kafka消费者API魔术v1不支持记录头

要解决“kafka消费者API魔术v1不支持记录头”这个问题，可以尝试使用新版本的Kafka消费者API或者手动处理记录头。

以下是使用新版本Kafka消费者API的示例代码：

import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.common.serialization.StringDeserializer;

import java.util.Collections;
import java.util.Properties;

public class KafkaConsumerExample {
    public static void main(String[] args) {
        Properties props = new Properties();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
        props.put(ConsumerConfig.GROUP_ID_CONFIG, "test-group");
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());

        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
        consumer.subscribe(Collections.singletonList("test-topic"));

        while (true) {
            ConsumerRecords<String, String> records = consumer.poll(100);
            for (ConsumerRecord<String, String> record : records) {
                // 处理每条消息
                System.out.printf("Received message: key=%s, value=%s%n", record.key(), record.value());
            }
        }
    }
}

如果你仍然希望使用旧版本的Kafka消费者API，你可以手动处理记录头。以下是一个示例代码：

import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.common.header.Header;
import org.apache.kafka.common.header.Headers;
import org.apache.kafka.common.serialization.StringDeserializer;

import java.util.Collections;
import java.util.Iterator;
import java.util.Properties;

public class KafkaConsumerExample {
    public static void main(String[] args) {
        Properties props = new Properties();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
        props.put(ConsumerConfig.GROUP_ID_CONFIG, "test-group");
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());

        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
        consumer.subscribe(Collections.singletonList("test-topic"));

        while (true) {
            ConsumerRecords<String, String> records = consumer.poll(100);
            for (ConsumerRecord<String, String> record : records) {
                // 获取记录头
                Headers headers = record.headers();
                Iterator<Header> iterator = headers.iterator();
                while (iterator.hasNext()) {
                    Header header = iterator.next();
                    System.out.printf("Header: key=%s, value=%s%n", header.key(), new String(header.value()));
                }

                // 处理每条消息
                System.out.printf("Received message: key=%s, value=%s%n", record.key(), record.value());
            }
        }
    }
}

这样，你就可以使用新版本的Kafka消费者API或者手动处理记录头来解决“kafka消费者API魔术v1不支持记录头”的问题。