我建议使用request module，下载文件就像下面的代码一样简单：

var fs = require('fs'),
    request = require('request');

var download = function(uri, filename, callback){
  request.head(uri, function(err, res, body){
    console.log('content-type:', res.headers['content-type']);
    console.log('content-length:', res.headers['content-length']);

    request(uri).pipe(fs.createWriteStream(filename)).on('close', callback);
  });
};

download('https://www.google.com/images/srpr/logo3w.png', 'google.png', function(){
  console.log('done');
});

几天前我遇到了这个问题，对于一个纯粹的NodeJS答案，我建议使用Stream将块合并在一起。

var http = require('http'),                                                
    Stream = require('stream').Transform,                                  
    fs = require('fs');                                                    

var url = 'http://www.google.com/images/srpr/logo11w.png';                    

http.request(url, function(response) {                                        
  var data = new Stream();                                                    

  response.on('data', function(chunk) {                                       
    data.push(chunk);                                                         
  });                                                                         

  response.on('end', function() {                                             
    fs.writeFileSync('image.png', data.read());                               
  });                                                                         
}).end();

最新的Node版本不能很好地处理二进制字符串，因此在处理二进制数据时，将块与字符串合并不是一个好主意。

• 使用'data.read（）'时要小心，它会清空流以备下一个'read（）'操作使用。如果您想多次使用它，请将其存储在某个地方。

您可以使用**Axios**（Node.js的基于promise的HTTP客户端）按照您在asynchronous environment中选择的顺序下载图像：

npm i axios

然后，您可以使用以下基本示例开始下载映像：

const fs = require('fs');
const axios = require('axios');

/* ============================================================
  Function: Download Image
============================================================ */

const download_image = (url, image_path) =>
  axios({
    url,
    responseType: 'stream',
  }).then(
    response =>
      new Promise((resolve, reject) => {
        response.data
          .pipe(fs.createWriteStream(image_path))
          .on('finish', () => resolve())
          .on('error', e => reject(e));
      }),
  );

/* ============================================================
  Download Images in Order
============================================================ */

(async () => {
  let example_image_1 = await download_image('https://example.com/test-1.png', 'example-1.png');

  console.log(example_image_1.status); // true
  console.log(example_image_1.error); // ''

  let example_image_2 = await download_image('https://example.com/does-not-exist.png', 'example-2.png');

  console.log(example_image_2.status); // false
  console.log(example_image_2.error); // 'Error: Request failed with status code 404'

  let example_image_3 = await download_image('https://example.com/test-3.png', 'example-3.png');

  console.log(example_image_3.status); // true
  console.log(example_image_3.error); // ''
})();

const fs = require('fs');
const http = require('http');
const https = require('https');

const downloadImageToUrl = (url, filename) => {

   let client = http;
   if (url.toString().indexOf("https") === 0) {
      client = https;
   }
   return new Promise((resolve, reject) => {
      client.get(url, (res) => {
          res.pipe(fs.createWriteStream(filename))
          .on('error', reject)
          .once('close', () => resolve(filename))
      })
  })
};

await downloadImageToUrl('https://www.google.com/images/srpr/logo11w.png', 'public/uploads/users/abc.jpg');

如果你想要进度下载，试试这个：

var fs = require('fs');
var request = require('request');
var progress = require('request-progress');

module.exports = function (uri, path, onProgress, onResponse, onError, onEnd) {
    progress(request(uri))
    .on('progress', onProgress)
    .on('response', onResponse)
    .on('error', onError)
    .on('end', onEnd)
    .pipe(fs.createWriteStream(path))
};

使用方法：

var download = require('../lib/download');
  download("https://www.google.com/images/branding/googlelogo/2x/googlelogo_color_150x54dp.png", "~/download/logo.png", function (state) {
            console.log("progress", state);
        }, function (response) {
            console.log("status code", response.statusCode);
        }, function (error) {
            console.log("error", error);
        }, function () {
            console.log("done");
        });

注意：您应该使用以下命令安装request和request-progress模块：

npm install request request-progress --save

这是Cezary答案的一个扩展。如果你想把它下载到一个特定的目录，使用这个。另外，使用const代替var。这样是安全的。

const fs = require('fs');
const request = require('request');
var download = function(uri, filename, callback){
  request.head(uri, function(err, res, body){    
    request(uri).pipe(fs.createWriteStream(filename)).on('close', callback);
  });
};

download('https://www.google.com/images/srpr/logo3w.png', './images/google.png', function(){
  console.log('done');
});

基于以上内容，如果有人需要处理写/读流中的错误，我使用了这个版本。注意stream.read()在写错误的情况下，它是必需的，这样我们就可以完成阅读并在读流上触发close。

var download = function(uri, filename, callback){
  request.head(uri, function(err, res, body){
    if (err) callback(err, filename);
    else {
        var stream = request(uri);
        stream.pipe(
            fs.createWriteStream(filename)
                .on('error', function(err){
                    callback(error, filename);
                    stream.read();
                })
            )
        .on('close', function() {
            callback(null, filename);
        });
    }
  });
};