bundler support for jars for jruby
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Latest commit 08f19e1 May 21, 2018



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Manage jar dependencies similar to how bundler manages gem dependencies:

  • the DSL mimics the one from bundler
  • you can use maven-like version declarations or rubygems/bundler version ranges
  • it locks down the jar versions inside "Jarfile.lock"
  • you can declare jar dependencies within a gem using the requirements directive of the gem specification. jbundler will include those jar dependencies into its classpath

differences compared to bundler

  • you need to run bundle install first if any of the gems have jar dependencies.
  • all one command jbundle, see jbundle help on the possible options and how to update a single jar, etc.

Get started

Install JBundler with:

jruby -S gem install jbundler

First, create a Jarfile, something like:

jar 'org.yaml:snakeyaml', '1.14'
jar 'org.slf4j:slf4j-simple', '>1.1'

Install jar dependencies

jruby -S jbundle install

Loading the jar files

require 'jbundler'

It will add all the jar dependencies in the java classpath from the Jarfile.lock.


More info about the Jarfile and about versions.

For adding a maven repository see Jarfile.

Building the jbundler gem

Running the integration test

./mvnw verify

Building the gem (see ./pkg)

./mvnw package -Dinvoker.skip

Or just

gem build jbundler.gemspec


Here is an example usage of the AliasEvent class from the snakeyaml package

require 'jbundler'
require 'java'

java_import 'org.yaml.snakeyaml.events.AliasEvent'

class TestClass
  def my_method
    puts AliasEvent.methods



Since the version resolution happens in two steps - first the gems, and then the jars/poms - it is possible in case of a failure that there is a valid gems/jars version resolution which satisfies all version contraints. So there is plenty of space for improvements (like maven could resolve the gems as well, etc).

Special thanks

The whole project actually started with a controversial discussion on a pull request on bundler. This very same pull request were the starting point of that project here. Probably by now there is not much left of the original code, but many thanks to ANithian for giving the seed of that project.


Almost all code is under the MIT license but the java class (AetherSettings.java)[https://github.com/mkristian/jbundler/blob/master/src/main/java/jbundler/AetherSettings.java] which was derived from EPL licensed code.


  1. Fork it
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Added some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create new Pull Request


enjoy :)