How to start a java file from a javascript file (Node.js)

Question

Hello I have got a jar file lavalink to be exact which is basically a music module now i would like to start the jar file from my index.js(Main bot file) as I am not in the financial state to pay for a separate host for the lavalink server and would like to start and use the lavalink server in the same hosting container

No I am not running it in a browser I am using discord.js wrapper to interact with the discord API to make a backend program

question from:https://stackoverflow.com/questions/65643700/how-to-start-a-java-file-from-a-javascript-file-node-js

Answer 1

Installation

Install child process npm i child-process this allows you to execute shell comands

Command

give the exec function as first parameter your command

• exec("cd ~/<path-to-directory-jarFile> && java -jar Myjar_file.jar

• cd ~/<path-to-directory-jarFile> goes in the directory where your jar file is

• java -jar Myjar_file.jar executes your jar file

• the && executes your commands consecutevely first the one before then the one after

Example

const { exec } = require("child_process");

exec("cd ~/<path-to-directory-jarFile>  && java -jar Myjar_file.jar ", (error, stdout, stderr) => {
    if (error) {
        console.log(`error: ${error.message}`);
        return;
    }
    if (stderr) {
        console.log(`stderr: ${stderr}`);
        return;
    }
    console.log(`stdout: ${stdout}`);
});

Executing Shell Commands in NodeJS:

• https://stackabuse.com/executing-shell-commands-with-node-js/