Java tutorial
package com.devicehive.shim.config.server; /* * #%L * DeviceHive Shim Kafka Implementation * %% * Copyright (C) 2016 DataArt * %% * Licensed 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. * #L% */ import com.devicehive.shim.api.Response; import com.devicehive.shim.api.server.RequestHandler; import com.devicehive.shim.api.server.RpcServer; import com.devicehive.shim.kafka.server.KafkaRpcServer; import com.devicehive.shim.kafka.server.RequestConsumer; import com.devicehive.shim.kafka.server.ServerEvent; import com.devicehive.shim.kafka.server.ServerEventHandler; import com.devicehive.shim.kafka.serializer.RequestSerializer; import com.devicehive.shim.kafka.serializer.ResponseSerializer; import com.google.gson.Gson; import com.lmax.disruptor.*; import com.lmax.disruptor.dsl.Disruptor; import com.lmax.disruptor.dsl.ProducerType; import org.apache.kafka.clients.consumer.ConsumerConfig; import org.apache.kafka.clients.producer.KafkaProducer; import org.apache.kafka.clients.producer.Producer; import org.apache.kafka.clients.producer.ProducerConfig; import org.apache.kafka.common.serialization.StringDeserializer; import org.apache.kafka.common.serialization.StringSerializer; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.Profile; import org.springframework.context.annotation.PropertySource; import org.springframework.core.env.Environment; import java.util.Properties; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; @Configuration @Profile("rpc-server") @PropertySource("classpath:kafka.properties") public class KafkaRpcServerConfig { public static final String REQUEST_TOPIC = "request_topic"; @Autowired private Environment env; @Value("${rpc.server.request-consumer.group}") private String requestConsumerGroup; @Value("${rpc.server.request-consumer.threads:1}") private int consumerThreads; @Value("${rpc.server.worker.threads:1}") private int workerThreads; @Value("${lmax.buffer-size:1024}") private int bufferSize; @Value("${rpc.server.disruptor.wait-strategy}") private String waitStrategyType; @Bean(name = "server-producer") public Producer<String, Response> kafkaResponseProducer(Gson gson) { return new KafkaProducer<>(producerProps(), new StringSerializer(), new ResponseSerializer(gson)); } @Bean public ExecutorService workerExecutor() { return Executors.newFixedThreadPool(workerThreads); } @Bean public WaitStrategy disruptorWaitStrategy() { WaitStrategy strategy; switch (waitStrategyType) { case "sleeping": strategy = new SleepingWaitStrategy(); break; case "yielding": strategy = new YieldingWaitStrategy(); break; case "busy-spin": strategy = new BusySpinWaitStrategy(); break; case "blocking": default: strategy = new BlockingWaitStrategy(); } return strategy; } @Bean public Disruptor<ServerEvent> disruptor(@Qualifier("workerExecutor") ExecutorService workerExecutor, WaitStrategy waitStrategy) { ProducerType producerType = ProducerType.SINGLE; if (consumerThreads > 1) { producerType = ProducerType.MULTI; } return new Disruptor<>(ServerEvent::new, bufferSize, workerExecutor, producerType, waitStrategy); } @Bean public ServerEventHandler serverEventHandler(RequestHandler requestHandler, @Qualifier("server-producer") Producer<String, Response> responseProducer) { return new ServerEventHandler(requestHandler, responseProducer); } @Bean public RequestConsumer requestConsumer(Gson gson) { return new RequestConsumer(REQUEST_TOPIC, consumerProps(), consumerThreads, new RequestSerializer(gson)); } @Bean public RpcServer rpcServer(Disruptor<ServerEvent> disruptor, RequestConsumer requestConsumer, ServerEventHandler eventHandler) { RpcServer server = new KafkaRpcServer(disruptor, requestConsumer, eventHandler); server.start(); return server; } private Properties producerProps() { Properties props = new Properties(); props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, env.getProperty("bootstrap.servers")); return props; } private Properties consumerProps() { Properties props = new Properties(); props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, env.getProperty("bootstrap.servers")); props.put(ConsumerConfig.GROUP_ID_CONFIG, requestConsumerGroup); props.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG, env.getProperty(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG)); return props; } }