njar

Running JAR files on node.js

This package helps with running JAR files or Java classes on Node.js.

Preview

Example

For more details, see the example.

Install

npm install njar --save # install locally
npm install njar -g # or install globally

Usage

Install a specify version of openJDK

njar install 16 # install openjdk16
njar use 16 # use openjdk16

Running JAR files on CLI

# running jar files
njar exec ./Math.jar add 11 22

# running jar files with cp
njar exec -cp ./Math.jar App.Main add 11 22
# running compiled classes with cp
njar exec -cp . App.Main add 11 22

Running JAR files programmatically

const path = require('path')
const { execute } = require('njar')

async function main() {
  const jarPath = path.join(__dirname, './Math.jar')
  const result = await execute(jarPath, ['add', '2', '4'])
  console.log(result) // '6'
}

main()

Running with cp

const path = require('path')
const { executeWithCP } = require('njar')

async function main() {
  const className = 'App.Main'
  const classPaths = path.join(__dirname, '.')
  const result = await executeWithCP(classPaths, className, [
    'multiply',
    '2',
    '3',
  ])
  console.log(result) // '6'
}

main()

All CLI commands

njar install [version]  # Install a JDK version
njar use [version]      # Set the JDK version
njar versions           # List all JDK versions available to njar
njar which              # Display the full path to an executable
njar exec               # Running java application
njar --help             # Show help information