How to create an observer, like communication between actors with Akka

Question

In classic programming, I use the obeserver pattern in case I want to notify observers of changes.

What is the equivalent model in Akka?

Use Case:

• Actor (PropertyServiceActor) - these are properties for reading and caching from the database
• Different members can register with PropertyServiceActor
• If the property changes, the PropertyServiceActor notifies registered members of the change

Answer 1

Take a look at BroadcastGroup

//Create group val paths = List("/user/workers/w1", "/user/workers/w2", "/user/workers/w3") val observers: ActorRef = context.actorOf(BroadcastGroup(paths).props(), "observers") 

To notify all observers, simply send a message to observers ActorRef. You can also add and remove observers by sending akka.routing.AddRoutee and akka.routing.RemoveRoutee .

You can find more routing docs.