package domain;

interface Data {
    public String getData();
    public void setData(String data);
}

package persistence;

@Data
class DataEntity implements Data {
    private String data;  // lombok generates getter/setters
}

@Component
class DataPublisher implements ApplicationListener<DataEvent> {
    @Autowired private KafkaTemplate<String,Data> template;

    // I left out DataEvent which is a straightforward ApplicationEvent override
    @EventListener(classes = DataEvent.class)
    public void onApplicationEvent(DataEvent event) {
        template.send("data", (Data) event.getSource());
    }
}
// triggered by this call in a service
    eventPublisher.publishEvent(new DataEvent(updatedData));

spring:
    kafka:
        consumer:
            value-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer
            properties.spring.json.value.default.type: domain.Data

@KafkaListener(topics = "data")
public void dataUpdated(@Payload Data data) {
    dataService.updateData(data);
}