AKKA sample to demonstrate the message communication between actors using Inbox.

ActorInboxMain.java

package com.akkasample.inbox;

import java.util.concurrent.TimeUnit;

import com.akkasample.actor.InboxSampleActor;
import com.akkasample.bean.Greeting;

import akka.actor.ActorRef;
import akka.actor.ActorSystem;
import akka.actor.Inbox;
import akka.actor.Props;
import scala.concurrent.duration.FiniteDuration;
/**
 * Actor call from outside the system
 * @author Rakesh
 *
 */
public class ActorInboxMain {
	/**
	 * Main program
	 * @param args
	 */
	public static void main(String args[]){
		ActorSystem system = ActorSystem.create("SampleActorSystem");
		Inbox inbox = Inbox.create(system); // create Inbox using AKKA system.
		ActorRef ref = system.actorOf(Props.create(InboxSampleActor.class), "InboxSampleActor");
		inbox.send(ref, new Greeting("Hello From Inbox")); // Pass message to Actor
		System.out.println("Message Received from the Actor :: "+inbox.receive(FiniteDuration.create(5, TimeUnit.SECONDS))); // prints the reply from the actor
		
	}

}

Greeting.java

/**
 * 
 */
package com.akkasample.bean;

import java.io.Serializable;

/**
 * @author Rakesh
 *
 */
public class Greeting implements Serializable {

	/**
	 * Serial Version ID
	 */
	private static final long serialVersionUID = 1575217482200420484L;
	private final String message;
	
	public Greeting(String message) {
		this.message = message;
	}
	
	/**
	 * Method to get the Message
	 * @return
	 */
	public String getMessage() {
		return message;
	}
	
	
}

InboxSampleActor.java

package com.akkasample.actor;

import com.akkasample.bean.Greeting;

import akka.actor.UntypedActor;

/**
 * Akka actor which recieves the message and prints it.
 * @author Rakesh
 *
 */
public class InboxSampleActor extends UntypedActor {

	/* (non-Javadoc)
	 * @see akka.actor.UntypedActor#onReceive(java.lang.Object)
	 */
	public void onReceive(Object object) throws Exception {
		if(object instanceof Greeting){
			String message = ((Greeting)object).getMessage();
			System.out.println("Got Message Inside Actor :: " + message); // message given by the main program
			getSender().tell("Greetings from the Actor", getSelf()); // Reply to the main program (Sender)
			
		}else{
			unhandled(object); // The AKKA system will handle this message.
		}
	}

}