jruby integer unboxing / type selection issue

example.rb

#!/Users/fsg/projects/jruby-1.7.1/bin/jruby

require 'java'
require 'pry'

# $CLASSPATH << "jars/netty-4.0.0.Alpha7/jar/all-in-one/"

require 'jars/netty-4.0.0.Alpha7/jar/all-in-one/netty-4.0.0.Alpha7.jar'

java_import 'java.net.InetSocketAddress'
java_import 'java.util.concurrent.Executors'

java_import 'io.netty.buffer.Unpooled'
java_import 'io.netty.buffer.DefaultMessageBuf'
java_import 'io.netty.bootstrap.ServerBootstrap'
java_import 'io.netty.bootstrap.Bootstrap'
java_import 'io.netty.channel.ChannelPipeline'
java_import 'io.netty.channel.Channel'
java_import 'io.netty.channel.socket.nio.NioDatagramChannel'
java_import 'io.netty.channel.ChannelInboundHandlerAdapter'
java_import 'io.netty.channel.ChannelInboundMessageHandlerAdapter'
java_import 'io.netty.channel.ChannelInboundMessageHandler'
java_import 'io.netty.channel.ChannelInitializer'
java_import 'io.netty.channel.socket.nio.NioEventLoopGroup'
java_import 'io.netty.channel.socket.nio.NioServerSocketChannel'
java_import 'io.netty.channel.ChannelOption'
java_import 'io.netty.channel.socket.DatagramPacket'

class Incoming < ChannelInboundHandlerAdapter
  def newInboundBuffer(ctx)
    puts "got into incoming.newinboundbuffer\n"
    return Unpooled.buffer(512)
  end

  def exceptionCaught(ctx,cause)
    puts "exception caught: #{cause.inspect}\n"
  end

  def inboundBufferUpdated(ctx)
    puts "got something\n"
    ctx.flush()
  end
end

class MyInitializer < ChannelInitializer

  def initChannel(sch)
    sch.pipeline().addLast(Incoming.new())
  end

  def self.exceptionCaught(ctx,throwable)
    puts "exception caught\n"
  end
end

x = ServerBootstrap.new()
  .group(NioEventLoopGroup.new(), NioEventLoopGroup.new())
  .channel(NioServerSocketChannel.new().java_class)
  .localAddress(8080)
  .option(ChannelOption::SO_BACKLOG, 100.to_java(:int))
  .childOption(ChannelOption::TCP_NODELAY, true)
  .childHandler(MyInitializer.new())
f = x.bind().sync()

# NOTE: crashes because it tries to convert the '100' into a Long on the 'option' line, but option
# expects a java plain integer.