pekko/akka-docs/java/code/akka/docs/actor/FaultHandlingTestBase.java

/**
 * Copyright (C) 2009-2011 Typesafe Inc. <http://www.typesafe.com>
 */
package akka.docs.actor;

//#testkit
import akka.actor.ActorRef;
import akka.actor.ActorSystem;
import akka.actor.FaultHandlingStrategy;
import static akka.actor.FaultHandlingStrategy.*;
import akka.actor.OneForOneStrategy;
import akka.actor.Props;
import akka.actor.Terminated;
import akka.actor.UntypedActor;
import akka.dispatch.Await;
import akka.util.Duration;
import akka.testkit.AkkaSpec;
import akka.testkit.TestProbe;

//#testkit
import akka.testkit.ErrorFilter;
import akka.testkit.EventFilter;
import akka.testkit.TestEvent;
import static java.util.concurrent.TimeUnit.SECONDS;
import akka.japi.Function;
import scala.Option;
import scala.collection.JavaConverters;
import scala.collection.Seq;

import org.junit.Test;
import org.junit.BeforeClass;
import org.junit.AfterClass;

//#testkit
public class FaultHandlingTestBase {
  //#testkit
  //#supervisor
  static public class Supervisor extends UntypedActor {
    public void onReceive(Object o) {
      if (o instanceof Props) {
        getSender().tell(getContext().actorOf((Props) o));
      }
    }
  }
  //#supervisor
  
  //#supervisor2
  static public class Supervisor2 extends UntypedActor {
    public void onReceive(Object o) {
      if (o instanceof Props) {
        getSender().tell(getContext().actorOf((Props) o));
      }
    }
    
    @Override
    public void preRestart(Throwable cause, Option<Object> msg) {
      // do not kill all children, which is the default here
    }
  }
  //#supervisor2
  
  //#child
  static public class Child extends UntypedActor {
    int state = 0;
    
    public void onReceive(Object o) throws Exception {
      if (o instanceof Exception) {
        throw (Exception) o;
      } else if (o instanceof Integer) {
        state = (Integer) o;
      } else if (o.equals("get")) {
        getSender().tell(state);
      }
    }
  }
  //#child
  
  //#strategy
  static FaultHandlingStrategy strategy = new OneForOneStrategy(new Function<Throwable, Action>() {
    @Override
    public Action apply(Throwable t) {
      if (t instanceof ArithmeticException) {
        return resume();
      } else if (t instanceof NullPointerException) {
        return restart();
      } else if (t instanceof IllegalArgumentException) {
        return stop();
      } else {
        return escalate();
      }
    }
  }, 10, 60000);
  //#strategy
  
  //#testkit
  static ActorSystem system;
  Duration timeout = Duration.create(5, SECONDS);
  
  @BeforeClass
  public static void start() {
    system = ActorSystem.create("test", AkkaSpec.testConf());
  }
  
  @AfterClass
  public static void cleanup() {
    system.shutdown();
  }
  
  @Test
  public void mustEmployFaultHandler() {
    // code here
    //#testkit
    EventFilter ex1 = (EventFilter) new ErrorFilter(ArithmeticException.class);
    EventFilter ex2 = (EventFilter) new ErrorFilter(NullPointerException.class);
    EventFilter ex3 = (EventFilter) new ErrorFilter(IllegalArgumentException.class);
    EventFilter ex4 = (EventFilter) new ErrorFilter(Exception.class);
    Seq<EventFilter> ignoreExceptions = seq(ex1, ex2, ex3, ex4);
    system.eventStream().publish(new TestEvent.Mute(ignoreExceptions));
    
    //#create
    Props superprops = new Props(Supervisor.class).withFaultHandler(strategy);
    ActorRef supervisor = system.actorOf(superprops, "supervisor");
    ActorRef child = (ActorRef) Await.result(supervisor.ask(new Props(Child.class), 5000), timeout);
    //#create
    
    //#resume
    child.tell(42);
    assert Await.result(child.ask("get", 5000), timeout).equals(42);
    child.tell(new ArithmeticException());
    assert Await.result(child.ask("get", 5000), timeout).equals(42);
    //#resume
    
    //#restart
    child.tell(new NullPointerException());
    assert Await.result(child.ask("get", 5000), timeout).equals(0);
    //#restart
    
    //#stop
    final TestProbe probe = new TestProbe(system);
    probe.watch(child);
    child.tell(new IllegalArgumentException());
    probe.expectMsg(new Terminated(child));
    //#stop
    
    //#escalate-kill
    child = (ActorRef) Await.result(supervisor.ask(new Props(Child.class), 5000), timeout);
    probe.watch(child);
    assert Await.result(child.ask("get", 5000), timeout).equals(0);
    child.tell(new Exception());
    probe.expectMsg(new Terminated(child));
    //#escalate-kill
    
    //#escalate-restart
    superprops = new Props(Supervisor2.class).withFaultHandler(strategy);
    supervisor = system.actorOf(superprops, "supervisor2");
    child = (ActorRef) Await.result(supervisor.ask(new Props(Child.class), 5000), timeout);
    child.tell(23);
    assert Await.result(child.ask("get", 5000), timeout).equals(23);
    child.tell(new Exception());
    assert Await.result(child.ask("get", 5000), timeout).equals(0);
    //#escalate-restart
    //#testkit
  }
//#testkit
  public <A> Seq<A> seq(A... args) {
    return JavaConverters.collectionAsScalaIterableConverter(java.util.Arrays.asList(args)).asScala().toSeq();
  }
//#testkit
}
//#testkit