Nodejs：通过循环链接数组下载多个文件时出错

Question

var ultUrls = [{
  url: 'https://i.redd.it/kl44uq60z4631.png',
  name: 'pics/A bison in steam during winter at Yellowstone National Park.png'
}, {
  url: 'https://i.redd.it/9eocp20xr6631.jpg',
  name: 'pics/Athens at night.jpg'
}, {
  url: 'https://i.redd.it/0gezn9zjr6631.jpg',
  name: 'pics/This is Rayne. Her favorite color is orange. Her job is a clown for the circus. Her motto is *honk honk*..jpg'
}, {
  url: 'https://i.redd.it/fxcivargr6631.png',
  name: 'pics/Reddit your input is greatly appreciated.png'
}, {
  url: 'https://i.redd.it/xzpukskhr6631.jpg',
  name: 'pics/Cranberry lake Ontario.jpg'
}, {
  url: 'https://i.redd.it/4mplt3joh5631.jpg',
  name: 'pics/Pics of insects are the best.jpg'
}, {
  url: 'https://i.redd.it/03q4c5ndq6631.jpg',
  name: 'pics/Elvis Presley during his service in the U.S. Army.jpg'
}]

While downloading files in this array I'm getting ENONENT:no such file or directory, open ...

 var downloadImages = function(callback) {

    ultUrls.forEach( function(str) {

     download_file_httpget(str.url, str.name, function(){console.log('Finished Downloading' + filename)});
   });

 }
var download_file_httpget = function(url, dest, callback){

     request.get(url)
     .on('error', function(err) {console.log(err)} )
     .pipe(fs.createWriteStream(dest))
     .on('close', callback);

 };

Tried with destination

 var download_file_httpget = function(url, dest, callback){
     let destn = 'C:\\Users\\Downloads\\' + dest;
     request.get(url)
     .on('error', function(err) {console.log(err)} )
     .pipe(fs.createWriteStream(destn))
     .on('close', callback);

 };

UnCaught Exception: Error:ENONENT: no such file or directory, open 'C:\\Users\\Downloads\\pics\\A bison in steam during winter at Yellowstone National Park.png

Answer 1

Just change the name attribute of each image by removing 'pics/'. It will work.

Here is the final code:

const request = require('request');
const fs = require('fs');
var ultUrls = [ { url: 'https://i.redd.it/kl44uq60z4631.png', name: 'A bison in steam during winter at Yellowstone National Park.png' }, { url: 'https://i.redd.it/9eocp20xr6631.jpg', name: 'Athens at night.jpg' }, { url: 'https://i.redd.it/0gezn9zjr6631.jpg', name: 'This is Rayne. Her favorite color is orange. Her job is a clown for the circus. Her motto is honk honk..jpg' }, { url: 'https://i.redd.it/fxcivargr6631.png', name: 'Reddit your input is greatly appreciated.png' }, { url: 'https://i.redd.it/xzpukskhr6631.jpg', name: 'Cranberry lake Ontario.jpg' }, { url: 'https://i.redd.it/4mplt3joh5631.jpg', name: 'Pics of insects are the best.jpg' }, { url: 'https://i.redd.it/03q4c5ndq6631.jpg', name: 'Elvis Presley during his service in the U.S. Army.jpg' } ]

var downloadImages = function(callback) {

    ultUrls.forEach( function(str) {

     download_file_httpget(str.url, str.name, function(){console.log('Finished Downloading' + str.name)});
   });

 }

 var download_file_httpget = function(url, dest, callback){
     let destn = 'C:\\Users\\Downloads\\pics\\' + dest;
     request.get(url)
     .on('error', function(err) {console.log(err)} )
     .pipe(fs.createWriteStream(destn))
     .on('close', callback);

 };

 downloadImages();

As pointed out by @hoangdv create a pics folder and also remove 'pics/' from str.name that is being passed to download_file_httpget

Answer 2

This complete example works correctly, provided that you create a folder called pics .

You'll need to install the request module first too.

npm install request --save

I didn't change much except:

1. formatted the ultUrls declaration
2. replaced the code + filename with + str.name because filename was undefined.

Here's the code:

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

var ultUrls = [
  { url: 'https://i.redd.it/kl44uq60z4631.png', name: 'pics/A bison in steam during winter at Yellowstone National Park.png' },
  { url: 'https://i.redd.it/9eocp20xr6631.jpg', name: 'pics/Athens at night.jpg' },
  { url: 'https://i.redd.it/0gezn9zjr6631.jpg', name: 'pics/This is Rayne. Her favorite color is orange. Her job is a clown for the circus. Her motto is honk honk..jpg' },
  { url: 'https://i.redd.it/fxcivargr6631.png', name: 'pics/Reddit your input is greatly appreciated.png' },
  { url: 'https://i.redd.it/xzpukskhr6631.jpg', name: 'pics/Cranberry lake Ontario.jpg' },
  { url: 'https://i.redd.it/4mplt3joh5631.jpg', name: 'pics/Pics of insects are the best.jpg' },
  { url: 'https://i.redd.it/03q4c5ndq6631.jpg', name: 'pics/Elvis Presley during his service in the U.S. Army.jpg' }
];

var downloadImages = function (callback) {
  ultUrls.forEach(function (str) {
    download_file_httpget(str.url, str.name, function () { console.log('Finished Downloading' + str.name) });
  });

}
var download_file_httpget = function (url, dest, callback) {

  request.get(url)
    .on('error', function (err) { console.log(err) })
    .pipe(fs.createWriteStream(dest))
    .on('close', callback);

};

downloadImages();

Answer 3

I solved the issue by removing '/pics' from the url.

var ultUrls = [{
  url: 'https://i.redd.it/kl44uq60z4631.png',
  name: 'A bison in steam during winter at Yellowstone National Park.png'
}, {
  url: 'https://i.redd.it/9eocp20xr6631.jpg',
  name: 'Athens at night.jpg'
}, {
  url: 'https://i.redd.it/0gezn9zjr6631.jpg',
  name: 'This is Rayne. Her favorite color is orange. Her job is a clown for the circus. Her motto is *honk honk*..jpg'
}, {
  url: 'https://i.redd.it/fxcivargr6631.png',
  name: 'pics/Reddit your input is greatly appreciated.png'
}, {
  url: 'https://i.redd.it/xzpukskhr6631.jpg',
  name: 'Cranberry lake Ontario.jpg'
}, {
  url: 'https://i.redd.it/4mplt3joh5631.jpg',
  name: 'Pics of insects are the best.jpg'
}, {
  url: 'https://i.redd.it/03q4c5ndq6631.jpg',
  name: 'Elvis Presley during his service in the U.S. Army.jpg'
}]

Then used promise like so

Promise.each(ultUrls, url=> new Promise((resolve, reject) => {
    console.log('Downloading Image: ' + url.file_name);
    request(url.url).on('error', reject).pipe(fs.createWriteStream(path.join(__dirname, url.file_name))).on('finish', () => {
        console.log('Downloaded Image: ' + url.file_name);
        resolve();
    });
})).then(() => {
    console.log('All Image Downloaded!');
}).catch(err => {
    console.error('Failed: ' + err.message);
});

Reference: https://stackoverflow.com/a/36666258/7599905

Answer 4

这是因为您之前没有创建过pics目录