rename akka-docs dir to docs (#62)

docs/src/test/java/jdocs/cluster/StatsAggregator.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2018-2022 Lightbend Inc. <https://www.lightbend.com>
+ */
+
+package jdocs.cluster;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.time.Duration;
+
+import jdocs.cluster.StatsMessages.JobFailed;
+import jdocs.cluster.StatsMessages.StatsResult;
+import org.apache.pekko.actor.ActorRef;
+import org.apache.pekko.actor.ReceiveTimeout;
+import org.apache.pekko.actor.AbstractActor;
+
+// #aggregator
+public class StatsAggregator extends AbstractActor {
+
+  final int expectedResults;
+  final ActorRef replyTo;
+  final List<Integer> results = new ArrayList<Integer>();
+
+  public StatsAggregator(int expectedResults, ActorRef replyTo) {
+    this.expectedResults = expectedResults;
+    this.replyTo = replyTo;
+  }
+
+  @Override
+  public void preStart() {
+    getContext().setReceiveTimeout(Duration.ofSeconds(3));
+  }
+
+  @Override
+  public Receive createReceive() {
+    return receiveBuilder()
+        .match(
+            Integer.class,
+            wordCount -> {
+              results.add(wordCount);
+              if (results.size() == expectedResults) {
+                int sum = 0;
+                for (int c : results) {
+                  sum += c;
+                }
+                double meanWordLength = ((double) sum) / results.size();
+                replyTo.tell(new StatsResult(meanWordLength), getSelf());
+                getContext().stop(getSelf());
+              }
+            })
+        .match(
+            ReceiveTimeout.class,
+            x -> {
+              replyTo.tell(new JobFailed("Service unavailable, try again later"), getSelf());
+              getContext().stop(getSelf());
+            })
+        .build();
+  }
+}
+// #aggregator