最近在做微服务的迁移改造工作，其中有一个服务需要订阅多个Kafka，如果使用spring kafka自动配置的话只能配置一个Kafka，不符合需求，该文总结了如何配置多个Kafka，希望对您有帮助。

准备工作

• 自己搭建一个Kafka
  从官方下载Kafka，选择对应Spring Boot 的版本，好在Kafka支持的版本范围比较广，当前最新版本是3.2.1,支持2.12-3.2.1 范围的版本，覆盖了Spring Boot 2.0x-Spring Boot 3.0.x。
  https://kafka.apache.org/downloads
  
• 解压安装
  进入bin目录，执行如下命令，按照如下顺序启动
  Linux

# 配置文件选择自己对应的目录
zookeeper-server-start.sh ../config/zookeeper.properties

Windows

windows/zookeeper-server-start.bat ../config/zookeeper.properties

打开另外一个终端，启动KafkaServer
Linux

kafka-server-start.sh ../config/server.properties

Windows

windows/kafka-server-start.bat ../config/server.properties

最小化配置Kafka

如下是最小化配置Kafka
pom.xml 引入依赖

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

application.properties

server.port=8090
spring.application.name=single-kafka-server

#kafka 服务器地址
spring.kafka.bootstrap-servers=localhost:9092
#消费者分组，配置后，自动创建
spring.kafka.consumer.group-id=default_group

KafkaProducer 生产者

@Slf4j
@Component
@EnableScheduling
public class KafkaProducer {
    
    

    @Resource
    private KafkaTemplate kafkaTemplate;

    private void sendTest() {
    
    
    	//topic 会自动创建
        kafkaTemplate.send("topic1", "hello kafka");
    }

    @Scheduled(fixedRate = 1000 * 10)
    public void testKafka() {
    
    
        log.info("send message...");
        sendTest();
    }
}

KafkaConsumer 消费者

@Slf4j
@Component
public class KafkaConsumer {
    
    

    @KafkaListener(topics = {
    
    "topic1"})
    public void processMessage(String spuId) {
    
    
        log.warn("process spuId ={}", spuId);
    }

}

运行效果：

多Kafka配置

配置稍微复杂了一点，灵魂就是手动创建，同样引入依赖
pom.xml

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

application.properties

server.port=8090
spring.application.name=kafka-server

#kafka1
#服务器地址
spring.kafka.one.bootstrap-servers=localhost:9092
spring.kafka.one.consumer.group-id=default_group


#kafka2
spring.kafka.two.bootstrap-servers=localhost:9092
spring.kafka.two.consumer.group-id=default_group2

第一个Kafka配置，需要区分各Bean的名称
KafkaOneConfig

@Configuration
public class KafkaOneConfig {
    
    

    @Value("${spring.kafka.one.bootstrap-servers}")
    private String bootstrapServers;
    @Value("${spring.kafka.one.consumer.group-id}")
    private String groupId;

    @Bean
    public KafkaTemplate<String, String> kafkaOneTemplate() {
    
    
        return new KafkaTemplate<>(producerFactory());
    }

    @Bean(name = "kafkaOneContainerFactory")
    KafkaListenerContainerFactory<ConcurrentMessageListenerContainer<Integer, String>> kafkaOneContainerFactory() {
    
    
        ConcurrentKafkaListenerContainerFactory<Integer, String> factory = new ConcurrentKafkaListenerContainerFactory<>();
        factory.setConsumerFactory(consumerFactory());
        factory.getContainerProperties().setPollTimeout(3000);
        return factory;
    }

    private ProducerFactory<String, String> producerFactory() {
    
    
        return new DefaultKafkaProducerFactory<>(producerConfigs());
    }

    private ConsumerFactory<Integer, String> consumerFactory() {
    
    
        return new DefaultKafkaConsumerFactory<>(consumerConfigs());
    }

    private Map<String, Object> producerConfigs() {
    
    
        Map<String, Object> props = new HashMap<>();
        props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        return props;
    }

    private Map<String, Object> consumerConfigs() {
    
    
        Map<String, Object> props = new HashMap<>();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ConsumerConfig.GROUP_ID_CONFIG, groupId);
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        return props;
    }

}

kafkaOneTemplate 定义第一个Kafka的高级模板，用来发送消息
kafkaOneContainerFactory 消费监听容器，配置在@KafkaListener中，
producerFactory 生产者工厂
consumerFactory 消费者工厂
producerConfigs 生产者配置
consumerConfigs 消费者配置

同样创建第二个Kafka，配置含义，同第一个Kafka
KafkaTwoConfig

@Configuration
public class KafkaTwoConfig {
    
    

    @Value("${spring.kafka.two.bootstrap-servers}")
    private String bootstrapServers;
    @Value("${spring.kafka.two.consumer.group-id}")
    private String groupId;

    @Bean
    public KafkaTemplate<String, String> kafkaTwoTemplate() {
    
    
        return new KafkaTemplate<>(producerFactory());
    }

    @Bean(name = "kafkaTwoContainerFactory")
    KafkaListenerContainerFactory<ConcurrentMessageListenerContainer<Integer, String>> kafkaTwoContainerFactory() {
    
    
        ConcurrentKafkaListenerContainerFactory<Integer, String> factory = new ConcurrentKafkaListenerContainerFactory<>();
        factory.setConsumerFactory(consumerFactory());
        factory.getContainerProperties().setPollTimeout(3000);
        return factory;
    }

    private ProducerFactory<String, String> producerFactory() {
    
    
        return new DefaultKafkaProducerFactory<>(producerConfigs());
    }

    public ConsumerFactory<Integer, String> consumerFactory() {
    
    
        return new DefaultKafkaConsumerFactory<>(consumerConfigs());
    }

    private Map<String, Object> producerConfigs() {
    
    
        Map<String, Object> props = new HashMap<>();
        props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        return props;
    }

    private Map<String, Object> consumerConfigs() {
    
    
        Map<String, Object> props = new HashMap<>();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ConsumerConfig.GROUP_ID_CONFIG, groupId);
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        return props;
    }

}

创建一个测试的消费者，注意配置不同的监听容器containerFactory
KafkaConsumer

@Slf4j
@Component
public class KafkaConsumer {
    
    

    @KafkaListener(topics = {
    
    "topic1"}, containerFactory = "kafkaOneContainerFactory")
    public void oneProcessItemcenterSpuMessage(String spuId) {
    
    
        log.warn("one process spuId ={}", spuId);
    }

    @KafkaListener(topics = {
    
    "topic2"},containerFactory = "kafkaTwoContainerFactory")
    public void twoProcessItemcenterSpuMessage(String spuId) {
    
    
        log.warn("two process spuId ={}", spuId);
    }
}

创建一个测试的生产者，定时往两个topic中发送消息
KafkaProducer

@Slf4j
@Component
public class KafkaProducer {
    
    

    @Resource
    private KafkaTemplate kafkaOneTemplate;
    @Resource
    private KafkaTemplate kafkaTwoTemplate;

    private void sendTest() {
    
    
        kafkaOneTemplate.send("topic1", "hello kafka one");
        kafkaTwoTemplate.send("topic2", "hello kafka two");
    }

    @Scheduled(fixedRate = 1000 * 10)
    public void testKafka() {
    
    
        log.info("send message...");
        sendTest();
    }
}

最后运行效果：

其他kafka文章：
【从面试题看源码】-看完Kafka性能优化-让你吊打面试官