gistfile1.scala

import org.jboss.netty.channel.{
    ChannelPipelineCoverage,
    SimpleChannelHandler,
    ChannelHandlerContext,
    MessageEvent,
    ExceptionEvent
}
import org.jboss.netty.channel.socket.nio.NioDatagramChannelFactory
import org.jboss.netty.bootstrap.ConnectionlessBootstrap
import java.util.concurrent.Executors
import java.net.InetSocketAddress

object EchoServerApp {
    def main (args: Array[String]) {
        val server = new EchoServer(1234)
        server.start
    }
}

@ChannelPipelineCoverage("all")
class EchoServerHandler extends SimpleChannelHandler {
    override def messageReceived (context: ChannelHandlerContext, event: MessageEvent) {
        event.getChannel.write(event.getMessage, event.getRemoteAddress)
        println("Echoed back packet from %s".format(event.getRemoteAddress.toString))
    }
    
    override def exceptionCaught (context: ChannelHandlerContext, event: ExceptionEvent) {
        println("Exception caught...")
        event.getCause.printStackTrace
    }
}

class EchoServer (port: Int) {
    val channelFactory = new NioDatagramChannelFactory(Executors.newCachedThreadPool())
    val boostrap = new ConnectionlessBootstrap(channelFactory)
    
    def start () {
        boostrap.getPipeline.addLast("handler", new EchoServerHandler())
        boostrap.bind(new InetSocketAddress(port))
        println("EchoServer started on port %d".format(port))
    }
}