| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.flink.streaming.connectors.akka; |
| |
| import akka.actor.ActorRef; |
| import akka.actor.ActorSystem; |
| import akka.actor.PoisonPill; |
| import akka.actor.Props; |
| import com.typesafe.config.Config; |
| import com.typesafe.config.ConfigValueFactory; |
| import org.apache.flink.api.common.functions.StoppableFunction; |
| import org.apache.flink.configuration.Configuration; |
| import org.apache.flink.streaming.api.functions.source.RichSourceFunction; |
| import org.apache.flink.streaming.api.functions.source.SourceFunction; |
| import org.apache.flink.streaming.connectors.akka.utils.ReceiverActor; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.util.Collections; |
| |
| /** |
| * Implementation of {@link SourceFunction} specialized to read messages |
| * from Akka actors. |
| */ |
| public class AkkaSource extends RichSourceFunction<Object> |
| implements StoppableFunction { |
| |
| private static final Logger LOG = LoggerFactory.getLogger(AkkaSource.class); |
| |
| private static final long serialVersionUID = 1L; |
| |
| // --- Fields set by the constructor |
| |
| private final Class<?> classForActor; |
| |
| private final String actorName; |
| |
| private final String urlOfPublisher; |
| |
| private final Config configuration; |
| |
| // --- Runtime fields |
| private transient ActorSystem receiverActorSystem; |
| private transient ActorRef receiverActor; |
| |
| protected transient boolean autoAck; |
| |
| /** |
| * Creates {@link AkkaSource} for Streaming |
| * |
| * @param actorName Receiver Actor name |
| * @param urlOfPublisher tcp url of the publisher or feeder actor |
| */ |
| public AkkaSource(String actorName, |
| String urlOfPublisher, |
| Config configuration) { |
| super(); |
| this.classForActor = ReceiverActor.class; |
| this.actorName = actorName; |
| this.urlOfPublisher = urlOfPublisher; |
| this.configuration = configuration; |
| } |
| |
| @Override |
| public void open(Configuration parameters) throws Exception { |
| receiverActorSystem = createDefaultActorSystem(); |
| |
| if (configuration.hasPath("akka.remote.auto-ack") && |
| configuration.getString("akka.remote.auto-ack").equals("on")) { |
| autoAck = true; |
| } else { |
| autoAck = false; |
| } |
| } |
| |
| @Override |
| public void run(SourceFunction.SourceContext<Object> ctx) throws Exception { |
| LOG.info("Starting the Receiver actor {}", actorName); |
| receiverActor = receiverActorSystem.actorOf( |
| Props.create(classForActor, ctx, urlOfPublisher, autoAck), actorName); |
| |
| LOG.info("Started the Receiver actor {} successfully", actorName); |
| receiverActorSystem.awaitTermination(); |
| } |
| |
| @Override |
| public void close() { |
| LOG.info("Closing source"); |
| if (receiverActorSystem != null) { |
| receiverActor.tell(PoisonPill.getInstance(), ActorRef.noSender()); |
| receiverActorSystem.shutdown(); |
| } |
| } |
| |
| @Override |
| public void cancel() { |
| LOG.info("Cancelling akka source"); |
| close(); |
| } |
| |
| @Override |
| public void stop() { |
| LOG.info("Stopping akka source"); |
| close(); |
| } |
| |
| /** |
| * Creates an actor system with default configurations for Receiver actor. |
| * |
| * @return Actor System instance with default configurations |
| */ |
| private ActorSystem createDefaultActorSystem() { |
| String defaultActorSystemName = "receiver-actor-system"; |
| |
| Config finalConfig = getOrCreateMandatoryProperties(configuration); |
| |
| return ActorSystem.create(defaultActorSystemName, finalConfig); |
| } |
| |
| private Config getOrCreateMandatoryProperties(Config properties) { |
| if (!properties.hasPath("akka.actor.provider")) { |
| properties = properties.withValue("akka.actor.provider", |
| ConfigValueFactory.fromAnyRef("akka.remote.RemoteActorRefProvider")); |
| } |
| |
| if (!properties.hasPath("akka.remote.enabled-transports")) { |
| properties = properties.withValue("akka.remote.enabled-transports", |
| ConfigValueFactory.fromAnyRef(Collections.singletonList("akka.remote.netty.tcp"))); |
| } |
| return properties; |
| } |
| } |