The routing logic used to decide which actor will handle a sales or purchase order.

Main4.java

public static class PartitioningRoutingLogic implements RoutingLogic {

    private Map<String, ActorRef> kids;

    public PartitioningRoutingLogic(Map<String, ActorRef> kids) {
        this.kids = kids;
    }

    @Override
    public Routee select(Object message, IndexedSeq<Routee> routees) {

        //find which product ID is relevant here
        String productId = null;
        if(message instanceof PurchaseOrder){
            productId = ((PurchaseOrder) message).getProductId();
        }else if(message instanceof SalesOrder){
            productId = ((SalesOrder) message).getProductId();
        }
        ActorRef actorHandlingProduct = kids.get(productId);

        //no go find the routee for the relevant actor
        for(Routee r : JavaConversions.asJavaIterable(routees)){
            ActorRef a = ((ActorRefRoutee) r).ref(); //cast ok, since the are by definition in this program all routees to ActorRefs
            if(a.equals(actorHandlingProduct)){
                return r;
            }
        }
        
        return akka.routing.NoRoutee$.MODULE$; //none found, return NoRoutee
    }
}