How Create Redis Idempotency Manager Service with Spring?

As mentioned in previous title;
https://medium.com/@ozanakkoca/how-avoid-idempotency-problem-from-apache-kafka-consumers-with-in-memory-data-structure-store-8083abb40999

Idempotency might be a problem for consuming messages from Kafka,
This problem can cause unexpected results like sending same mails to your customers or doing multiple same service calls and so on.

https://www.waitingforcode.com/data-engineering-patterns/idempotent-consumer-pattern/read

So u can simply create a service with Spring to manage or control the consumers on Topics.

Component

https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/stereotype/Component.html

Create a custom bean as a Component for Spring to detect it automatically and then inject them wherever your needed.

@Component
@RequiredArgsConstructor
public class RedisRepository {

    private final RedisTemplate<String, MailDto> redisTemplate;

    public Optional<MailDto> find(String mailId, String mailName) {
        return Optional.ofNullable(redisTemplate.opsForValue().get(defineHeader(mailId, mailName)));
    }

    public void put(final @NonNull MailDto mailDto) {
        redisTemplate.opsForValue().set(defineHeader(mailDto.getmailId(), mailDto.getMailName()), mailDto));
    }

    public void delete(String mailId, String mailName) {
        redisTemplate.delete(defineHeader(mailId, mailName));
    }

    private String defineHeader(String mailId, String mailName) {
        return String.format("Mail:%s:%s", mailName, mailId);
    }
}

Service

https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/stereotype/Service.html

Create a class as a Service provider for business layer to hold business logic.

@Service
public class RIManager {  
  
    private final RedisRepository redisRepository;
 
    public boolean IsMailFoundAndPresentOnRedis(String mailId, String mailName) {
        MailDto foundMail = null;
  
        try {
            Optional<MailDto> optionalMailDto = this.redisRepository.find(mailId, mailName);
            if (optionalMailDto.isPresent()) {
                foundMail = (MailDto)optionalMailDto.get();
            }
        } catch (Exception e) {            
        }
  
        boolean isFound = foundMail == null;
        
        return isFound;
    }

    public MailDto PutMailToRedis(String mailId, String mailName) {
        MailDto mail = new MailDto();
        mail.setmailId(mailId);
        mail.setmailName(mailName);

        try {
            this.redisRepository.put(mail);
            
        } catch (Exception e) {            
        }

        return mail;
    }

    public boolean DeleteMailFromRedis(String mailId, String mailName) {
 
        try {
            this.redisRepository.delete(mailId, mailName);
            
        } catch (Exception e) {            
        }

        return true;
    }  

    public RIManager(final RedisRepository redisRepository) {
 
        this.redisRepository = redisRepository;
  
    }
}

And now use ManagerService on code ;

if (!riManager.IsMailFoundAndPresentOnRedis(maiId, mailName)) {                   
    ....
}