Java example code for Getting Started

* WiP on Java version of new Hello World Done: - implementation for first 3 sections - tests for first 2 sections To do: - formatting - tests for section 3 - section 4 and 5 - hooking the fragments into the docs themselves * Finish tutorial_03 conversion * Converted tutorial 04 * Convert step 5 scala->java * Reformat Java code (thx IntelliJ IDEA) * Format using 2 spaces Really it'd be neat to have something like scalariform for the Java code, too * Make fields 'private final' * Make message classes 'public static final' * Use primitive long/double where possible * sender() -> getSender() * Static import of org.junit.Assert.... * Final actor fields * println() the instruction to hit ENTER to quit * Use jdocs package for quickstart, too * Use helper methods for message handling * Compare doubles specifying a delta * Keep tutorial steps independent
2017-05-10 02:24:11 -07:00 · 2017-05-10 02:24:11 -07:00 · f064d1321a
commit f064d1321a
parent 20b5e6b955
30 changed files with 2848 additions and 0 deletions
--- a/akka-docs-new/src/test/java/jdocs/tutorial_5/DeviceGroupQuery.java
+++ b/akka-docs-new/src/test/java/jdocs/tutorial_5/DeviceGroupQuery.java
@ -0,0 +1,108 @@
+/**
+ * Copyright (C) 2009-2017 Lightbend Inc. <http://www.lightbend.com>
+ */
+package jdocs.tutorial_5;
+
+import akka.actor.*;
+import akka.event.Logging;
+import akka.event.LoggingAdapter;
+import scala.concurrent.duration.FiniteDuration;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+public class DeviceGroupQuery extends AbstractActor {
+  public static final class CollectionTimeout {
+  }
+
+  private final LoggingAdapter log = Logging.getLogger(getContext().getSystem(), this);
+
+  final Map<ActorRef, String> actorToDeviceId;
+  final long requestId;
+  final ActorRef requester;
+
+  Cancellable queryTimeoutTimer;
+
+  public DeviceGroupQuery(Map<ActorRef, String> actorToDeviceId, long requestId, ActorRef requester, FiniteDuration timeout) {
+    this.actorToDeviceId = actorToDeviceId;
+    this.requestId = requestId;
+    this.requester = requester;
+
+    queryTimeoutTimer = getContext().getSystem().scheduler().scheduleOnce(
+            timeout, getSelf(), new CollectionTimeout(), getContext().dispatcher(), getSelf()
+    );
+  }
+
+  public static Props props(Map<ActorRef, String> actorToDeviceId, long requestId, ActorRef requester, FiniteDuration timeout) {
+    return Props.create(DeviceGroupQuery.class, actorToDeviceId, requestId, requester, timeout);
+  }
+
+  @Override
+  public void preStart() {
+    for (ActorRef deviceActor : actorToDeviceId.keySet()) {
+      getContext().watch(deviceActor);
+      deviceActor.tell(new Device.ReadTemperature(0L), getSelf());
+    }
+  }
+
+  @Override
+  public void postStop() {
+    queryTimeoutTimer.cancel();
+  }
+
+  @Override
+  public Receive createReceive() {
+    return waitingForReplies(new HashMap<>(), actorToDeviceId.keySet());
+  }
+
+  public Receive waitingForReplies(
+          Map<String, DeviceGroup.TemperatureReading> repliesSoFar,
+          Set<ActorRef> stillWaiting) {
+    return receiveBuilder()
+            .match(Device.RespondTemperature.class, r -> {
+              ActorRef deviceActor = getSender();
+              DeviceGroup.TemperatureReading reading = r.value
+                      .map(v -> (DeviceGroup.TemperatureReading) new DeviceGroup.Temperature(v))
+                      .orElse(new DeviceGroup.TemperatureNotAvailable());
+              receivedResponse(deviceActor, reading, stillWaiting, repliesSoFar);
+            })
+            .match(Terminated.class, t -> {
+              if (stillWaiting.contains(t.getActor())) {
+                receivedResponse(t.getActor(), new DeviceGroup.DeviceNotAvailable(), stillWaiting, repliesSoFar);
+              }
+              // else ignore
+            })
+            .match(CollectionTimeout.class, t -> {
+              Map<String, DeviceGroup.TemperatureReading> replies = new HashMap<>(repliesSoFar);
+              for (ActorRef deviceActor : stillWaiting) {
+                String deviceId = actorToDeviceId.get(deviceActor);
+                replies.put(deviceId, new DeviceGroup.DeviceTimedOut());
+              }
+              requester.tell(new DeviceGroup.RespondAllTemperatures(requestId, replies), getSelf());
+              getContext().stop(getSelf());
+            })
+            .build();
+  }
+
+  public void receivedResponse(ActorRef deviceActor,
+                               DeviceGroup.TemperatureReading reading,
+                               Set<ActorRef> stillWaiting,
+                               Map<String, DeviceGroup.TemperatureReading> repliesSoFar) {
+    getContext().unwatch(deviceActor);
+    String deviceId = actorToDeviceId.get(deviceActor);
+
+    Set<ActorRef> newStillWaiting = new HashSet<>(stillWaiting);
+    newStillWaiting.remove(deviceActor);
+
+    Map<String, DeviceGroup.TemperatureReading> newRepliesSoFar = new HashMap<>(repliesSoFar);
+    newRepliesSoFar.put(deviceId, reading);
+    if (newStillWaiting.isEmpty()) {
+      requester.tell(new DeviceGroup.RespondAllTemperatures(requestId, newRepliesSoFar), getSelf());
+      getContext().stop(getSelf());
+    } else {
+      getContext().become(waitingForReplies(newRepliesSoFar, newStillWaiting));
+    }
+  }
+}