1.调用模块

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

2.创建服务器

var server = http.createServer(function(req,res) {
  routePath(req,res)
})

3.服务器接收到请求后的处理

function routePath(req,res) {
  var pathObj = url.parse(req.url,true)
  var handleFn = routes[pathObj.pathname]
  if(handleFn) {
    req.query = pathObj.query   //处理GET请求

    //处理POST请求，
    var body = ''
    req.on('data',function(chunk){
        body += chunk
    }).on('end',function(){
        req.body = parseBody(body)
        handleFn(req,res)
    })
    }else{
    staticRoot(path.resolve(__dirname,"static"),req,res)
  }
}

4.处理POST请求中的参数

function parseBody(body) {
  var obj = {}
  body.split('&').forEach(function(ele){
    obj[ele.split('=')[0]] = ele.split('=')[1]
  })
  return obj
}

5.路由及其对应的处理

var routes = {
  '/login': function(req,res) {
    var username = req.body.username
    res.end('登陆账户' + username)
  },
  '/search': function(req,res) {
    var team = req.query.team
    switch(team){
        case '马刺':
            res.end('15胜-5负')
            break;
        case '火箭':
            res.end('17胜-3负')
            break;
        case '湖人':
            res.end('10胜-10负')
            break;
        default:
            res.end('Not Found') 
    }
  }
}

6.没有路由时，静态目录的处理

function staticRoot(staticPath,req,res) {
  var pathObj = url.parse(req.url,true)
  var filePath = path.join(staticPath,pathObj.pathname)
  fs.readFile(filePath,function(err,content){
    if(err) {
        res.writeHead('404','Page Not Found')
        return res.end()
    }
    res.writeHead(200,'ok')
    res.write(content)
    res.end()
  })
}

7.监听端口

server.listen(8090)