Sample Ruby code for working with Akka in JRuby

akka_sample1.rb

require 'java'
require 'akka-actor-1.2-RC6.jar'
require 'scala-library.jar'

java_import 'akka.actor.UntypedActor'
java_import 'akka.actor.Actors'

# Start with something simple.  Implement the actor as a distinct
# class and start it up within the Akka runtime.

# Look, I've implemented the actor API!
class SomeActor < UntypedActor

  def onReceive msg
    puts "Received message: #{msg.to_s}"
  end
end

# So we should be fine then, right?
ref = Actors.actorOf SomeActor.new
ref.start
ref.tell "foo"

akka_sample2.rb

require 'java'
require 'akka-actor-1.2-RC6.jar'
require 'scala-library.jar'

java_import 'akka.actor.UntypedActor'
java_import 'akka.actor.Actors'

# A second attempt.  Define our actor in a standlone class again
# but this time use an ActorFactory (via closure coercion) to
# interact with Akka.

# Define our actor in a class again...
class SomeActor < UntypedActor

  def onReceive msg
    puts "Received message: #{msg.to_s}"
  end
end

# ... and then provide an UntypedActorFactory to instantiate
# the actor.  The factory interface qualifies as a SAM so
# we only need to provide a closure to generate the actor and
# let JRuby's closure coercion handle the rest.
ref = Actors.actorOf do
  SomeActor.new
end

ref.start
ref.tell "foo"

akka_sample3.rb

require 'java'
require 'akka-actor-1.2-RC6.jar'
require 'scala-library.jar'

java_import 'akka.actor.UntypedActor'
java_import 'akka.actor.UntypedActorFactory'
java_import 'akka.actor.Actors'

# Shift to working with code blocks via a generic actor and a simple
# factory for creating them.

class SomeActor < UntypedActor

  # Look, I've got a constructor... but it'll get ignored!
  def initialize(proc)
    @proc = proc
  end

  def onReceive(msg)
    @proc.call msg
  end
end

class SomeActorFactory
  include UntypedActorFactory

  def initialize(&b)
    @proc = b
  end

  def create
    SomeActor.new @proc
  end
end

# Create a factory for an actor that uses the input block to pass incoming messages.
factory = SomeActorFactory.new do |msg|
  puts "Message recieved: #{msg.to_s}"
end
ref = Actors.actorOf factory

ref.start
ref.tell "foo"

akka_sample4.rb

require 'java'
require 'akka-actor-1.2-RC6.jar'
require 'scala-library.jar'

java_import 'akka.actor.UntypedActor'
java_import 'akka.actor.UntypedActorFactory'
java_import 'akka.actor.Actors'

# Continue with the generic actor implementation, but shift to using a setter
# for passing in the Proc to which we'll delegate message handling.

class SomeActor < UntypedActor

  def proc=(b)
    @proc = b
  end

  def onReceive(msg)
    @proc.call msg
  end
end

class SomeActorFactory
  include UntypedActorFactory

  def initialize(&b)
    @proc = b
  end

  def create
    rv = SomeActor.new
    rv.proc = @proc
    rv
  end
end

# Create a factory for an actor that uses the input block to pass incoming messages.
factory = SomeActorFactory.new do |msg|
  puts "Message recieved: #{msg.to_s}"
end
ref = Actors.actorOf factory

ref.start
ref.tell "foo"