tencent cloud

import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.clients.producer.RecordMetadata;

import java.util.Properties;

public class TransactionalProducerDemo {
    public static void main(String[] args) {
        // Kafka configuration.
        Properties props = new Properties();
        props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092"); // Kafka broker address.
        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");
        props.put(ProducerConfig.TRANSACTIONAL_ID_CONFIG, "my-transactional-id"); // Transaction ID.
        props.put(ProducerConfig.ENABLE_IDEMPOTENCE_CONFIG, "true"); // Enable idempotency.

        // Create a Kafka producer.
        KafkaProducer<String, String> producer = new KafkaProducer<>(props);

        // Initialize the transaction.
        producer.initTransactions();

        try {
            // Start the transaction.
            producer.beginTransaction();

            // Send messages.
            for (int i = 0; i < 10; i++) {
                ProducerRecord<String, String> record = new ProducerRecord<>("my-topic", "key-" + i, "value-" + i);
                RecordMetadata metadata = producer.send(record).get(); // Send messages and wait for acknowledgment.
                System.out.printf("Sent message: key=%s, value=%s, partition=%d, offset=%d%n", 
                                  record.key(), record.value(), metadata.partition(), metadata.offset());
            }

            // Commit the transaction.
            producer.commitTransaction();
            System.out.println("Transaction committed successfully.");
        } catch (Exception e) {
            // If an exception occurs, roll back the transaction.
            producer.abortTransaction();
            System.err.println("Transaction aborted due to an error: " + e.getMessage());
        } finally {
            // Disable the producer.
            producer.close();
        }
    }
}

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

import java.time.Duration;
import java.util.Collections;
import java.util.Properties;

public class TransactionalConsumerDemo {
    public static void main(String[] args) {
        // Kafka configuration.
        Properties props = new Properties();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092"); // Kafka broker address.
        props.put(ConsumerConfig.GROUP_ID_CONFIG, "my-consumer-group"); // Consumer 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");
        props.put(ConsumerConfig.ISOLATION_LEVEL_CONFIG, "read_committed"); // Read committed transactional messages only.

        // Create a Kafka consumer.
        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);

        // Subscribe to a topic.
        consumer.subscribe(Collections.singletonList("my-topic"));

        try {
            while (true) {
                // Pull messages.
                ConsumerRecords<String, String> records = consumer.poll(Duration.ofMillis(100));
                for (ConsumerRecord<String, String> record : records) {
                    System.out.printf("Consumed message: key=%s, value=%s, partition=%d, offset=%d%n",
                            record.key(), record.value(), record.partition(), record.offset());
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // Disable the consumer.
            consumer.close();
        }
    }
}