@Override
        public RocketMQLocalTransactionState checkLocalTransaction(Message msg) {
            System.out.printf("ExtTransactionListenerImpl checkLocalTransaction and return COMMIT. \n");
            return RocketMQLocalTransactionState.COMMIT;
        }
Producer, using RocketMQTemplate sends a variety of messages
rocketmq-spring-boot-samples/rocketmq-produce-demo/src/main/java/org/apache/rocketmq/samples/springboot/ProducerApplication.java