Skip to content
bundler support for jars for jruby
Ruby Shell Batchfile CSS HTML JavaScript Other
Find file
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.


  • Build Status #

manage jar dependencies similar than bundler manages gem dependencies.

  • the DSL mimics the one from bundler
  • you can use maven like version declaration or rubygems/bundler like version ranges
  • it locks down the jar versions inside "Jarfile.lock"
  • you can declare jar dependency within a rubygems using the requirements directive of the gem specification. jbundler will include those jar dependencies into its classpath
  • on the first run everything get resolved, any further run just the setup of classpath is done (without any maven involved)
  • it integrates nicely with bundler when Bundler.require is used (like Rails does it)

get started

install JBundler with

jruby -S gem install jbundler

first create a Jarfile, something like

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

together with Bundler

just add it as first entry in your Gemfile

gem 'jbundler'

and now install the bundle both gems and jars

jbundle install


building the jar rake jar

building the gem rake build

running the junit test rake junit

running the minitest rake minitest

make sure you use jruby ;)

Gemfile and Jarfile

if there is only a Gemfile and no Jarfile jbundler handles all the declared jar dependencies of gems as well all the jars from the Jarfile. it will only look into gems which bundler loaded.

without Bundler - Jarfile only

requiring jbundler will trigger the classpath setup

require 'jbundler'

this you can use with rubygems or isolate or . . .


more info about the Jarfile and about versions.

for adding a maven repository see Jarfile.


like bundler there is a console which sets up the gems (if there is Gemfile otherwise that part get skipped) and sets up the classloader:

jbundle console

further it adds two methods to the root level:

> jars

to list the loaded jars and

> jar 'org.yaml:snakeyaml'

using the same syntax as use in the Jarfile. there are limitations with such a lazy jar loading but it is very convenient when trying out things.

lazy jar loading

require 'jbundler/lazy'
include JBundler::Lazy

will offer the same jar/jars method than you have inside the console.

extra commands

jbundler tree

shows the dependency tree - without the locked version. i.e. an install or update would result in the shown version.

with locked down versions that tree is more hint then a real picture of the situation !!

jruby executable -b start.rb

will create an executable jar file using the given ruby script as bootstrap script. it will include the comple jruby and all the dependent jars as well all the gems packed into it as well. the

 jruby '1.7.4'

declaration in the Jarfile will determinate the jruby version to use for the executable jar.


src/example/my_project has a Gemfile which uses a gem which depends on jar dependency. see src/example/gem_with_jar/gem_with_jar.gemspec how the jar gets declared.

execute src/example/my_project/info.rb to see it in action:

  cd src/example/my_project
  jbundle install
  bundle exec info.rb


update of single artifacts is not possible.

since the version resolution happens in two steps - first the gems 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)

Jarfile is not a DSL but it could use a ruby DSL to read the data (any contribution welcome).

jbundler does not completely obey the $HOME/.m2/settings.xml from maven where you usually declare proxies, mirrors, etc. see jbundler configuration for what is already possible.

RVM and/or rubygems-bundler

some tests did not work with RVM and/or rubygems-bundler - there are some weird classloader issue popping up. there is a problem with the way the classloader gets setup. but a manual jruby installion or using rbenv is just working fine.

those issue might pop up with jbunle tree and jbundle executable

running tests

  • rake will just execute all tests (skips some with rvm)
  • rake minitest runs the minitest specs
  • rake junit runs the junit java tests
  • jruby spec/abc_spec.rb runs that given tests (just use the right file)
  • mvn test will also run all tests (skips some)
  • rmvn test`` same asmvn test```


update of a single artifact is not possible (yet). but to update the whole set of artifacts just delete the lockfile Jarfile.lock

if jbundler sees that Gemfile.lock or Jarfile is newer then the .jbundler/classpath.rb file then jbundler tries to gracefully upgrade towards the changes.

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 no much left of the original code but many thanks to ANithian for given the seed of that project.


Almost all code is under the MIT license but the java class ([] 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 :)

Something went wrong with that request. Please try again.