Scala Reactive Programming

Actor to Actor communication

Consider that an Actor-1 sends a message to Actor-2 using the ask function to know the response from that Actor; it is as shown here:

actor1 ? HelloMessage

In Actor-2, when it receives it, it should process it and reply to that Actor-2, as shown here:

def receive = { 
   case HelloMessage =>  
           println("Actor-2: Process the message") 
           sender ! HowDoYouDo 
} 

Here, Actor-2 uses the sender object to reply with a message back to that message sender directly.

Here, sender is a function defined in an Actor trait to access the current processing message's sender Actor reference directly, as follows:

final def sender(): ActorRef = context.sender()