package com.example.kafka;

import org.apache.kafka.clients.producer.*;
import org.apache.kafka.common.serialization.StringSerializer;

import java.util.Properties;

public class KafkaProducerWithCallback {
    public static void main(String[] args) {
        System.out.println("My first Kafka Producer");

        String bootstrapServers = "kafka1:9092";

        // create Producer properties
        Properties properties = new Properties();
        properties.setProperty(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        properties.setProperty(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
        properties.setProperty(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());

        // create the producer
        KafkaProducer<String, String> producer = new KafkaProducer<String, String>(properties);

        // create a producer record
        ProducerRecord<String, String> record =
                new ProducerRecord<String, String>("my-topic10", "Java message");

        // send data - asynchronous
        producer.send(record, new Callback() {
            public void onCompletion(RecordMetadata recordMetadata, Exception e) {
                if (e == null) {
                    // the record was successfully sent
                    System.out.println("Received info about metadata. \n" +
                    "Topic:" + recordMetadata.topic() + "\n" +
                            "Partition: " + recordMetadata.partition() + "\n" +
                            "Offset: " + recordMetadata.offset() + "\n" +
                            "Timestamp: " + recordMetadata.timestamp());

                } else {
                    System.out.println("Error while producing: "+ e);
                }
            }
        });

        // Flush the data - is sent
        producer.flush();

        // Flush and Close the producer
        producer.close();

        System.out.println("Producer has been closed.");
    }
}