bootstrap.sh

#!/usr/bin/env bash

mkdir -p common
mkdir -p app
mkdir -p config
mkdir -p bin
mkdir -p dist

cat <<RB > config/warble.rb
Warbler::Config.new do |config|
  config.features = %w(gemjar)
  config.dirs = %w[common app].select { |e| File.directory? e }
  config.includes = FileList['bin/**']
  config.jar_extension = 'jar'
  config.autodeploy_dir = 'dist/'
  config.bytecode_version = '1.8'
end
RB

cat <<RB > common/logger.rb
require 'logger'
class Logger
  def self.verbose?
    java.lang.Boolean.value_of(ENV_JAVA.fetch('DEBUG', ENV.fetch('DEBUG', 'false')))
  end

  def self.on(io_or_filename, verbose: verbose?)
    Logger.new(
      io_or_filename,
      datetime_format: '%Y-%m-%d %H:%M:%S %z',
      level: verbose ? Logger::DEBUG : Logger::INFO,
      formatter: proc { |severity, datetime, _program_name, msg|
        context = Thread.current.key?(:context) && !Thread.current[:context].nil? && !Thread.current[:context].empty? \
          ? "[#{Thread.current[:context]}] " \
          : nil
        "[#{datetime}] [#{severity}] [#{Process.pid}] #{context}#{msg}\n"
      },
    )
  end
end
RB

cat <<RB > common/example_thread_context.rb
module ExampleThreadContext
  def clear_thread_context
    Thread.current[:context] = nil
  end

  def thread_context
    Thread.current[:context] ||= {}
  end
end
RB

cat <<RB > app/example.rb
require_relative '../common/example_thread_context'

LOGGER=Logger.on(STDOUT)

class Example
  include ExampleThreadContext
  
  def go(message:, **context)
    thread_context.merge!(context)
    LOGGER.info message
    clear_thread_context
    context.merge!(message: message)
  end

  class Task
    include java.util.concurrent.Callable

    def initialize(count, message)
      @c = count
      @m = message
    end

    def call
      Example.new.go(message: @m, tid: @c)
    end
  end
end
RB

cat <<RB > bin/example
require_relative '../common/logger'
require_relative '../app/example'
message = ARGV[0] || "test message"
Example.new.go message: 'main thread'

es = java.util.concurrent.Executors.newFixedThreadPool 4
futures = (0...5).map do |count|
  es.submit Example::Task.new(count + 1, message)
end
es.shutdown
pp futures.map(&:get)
RB

cat <<RB > Gemfile
source "https://rubygems.org"

gem 'jruby-jars', '~> 9.2', '= 9.2.8.0'
gem 'warbler', '2.0.5'
RB

which bundle > /dev/null
[[ "$?" != "0" ]] && gem install bundler
bundle info warbler > /dev/null
[[ "$?" != "0" ]] && bundle install --path=vendor

bundle exec warble

run.sh

#!/usr/bin/env bash

[[ "$#" == "0" ]] && echo 'you need to pass at least one arg' && exit 1

for message in "$@"; do
  java -jar dist/example.jar $message
done