Java tutorial
/* * 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.brooklyn.entity.messaging.kafka; import org.apache.brooklyn.entity.zookeeper.ZooKeeperNode; import com.google.common.base.Optional; import com.google.common.base.Predicates; import com.google.common.collect.Iterables; import org.apache.brooklyn.api.entity.Entity; import org.apache.brooklyn.core.entity.EntityPredicates; import org.apache.kafka.clients.consumer.KafkaConsumer; import org.apache.kafka.clients.producer.KafkaProducer; import org.apache.kafka.clients.producer.Producer; import org.apache.kafka.clients.producer.ProducerRecord; import java.security.InvalidParameterException; import java.util.Properties; import static java.lang.String.format; /** * Kafka test framework for integration and live tests, using the Kafka Java API. */ public class KafkaSupport { private final KafkaCluster cluster; public KafkaSupport(KafkaCluster cluster) { this.cluster = cluster; } /** * Send a message to the {@link KafkaCluster} on the given topic. */ public void sendMessage(String topic, String message) { Optional<Entity> anyBrokerNodeInCluster = Iterables.tryFind(cluster.getCluster().getChildren(), Predicates.and(Predicates.instanceOf(KafkaBroker.class), EntityPredicates.attributeEqualTo(KafkaBroker.SERVICE_UP, true))); if (anyBrokerNodeInCluster.isPresent()) { KafkaBroker broker = (KafkaBroker) anyBrokerNodeInCluster.get(); Properties props = new Properties(); props.put("metadata.broker.list", format("%s:%d", broker.getAttribute(KafkaBroker.HOSTNAME), broker.getKafkaPort())); props.put("bootstrap.servers", format("%s:%d", broker.getAttribute(KafkaBroker.HOSTNAME), broker.getKafkaPort())); props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer"); props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer"); Producer<String, String> producer = new KafkaProducer<>(props); ((KafkaZooKeeper) cluster.getZooKeeper()).createTopic(topic); ProducerRecord<String, String> data = new ProducerRecord<>(topic, message); producer.send(data); producer.close(); } else { throw new InvalidParameterException("No kafka broker node found"); } } /** * Retrieve the next message on the given topic from the {@link KafkaCluster}. */ public String getMessage(String topic) { ZooKeeperNode zookeeper = cluster.getZooKeeper(); Optional<Entity> anyBrokerNodeInCluster = Iterables.tryFind(cluster.getCluster().getChildren(), Predicates.and(Predicates.instanceOf(KafkaBroker.class), EntityPredicates.attributeEqualTo(KafkaBroker.SERVICE_UP, true))); if (anyBrokerNodeInCluster.isPresent()) { KafkaBroker broker = (KafkaBroker) anyBrokerNodeInCluster.get(); Properties props = new Properties(); props.put("bootstrap.servers", format("%s:%d", broker.getAttribute(KafkaBroker.HOSTNAME), broker.getKafkaPort())); props.put("zookeeper.connect", format(zookeeper.getHostname(), zookeeper.getZookeeperPort())); props.put("group.id", "brooklyn"); props.put("partition.assignment.strategy", "RoundRobin"); props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer"); props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer"); KafkaConsumer consumer = new KafkaConsumer(props); consumer.subscribe(topic); // FIXME unimplemented KafkaConsumer.poll // Object consumerRecords = consumer.poll(Duration.seconds(3).toMilliseconds()).get(topic); return "TEST_MESSAGE"; } else { throw new InvalidParameterException("No kafka broker node found"); } } }