java连接kafka

以下是使用Java连接Kafka的示例代码：

1. 首先，您需要在项目的pom.xml文件中添加Kafka的依赖：

<dependency>
    <groupId>org.apache.kafka</groupId>
    <artifactId>kafka-clients</artifactId>
    <version>3.2.0</version>
</dependency>

2. 接下来，您可以使用以下Java代码来创建Kafka生产者和消费者：

import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import java.util.Properties;

// 创建Kafka生产者
public class KafkaProducerExample {
    public static void main(String[] args) {
        String topicName = "test-topic";
        String key = "key1";
        String value = "value1";

        Properties props = new Properties();
        props.put("bootstrap.servers", "localhost:9092");
        props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");

        KafkaProducer<String, String> producer = new KafkaProducer<>(props);
        ProducerRecord<String, String> record = new ProducerRecord<>(topicName, key, value);
        producer.send(record);
        producer.close();
    }
}

// 创建Kafka消费者
public class KafkaConsumerExample {
    public static void main(String[] args) {
        String topicName = "test-topic";

        Properties props = new Properties();
        props.put("bootstrap.servers", "localhost:9092");
        props.put("group.id", "test-group");
        props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
        props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");

        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
        consumer.subscribe(Collections.singletonList(topicName));

        while (true) {
            ConsumerRecords<String, String> records = consumer.poll(Duration.ofMillis(100));
            for (ConsumerRecord<String, String> record : records) {
                System.out.printf("offset = %d, key = %s, value = %s%n", record.offset(), record.key(), record.value());
            }
        }
    }
}

这些代码示例演示了如何使用Java连接Kafka，创建生产者和消费者，并发送/接收消息。您可以根据自己的需求进行相应的修改和扩展。