RocketMQ延迟消息

1.代码

（1）生产者

package com.mq.rocket.delay;

import org.apache.rocketmq.client.exception.MQBrokerException;
import org.apache.rocketmq.client.exception.MQClientException;
import org.apache.rocketmq.client.producer.DefaultMQProducer;
import org.apache.rocketmq.client.producer.SendResult;
import org.apache.rocketmq.common.message.Message;
import org.apache.rocketmq.remoting.exception.RemotingException;

import java.util.concurrent.TimeUnit;

public class DelayProducer {
    public static void main(String[] args) throws MQClientException, MQBrokerException, RemotingException, InterruptedException {
        // 1.创建消息生产者producer，并指定生产者组名
        DefaultMQProducer producer = new DefaultMQProducer("group1");
        // 2.指定Nameserver地址
        producer.setNamesrvAddr("127.0.0.1:9876");
        producer.setSendMsgTimeout(5000);
        // 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
            /**
             * 参数说明：
             * 参数一：消息主题Topic
             * 参数二：消息Tag
             * 参数三：消息内容
             */
            Message msg = new Message("DELAY_TOPIC", "*", ("Hello RocketMQ"+i).getBytes());
            // 设置延迟时间
            msg.setDelayTimeLevel(2);
            // 5.发送消息
            SendResult result = producer.send(msg);
            System.out.println("发送结果：" + result);
            TimeUnit.SECONDS.sleep(1); // 线程睡1秒
        }

        // 6.关闭生产者producer
        producer.shutdown();
    }
}

（2）消费者

package com.mq.rocket.delay;

import org.apache.rocketmq.client.consumer.DefaultMQPushConsumer;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyContext;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
import org.apache.rocketmq.client.consumer.listener.MessageListenerConcurrently;
import org.apache.rocketmq.client.exception.MQClientException;
import org.apache.rocketmq.common.message.MessageExt;
import org.apache.rocketmq.common.protocol.heartbeat.MessageModel;

import java.util.List;

/**
 * 消息接收者
 */
public class DelayConsumer {
    public static void main(String[] args) throws MQClientException {
        // 1.创建消费者consumer，指定消费者组名
        DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("group1");
        // 2.指定Nameserver地址
        consumer.setNamesrvAddr("127.0.0.1:9876");
        // 设置超时
        consumer.setConsumeTimeout(5000);
        // 3.订阅主题topic和tag
        consumer.subscribe("DELAY_TOPIC", "*");
        // 4.设置回调函数,处理消息
        consumer.registerMessageListener(new MessageListenerConcurrently() {
            // 接收消息内容
            @Override
            public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> msgList, ConsumeConcurrentlyContext consumeConcurrentlyContext) {
                for (MessageExt msg:msgList) {
                    System.out.println("延迟消息：" + new String(msg.getBody()));
                }
                return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
            }
        });
        // 5.启动消费者consumer
        consumer.start();
    }
}

2.执行