Node.js 学习笔记（一）

var fs= requeir("fs")；
//异步读取
fs.readFile("index.html",function(err,data){
if(err){
return console.error(err);
}
console.log("异步读取："+data.toString())；//这里如果不加 toString() 会显示一堆二进制
})；
//同步读取
var data =fs.readFileSync(‘index.html‘);
console.log("同步读取："+data.toString());
console.log("程序执行完毕。");

同步读取：www.nodeJs.com
 
程序执行完毕。//注意这里是程序先执行完毕
异步读取：www.nodeJs.com

<form action="http://localhost:8080/aaa" method="get">
    用户:<input type="text" name="user" value="" /><br />
    密码:<input type="password" name="pass" value="" /><br />
    <input type="submit" value="提交" />
  </form>
node.js代码：
var http=require(‘http‘);
http.createServer(function(req,res){
  console.log(req.url);
  res.write(‘submit success‘);
  res.end();
}).listen(8080);

var http = require(‘http‘);
http.createServer(function(req, res) {
  var GET = {};
  if (req.url.indexOf(‘?‘)!=-1){
    var arr = req.url.split(‘?‘);
    var url = arr[0];
    //arr[0]=>地址 ‘/aaa‘
    //arr[1]=>数据 ‘user=xuhuihong&pass=123456‘
    var arr2 = arr[1].split(‘&‘);
    //arr2=>[‘user=blue‘,‘pass=123456‘]
    for (var i = 0; i < arr2.length; i++) {
      var arr3 = arr2[i].split(‘=‘);
      //arr3[0]=>名字 ‘user‘
      //arr3[1]=>数据 ‘blue‘
      GET[arr3[0]] = arr3[1]; //键值对
    }
  }else {
    var url = req.url;
  }
  console.log(url, GET);
  res.write(‘submit success‘);
  res.end();
}).listen(8080);

var http = require(‘http‘);
const querystring = require(‘querystring‘);
http.createServer(function(req, res) {
  var GET = {};
  if (req.url.indexOf(‘?‘)!=-1){
    var arr = req.url.split(‘?‘);
    var url = arr[0];
    GET=querystring.parse(arr[1]);
  }else {
    var url = req.url;
  }
  console.log(url, GET);
  res.write(‘submit success‘);
  res.end();
}).listen(8080);

nodejs代码
const urlLib=require(‘url‘);
var obj=urlLib.parse(‘https://www.bilibili.com/index?a=55&b=6600‘);
console.log(obj);

Url {
protocol: ‘https:‘,
slashes: true,
auth: null,
host: ‘www.bilibili.com‘,
port: null,
hostname: ‘www.bilibili.com‘,
hash: null,
search: ‘?a=55&b=6600‘,
query: ‘a=55&b=6600‘,   
pathname: ‘/index‘,
path: ‘/index?a=55&b=6600‘,
href: ‘https://www.bilibili.com/index?a=55&b=6600‘ }

var obj=urlLib.parse(‘https://www.bilibili.com/index?a=55&b=6600‘,true);

query: { a: ‘55‘, b: ‘6600‘ },

var http = require(‘http‘);
const urlLib=require(‘url‘);
http.createServer(function(req, res) {
  var obj=urlLib.parse(req.url,true);
  var url=obj.pathname;
  var GET=obj.query;
  console.log(url, GET);
  res.write(‘submit success‘);
  res.end();
}).listen(8080);

const http = require(‘http‘);
const querystring=require(‘querystring‘);
http.createServer(function(req, res) {
  //post--req
  var str="";//接受数据
  //data--有一段数据到达（很多次）
  var i=0;
  req.on(‘data‘,function(data){
    console.log(‘第${i++}次收到数据‘);
    str+=data;
  });
  //end-数据全部到达（一次）
  req.on(‘end‘,function(){
    var POST=querystring.parse(str);
    console.log(str);
  });
}).listen(8080);

user=qqqqqq&pass=aaaaaaaaa

const http=require(‘http‘);
const fs=require(‘fs‘);
const queryString=require(‘querystring‘);
const urlLib=require(‘url‘);
 
var server = http.createServer(function(req,res){
  //GET
  var obj=urlLib.parse(req.url,true);
  var url=obj.pathname;
  const GET=obj.query;
  //POST
  var str=‘‘;
  req.on(‘data‘,function(data){
    str+=data;
  });
  req.on(‘end‘,function(){
    var POST=queryString.parse(str);
    /*
    url--要什么
    GET--get数据
    POST--post数据
    */
    console.log(url,GET,POST);
    //文件请求
    var file_name=‘./www‘+url; //这里url要输完后缀
    fs.readFile(file_name,function(err,data){
      if(err){
        res.write(‘404‘);
      }else{
        res.write(data);
      }
      res.end();
    });
  });
});
server.listen(8080);