buildr-gemjar is distributed as a rubygem on
rubygems.org. Install it as you would any other gem:
$ gem install buildr-gemjar
buildr-gemjar provides a package type called
:gemjar. Sample use:
# buildfile require 'buildr-gemjar' define 'sinatra-gems' do project.version = '1.1.2' package(:gemjar).with_gem('sinatra', project.version) end
When you run
buildr package, the result will be a JAR which contains
sinatra 1.1.2 and all its dependencies.
You can specify multiple gems:
package(:gemjar). with_gem('activesupport', '2.3.10'). with_gem('facets, '2.4.5')
You can specify additional sources on top of rubygems.org:
package(:gemjar). add_source('http://myrepo.local/gems'). with_gem('my-orm', '1.0.3')
You can also include a gem for which you have a
package(:gemjar).with_gem(:file => _('snapshot-gem-2.0.7.pre.gem'))
JARs embedded in gems
Many gems that are intended for use in JRuby embed one or more JARs containing "native" java code. jruby-openssl is a popular example of this practice. If these jars are embedded as-is into the gemjar, they won't be visible to ruby code.
To resolve this,
buildr-gemjar will unpack any jar found under the
lib directory of any installed gem (including dependent gems) and
include its contents in the gemjar directly. You can control this
behavior for an individual gem with the
:unpack_jars option to
with_gems. It can be set to one of the following values:
- an array of globs; e.g.,
["lib/shared/**/*.jar"]. Each glob will be applied at the root of the installed gem's contents and each match will be unpacked into the gemjar.
true. Equivalent to
["lib/**/*.jar"]. This is the default.
false. Do not unpack any jars from this gem.
The default is
:unpack_jars => true. Note that you can only apply
different unpack behavior for gems which are explicitly included via
with_gem. Any transitively installed gems will have the default
unpack behavior (i.e., unpack every JAR under lib) applied.
It's important that the name of your JAR not be the same as anything
require from it. E.g., in the sample above, if the JAR
sinatra.jar, it would not be possible to
"sinatra" from it. (This is a general JRuby requirement, not
something that's specific to this tool.)
Embedded JARs will not have any of their metadata (manifests, META-INF service registrations, etc.) preserved if they are unpacked.
buildr-gemjar has been tested with buildr 1.4.4 on ruby 1.8.7,
1.9.2, and JRuby* 1.5.6. It's expected that it will work with any
fairly recent version of buildr. It's been tested on OS X and Linux;
it may or may not work on Windows.
(*The spec suite does not execute on JRuby for no reason I've yet been able to track down, but manual testing indicates that the extension works fine on that platform.)
- Remember requested gems so that rebuilds can automatically happen on configuration changes. (Workaround: build clean.)
- Use bundler to get a coherent list of dependencies across
several gems. (It would already do this, except that bundler
doesn't support sourcing a gem from a
.gemfile, which is a more important feature.)
- Improve performance. Currently a new JVM is spun up to do each gem install, which can be slow if there are a lot of gems. However, the install process needs to change the environment for rubygems so I'm not sure this can be avoided.
- Support Windows.
Copyright 2011, Rhett Sutphin.
buildr-gemjar was built at NUBIC.