public class Farewell {

​

    private String message;

    private Integer remainingMinutes;

​

    // standard getters, setters and constructor

}

configProps.put(JsonSerializer.TYPE_MAPPINGS, "greeting:com.baeldung.spring.kafka.Greeting, farewell:com.baeldung.spring.kafka.Farewell");

@Bean

public ProducerFactory<String, Object> multiTypeProducerFactory() {

    Map<String, Object> configProps = new HashMap<>();

    configProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapAddress);

    configProps.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);

    configProps.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, JsonSerializer.class);

    configProps.put(JsonSerializer.TYPE_MAPPINGS, 

      "greeting:com.baeldung.spring.kafka.Greeting, farewell:com.baeldung.spring.kafka.Farewell");

    return new DefaultKafkaProducerFactory<>(configProps);

}

​

@Bean

public KafkaTemplate<String, Object> multiTypeKafkaTemplate() {

    return new KafkaTemplate<>(multiTypeProducerFactory());

}

multiTypeKafkaTemplate.send(multiTypeTopicName, new Greeting("Greetings", "World!"));

multiTypeKafkaTemplate.send(multiTypeTopicName, new Farewell("Farewell", 25));

multiTypeKafkaTemplate.send(multiTypeTopicName, "Simple string message");