kafka完整代码示例

以下是一个简单的 Kafka 生产者和消费者的完整代码示例：

生产者代码：

import java.util.Properties;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerRecord;

public class KafkaProducerExample {
    public static void main(String[] args) throws Exception{
        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();
    }
}

消费者代码：

import java.util.Collections;
import java.util.Properties;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.KafkaConsumer;

public class KafkaConsumerExample {
    public static void main(String[] args) throws Exception{
        String topicName = "test-topic";

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

        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);

        consumer.subscribe(Collections.singletonList(topicName));

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