要使用不启动Kafka监听器的模式确认消费者/生产者,可以使用KafkaConsumer和KafkaProducer类的poll()方法来手动控制消息的消费和生产。
下面是一个示例代码:
生产者代码:
import org.apache.kafka.clients.producer.*;
import java.util.Properties;
public class ProducerExample {
private static final String TOPIC_NAME = "my-topic";
private static final String BOOTSTRAP_SERVERS = "localhost:9092";
public static void main(String[] args) {
Properties props = new Properties();
props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, BOOTSTRAP_SERVERS);
props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringSerializer");
props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringSerializer");
KafkaProducer producer = new KafkaProducer<>(props);
for (int i = 0; i < 10; i++) {
ProducerRecord record = new ProducerRecord<>(TOPIC_NAME, Integer.toString(i), "Message " + i);
producer.send(record, new Callback() {
@Override
public void onCompletion(RecordMetadata metadata, Exception exception) {
if (exception != null) {
System.err.println("Error producing message: " + exception.getMessage());
} else {
System.out.println("Message sent successfully. Offset: " + metadata.offset());
}
}
});
}
producer.close();
}
}
消费者代码:
import org.apache.kafka.clients.consumer.*;
import java.util.Arrays;
import java.util.Properties;
public class ConsumerExample {
private static final String TOPIC_NAME = "my-topic";
private static final String BOOTSTRAP_SERVERS = "localhost:9092";
private static final String GROUP_ID = "my-group";
public static void main(String[] args) {
Properties props = new Properties();
props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, BOOTSTRAP_SERVERS);
props.put(ConsumerConfig.GROUP_ID_CONFIG, GROUP_ID);
props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");
props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");
KafkaConsumer consumer = new KafkaConsumer<>(props);
consumer.subscribe(Arrays.asList(TOPIC_NAME));
while (true) {
ConsumerRecords records = consumer.poll(1000);
for (ConsumerRecord record : records) {
System.out.println("Received message: " + record.value() + ", Offset: " + record.offset());
}
}
}
}
这个示例代码中,生产者会发送10条消息到名为"my-topic"的主题,而消费者会从该主题中接收消息并打印出来。注意消费者使用了一个永不退出的循环来持续消费消息,直到程序被终止。
你需要确保Kafka集群已经运行在本地,并且主题"my-topic"已经存在。你可以根据需要修改代码中的主题名称、引导服务器地址和其他配置。