如何使用node.js加载和保存图像?

A have this code:

一个有这段代码:

var http = require('http');
var fs = require('fs');
var data;
var options = {
  host: 'nodejs.org',
  port: 80,
  path: '/images/logo.png',
  method: 'GET'
};
var req = http.request(options, function(res) {
  res.on('data', function (chunk) {
    data += chunk;
  });
  res.on('end', function () {
    fs.writeFile('1.png', data, function (err) {
      if(err) 
        console.log('NNOOOOOOOOOOOO');
    });
  });
});
req.on('error', function(e) {
  console.log('error: ' + e.message);
});
req.end();
var http = requi