系列十、Java操作RocketMQ之批量消息

一、概述

        RocketMQ可以一次性发送一组消息，那么这一组消息会被当做一个消息进行消费。

二、案例代码

2.1、pom

        同系列五

2.2、RocketMQConstant

        同系列五

2.3、BatchConsumer

package org.star.batch.consumer;

import cn.hutool.core.util.StrUtil;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.collections4.CollectionUtils;
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.common.message.MessageExt;
import org.star.constants.RocketMQConstant;

import java.util.List;

/**
 * @Author: 一叶浮萍归大海
 * @Date: 2023/8/30 09:40
 * @Description: 批量消息消费者
 */
@Slf4j
public class BatchConsumer {

    public static void main(String[] args) throws Exception {
        DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("BatchConsumerGroup");
        consumer.setNamesrvAddr(RocketMQConstant.NAME_SERVER_ADDR);
        consumer.subscribe("BatchTopic","*");
        consumer.setMessageListener(new MessageListenerConcurrently() {
            @Override
            public ConsumeConcurrentlyStatus consumeMessage(List list, ConsumeConcurrentlyContext context) {
                if (CollectionUtils.isNotEmpty(list)) {
                    String body = StrUtil.utf8Str(list.get(0).getBody());
                    log.info(Thread.currentThread().getName() + " 收到消息 body:{}",body);
                }
                return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
            }
        });
        consumer.start();
        log.info("BatchConsumer start success!");
    }

}

2.4、BatchProducer

package org.star.batch.producer;

import com.alibaba.fastjson.JSON;
import lombok.extern.slf4j.Slf4j;
import org.apache.rocketmq.client.producer.DefaultMQProducer;
import org.apache.rocketmq.client.producer.SendResult;
import org.apache.rocketmq.common.message.Message;
import org.star.constants.RocketMQConstant;

import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;

/**
 * @Author: 一叶浮萍归大海
 * @Date: 2023/8/30 09:31
 * @Description: 批量消息生产者
 * 批量消息是指将多条消息合并成一个批量消息，一次发送出去，这样的好处是可以减少网络IO，提升吞吐量。
 * 注意事项：
 * 1、消息大小不能超过4MB，虽然源码注释不能超过1MB，但是实际使用不超过4MB即可，建议保持在1MB左右
 * 2、相同的Topic
 * 3、相同的waitStoreMsgOK
 * 4、不能是延迟消息，事务消息等
 */
@Slf4j
public class BatchProducer {

    public static void main(String[] args) throws Exception {
        DefaultMQProducer producer = new DefaultMQProducer("BatchProducerGroup");
        producer.setNamesrvAddr(RocketMQConstant.NAME_SERVER_ADDR);
        producer.start();
        log.info("BatchProducer start success");
        List messages = new ArrayList<>();
        for (int i = 0; i < 3; i++) {
            Message message = new Message("BatchTopic", ("我是批量消息，消息编号[" + i + "]").getBytes(StandardCharsets.UTF_8));
            messages.add(message);
        }
        SendResult result = producer.send(messages);
        log.info("BatchProducer sendStatus:{},queueId:{},msgId:{}", result.getSendStatus(), result.getMessageQueue().getQueueId(), result.getMsgId());
        producer.shutdown();
    }

}

2.5、控制台打印

# 生产者端
22:49:44.236 [main] INFO org.star.batch.producer.BatchProducer - BatchProducer start success
22:49:45.625 [main] INFO org.star.batch.producer.BatchProducer - BatchProducer sendStatus:SEND_OK,queueId:0,msgId:C0A81FB287E018B4AAC20F32C5870000,C0A81FB287E018B4AAC20F32C5880001,C0A81FB287E018B4AAC20F32C5880002

# 消费者端
22:47:20.127 [main] INFO org.star.batch.consumer.BatchConsumer - BatchConsumer start success!
22:49:45.644 [ConsumeMessageThread_2] INFO org.star.batch.consumer.BatchConsumer - ConsumeMessageThread_2 收到消息 body:我是批量消息，消息编号[1]
22:49:45.644 [ConsumeMessageThread_3] INFO org.star.batch.consumer.BatchConsumer - ConsumeMessageThread_3 收到消息 body:我是批量消息，消息编号[2]
22:49:45.644 [ConsumeMessageThread_1] INFO org.star.batch.consumer.BatchConsumer - ConsumeMessageThread_1 收到消息 body:我是批量消息，消息编号[0]