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() {@Overridepublic ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> 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<Message> 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]