Kafka + SpringBoot集成

学习贴：参考https://blog.csdn.net/qq_20865839/article/details/133948989

简单SpringBoot整合：

依赖：

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

生产者

@RestController
public class kafkaProducer {
 
    @Autowired
    private KafkaTemplate<String, Object> kafkaTemplate;
    
    @GetMapping("/kafka/normal/{message}")
    public void sendNormalMessage(@PathVariable("message") String message) {
        kafkaTemplate.send("sb_topic", message);
    }

消费者：

@Component
public class KafkaConsumer {
 
    //监听消费
    @KafkaListener(topics = {"sb_topic"})
    public void onNormalMessage(ConsumerRecord<String, Object> record) {
        System.out.println("简单消费：" + record.topic() + "-" + record.partition() + "=" +
                record.value());
    }

生产者

带回调的生产者
kafkaTemplate提供了一个回调方法addCallback，我们可以在回调方法中监控消息是否发送成功 或 失败时做补偿处理

    /**
     * 回调的第二种写法
     * @param message
     */
    @GetMapping("/kafka/callbackTwo/{message}")
    public void sendCallbackTwoMessage(@PathVariable("message") String message) {
        kafkaTemplate.send("sb_topic", message).addCallback(new ListenableFutureCallback<SendResult<String, Object>>() {
            @Override
            public void onFailure(Throwable throwable) {
                System.out.println("发送消息失败2："+throwable.getMessage());
            }
 
            @Override
            public void onSuccess(SendResult<String, Object> result) {
                System.out.println("发送消息成功2：" + result.getRecordMetadata().topic() + "-"
                        + result.getRecordMetadata().partition() + "-" + result.getRecordMetadata().offset());
            }
        });
    }

监听器

Kafka提供了ProducerListener 监听器来异步监听生产者消息是否发送成功，我们可以自定义一个kafkaTemplate添加ProducerListener，当消息发送失败我们可以拿到消息进行重试或者把失败消息记录到数据库定时重试。

注意：
当我们发送一条消息，既会走 ListenableFutureCallback 回调，也会走ProducerListener回调。

@Configuration
public class KafkaConfig {
 
    @Autowired
    ProducerFactory producerFactory;
 
    @Bean
    public KafkaTemplate<String, Object> kafkaTemplate() {
        KafkaTemplate<String, Object> kafkaTemplate = new KafkaTemplate<String, Object>(producerFactory);
        kafkaTemplate.setProducerListener(new ProducerListener<String, Object>() {
            @Override
            public void onSuccess(ProducerRecord<String, Object> producerRecord, RecordMetadata recordMetadata) {
                System.out.println("发送成功 " + producerRecord.toString());
            }
 
            @Override
            public void onSuccess(String topic, Integer partition, String key, Object value, RecordMetadata recordMetadata) {
                System.out.println("发送成功 topic = " + topic + " ; partion = " + partition + "; key = " + key + " ; value=" + value);
            }
 
            @Override
            public void onError(ProducerRecord<String, Object> producerRecord, Exception exception) {
                System.out.println("发送失败" + producerRecord.toString());
                System.out.println(exception.getMessage());
            }
 
            @Override
            public void onError(String topic, Integer partition, String key, Object value, Exception exception) {
                System.out.println("发送失败" + "topic = " + topic + " ; partion = " + partition + "; key = " + key + " ; value=" + value);
                System.out.println(exception.getMessage());
            }
        });
        return kafkaTemplate;
    }
}