Were transactional message processing mechanisms implemented in your project?

In Java projects, mechanisms provided by message brokers (e.g., JMS) or frameworks (Spring) are often used to ensure transactional message processing.

Transactional message processing guarantees that a message will be processed exactly once, and in case of an error, the processing will be rolled back to prevent data loss or duplication.

Example using JMS:

Connection connection = connectionFactory.createConnection();
Session session = connection.createSession(true, Session.SESSION_TRANSACTED);
try {
    MessageConsumer consumer = session.createConsumer(destination);
    Message message = consumer.receive();
    // process message
    session.commit(); // confirm transaction
} catch (Exception e) {
    session.rollback(); // rollback transaction on error
} finally {
    session.close();
    connection.close();
}

Thus, if your project used message brokers or similar technologies, transactional processing was most likely applied for reliability.