Using Java futures with JRuby

java_future.rb

require 'java'
java_import 'java.util.concurrent.FutureTask'
java_import 'java.util.concurrent.Executors'

class JavaFuture

  class Callable
    def initialize(block)
      @block = block
    end

    def call
      @block.call
      return true
    end
  end

  def initialize(&block)
    @executor = Executors.new_cached_thread_pool
    @task = Callable.new(block)
  end

  def executor
    @executor
  end

  def execute
    @executor.submit(FutureTask.new(@task))
  end

end

f = JavaFuture.new { puts "Hello"; sleep(10); puts 'Again' }
f.execute