rocketMQ中事务发送消息

rocketMQ中有关事务的发送消息方式，写的一个demo

1、在MyProducer类中的方法，即先定义调用

@Component
public class MyProducer {

    @Autowired
    private RocketMQTemplate template;
public void sendTractionMessage(String topic, String msg) throws InterruptedException {
        String[] tags = new String[]{"TagA","TagB","TagC","TagD","TagE"};   //这里的tag是标签，具体使用的时候，可以自行根据规则赋值，可以是订单编号
        for (int i = 0; i < 10; i++) {     //这个10也是demo时候用的，实际使用可以根据具体需求
            Message<String> message = MessageBuilder.withPayload(msg).build();
            String destination = topic + ":" + tags[i % tags.length];  //这里是取模
            TransactionSendResult transactionSendResult = template.sendMessageInTransaction(destination, message, destination);
            System.out.println("transactionSendResult = " + transactionSendResult);
           
        }
    }

}

2、监听MyTransactionListener这个类作用是对不同tag的处理方式

@RocketMQTransactionListener(rocketMQTemplateBeanName = "rocketMQTemplate")  //使用rocketMQTemplate
public class MyTransactionListener implements RocketMQLocalTransactionListener {  //需要实现该类


    @Override
    public RocketMQLocalTransactionState executeLocalTransaction(Message msg, Object o) {
        String destination = (String) o;
        org.apache.rocketmq.common.message.Message message = RocketMQUtil.convertToRocketMessage(
                new StringMessageConverter(),
                String.valueOf(StandardCharsets.UTF_8),
                destination,
                msg
        );
        String tags = message.getTags();
        if (StringUtils.contains(tags,"TagA")){   //对于不同的tag标签，返回不同的状态，rocketMQ会根据状态来决定两阶段提交的第二阶段决定消息是提交还是放弃
            return RocketMQLocalTransactionState.COMMIT;
        }else if (StringUtils.contains(tags,"TagB")){
            return RocketMQLocalTransactionState.ROLLBACK;
        }else {
            return RocketMQLocalTransactionState.UNKNOWN;
        }
    }

    @Override
    public RocketMQLocalTransactionState checkLocalTransaction(Message message) {
        return null;
    }
}

3、使用测试类测试

    @Test
    void testSendTransactionMessage() throws InterruptedException {
        String topic = "my-boot-topic";
        String message = "hello rocket mq transaction springboot message";
        myProducer.sendTractionMessage(topic,message);
        System.out.println("事务消息发送成功~");
    }

4、消费端消费情况，demo中循环是10，但只有2条被消费者接收处理，就是那TagA的两条数据，因为他们的状态是commit