<dependency>
    <groupId>org.apache.kafka</groupId>
    <artifactId>kafka-clients</artifactId>
    <version>3.4.0</version>
</dependency>

import org.apache.kafka.clients.producer.*;
import java.util.Properties;
public class KafkaProducerExample {
    public static void main(String[] args) {
        // 配置生產(chǎn)者屬性
        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");
        // 創(chuàng)建生產(chǎn)者實(shí)例
        Producer<String, String> producer = new KafkaProducer<>(props);
        // 發(fā)送消息
        for (int i = 0; i < 10; i++) {
            ProducerRecord<String, String> record = new ProducerRecord<>(
                "test-topic", 
                "key-" + i, 
                "message-" + i
            );
            producer.send(record, (metadata, exception) -> {
                if (exception != null) {
                    exception.printStackTrace();
                } else {
                    System.out.printf("Message sent to partition %d with offset %d%n",
                            metadata.partition(), metadata.offset());
                }
            });
        }
        // 關(guān)閉生產(chǎn)者
        producer.close();
    }
}

import org.apache.kafka.clients.consumer.*;
import java.time.Duration;
import java.util.Collections;
import java.util.Properties;
public class KafkaConsumerExample {
    public static void main(String[] args) {
        // 配置消費(fèi)者屬性
        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");
        // 創(chuàng)建消費(fèi)者實(shí)例
        Consumer<String, String> consumer = new KafkaConsumer<>(props);
        // 訂閱Topic
        consumer.subscribe(Collections.singletonList("test-topic"));
        // 輪詢獲取消息
        try {
            while (true) {
                ConsumerRecords<String, String> records = consumer.poll(Duration.ofMillis(100));
                for (ConsumerRecord<String, String> record : records) {
                    System.out.printf("Received message: key = %s, value = %s, partition = %d, offset = %d%n",
                            record.key(), record.value(), record.partition(), record.offset());
                }
            }
        } finally {
            consumer.close();
        }
    }
}

// 簡(jiǎn)單的流處理示例
StreamsBuilder builder = new StreamsBuilder();
builder.stream("input-topic")
       .mapValues(value -> value.toString().toUpperCase())
       .to("output-topic");
KafkaStreams streams = new KafkaStreams(builder.build(), props);
streams.start();