nodejs 如何使用 Node.js 将文件转换为 zip 文件并下载？

如何使用 Node.js 将文件转换为 zip 文件并下载？

原文:https://www . geesforgeks . org/如何使用节点 js/将文件转换为 zip 文件并下载

压缩文件是存储压缩文件和文件夹的常用方式。在本文中，我将演示如何使用 adm-zip 模块(NPM 包)将文件转换为 zip 格式。

ADM-ZIP 的用途

压缩原始文件并将其更改为 zip 格式。
更新/删除现有文件(。zip 格式)。

安装 ADM-ZIP:

步骤 1: 在终端中使用以下命令安装模块。

npm install adm-zip

步骤 2: 使用以下命令检查安装模块的版本。

npm version adm-zip

我们将使用 adm-zip 模块将这个 upload_data 文件夹更改为 zip 文件！

upload_data FOLDER

转换下载 zip 文件代码:

java 描述语言

// express is a node framework that is helps in creating
// 2 or more web-pages application
const express = require('express')

// filesystem is a node module that allows us to work with
// the files that are stored on our pc
const file_system = require('fs')

// it is an npm package.this is to be required in our JS 
// file for the conversion of data to a zip file!
const admz = require('adm-zip')

// stores the express module into the app variable!
const app = express()

// this is the name of specific folder which is to be 
// changed into zip file1
var to_zip = file_system.readdirSync(__dirname+'/'+'upload_data')

// this is used to request the specific file and then print 
// the data in it!
app.get('/',function(req,res){
    res.sendFile(__dirname+'/'+'index.html')

    // zp is created as an object of class admz() which 
    // contains functionalities
    var zp = new admz();

    // this is the main part of our work!
    // here for loop check counts and passes each and every 
    // file of our folder "upload_data"
    // and convert each of them to a zip!
    for(var k=0 ; k<to_zip.length ; k++){
        zp.addLocalFile(__dirname+'/'+'upload_data'+'/'+to_zip[k])
    }

    // here we assigned the name to our downloaded file!
    const file_after_download = 'downloaded_file.zip';

    // toBuffer() is used to read the data and save it
    // for downloading process!
    const data = zp.toBuffer();

    // this is the code for downloading!
    // here we have to specify 3 things:
        // 1\. type of content that we are downloading
        // 2\. name of file to be downloaded
        // 3\. length or size of the downloaded file!

    res.set('Content-Type','application/octet-stream');
    res.set('Content-Disposition',`attachment; filename=${file_after_download}`);
    res.set('Content-Length',data.length);
    res.send(data);

})

// this is used to listen a specific port!
app.listen(7777,function(){
    console.log('port is active at 7777');
})

运行程序的步骤: