Example for a question about jar-packaged gems in JRuby

.gitignore

aker-gems.jar
gem_home

gemjar-test.sh

#!/bin/bash -e

##
# Demonstrates a difference in gem handling for jar-packaged gems in
# JRuby. If the the jar is `require`d, the gems are available. If the
# jar is placed on the classpath manually, the gems are not
# available. The text of [1] suggests both should work.
#
# [1]: http://blog.nicksieger.com/articles/2009/01/10/jruby-1-1-6-gems-in-a-jar

JRUBY_VERSION=1.6.6
if [ -z $JRUBY_COMPLETE ]; then
    JRUBY_COMPLETE="$HOME/.m2/repository/org/jruby/jruby-complete/${JRUBY_VERSION}/jruby-complete-${JRUBY_VERSION}.jar"
fi

echo "Using jruby-complete jar '${JRUBY_COMPLETE}'"

echo "Creating gemjar"
mkdir -p gem_home
GEM_HOME=`pwd`/gem_home GEM_PATH='' java -jar ${JRUBY_COMPLETE} -S gem install aker -v 3.0.3
cd gem_home
jar cf ../aker-gems.jar .
cd ..

echo
echo "gem list with gemjar required:"
GEM_HOME='' GEM_PATH='' java -jar ${JRUBY_COMPLETE} -raker-gems.jar -S gem list

echo
echo "gem list with gemjar on classpath:"
GEM_HOME='' GEM_PATH='' java -cp aker-gems.jar -jar ${JRUBY_COMPLETE} -S gem list

output.txt

$ ./gemjar-test.sh 
Using jruby-complete jar '/Users/rsutphin/.m2/repository/org/jruby/jruby-complete/1.6.6/jruby-complete-1.6.6.jar'
Creating gemjar
Fetching: rubytree-0.7.0.gem (100%)
========================================================================

 Thank you for installing rubytree.

 Please note that a few APIs have been deprecated since Version 0.6.1.

 Specifically, the 'Tree::TreeNode#depth' method is now deprecated, and
 a new nodeDepth() method has been introduced.

 Details of the API changes are documented in the API-CHANGES file.

========================================================================
Fetching: i18n-0.6.0.gem (100%)
Fetching: multi_json-1.0.4.gem (100%)
Fetching: activesupport-3.2.1.gem (100%)
Fetching: net-ldap-0.1.1.gem (100%)
Fetching: castanet-1.0.1.gem (100%)
Fetching: rack-1.4.1.gem (100%)
Fetching: warden-1.1.0.gem (100%)
Fetching: aker-3.0.3.gem (100%)
Successfully installed rubytree-0.7.0
Successfully installed i18n-0.6.0
Successfully installed multi_json-1.0.4
Successfully installed activesupport-3.2.1
Successfully installed net-ldap-0.1.1
Successfully installed castanet-1.0.1
Successfully installed rack-1.4.1
Successfully installed warden-1.1.0
Successfully installed aker-3.0.3
9 gems installed

gem list with gemjar required:

*** LOCAL GEMS ***

activesupport (3.2.1)
aker (3.0.3)
castanet (1.0.1)
i18n (0.6.0)
multi_json (1.0.4)
net-ldap (0.1.1)
rack (1.4.1)
rubytree (0.7.0)
warden (1.1.0)

gem list with gemjar on classpath:

*** LOCAL GEMS ***