Springboot-@KafkaListener 使用方式

2. consumer

使用了@KafkaListener注解。

2.1. pom.xml

引入以下依赖

<dependency> <groupId>org.springframework.kafka</groupId> <artifactId>spring-kafka</artifactId> <version>1.2.0.RELEASE</version> </dependency>

2.2. 配置类

@Configuration @EnableKafka public class KafkaConfig { @Value("${kafka.bootstrap.servers}") private String kafkaBootstrapServers; @Value("${session.timeout.ms}") private Integer sessionTimeoutMs; @Value("${enable.auto.commit}") private boolean enableAutoCommit; @Value("${auto.commit.interval.ms}") private Integer autoCommitIntervalMs; @Value("${auto.offset.reset}") private String autoOffsetReset; @Value("${group.id}") private String groupId; @Bean KafkaListenerContainerFactory<ConcurrentMessageListenerContainer<Integer, String>> kafkaListenerContainerFactory() { ConcurrentKafkaListenerContainerFactory<Integer, String> factory = new ConcurrentKafkaListenerContainerFactory<>(); factory.setConsumerFactory(consumerFactory()); factory.setConcurrency(3); factory.getContainerProperties().setPollTimeout(3000); return factory; } @Bean public ConsumerFactory<Integer, String> consumerFactory() { return new DefaultKafkaConsumerFactory<>(consumerConfigs()); } @Bean public Map<String, Object> consumerConfigs() { Map<String, Object> props = new HashMap<>(); props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, kafkaBootstrapServers); props.put(ConsumerConfig.GROUP_ID_CONFIG, groupId); props.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, enableAutoCommit); props.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG, autoCommitIntervalMs); props.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, sessionTimeoutMs); props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, autoOffsetReset); props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, IntegerDeserializer.class); props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class); return props; } @Bean public KafkaConsumer consumer() { return new KafkaConsumer(); } }

2.3. 消费处理

public class KafkaConsumer { @KafkaListeners({@KafkaListener(topics="topic1"), @KafkaListener(topics="topic2")}) public void listen(ConsumerRecord<Integer, String> msg) { // 消费到数据后的处理逻辑 } }

2.4. @KafkaListener和@KafkaListners

@KafkaListeners是@KafkaListener的Container Annotation，这也是jdk8的新特性之一，注解可以重复标注。

@KafkaListeners({@KafkaListener(topics="topic1"), @KafkaListener(topics="topic2")}) public void listen(ConsumerRecord<Integer, String> msg) {} 等同于 @KafkaListener(topics="topic1") @KafkaListener(topics="topic2") public void listen(ConsumerRecord<Integer, String> msg) {}

2.5. @KafkaListener使用小结

在注解上可以方便地进行各种配置，但是如果要消费的topic个数不定，用@KafkaListener就很难优雅解决。

注解要求必须在compile-time就能确定值，可以移步stackOverFlow查看更加详细的解释。

@KafkaListener和@KafkaListeners的使用

原文：https://www.cnblogs.com/gxyandwmm/p/11849786.html