NodeJs内置模块超详细讲解

const fs = require('fs')
fs.readFile('./hello.txt','utf8',function(err,dataStr) {
	// 如果读取成功，则err值为null
	// 如果读取失败，则err值为错误对象，dataStr值为undefined
	if(err) {
		return console.log('文件读取失败：' + err.message)
	}
	console.log('文件读取成功：' + dataStr)
})

const fs = require('fs')
fs.readFile('./hello.txt','hello world',function(err) {
	// 如果写入成功，则err值为null
	// 如果写入失败，则err值为错误对象
	if(err) {
		return console.log('文件写入失败：' + err.message)
	}
	console.log('文件写入成功')
})

// __dirname 表示当前文件所处的目录
fs.readFile(__dirname + '/hello.txt','utf8',function(err,dataStr) {
})

const path = require('path')
const pathStr = path.join('/a','/b/c','../','/d','/e')
console.log(pathStr) // \a\b\d\e

const path = require('path')
const fpath = '/a/b/c/index.html'
const fullName = path.basename(fpath)
console.log(fullName); // index.html
const nameWithoutExt = path.basename(fpath,'.html')
console.log(nameWithoutExt ); // index

const path = require('path')
const fpath = '/a/b/c/index.html'
const fext = path.extname(fpath)
console.log(fext); // .html

const http = require('http')
const server = http.createServer()
server.on('request',function(req,res) {
	console.log('Someone visit our web server.')
})
server.listen(8080,function() {
	console.log('server running at http://127.0.0.1:8080')
})

server.on('request',(req) => {
	// req.url 是客户端请求的 URL 地址
	// req.method 是客户端的 method 请求类型
})

server.on('request',(req,res) => {
	const str = `您请求的URL地址是${req.url}，请求的method类型为${req.method}`
	// 调用 res.setHeader()方法设置 Content-Type 响应头，解决中文乱码的问题
	res.setHeader('Content-Type','text/html;charset=utf-8')
	// res.end()方法，向客户端响应内容
	res.end(str)
})

server.on('request',(req,res) => {
	const url = req.url
	let content = '<h1>404 Not Found</h1>'
	if(url === '/' || url === '/index.html') {
		content = '<h1>首页</h1>'
	} else if(url === '/about.html') {
		content = '<h1>关于</h1>'
	}
	res.setHeader('Content-Type','text/html;charset=utf-8')
	res.end(content)
})