Spring Boot中创建KafkaTemplate的正确方法

在Spring Boot中，使用Kafka进行消息传递是一种非常常见的方式。Kafka是一个分布式流处理平台，可以提供高吞吐量、可扩展性和可靠性的消息传递。在Spring Boot中，我们可以使用KafkaTemplate来简化与Kafka的交互。本文将介绍如何正确地创建KafkaTemplate，并提供一个简单的案例代码来演示其用法。

xml
    org.springframework.kafka
    spring-kafka
    2.7.2

properties
spring.kafka.bootstrap-servers=localhost:9092
spring.kafka.consumer.group-id=my-group
spring.kafka.consumer.auto-offset-reset=earliest

java
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.kafka.core.DefaultKafkaProducerFactory;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.core.ProducerFactory;
@Configuration
public class KafkaConfig {
    @Bean
    public ProducerFactory producerFactory() {
        return new DefaultKafkaProducerFactory<>(producerConfigs());
    }
    @Bean
    public Map producerConfigs() {
        Map props = new HashMap<>();
        props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
        props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        return props;
    }
    @Bean
    public KafkaTemplate kafkaTemplate() {
        return new KafkaTemplate<>(producerFactory());
    }
}

java
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.stereotype.Component;
@Component
public class MessageProducer {
    @Autowired
    private KafkaTemplate kafkaTemplate;
    public void sendMessage(String topic, String message) {
        kafkaTemplate.send(topic, message);
    }
}