#22903 Fix code snippeds

* move scala and java sources out of paradox sources
* replace relative paths with $code$ and $akka$
* fix broken includes

akka-docs/src/main/java/jdocs/cluster/StatsAggregator.java

@@ -0,0 +1,55 @@
+package jdocs.cluster;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+import jdocs.cluster.StatsMessages.JobFailed;
+import jdocs.cluster.StatsMessages.StatsResult;
+import scala.concurrent.duration.Duration;
+import akka.actor.ActorRef;
+import akka.actor.ReceiveTimeout;
+import akka.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.create(3, TimeUnit.SECONDS));
+  }
+
+  @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