.params.id == 0) next('route')
  // 负责将控制权交给栈中下一个中间件
  else next() //
}, function (req, res, next) {
  // 渲染常规页面
  res.render('regular')
})

// 处理 /user/:id， 渲染一个特殊页面
router.get('/user/:id', function (req, res, next) {
  console.log(req.params.id)
  res.render('special')
})

// 将路由挂载至应用
app.use('/', router)

app.use(function(err, req, res, next) {
  console.error(err.stack)
  res.status(500).send('Something broke!')
})

var options = {
  dotfiles: 'ignore',
  etag: false,
  extensions: ['htm', 'html'],
  index: false,
  maxAge: '1d',
  redirect: false,
  setHeaders: function (res, path, stat) {
    res.set('x-timestamp', Date.now())
  }
}

app.use(express.static('public', options))

app.use(express.static('public'))
app.use(express.static('uploads'))
app.use(express.static('files'))

var express = require('express')
var app = express()

// view engine setup
app.engine('art', require('express-art-template'))
app.set('view', {
    debug: process.env.NODE_ENV !== 'production'
})
app.set('views', path.join(__dirname, 'views'))
app.set('view engine', 'art')

// routes
app.get('/', function (req, res) {
    res.render('index.art', {
        user: {
            name: 'aui',
            tags: ['art', 'template', 'nodejs']
        }
    })
})

const Koa = require('koa')
const app = new Koa()

app.use( async ( ctx ) => {
  ctx.body = 'hello koa2'
})

app.listen(3000)
console.log('[demo] start-quick is starting at port 3000')

function getSyncTime() {
  return new Promise((resolve, reject) => {
    try {
      let startTime = new Date().getTime()
      setTimeout(() => {
        let endTime = new Date().getTime()
        let data = endTime - startTime
        resolve( data )
      }, 500)
    } catch ( err ) {
      reject( err )
    }
  })
}

async function getSyncData() {
  let time = await getSyncTime()
  let data = `endTime - startTime = ${time}`
  return data
}

async function getData() {
  let data = await getSyncData()
  console.log( data )
}

getData()

/* ./middleware/logger-generator.js */
function log( ctx ) {
  console.log( ctx.method, ctx.header.host + ctx.url )
}

module.exports = function () {
  return function * ( next ) {

    // 执行中间件的操作
    log( this )

    if ( next ) {
      yield next
    }
  }
}

const koa = require('koa')  // koa v1
const loggerGenerator  = require('./middleware/logger-generator')
const app = koa()

app.use(loggerGenerator())

app.use(function *( ) {
    this.body = 'hello world!'
})

app.listen(3000)
console.log('the server is starting at port 3000')

const Koa = require('koa') // koa v2
const convert = require('koa-convert')
const loggerGenerator  = require('./middleware/logger-generator')
const app = new Koa()

app.use(convert(loggerGenerator()))

app.use(( ctx ) => {
    ctx.body = 'hello world!'
})

app.listen(3000)
console.log('the server is starting at port 3000')

/* ./middleware/logger-async.js */

function log( ctx ) {
    console.log( ctx.method, ctx.header.host + ctx.url )
}

module.exports = function () {
  return async function ( ctx, next ) {
    log(ctx);
    await next()
  }
}

const Koa = require('koa') // koa v2
const loggerAsync  = require('./middleware/logger-async')
const app = new Koa()

app.use(loggerAsync())

app.use(( ctx ) => {
    ctx.body = 'hello world!'
})

app.listen(3000)
console.log('the server is starting at port 3000')

const Koa = require('koa')
const app = new Koa()

app.use( async ( ctx ) => {
  let url = ctx.request.url
  ctx.body = url
})
app.listen(3000)