ProducerDemo.java

package com.github.simple;

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.common.serialization.StringSerializer;

import java.util.Properties;

public class ProducerDemo {
    public static void main(String[] args) {

        String bootstrapServers="127.0.0.1:9092";

        // 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 Producer

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

        // Create a producer record
        ProducerRecord<String, String> record =
                new ProducerRecord<>("first_topic", "Henlo");

        // send data
        producer.send(record);

        // flush data
        producer.flush();

        // flush and close program
        producer.close();

    }
}