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object Pub {
  println("starting publishing service ..")
  val p = new Publisher(new RedisClient("localhost", 6379))
  p.start

  def publish(channel: String, message: String) = {
    p ! Publish(channel, message)
  }
}

debasishg

sealed trait PubSubMessage
case class S(channel: String, noSubscribed: Int) extends PubSubMessage
case class U(channel: String, noSubscribed: Int) extends PubSubMessage
case class M(origChannel: String, message: String) extends PubSubMessage

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1. Open a shell and set AKKA_HOME to the distribution root
2. cd $AKKA_HOME
3. sbt console
4. scala> import sample.pubsub._
5. scala> Sub.sub("a", "b") // starts Subscription server & subscribes to channels "a" and "b"

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1. Open up another shell similarly as the above and set AKKA_HOME
2. cd $AKKA_HOME
3. sbt console
4. scala> import sample.pubsub._
5. scala> Pub.publish("a", "hello") // the first shell should get the message
6. scala> Pub.publish("c", "hi") // the first shell should NOT get this message

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Open up a redis-client from where you installed redis and issue a publish command
 ./redis-cli publish a "hi there" ## the first shell should get the message

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1. Go back to the first shell
2. Sub.unsub("a") // should unsubscribe the first shell from channel "a"
3. Study the callback function defined below. It supports many other message formats.
4. In the second shell window do the following:

  scala> Pub.publish("b", "+c")  // will subscribe the first window to channel "c"
  scala> Pub.publish("b", "+d")  // will subscribe the first window to channel "d"
  scala> Pub.publish("b", "-c")  // will unsubscribe the first window from channel "c"
  scala> Pub.publish("b", "exit")  // will unsubscribe the first window from all channels

debasishg

class Publisher(client: RedisClient) extends Actor {
  def receive = {
    case Publish(channel, message) =>
      client.publish(channel, message)
      reply(true)
  }
}

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newOrder.to.buy(100.shares.of('IBM')) {
  limitPrice   300
  allOrNone    true
  valueAs      {qty, unitPrice -> qty * unitPrice - 500}
}

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ScriptEngineManager factory = new ScriptEngineManager();
ScriptEngine engine = factory.getEngineByName("groovy");

List<?> orders = (List<?>)
  engine.eval(new InputStreamReader(
    new BufferedInputStream(
      new SequenceInputStream(
        new FileInputStream("ClientOrder.groovy"),
        new FileInputStream("order.dsl")))));

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public class RunScript {
  public static void main(String[] args)
    throws CompilationFailedException, IOException,
           InstantiationException, IllegalAccessException {

    final ClientOrder clientOrder = new ClientOrder();

    clientOrder.run();

    final Closure dsl =