RocketMQ：延时消息-蒲公英云

RocketMQ：延时消息

<dependency>
     <groupId>org.apache.rocketmq</groupId>
     <artifactId>rocketmq-client</artifactId>
     <version>4.4.0</version>
</dependency>

生产者

public class Producer {
    public static void main(String[] args) throws Exception {
        // 1.创建消息生产者producer，并制定生产者组名
        DefaultMQProducer producer = new DefaultMQProducer("group1");
        // 2.指定NameServer地址
        producer.setNamesrvAddr("localhost:9876");
        // 3.启动producer
        producer.start();
        for (int i = 0; i < 10; i++) {
            // 4.创建消息对象，指定主题Topic、Tag和消息体
            /*
            参数1：消息主题Topic
            参数2：消息Tag
            参数3：消息内容
             */
            Message msg = new Message("DelayTopic","tag1",("hello world"+i).getBytes());
            // 设置延迟时间 RocketMq并不支持任意时间的延时，需要试着几个固定的延时等级
            // 从1s到2h分别对应着等级1到18  1s 5s 10s 30s 1m 2m 3m 4m 5m 6m 7m 8m 9m 10m 20m 30m 1h 2h
            msg.setDelayTimeLevel(2);
            // 5.发送消息结果包含  发送状态  消息id 消息接收队列id等
            SendResult result = producer.send(msg);
            System.out.println("发送结果"+result);
            // 线程睡眠1秒
            TimeUnit.SECONDS.sleep(1);
        }
        // 6关闭生产者producer
        producer.shutdown();
    }
}

消费者

public class Consumer {
    public static void main(String[] args) throws MQClientException {
        // 1.创建消费者Consumer，制定消费者组名
        DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("group1");
        // 2.指定Nameserver地址
        consumer.setNamesrvAddr("localhost:9876");
        // 3.订阅主题Topic和Tag
        consumer.subscribe("DelayTopic","tag1");
        // 消费模式：默认是负载均衡模式，还有一种是广播模式
//        consumer.setMessageModel(MessageModel.BROADCASTING);
        // 4.设置回调函数，处理消息
        consumer.registerMessageListener(new MessageListenerConcurrently() {
            //接收消息内容
            public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> list, ConsumeConcurrentlyContext consumeConcurrentlyContext) {
                for (MessageExt messageExt : list) {
                    System.out.println("消息id：【"+messageExt.getMsgId()+"】，延时时间："+(System.currentTimeMillis()-messageExt.getStoreTimestamp()));
                }
                return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
            }
        });
        // 5.启动消费者consumer
        consumer.start();
        System.out.println("消费者启动");
    }
}