Akka/Scala example source code file (PersistentActorFailureExample.java)

This example Akka source code file (PersistentActorFailureExample.java) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

actor, actorref, actorsystem, akka, arraylist, examplepersistentactor, exception, japi, override, persistence, persistentactorfailureexample, procedure, string, untypedpersistentactor

The PersistentActorFailureExample.java Akka example source code

package sample.persistence;

import akka.actor.ActorRef;
import akka.actor.ActorSystem;
import akka.actor.Props;
import akka.japi.Procedure;
import akka.persistence.UntypedPersistentActor;

import java.util.ArrayList;

public class PersistentActorFailureExample {
  public static class ExamplePersistentActor extends UntypedPersistentActor {
    @Override
    public String persistenceId() { return "sample-id-2"; }

    private ArrayList<Object> received = new ArrayList<Object>();

    @Override
    public void onReceiveCommand(Object message) throws Exception {
      if (message.equals("boom")) {
        throw new Exception("boom");
      } else if (message.equals("print")) {
        System.out.println("received " + received);
      } else if (message instanceof String) {
        String s = (String) message;
        persist(s, new Procedure<String>() {
          public void apply(String evt) throws Exception {
            received.add(evt);
          }
        });
      } else {
        unhandled(message);
      }
    }
    
    @Override
    public void onReceiveRecover(Object message) {
      if (message instanceof String) {
        received.add((String) message);
      } else {
        unhandled(message);
      }
    }
  }

  public static void main(String... args) throws Exception {
    final ActorSystem system = ActorSystem.create("example");
    final ActorRef persistentActor = system.actorOf(Props.create(ExamplePersistentActor.class), "persistentActor-2");

    persistentActor.tell("a", null);
    persistentActor.tell("print", null);
    persistentActor.tell("boom", null);
    persistentActor.tell("print", null);
    persistentActor.tell("b", null);
    persistentActor.tell("print", null);
    persistentActor.tell("c", null);
    persistentActor.tell("print", null);

    // Will print in a first run (i.e. with empty journal):

    // received [a]
    // received [a, b]
    // received [a, b, c]

    // Will print in a second run:

    // received [a, b, c, a]
    // received [a, b, c, a, b]
    // received [a, b, c, a, b, c]

    // etc ...

    Thread.sleep(1000);
    system.shutdown();
  }
}