feat: update Actor Model implementation with multi-actor logic #3251

Author: ssrijan-007-sys

Diff for: actor-model/src/main/java/com/iluwatar/actormodel/Actor.java

@@ -24,10 +24,16 @@
  */
 package com.iluwatar.actormodel;
 
+import lombok.Getter;
+import lombok.Setter;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.LinkedBlockingQueue;
 
 public abstract class Actor implements Runnable {
+
+  @Setter
+  @Getter
+  private String actorId;
   private final BlockingQueue<Message> mailbox = new LinkedBlockingQueue<>();
   private volatile boolean active =
       true; // always read from main memory and written back to main memory,
@@ -44,7 +50,7 @@ public void stop() {
 
   @Override
   public void run() {
-    while (active) {
+    while ( active ) {
       try {
         Message message = mailbox.take(); // Wait for a message
         onReceive(message); // Process it

Diff for: actor-model/src/main/java/com/iluwatar/actormodel/ActorSystem.java

@@ -24,15 +24,25 @@
  */
 package com.iluwatar.actormodel;
 
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.AtomicInteger;
 
 public class ActorSystem {
   private final ExecutorService executor = Executors.newCachedThreadPool();
+  private final ConcurrentHashMap<String ,Actor > actorRegister = new ConcurrentHashMap<>();
+  private final AtomicInteger idCounter = new AtomicInteger(0);
 
-  public Actor actorOf(Actor actor) {
+  public void startActor(Actor actor) {
+    String actorId = "actor-" + idCounter.incrementAndGet(); //Generate a new and unique ID
+    actor.setActorId(actorId); // assign the actor it's ID
+    actorRegister.put(actorId,actor); //Register and save the actor with it's ID
     executor.submit(actor); // Run the actor in a thread
-    return actor;
+  }
+
+  public Actor getActorById(String actorId){
+    return actorRegister.get(actorId); //  Find by Id
   }
 
   public void shutdown() {

Diff for: actor-model/src/main/java/com/iluwatar/actormodel/App.java

@@ -27,18 +27,17 @@
 public class App {
   public static void main(String[] args) throws InterruptedException {
     ActorSystem system = new ActorSystem();
-    Actor Srijan = system.actorOf(new ExampleActor());
-
-    /* Actor Srijan = new ExampleActor() ;
-      system.actorOf(Srijan);  this is also acceptable
-    */
-
-    Srijan.send(new Message("Hello Actor!", Srijan));
-    Srijan.send(new Message("Another message", Srijan));
+    Actor srijan = new ExampleActor(system);
+    system.startActor(srijan);
+    Actor ansh = new ExampleActor2(system);
+    system.startActor(ansh);
+    ansh.send(new Message("Hello Srijan" , srijan.getActorId()));
+    srijan.send(new Message("Hello ansh!", srijan.getActorId()));
 
     Thread.sleep(1000); // Give time for messages to process
 
-    Srijan.stop(); // Stop the actor gracefully
+    srijan.stop(); // Stop the actor gracefully
+    ansh.stop();
     system.shutdown(); // Stop the actor system
   }
 }

Diff for: actor-model/src/main/java/com/iluwatar/actormodel/ExampleActor.java

@@ -24,9 +24,24 @@
  */
 package com.iluwatar.actormodel;
 
+import java.util.logging.Logger;
+
 public class ExampleActor extends Actor {
+  private  final ActorSystem actorSystem;
+
+  public ExampleActor(ActorSystem actorSystem) {
+    this.actorSystem = actorSystem;
+  }
+  Logger logger = Logger.getLogger(getClass().getName());
+
   @Override
   protected void onReceive(Message message) {
-    System.out.println("Received :" + message.getContent());
+    logger.info("[" +getActorId()+ "]" + "Received : " + message.getContent());
+
+    Actor sender = actorSystem.getActorById(message.getSenderId());// sender actor id
+    if(sender!=null && !message.getSenderId().equals(getActorId())) {
+      sender.send(new Message("I got your message ", getActorId()));
+    }
+
   }
 }

Diff for: actor-model/src/main/java/com/iluwatar/actormodel/ExampleActor2.java

@@ -0,0 +1,17 @@
+package com.iluwatar.actormodel;
+
+import java.util.logging.Logger;
+
+public class ExampleActor2 extends Actor{
+  private final ActorSystem actorSystem;
+
+  public ExampleActor2(ActorSystem actorSystem) {
+    this.actorSystem = actorSystem;
+  }
+  Logger logger = Logger.getLogger(getClass().getName());
+
+  @Override
+  protected void onReceive(Message message) {
+    logger.info("[" + getActorId()+"]" + "Received : " +message.getContent());
+  }
+}

Diff for: actor-model/src/main/java/com/iluwatar/actormodel/Message.java

@@ -26,18 +26,16 @@
 
 public class Message {
   private final String content;
-  private final Actor sender;
+  private final String senderId;
 
-  public Message(String content, Actor sender) {
+  public Message(String content, String senderId) {
     this.content = content;
-    this.sender = sender;
+    this.senderId = senderId;
   }
 
-  public String getContent() {
-    return content;
-  }
+  public String getContent() { return content; }
 
-  public Actor getSender() {
-    return sender;
+  public String getSenderId() {
+    return senderId;
   }
 }