Hello Juby with warbler

Lets have a Hello world program through jruby and prepare a executable jar through warbler.

Let's assume jruby already installed . In my case I used jruby 1.7.8

Please create the below directory structure :

HelloWorld---|
                       |--bin--main.rb
                       |--lib--hello--hello.rb
                       |--Gemfile                      -------File
                       |--helloworld.gemspec   -------File

copy the below content to the respective file, then execute the below steps through terminal. at the end you should have a HelloWorld.jar in your project directory and follow the step number (5) to get the output.

1. install bundler gem : gem install bundler
2. change to the directory HelloWorld 
3. execute bundle : $> bundle
4. warble compiled jar
5. java -jar HelloWorld.jar

helloworld.gemspec :

Gem::Specification.new do |s|  s.name             = 'helloworld'  s.version          = '1.0.0'  s.authors          = ['Khirod Patra']
  s.date             = '2013-07-03'  s.description      = 'Hello World'  s.email            = ['khirodpatra@gmail.com']
  s.homepage         ='khirodblog.blogspot.com/'

  s.require_paths    = ['lib','bin']
  s.files            = Dir.glob("{bin,lib}/**/*")
  s.executables   = s.files.select { |f| f =~ /^bin\// }.map{ |f| File.basename(f) }
  s.default_executable = 'bin/main.rb'  end

GemFile :

source 'https://rubygems.org'

gem 'warbler'

hello.rb :

module Hello
  class SayHello
    def hello
      puts "hello World"    end  endend

main.rb :

#!/usr/bin/env ruby
require 'rubygems'

require 'java'
my_lib = File.expand_path(File.dirname(__FILE__) + "/../lib")$LOAD_PATH.unshift(my_lib) unless $LOAD_PATH.include?(my_lib)
require 'hello/hello'
module Hello
  class Main    SayHello.new.hello
  endend