Blatt 04

README.md

@@ -0,0 +1,41 @@
+# Blatt 04 - Timed Messages
+
+In diesem Blatt ging es allen voran, um die möglichkeit Zeitgesteuert Nachrichten zu senden. Möglich macht es der 
+`TimerScheduler`. 
+
+Damit ein Aktor zugriff auf einen `TimerScheduler` hat, muss der Aktor damit erstellt werden. Anstelle dem _regulärem_
+
+```java
+public static Behavior<Message> create(... arguments ...) {
+    return Behaviors.setup(context -> new Actor(context, ... arguments ...));
+}
+```
+
+muss ein Aktor nun mit `Timers` erstellt werden.
+
+```java
+public static Behavior<Message> create(... arguments ...) {
+    return Behaviors.setup(context -> Behaviors.withTimers(timers -> new Actor(context, timers, ... arguments ...)));
+}
+```
+
+Entsprechend muss im Konstruktor dann auch an der entsprechenden Stelle ein `TimerScheduler` erwartet werden.
+
+```java
+private Actor(ActorContext<Message> context, TimerScheduler<Message> timers, ... arguments ...) {
+    super(context);
+    this.timers = timers; // wir speichern uns einfach den TimerScheduler
+    // restliche argumente setzen
+}
+```
+
+Nun kann der `TimerScheduler` genutzt werden. Grundsätzlich wird mit dem `TimerScheduler` eine Nachricht nach einer 
+bestimmten Zeit **an sich selbst** gesendet. Diese muss (wie jede Nachricht) dann auch behandelt werden.
+
+Der Code
+```java
+this.timers.startSingleTimer(new Message(), Duration.ofSeconds(10));
+```
+sendet eine Nachricht (`Message`) nach 10 Sekunden an sich selbst.
+
+`TimerScheduler` können noch mehr, aber das ist erstmal alles, was zum Verständnis der Aufgabe gebraucht wird.

src/main/java/com/example/AkkaMainSystem.java

@@ -4,31 +4,62 @@ import akka.actor.typed.ActorRef;
 import akka.actor.typed.Behavior;
 import akka.actor.typed.javadsl.*;
 
-public class AkkaMainSystem extends AbstractBehavior<AkkaMainSystem.Create> {
+import java.time.Duration;
+import java.util.ArrayList;
 
-    public static class Create {
+public class AkkaMainSystem extends AbstractBehavior<AkkaMainSystem.Message> {
+
+
+
+    public interface Message { }
+    public static class Create implements Message { }
+    public static class Terminate implements Message { }
+
+    public static Behavior<Message> create() {
+        return Behaviors.setup(context -> Behaviors.withTimers(timers -> new AkkaMainSystem(context, timers)));
     }
 
-    public static Behavior<Create> create() {
+    private final TimerScheduler<Message> timers;
-        return Behaviors.setup(AkkaMainSystem::new);
+    private ArrayList<ActorRef<TimerActor.Message>> all_actors;
-    }
 
-    private AkkaMainSystem(ActorContext<Create> context) {
+    private AkkaMainSystem(ActorContext<Message> context, TimerScheduler<Message> timers) {
         super(context);
+        this.timers = timers;
     }
 
     @Override
-    public Receive<Create> createReceive() {
+    public Receive<Message> createReceive() {
-        return newReceiveBuilder().onMessage(Create.class, this::onCreate).build();
+        return newReceiveBuilder().onMessage(Create.class, this::onCreate).onMessage(Terminate.class, this::onTerminate).build();
     }
 
-    private Behavior<Create> onCreate(Create command) {
+    private Behavior<Message> onTerminate(Terminate msg) {
-        //#create-actors
+        for (ActorRef<TimerActor.Message> actor : all_actors) {
-        ActorRef<ExampleActor.Message> a = this.getContext().spawn(ExampleActor.create("Alice"), "alice");
+            actor.tell(new TimerActor.Terminate());
-        ActorRef<ExampleTimerActor.Message> b = this.getContext().spawn(ExampleTimerActor.create(), "timeractor");
+        }
-        //#create-actors
+        return this;
+    }
+
+    private Behavior<Message> onCreate(Create command) {
+        var alice = this.getContext().spawn(TimerActor.create("alice"), "alice");
+        var bob = this.getContext().spawn(TimerActor.create("bob"), "bob");
+        var charlie = this.getContext().spawn(TimerActor.create("charlie"), "charlie");
+
+        ArrayList<ActorRef<TimerActor.Message>> clock_reihenfolge = new ArrayList<>();
+        clock_reihenfolge.add(bob);
+        clock_reihenfolge.add(charlie);
+        clock_reihenfolge.add(alice);
+
+        ArrayList<ActorRef<TimerActor.Message>> counterclock_reihenfolge = new ArrayList<>();
+        counterclock_reihenfolge.add(bob);
+        counterclock_reihenfolge.add(charlie);
+        counterclock_reihenfolge.add(alice);
+
+        this.all_actors = new ArrayList<>(clock_reihenfolge);
+        alice.tell(new TimerActor.Clockwise(clock_reihenfolge));
+        alice.tell(new TimerActor.CounterClockwise(counterclock_reihenfolge));
+
+        timers.startSingleTimer(new Terminate(), Duration.ofSeconds(60));
 
-        a.tell(new ExampleActor.ExampleMessage(this.getContext().getSelf(),"Test123"));
         return this;
     }
 }

src/main/java/com/example/AkkaStart.java

@@ -5,7 +5,7 @@ import akka.actor.typed.ActorSystem;
 import java.io.IOException;
 public class AkkaStart {
   public static void main(String[] args) {
-    final ActorSystem<AkkaMainSystem.Create> messageMain = ActorSystem.create(AkkaMainSystem.create(), "akkaMainSystem");
+    final ActorSystem<AkkaMainSystem.Message> messageMain = ActorSystem.create(AkkaMainSystem.create(), "akkaMainSystem");
 
     messageMain.tell(new AkkaMainSystem.Create());
 

src/main/java/com/example/ExampleActor.java

@@ -1,35 +0,0 @@
-package com.example;
-
-import akka.actor.typed.ActorRef;
-import akka.actor.typed.Behavior;
-import akka.actor.typed.javadsl.*;
-
-public class ExampleActor extends AbstractBehavior<ExampleActor.Message> {
-
-    public interface Message {};
-
-    public record ExampleMessage(ActorRef<AkkaMainSystem.Create> someReference, String someString) implements Message {  }
-
-    public static Behavior<Message> create(String name) {
-        return Behaviors.setup(context -> new ExampleActor(context, name));
-    }
-
-    private final String name;
-
-    private ExampleActor(ActorContext<Message> context, String name) {
-        super(context);
-        this.name = name;
-    }
-
-    @Override
-    public Receive<Message> createReceive() {
-        return newReceiveBuilder()
-                .onMessage(ExampleMessage.class, this::onExampleMessage)
-                .build();
-    }
-
-    private Behavior<Message> onExampleMessage(ExampleMessage msg) {
-        getContext().getLog().info("I ({}) got a message: ExampleMessage({},{})", this.name, msg.someReference, msg.someString);
-        return this;
-    }
-}

src/main/java/com/example/ExampleTimerActor.java

@@ -1,45 +0,0 @@
-package com.example;
-
-import akka.actor.typed.javadsl.TimerScheduler;
-import akka.actor.typed.Behavior;
-import akka.actor.typed.javadsl.AbstractBehavior;
-import akka.actor.typed.javadsl.ActorContext;
-import akka.actor.typed.javadsl.Behaviors;
-import akka.actor.typed.javadsl.Receive;
-
-import java.time.Duration;
-
-
-public class ExampleTimerActor extends AbstractBehavior<ExampleTimerActor.Message> {
-
-    public interface Message {};
-
-
-    public record ExampleMessage(String someString) implements Message {  }
-
-    public static Behavior<Message> create() {
-        return Behaviors.setup(context -> Behaviors.withTimers(timers -> new ExampleTimerActor(context, timers)));
-    }
-
-    private final TimerScheduler<ExampleTimerActor.Message> timers;
-
-    private ExampleTimerActor(ActorContext<Message> context, TimerScheduler<ExampleTimerActor.Message> timers) {
-        super(context);
-        this.timers = timers;
-
-        Message msg = new ExampleMessage("test123");
-        this.timers.startSingleTimer(msg, msg, Duration.ofSeconds(10));
-    }
-
-    @Override
-    public Receive<Message> createReceive() {
-        return newReceiveBuilder()
-                .onMessage(ExampleMessage.class, this::onExampleMessage)
-                .build();
-    }
-
-    private Behavior<Message> onExampleMessage(ExampleMessage msg) {
-        getContext().getLog().info("I have send myself this message after 10 Seconds: {}", msg.someString);
-        return this;
-    }
-}

src/main/java/com/example/TimerActor.java

@@ -0,0 +1,87 @@
+package com.example;
+
+import akka.actor.typed.ActorRef;
+import akka.actor.typed.javadsl.TimerScheduler;
+import akka.actor.typed.Behavior;
+import akka.actor.typed.javadsl.AbstractBehavior;
+import akka.actor.typed.javadsl.ActorContext;
+import akka.actor.typed.javadsl.Behaviors;
+import akka.actor.typed.javadsl.Receive;
+
+import java.time.Duration;
+import java.util.ArrayList;
+
+
+public class TimerActor extends AbstractBehavior<TimerActor.Message> {
+
+
+    public interface Message {};
+
+    public record Clockwise(ArrayList<ActorRef<Message>> reihenfolge) implements Message {}
+    public record CounterClockwise(ArrayList<ActorRef<Message>> reihenfolge) implements Message {}
+    public record Terminate() implements Message {}
+
+    public record Clockwise_wait(ArrayList<ActorRef<Message>> reihenfolge) implements Message {}
+    public record CounterClockwise_wait(ArrayList<ActorRef<Message>> reihenfolge) implements Message {}
+
+    public static Behavior<Message> create(String name) {
+        return Behaviors.setup(context -> Behaviors.withTimers(timers -> new TimerActor(context, timers, name)));
+    }
+
+    private final TimerScheduler<TimerActor.Message> timers;
+    private final String name;
+
+    private TimerActor(ActorContext<Message> context, TimerScheduler<Message> timers, String name) {
+        super(context);
+        this.timers = timers;
+        this.name = name;
+    }
+
+    @Override
+    public Receive<Message> createReceive() {
+        return newReceiveBuilder()
+                .onMessage(Clockwise.class, this::onClockwise)
+                .onMessage(CounterClockwise.class, this::onCounterClockwise)
+                .onMessage(Clockwise_wait.class, this::onClockwise_wait)
+                .onMessage(CounterClockwise_wait.class, this::onCounterClockwise_wait)
+                .onMessage(Terminate.class, this::onTerminate)
+                .build();
+    }
+
+    private Behavior<Message> onClockwise(Clockwise msg) {
+        getContext().getLog().info("Clockwise erhalten");
+        this.timers.startSingleTimer(new Clockwise_wait(msg.reihenfolge), Duration.ofSeconds(3));
+        return this;
+    }
+
+    private Behavior<Message> onClockwise_wait(Clockwise_wait msg) {
+        getContext().getLog().info("Clockwise senden");
+        var new_reihenfolge = msg.reihenfolge;
+        var next = new_reihenfolge.remove(0);
+        new_reihenfolge.add(next);
+
+        next.tell(new Clockwise(new_reihenfolge));
+        return this;
+    }
+
+    private Behavior<Message> onCounterClockwise(CounterClockwise msg) {
+        getContext().getLog().info("CounterClockwise erhalten");
+        this.timers.startSingleTimer(new CounterClockwise_wait(msg.reihenfolge), Duration.ofSeconds(5));
+        return this;
+    }
+
+    private Behavior<Message> onCounterClockwise_wait(CounterClockwise_wait msg) {
+        getContext().getLog().info("CounterClockwise senden");
+        var new_reihenfolge = msg.reihenfolge;
+        var next = new_reihenfolge.remove(0);
+        new_reihenfolge.add(next);
+
+        next.tell(new CounterClockwise(new_reihenfolge));
+        return this;
+    }
+
+    private Behavior<Message> onTerminate(Terminate msg) {
+        getContext().getLog().info("Terminate");
+        return Behaviors.stopped();
+    }
+}