spring整合kafka如何配置

在Spring Boot项目中整合Kafka，你需要遵循以下步骤进行配置：

1. 添加依赖

在你的pom.xml文件中添加Kafka和Spring Kafka的依赖：

<dependencies>
    <!-- Spring Kafka -->
    <dependency>
        <groupId>org.springframework.kafka</groupId>
        <artifactId>spring-kafka</artifactId>
    </dependency>
    <!-- Kafka Client -->
    <dependency>
        <groupId>org.apache.kafka</groupId>
        <artifactId>kafka-clients</artifactId>
    </dependency>
</dependencies>

2. 配置Kafka

在application.properties或application.yml文件中配置Kafka相关信息，例如：

# Kafka服务器地址
spring.kafka.bootstrap-servers=localhost:9092

# Kafka主题
spring.kafka.consumer.group-id=my-group
spring.kafka.consumer.auto-offset-reset=earliest
spring.kafka.consumer.key-deserializer=org.apache.kafka.common.serialization.StringDeserializer
spring.kafka.consumer.value-deserializer=org.apache.kafka.common.serialization.StringDeserializer

# Kafka生产者配置
spring.kafka.producer.key-serializer=org.apache.kafka.common.serialization.StringSerializer
spring.kafka.producer.value-serializer=org.apache.kafka.common.serialization.StringSerializer

3. 创建Kafka配置类

创建一个配置类，用于设置Kafka相关的Bean，例如：

@Configuration
public class KafkaConfig {

    @Value("${spring.kafka.bootstrap-servers}")
    private String bootstrapServers;

    @Bean
    public Map<String, Object> consumerConfigs() {
        Map<String, Object> props = new HashMap<>();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ConsumerConfig.GROUP_ID_CONFIG, "my-group");
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
        return props;
    }

    @Bean
    public 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;
    }

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

    @Bean
    public ProducerFactory<String, String> producerFactory() {
        return new DefaultKafkaProducerFactory<>(producerConfigs());
    }

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

4. 创建Kafka监听器

创建一个Kafka监听器，用于处理接收到的消息，例如：

@Service
public class KafkaListener {

    @KafkaListener(topics = "${spring.kafka.consumer.group-id}", groupId = "${spring.kafka.consumer.group-id}")
    public void listen(ConsumerRecord<String, String> record) {
        System.out.printf("Received message: key = %s, value = %s, partition = %d, offset = %d%n",
                record.key(), record.value(), record.partition(), record.offset());
    }
}

5. 发送消息

创建一个Kafka生产者，用于发送消息到Kafka主题，例如：

@Service
public class KafkaProducer {

    @Autowired
    private KafkaTemplate<String, String> kafkaTemplate;

    public void sendMessage(String topic, String message) {
        kafkaTemplate.send(topic, message);
    }
}

现在你已经成功地在Spring Boot项目中整合了Kafka，可以使用KafkaProducer发送消息，并使用KafkaListener监听和处理接收到的消息。