pekko/akka-samples/akka-sample-persistence-java/src/main/java/sample/persistence/ViewExample.java

78 lines
3.1 KiB
Java

package sample.persistence;
import java.util.concurrent.TimeUnit;
import scala.concurrent.duration.Duration;
import akka.actor.*;
import akka.persistence.*;
public class ViewExample {
public static class ExampleProcessor extends UntypedProcessor {
@Override
public String processorId() {
return "processor-5";
}
@Override
public void onReceive(Object message) throws Exception {
if (message instanceof Persistent) {
Persistent p = (Persistent)message;
System.out.println(String.format("processor received %s (sequence nr = %d)", p.payload(), p.sequenceNr()));
}
}
}
public static class ExampleView extends UntypedView {
private final ActorRef destination = getContext().actorOf(Props.create(ExampleDestination.class));
private final ActorRef channel = getContext().actorOf(Channel.props("channel"));
private int numReplicated = 0;
@Override
public String viewId() {
return "view-5";
}
@Override
public String processorId() {
return "processor-5";
}
@Override
public void onReceive(Object message) throws Exception {
if (message instanceof Persistent) {
Persistent p = (Persistent)message;
numReplicated += 1;
System.out.println(String.format("view received %s (sequence nr = %d, num replicated = %d)", p.payload(), p.sequenceNr(), numReplicated));
channel.tell(Deliver.create(p.withPayload("replicated-" + p.payload()), destination.path()), getSelf());
} else if (message instanceof SnapshotOffer) {
SnapshotOffer so = (SnapshotOffer)message;
numReplicated = (Integer)so.snapshot();
System.out.println(String.format("view received snapshot offer %s (metadata = %s)", numReplicated, so.metadata()));
} else if (message.equals("snap")) {
saveSnapshot(numReplicated);
}
}
}
public static class ExampleDestination extends UntypedActor {
@Override
public void onReceive(Object message) throws Exception {
if (message instanceof ConfirmablePersistent) {
ConfirmablePersistent cp = (ConfirmablePersistent)message;
System.out.println(String.format("destination received %s (sequence nr = %s)", cp.payload(), cp.sequenceNr()));
cp.confirm();
}
}
}
public static void main(String... args) throws Exception {
final ActorSystem system = ActorSystem.create("example");
final ActorRef processor = system.actorOf(Props.create(ExampleProcessor.class));
final ActorRef view = system.actorOf(Props.create(ExampleView.class));
system.scheduler().schedule(Duration.Zero(), Duration.create(2, TimeUnit.SECONDS), processor, Persistent.create("scheduled"), system.dispatcher(), null);
system.scheduler().schedule(Duration.Zero(), Duration.create(5, TimeUnit.SECONDS), view, "snap", system.dispatcher(), null);
}
}