RocketMQ：批量消息

￡神魔★判官ぃ 2023-06-26 11:00 4阅读 0赞

\* 批量发送消息能显著提高传递小消息的性能。限制是这些批量消息应该有相同的topic，相同的waitStoreMsgOk，

\* 而且不能是延时消息。此外，这一批消息的总大小不应超过4MB

\* 如果超过4MB，这时候最好把消息进行分割

<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 MQClientException, RemotingException, InterruptedException, MQBrokerException {
            // 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();
    
            List<Message> msgs = new ArrayList<Message>();
            // 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 msg1 = new Message("batchTopic","tag1",("hello world"+1).getBytes());
            Message msg2 = new Message("batchTopic","tag1",("hello world"+2).getBytes());
            Message msg3 = new Message("batchTopic","tag1",("hello world"+2).getBytes());
            msgs.add(msg1);
            msgs.add(msg2);
            msgs.add(msg3);
            // 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(msgs);
            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("batchTopic","*");
            // 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(new String(messageExt.getBody()));
                    }
                    return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
                }
            });
            // 5.启动消费者consumer
            consumer.start();
            System.out.println("消费者启动");
        }
    }