RocketMQ的四种常用消息队列及代码演示

@Service
public class MyProducer {
    @Autowired
    private RocketMQTemplate rocketMQTemplate;
    public void sendMessage(String message) {
        rocketMQTemplate.convertAndSend("myTopic", message);
    }
}

@Service
public class MyProducer {
    @Autowired
    private RocketMQTemplate rocketMQTemplate;
    public void sendOrderMessage(String message, int orderId) {
        rocketMQTemplate.setMessageQueueSelector(new OrderMessageQueueSelector());
        rocketMQTemplate.convertAndSend("myTopic", message, orderId);
    }
}
class OrderMessageQueueSelector implements MessageQueueSelector {
    @Override
    public MessageQueue select(List<MessageQueue> mqs, Message message, Object orderId) {
        int index = (int) orderId % mqs.size();
        return mqs.get(index);
    }
}

@Service
public class MyProducer {
    @Autowired
    private RocketMQTemplate rocketMQTemplate;
    public void sendDelayMessage(String message, long delayTime) {
        rocketMQTemplate.syncSend("myTopic", MessageBuilder.withPayload(message)
                .build(), 3000, 2, delayTime);
    }
}

@Service
public class MyTransactionListener implements RocketMQLocalTransactionListener {
    @Override
    public RocketMQLocalTransactionState executeLocalTransaction(Message message, Object o) {
        // 执行本地事务
        // 如果本地事务执行成功，则返回RocketMQLocalTransactionState.COMMIT
        // 如果本地事务执行失败，则返回RocketMQLocalTransactionState.ROLLBACK
        return RocketMQLocalTransactionState.UNKNOWN;
    }
    @Override
    public RocketMQLocalTransactionState checkLocalTransaction(Message message) {
        // 检查本地事务状态
        // 如果本地事务执行成功，则返回RocketMQLocalTransactionState.COMMIT
        // 如果本地事务执行失败，则返回RocketMQLocalTransactionState.ROLLBACK
        // 如果本地事务状态未知，则返回RocketMQLocalTransactionState.UNKNOWN
        return RocketMQLocalTransactionState.UNKNOWN;
    }
}
@Service
public class MyProducer {
    @Autowired
    private RocketMQTemplate rocketMQTemplate;
    @Autowired
    private MyTransactionListener transactionListener;
    public void sendTransactionMessage(String message) {
        rocketMQTemplate.setTransactionListener(transactionListener);
        rocketMQTemplate.sendMessageInTransaction("myTransactionGroup", "myTopic",
                MessageBuilder.withpayload(message).build(), null);
}
}