RocketMq的简单demo

首先要确定RocketMq安装成功，环境配置ok，并且启动了。

参考：Rocketmq安装与环境配置_小小舍的博客-CSDN博客

依赖：

            org.apache.rocketmq
            rocketmq-client
            4.3.0
        

生产者：

package com.xxs.rocketmqdemo.rocket;


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 java.util.Date;

/**
 * Created by xxs on 2021/12/15 18:16
 *
 * @Description
 */
public class Producer {
    public static void main(String[] args) throws MQClientException {
        //创建一个消息生产者，传入的是消息组名称
        DefaultMQProducer producer = new DefaultMQProducer("rmq-group");
        //输入nameserver服务的地址
        producer.setNamesrvAddr("127.0.0.1:9876");
        producer.setInstanceName("producer");
        //启动生产者
        producer.start();
        try {
            for (int i = 0; i < 10; i++) {
                Thread.sleep(1000);  //每秒发送一次MQ
                //创建消息
                Message msg = new Message("Topic-test",// topic
                        "testTag",// tag
                        (new Date() + " RocketMQ test msg " + i).getBytes()// body
                );

                //发送，返回结果对象
                SendResult sendResult = producer.send(msg);

                System.out.println(sendResult.getMsgId()); //消息id
                System.out.println(sendResult.getMessageQueue()); //队列信息
                System.out.println(sendResult.getSendStatus());  //发送结果
                System.out.println(sendResult.getOffsetMsgId()); //下一个要消费的消息的偏移量
                System.out.println(sendResult.getQueueOffset());  //队列消息偏移量
                System.out.println();
                System.out.println("================================================");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        producer.shutdown();
    }

}

消费者：

package com.xxs.rocketmqdemo.rocket;



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 java.util.List;

/**
 * Created by xxs on 2021/12/15 18:15
 *
 * @Description
 */
public class Consumer {

    public static void main(String[] args) throws MQClientException {
        DefaultMQPushConsumer consumer = new DefaultMQPushConsumer(
                "rmq-group");

        consumer.setNamesrvAddr("127.0.0.1:9876");
        consumer.setInstanceName("consumer");
        //订阅某个主题，然后使用tag过滤消息，不过滤可以用*代表
        consumer.subscribe("Topic-test", "testTag");

        //注册监听回调实现类来处理broker推送过来的消息,MessageListenerConcurrently是并发消费
        consumer.registerMessageListener(new MessageListenerConcurrently() {
            @Override
            public ConsumeConcurrentlyStatus consumeMessage(List messages, ConsumeConcurrentlyContext context) {
                for (MessageExt msg : messages) {
                    System.out.println(msg.getMsgId() + " ===== " + new String(msg.getBody()));
                }
                return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
            }
        });
        consumer.start();//消费者启动完成
        System.out.println("Consumer Started.");
    }

}

遇到问题：

运行报错：No route info of this topic

解决：依赖的版本要和本地rocketmq一致