Akka/Scala example source code file (UdpSupport.scala)

This example Akka source code file (UdpSupport.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

actor, address, akka, associationhandle, channel, channelbuffer, concurrent, inetsocketaddress, netty, nettytransport, promise, remote, socketaddress, transport, udphandlers, unit

The UdpSupport.scala Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */
package akka.remote.transport.netty

import akka.actor.Address
import akka.remote.transport.AssociationHandle
import akka.remote.transport.AssociationHandle.{ HandleEventListener, InboundPayload }
import akka.remote.transport.Transport.AssociationEventListener
import akka.util.ByteString
import java.net.{ SocketAddress, InetAddress, InetSocketAddress }
import org.jboss.netty.buffer.{ ChannelBuffer, ChannelBuffers }
import org.jboss.netty.channel._
import scala.concurrent.{ Future, Promise }

/**
 * INTERNAL API
 */
private[remote] trait UdpHandlers extends CommonHandlers {

  override def createHandle(channel: Channel, localAddress: Address, remoteAddress: Address): AssociationHandle =
    new UdpAssociationHandle(localAddress, remoteAddress, channel, transport)

  override def registerListener(channel: Channel,
                                listener: HandleEventListener,
                                msg: ChannelBuffer,
                                remoteSocketAddress: InetSocketAddress): Unit = {
    transport.udpConnectionTable.putIfAbsent(remoteSocketAddress, listener) match {
      case null ⇒ listener notify InboundPayload(ByteString(msg.array()))
      case oldReader ⇒
        throw new NettyTransportException(
          s"Listener $listener attempted to register for remote address $remoteSocketAddress but $oldReader was already registered.")
    }
  }

  override def onMessage(ctx: ChannelHandlerContext, e: MessageEvent): Unit = e.getRemoteAddress match {
    case inetSocketAddress: InetSocketAddress ⇒
      if (!transport.udpConnectionTable.containsKey(inetSocketAddress)) {
        e.getChannel.setReadable(false)
        initUdp(e.getChannel, e.getRemoteAddress, e.getMessage.asInstanceOf[ChannelBuffer])
      } else {
        val listener = transport.udpConnectionTable.get(inetSocketAddress)
        val bytes: Array[Byte] = e.getMessage.asInstanceOf[ChannelBuffer].array()
        if (bytes.length > 0) listener notify InboundPayload(ByteString(bytes))
      }
    case _ ⇒
  }

  def initUdp(channel: Channel, remoteSocketAddress: SocketAddress, msg: ChannelBuffer): Unit
}

/**
 * INTERNAL API
 */
private[remote] class UdpServerHandler(_transport: NettyTransport, _associationListenerFuture: Future[AssociationEventListener])
  extends ServerHandler(_transport, _associationListenerFuture) with UdpHandlers {

  override def initUdp(channel: Channel, remoteSocketAddress: SocketAddress, msg: ChannelBuffer): Unit =
    initInbound(channel, remoteSocketAddress, msg)
}

/**
 * INTERNAL API
 */
private[remote] class UdpClientHandler(_transport: NettyTransport, remoteAddress: Address)
  extends ClientHandler(_transport, remoteAddress) with UdpHandlers {

  override def initUdp(channel: Channel, remoteSocketAddress: SocketAddress, msg: ChannelBuffer): Unit =
    initOutbound(channel, remoteSocketAddress, msg)
}

/**
 * INTERNAL API
 */
private[remote] class UdpAssociationHandle(val localAddress: Address,
                                           val remoteAddress: Address,
                                           private val channel: Channel,
                                           private val transport: NettyTransport) extends AssociationHandle {

  override val readHandlerPromise: Promise[HandleEventListener] = Promise()

  override def write(payload: ByteString): Boolean = {
    if (!channel.isConnected)
      channel.connect(new InetSocketAddress(InetAddress.getByName(remoteAddress.host.get), remoteAddress.port.get))

    if (channel.isWritable && channel.isOpen) {
      channel.write(ChannelBuffers.wrappedBuffer(payload.asByteBuffer))
      true
    } else false
  }

  override def disassociate(): Unit = try channel.close()
  finally transport.udpConnectionTable.remove(transport.addressToSocketAddress(remoteAddress))

}