Include dependencies in Groovy application without repository access

Question

I have a Groovy project (using Eclipse) which makes use of several @Grab statements. This works fine on my development machine. However I need to distribute this application including all its dependencies to other machines which don't have any internet connection, i.e. it won't be possible to download the necessary JARs from these machines.

Is there a way to somehow automatically include the dependencies into the project, e.g. a lib folder? This way I could just copy the project to another machine and use it.

Answer 1

So, lets say for example you have a script Script.groovy like so, that you currently run with groovy Script.groovy:

@Grab('com.github.groovy-wslite:groovy-wslite:1.1.2')
import wslite.rest.*

def client = new RESTClient("http://httpbin.org")
def response = client.get(path:'/get')

assert 200 == response.statusCode
println "Received : $response.json"

Now, we want to get this into a jar file that you can distribute, and people can just run with java -jar myApp.jar

So make the following folder structure:

myApp
 |-- src
 |    |-- main
 |         |-- groovy
 |              |-- example
 |                   |-- Script.groovy
 |-- build.gradle

Then, in Script.groovy, put your script (with a package name, and no @Grab annotation):

package example

import wslite.rest.*

def client = new RESTClient("http://httpbin.org")
def response = client.get(path:'/get')

assert 200 == response.statusCode
println "Received : $response.json"

And in build.gradle, put this script which pulls down the groovy, and groovy-wslite dependencies, and applies the shadow-jar plugin to bundle all dependencies into one single fat jar:

plugins {
  id "com.github.johnrengelman.shadow" version "1.2.2"
}

apply plugin: 'groovy'
apply plugin: 'application'

repositories {
    jcenter()
}

mainClassName = 'example.Script'

dependencies {
    compile 'org.codehaus.groovy:groovy-all:2.4.5'
    compile 'com.github.groovy-wslite:groovy-wslite:1.1.2'
}

You can then (assuming you have installed Gradle), simply run:

gradle shadowJar

Which will compile your code, and put it and all its dependencies into build/libs/myApp-all.jar

So then, you can just run:

java -jar build/libs/myApp-all.jar

And your script should run as before...

You can then distribute this jar file, instead of just the script...

Hope this helps

Answer 2

I would suggest switching to Gradle or some other build tool that downloads the dependencies at build time. As you probably already know grape pulls down all the dependencies at runtime.

Grape (The Groovy Adaptable Packaging Engine or Groovy Advanced Packaging Engine) is the infrastructure enabling the grab() calls in Groovy, a set of classes leveraging Ivy to allow for a repository driven module system for Groovy. This allows a developer to write a script with an essentially arbitrary library requirement, and ship just the script. Grape will, at runtime, download as needed and link the named libraries and all dependencies forming a transitive closure when the script is run from existing repositories such as Ibiblio, Codehaus, and java.net.

This link might help you in your transition to using Gradle with your Groovy script.

Running Groovy scripts from Gradle