var http=require('http');
  var qs=require('querystring');
  var post_data={a:123,time:new Date().getTime()};//这是需要提交的数据
  var content=qs.stringify(post_data);

  var options = {
    host: 'localhost',
    port: 3000,
    path: '/',
    method: 'POST',
    headers:{
    'Content-Type':'application/x-www-form-urlencoded',
    'Content-Length':content.length
    }
  };
  console.log("post options:\n",options);
  console.log("content:",content);
  console.log("\n");

  var req = http.request(options, function(res) {
    console.log("statusCode: ", res.statusCode);
    console.log("headers: ", res.headers);
    var _data='';
    res.on('data', function(chunk){
       _data += chunk;
      console.log(_data);
    });
    res.on('end', function(){
       //data = qs.parse(_data);
      console.log('end is emitted');
      console.log("\n--->>\nresult:",_data)
    });
  });

  req.write(content);
  req.end();

  //服务器
  var http = require('http');
  var url = require('url');
  var util = require('util');
  var qs = require('querystring');
  http.createServer(function(req,res){
    var data = '';
      req.on('data',function(chunk){
          data+=chunk;
      });

  req.on('end',function(){
      res.writeHead(200, {
        'Content-Length': data.length,
      'Content-Type': 'text/plain' });
      data = qs.parse(data);
      console.log(data.a.toString());
      res.write(data.a.toString());
      res.end('hello');
      //data = qs.parse(data);
      console.log(data);
  });
  }).listen(3000);
  console.log("!!!");

在客户端 我的res.on（end）事件始终没有反应……这是为什么？