/**
* Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
*/
package sample.persistence;
//#persistent-actor-example
import akka.actor.ActorRef;
import akka.actor.ActorSystem;
import akka.actor.Props;
import akka.japi.pf.ReceiveBuilder;
import akka.persistence.AbstractPersistentActor;
import akka.persistence.SnapshotOffer;
import scala.PartialFunction;
import scala.runtime.BoxedUnit;
import java.io.Serializable;
import java.util.ArrayList;
import static java.util.Arrays.asList;
class Cmd implements Serializable {
private final String data;
public Cmd(String data) {
this.data = data;
}
public String getData() {
return data;
}
}
class Evt implements Serializable {
private final String data;
public Evt(String data) {
this.data = data;
}
public String getData() {
return data;
}
}
class ExampleState implements Serializable {
private final ArrayList<String> events;
public ExampleState() {
this(new ArrayList<>());
}
public ExampleState(ArrayList<String> events) {
this.events = events;
}
public ExampleState copy() {
return new ExampleState(new ArrayList<>(events));
}
public void update(Evt evt) {
events.add(evt.getData());
}
public int size() {
return events.size();
}
@Override
public String toString() {
return events.toString();
}
}
class ExamplePersistentActor extends AbstractPersistentActor {
private ExampleState state = new ExampleState();
public int getNumEvents() {
return state.size();
}
@Override
public String persistenceId() { return "sample-id-1"; }
@Override
public PartialFunction<Object, BoxedUnit> receiveRecover() {
return ReceiveBuilder.
match(Evt.class, state::update).
match(SnapshotOffer.class, ss -> state = (ExampleState) ss.snapshot()).build();
}
@Override
public PartialFunction<Object, BoxedUnit> receiveCommand() {
return ReceiveBuilder.
match(Cmd.class, c -> {
final String data = c.getData();
final Evt evt1 = new Evt(data + "-" + getNumEvents());
final Evt evt2 = new Evt(data + "-" + (getNumEvents() + 1));
persist(asList(evt1, evt2), (Evt evt) -> {
state.update(evt);
if (evt.equals(evt2)) {
context().system().eventStream().publish(evt);
}
});
}).
match(String.class, s -> s.equals("snap"), s -> saveSnapshot(state.copy())).
match(String.class, s -> s.equals("print"), s -> System.out.println(state)).
build();
}
}
//#persistent-actor-example
public class PersistentActorExample {
public static void main(String... args) throws Exception {
final ActorSystem system = ActorSystem.create("example");
final ActorRef processor = system.actorOf(Props.create(ExamplePersistentActor.class), "processor-4-java8");
processor.tell(new Cmd("foo"), null);
processor.tell(new Cmd("baz"), null);
processor.tell(new Cmd("bar"), null);
processor.tell("snap", null);
processor.tell(new Cmd("buzz"), null);
processor.tell("print", null);
Thread.sleep(1000);
system.terminate();
}
}