ConsumedMessage.java

package com.edu.samples.messagelog;

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import java.time.Instant;

@Entity
@Table(name = "consumed_messages")
public class ConsumedMessage {

    @Id
    private String eventId;

    private Instant timeOfReceiving;

    ConsumedMessage() {
    }

    public ConsumedMessage(String eventId, Instant timeOfReceiving) {
        this.eventId = eventId;
        this.timeOfReceiving = timeOfReceiving;
    }

    public String getEventId() {
        return eventId;
    }

    public void setEventId(String eventId) {
        this.eventId = eventId;
    }

    public Instant getTimeOfReceiving() {
        return timeOfReceiving;
    }

    public void setTimeOfReceiving(Instant timeOfReceiving) {
        this.timeOfReceiving = timeOfReceiving;
    }
}

MessageLog.java

package com.edu.samples.messagelog;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.enterprise.context.ApplicationScoped;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.transaction.Transactional;
import java.time.Instant;
import java.util.UUID;

@ApplicationScoped
public class MessageLog {

    private static final Logger LOG = LoggerFactory.getLogger(MessageLog.class);

    @PersistenceContext
    EntityManager entityManager;

    @Transactional(value= Transactional.TxType.MANDATORY)
    public void processed(String eventId) {
        entityManager.persist(new ConsumedMessage(eventId, Instant.now()));
    }

    @Transactional(value= Transactional.TxType.MANDATORY)
    public boolean alreadyProcessed(String eventId) {
        LOG.debug("Looking for event with id {} in message log", eventId);
        return entityManager.find(ConsumedMessage.class, eventId) != null;
    }
}