2019獨角獸企業重金招聘Python工程師標準>>>

前言

因工作需要，需在系統利用Kafka監聽接口，實現消息隊列中，對消息的消費，首選Kafka，因為看中其超高的吞吐量。

基本概念

• 1 Producer: 特指消息的生產者
• 2 Consumer :特指消息的消費者
• 3 Consumer Group :消費者組，可以并行消費Topic中partition的消息
• 4 Broker：緩存代理，Kafa 集群中的一臺或多臺服務器統稱為 broker。
• 5 Topic：特指 Kafka 處理的消息源（feeds of messages）的不同分類。
• 6 Partition：Topic 物理上的分組，一個 topic 可以分為多個 partition，每個 partition 是一個有序的隊列。partition 中的每條消息都會被分配一個有序的 id（offset）
• 7 Message：消息，是通信的基本單位，每個 producer 可以向一個 topic（主題）發布一些消息
• 8 稀疏索引：采用稀疏索引的方式，利用二分查找，定位消息。

集成Spring

• 添加Maven依賴?
  由于項目使用Maven進行管理，引入Kafka-Spring相關Jar包，需要添加依賴，此處使用的是Kafka0.10.2

<dependency><groupId>org.springframework.kafka</groupId><artifactId>spring-kafka</artifactId><version>1.2.2.RELEASE</version> </dependency>

• 1
• 2
• 3
• 4
• 5

• 1 版本兼容性?
  配置完Maven依賴以后，還需要確認，因為Kafka與Spring有依賴關系，需要確定Spring的版本是否能和Kafka0.10.2完美兼容，查閱Spring For Apache Kafka 文檔可知：?
  　　Compatibility

  • Apache Kafka 0.10.2.0
  • Tested with Spring Framework version dependency is 4.3.7 but it is expected that the framework will work with earlier versions of Spring.
  • Annotation-based listeners require Spring Framework 4.1 or higher, however.
  • Minimum Java version: 7.?
    Kafka 0.10.2 需要SpringFrameWork 4.3.7，但后續會逐漸兼容SpringFrameWork更早期的版本，實踐發現，Kafka的生產者里面的api會受SpringFrameWork版本影響，而消費者無影響，因此，可以保持項目中原有springframework不變。

• 2 排除重復包?
  引入Maven依賴以后，Kafka的maven依賴，自動包含了springframework相關jar包，需要排除。

<dependency><groupId>org.springframework</groupId><artifactId>spring-beans</artifactId><version>4.3.9.RELEASE</version><scope>compile</scope></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>4.3.9.RELEASE</version><scope>compile</scope></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-core</artifactId><version>4.3.9.RELEASE</version><scope>compile</scope></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-oxm</artifactId><version>4.3.9.RELEASE</version><scope>compile</scope><optional>true</optional></dependency>

• 3 接口區別?
  Kafka消費者，實現有兩種方式：client客戶端和listener監聽接口，這里因業務需要，采用監聽接口的方式實現，Spring提供了四種接口，如下所示：

public interface MessageListener<K, V> {} 1void onMessage(ConsumerRecord<K, V> data);}public interface AcknowledgingMessageListener<K, V> {} 2void onMessage(ConsumerRecord<K, V> data, Acknowledgment acknowledgment);}public interface BatchMessageListener<K, V> {} 3void onMessage(List<ConsumerRecord<K, V>> data);}public interface BatchAcknowledgingMessageListener<K, V> {} 4void onMessage(List<ConsumerRecord<K, V>> data, Acknowledgment acknowledgment);}

對應的解釋如下?
1、Use this for processing individual ConsumerRecord s received from the kafka consumer poll() operation when using auto-commit, or one of the container-managed commit methods.?
使用MessageListener接口實現時，當消費者拉取消息之后，消費完成會自動提交offset，即enable.auto.commit為true時，適合使用此接口?
2、Use this for processing individual ConsumerRecord s received from the kafka consumer poll() operation when using one of the manual commit methods.?
使用AcknowledgeMessageListener時，當消費者消費一條消息之后，不會自動提交offset，需要手動ack，即enable.auto.commit為false時，適合使用此接口?
3、Use this for processing all ConsumerRecord s received from the kafka consumer poll() operation when using auto-commit, or one of the container-managed commit methods. AckMode.RECORD is not supported when using this interface since the listener is given the complete batch.

4、Use this for processing all ConsumerRecord s received from the kafka consumer poll() operation when using one of the manual commit methods.

BatchMessageListener和BatchAcknowledgingMessageListener接口作用與上述兩個接口大體類似，只是適合批量消費消息決定是否自動提交offset

由于業務較重，且offset自動提交時，出現消費異常或者消費失敗的情況，消費者容易丟失消息，所以需要采用手動提交offset的方式，因此，這里實現了AcknowledgeMessageListener接口。

Spring配置文件

配置思路：?
1、確定需要定義的beans：

• 1 consumerProperties 消費者的基本屬性，包括指定bootstrap.servers,group.id等
• 2 consumerFactory ：消費者工廠，配置完consumerProperties 后，需要將consumerProperties 作為參數，配置進consumerFactory中
• 3 containProperties： 消費者容器屬性對象的bean，這個bean會指定后續自定義的監聽接口bean及ackMode（手動提交時，采取什么提交方式）
• 4 messageListenerContainer：消費者容器，啟動監聽接口的bean，需要將先前定義的consumerFactory 、containProperties配置進這個bean，并定義其init-method = doStart，在啟動spring時，便會自動啟動監聽接口，同時，此bean指定了topic
• 5 kafkaMessageListener：監聽接口，這個接口由自己定義，需要將其配置進containProperties中，?
  具體完整消費者的配置文件如下所示：

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"><!--1、consumer屬性配置，hashMap--><bean id="consumerProperties" class="java.util.HashMap"><constructor-arg><map><entry key="bootstrap.servers" value="${kafka.bootstrap.servers}"/><entry key="group.id" value="${kafka.group.id}"/><entry key="enable.auto.commit" value="false"/><entry key="session.timeout.ms" value="15000"/><!--<entry key="auto.offset.reset" value="earliest"/>--><entry key="key.deserializer" value="org.apache.kafka.common.serialization.StringDeserializer"/><entry key="value.deserializer" value="org.apache.kafka.common.serialization.StringDeserializer"/><entry key="value.deserializer.encoding" value="UTF8"/><entry key="value.deserializer.encoding" value="UTF8"/></map></constructor-arg></bean><!--2、Kafka消費者工廠，DefaultKafkaConsumerFactory--><bean id="consumerFactory" class="org.springframework.kafka.core.DefaultKafkaConsumerFactory"><constructor-arg><ref bean="consumerProperties"/></constructor-arg></bean><!--3、監聽接口，AcknowledgingMessageListener--><bean id="kafkaMessageListener" class="com.lianjia.bigdata.dataarch.auth.kafka.KafkaMessageListener"><property name="threadPool" ref="kafkaWorkerThreadPool"/></bean><bean id="kafkaWorkerThreadPool" class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor"><property name="corePoolSize" value="20"/><property name="maxPoolSize" value="200"/><property name="queueCapacity" value="500"/><property name="keepAliveSeconds" value="1800"/><property name="rejectedExecutionHandler"><bean class="java.util.concurrent.ThreadPoolExecutor$CallerRunsPolicy"/></property></bean><!--4、Kafka消費者容器，屬性配置--><bean id="containProperties" class="org.springframework.kafka.listener.config.ContainerProperties"><constructor-arg value="${kafka.topic}"/><property name="ackMode" value="MANUAL_IMMEDIATE"/><property name="messageListener" ref="kafkaMessageListener"/></bean><!--5、Kafka消費者容器--><bean id="messageListenerContainer" class="org.springframework.kafka.listener.KafkaMessageListenerContainer" init-method="doStart" ><constructor-arg ref="consumerFactory"/><constructor-arg ref="containProperties"/></bean> </bean>

示例代碼

寫了個簡單的測試用例?
生產者：?
實現每秒定時向brokers發送一條消息

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.clients.producer.ProducerRecord; import org.apache.kafka.common.serialization.IntegerSerializer; import org.apache.kafka.common.serialization.StringSerializer; import org.slf4j.Logger; import org.slf4j.LoggerFactory;import java.util.HashMap; import java.util.Map;public class SimpleKafkaProducer implements Runnable {protected static final Logger LOGGER = LoggerFactory.getLogger(SimpleKafkaProducer.class);@Overridepublic void run() {Map<String, Object> sendProps = senderProps();Producer producer = new KafkaProducer(sendProps);Integer currentNum = 0;try {LOGGER.info("start produce message");while (true){ProducerRecord<Integer, String> producerRecord = new ProducerRecord<>("testTopic",currentNum, currentNum);producer.send(producerRecord);LOGGER.info("send message:" + currentNum + " And value is " + producerRecord.value());currentNum++;Thread.sleep(1000);}}catch (Exception e){LOGGER.error("send message fail", e);}finally {producer.close();}}public static void main(String[] args) {SimpleKafkaProducer simpleKafkaProducer = new SimpleKafkaProducer();new Thread(simpleKafkaProducer).start();}private Map<String, Object> senderProps() {Map<String, Object> props = new HashMap<>();props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "10.33.106.94:9092");props.put(ProducerConfig.ACKS_CONFIG, "all");props.put(ProducerConfig.RETRIES_CONFIG, 0);props.put(ProducerConfig.BATCH_SIZE_CONFIG, 16384);props.put(ProducerConfig.LINGER_MS_CONFIG, 1);props.put(ProducerConfig.BUFFER_MEMORY_CONFIG, 33554432);props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, IntegerSerializer.class);props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);return props;} }

消費者

public class KafkaMessageListener implements AcknowledgingMessageListener<Integer, String> {private static final Logger LOGGER = LoggerFactory.getLogger(KafkaMessageListener.class);@Overridepublic void onMessage(final ConsumerRecord<Integer, String> message, final Acknowledgment acknowledgment) {//TODO 這里具體實現個人業務邏輯// 最后 調用acknowledgment的ack方法，提交offsetacknowledgment.acknowledge();} }

消費者使用示例：這里參考spring官方文檔，簡單實現了一個消費者監聽接口示例

import org.apache.kafka.clients.consumer.ConsumerConfig; import org.apache.kafka.clients.consumer.ConsumerRecord; import org.apache.kafka.common.serialization.IntegerDeserializer; import org.apache.kafka.common.serialization.StringDeserializer; import org.junit.Test; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.kafka.core.DefaultKafkaConsumerFactory; import org.springframework.kafka.listener.AbstractMessageListenerContainer; import org.springframework.kafka.listener.AcknowledgingMessageListener; import org.springframework.kafka.listener.KafkaMessageListenerContainer; import org.springframework.kafka.listener.config.ContainerProperties; import org.springframework.kafka.support.Acknowledgment;import javax.annotation.Resource; import java.util.HashMap; import java.util.Map; import java.util.concurrent.CountDownLatch;public class SimpleKafkaConsumer extends SpringUnitTest {protected static final Logger LOGGER = LoggerFactory.getLogger(SimpleKafkaConsumer.class);@Resource(name = "kafkaMessageListener")private KafkaMessageListener kafkaMessageListener;@Testpublic void TestLinstener(){ContainerProperties containerProps = new ContainerProperties("testTopic");containerProps.setMessageListener(kafkaMessageListener);KafkaMessageListenerContainer<Integer, String> container = createContainer(containerProps);container.setBeanName("messageListenerContainer");container.start();}private static KafkaMessageListenerContainer<Integer, String> createContainer(ContainerProperties containerProps) {Map<String, Object> props = consumerProps();DefaultKafkaConsumerFactory<Integer, String> cf =new DefaultKafkaConsumerFactory<>(props);KafkaMessageListenerContainer<Integer, String> container =new KafkaMessageListenerContainer<>(cf, containerProps);return container;}private static Map<String, Object> consumerProps() {Map<String, Object> props = new HashMap<>();props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "10.33.106.94:9092");props.put(ConsumerConfig.GROUP_ID_CONFIG, "test3");props.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, false); // props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG,"earliest");props.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, "15000");props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, IntegerDeserializer.class);props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);return props;}}

實現acknowledgeMessageListener接口之前，查閱了網上現有的文檔，結果不盡如人意，只能試著自己去參考spring官方文檔，慢慢摸索，最終實現手動提交offset的監聽接口，當然，Kafka的知識點，遠不止這些，后續還將繼續學習。

轉載于:https://my.oschina.net/xiaominmin/blog/1810338

總結

以上是生活随笔為你收集整理的Kafka集成Spring-AcknowledgeMessageListener接口实现的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。