Rakefile

task :java_compile do
  # Pick the right class path, depending if we're using an rvm installed JRuby
  jruby_cpath = ENV['MY_RUBY_HOME'] || ENV['JRUBY_HOME']
  raise 'MY_RUBY_HOME or JRUBY_HOME are not set' unless jruby_cpath

  puts 'Doing a simple compilation'
  sh %(javac -source 1.6 -target 1.6 -cp #{jruby_cpath}/lib/jruby.jar java/**/*.java)
  mkdir_p '../lib/jrubytesting'
  sh %(jar cf ../lib/jrubytesting/test_jruby_library.jar -C java jrubytesting/TestJrubyLibraryService.class)
  puts
end

task :c_compile do
  require 'rubygems/ext'

  gem_dir       = File.expand_path(File.dirname(__FILE__) + '../../')
  extension_dir = File.join(gem_dir, File.dirname('ext/jrubytesting/extconf.rb'))
  dest_path     = File.join(gem_dir, 'lib/jrubytesting')

  Dir.chdir(extension_dir) do
    results = Gem::Ext::ExtConfBuilder.build('extconf.rb', gem_dir, dest_path, [])
    say results.join("\n") if Gem.configuration.really_verbose
  end
end

def is_jruby?
  defined?(RUBY_ENGINE) && RUBY_ENGINE == 'jruby'
end

task :default => is_jruby? ? :java_compile : :c_compile