pekko/akka-docs/rst/java/code/jdocs/cluster/StatsAggregator.java
2017-03-16 09:30:00 +01:00

55 lines
1.5 KiB
Java

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