背景：

本文会介绍多种案例，教大家如何使用rocketmq。

一般rocketmq使用在微服务项目中，属于分模块使用。这里使用springboot单体项目来模拟使用。

本文以windows系统来做案例。

下载rocketmq和启动：

RocketMQ 在 windows 上运行 - 知乎 (zhihu.com)https://zhuanlan.zhihu.com/p/644944370

一、创建springboot项目

一直next进行下去就可以了。

二、pom文件依赖

   <dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>org.apache.rocketmq</groupId><artifactId>rocketmq-spring-boot-starter</artifactId><version>2.0.4</version></dependency><!-- 还有其它需要的jar包自由引入（注：fastjson不要使用低于1.2.60版本，会有安全漏洞） --><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.2.62</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency></dependencies>

三、代码实现

1.1目录结构

1.2生产者消费者解释

生产者：

什么是生产者？就比喻个简单的例子。比如我们要新增用户，那么这个新增保存动作可以认为是生产者，他产生了数据，要将数据保存进数据库。

消费者：

什么是消费者？就比喻个简单的例子。用户在新增的时候他会调用接口，用于保存到数据库，那么处理这个数据的方法你可以理解为消费者。不过在mq中，生产者是将消息发送到mq服务队列中，会根据主题Topic的不同，发往不同的频道。而消费者只需要监听这个Topic主题即可。只要这个topic有消息来了，那么消费者就会进行消费。后面代码里有详细的注释告知大家如何使用生产者和消费者。

1.3application.yml配置文件

# Tomcat
server:tomcat:uri-encoding: UTF-8max-threads: 1000min-spare-threads: 30servlet:context-path: /port: 8090rocketmq:name-server: 127.0.0.1:9876 # 访问地址producer:group: Pro_Group # 必须指定groupsend-message-timeout: 3000 # 消息发送超时时长，默认3sretry-times-when-send-failed: 3 # 同步发送消息失败重试次数，默认2retry-times-when-send-async-failed: 3 # 异步发送消息失败重试次数，默认2

1.4生产者服务

import com.alibaba.fastjson.JSON;
import com.example.rocketmqdemo.model.User;
import lombok.extern.slf4j.Slf4j;
import org.apache.rocketmq.client.producer.SendCallback;
import org.apache.rocketmq.client.producer.SendResult;
import org.apache.rocketmq.spring.core.RocketMQTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.messaging.support.MessageBuilder;
import org.springframework.stereotype.Component;
import org.springframework.util.CollectionUtils;import java.util.List;@Slf4j
@Component
public class MQProducerService {@Value("${rocketmq.producer.send-message-timeout}")private Integer messageTimeOut;// 建议正常规模项目统一用一个TOPICprivate static final String topic = "RLT_TEST_TOPIC";// 直接注入使用，用于发送消息到broker服务器@Autowiredprivate RocketMQTemplate rocketMQTemplate;/*** Tag：用于区分过滤同一主题下的不同业务类型的消息，非常实用* 普通发送（这里的参数对象User可以随意定义，可以发送个对象，也可以是字符串等）*/public void send(User user) {rocketMQTemplate.convertAndSend(topic + ":tag1", user);
//        rocketMQTemplate.send(topic + ":tag1", MessageBuilder.withPayload(user).build()); // 等价于上面一行}/*** 发送同步消息（阻塞当前线程，等待broker响应发送结果，这样不太容易丢失消息）* （msgBody也可以是对象，sendResult为返回的发送结果）*/public SendResult sendMsg(String msgBody) {SendResult sendResult = rocketMQTemplate.syncSend(topic, MessageBuilder.withPayload(msgBody).build());log.info("【sendMsg】sendResult={}", JSON.toJSONString(sendResult));return sendResult;}/*** 发送异步消息（通过线程池执行发送到broker的消息任务，执行完后回调：在SendCallback中可处理相关成功失败时的逻辑）* （适合对响应时间敏感的业务场景）*/public void sendAsyncMsg(String msgBody) {rocketMQTemplate.asyncSend(topic, MessageBuilder.withPayload(msgBody).build(), new SendCallback() {@Overridepublic void onSuccess(SendResult sendResult) {// 处理消息发送成功逻辑log.info("【sendMsg】sendResult={}", JSON.toJSONString(sendResult));}@Overridepublic void onException(Throwable throwable) {// 处理消息发送异常逻辑log.info("【sendMsg】sendResult={}", "发送异常" + throwable.getMessage());}});}/*** 发送延时消息（上面的发送同步消息，delayLevel的值就为0，因为不延时）* 在start版本中 延时消息一共分为18个等级分别为：1s 5s 10s 30s 1m 2m 3m 4m 5m 6m 7m 8m 9m 10m 20m 30m 1h 2h*/public void sendDelayMsg(String msgBody, int delayLevel) {rocketMQTemplate.syncSend(topic, MessageBuilder.withPayload(msgBody).build(), messageTimeOut, delayLevel);}/*** 发送单向消息（只负责发送消息，不等待应答，不关心发送结果，如日志）*/public void sendOneWayMsg(String msgBody) {rocketMQTemplate.sendOneWay(topic, MessageBuilder.withPayload(msgBody).build());}/*** 发送带tag的消息，直接在topic后面加上":tag"*/public SendResult sendTagMsg(String msgBody) {return rocketMQTemplate.syncSend(topic + ":tag2", MessageBuilder.withPayload(msgBody).build());}/**** 服务生产者，顺序消息* 把消息确保投递到同一条queue* 保证了消息的顺序性*/public void sendFIFOMsg(List<User> users) {//顺序消息//选择器规则构建rocketMQTemplate.setMessageQueueSelector((list, message, o) -> {int id = Integer.valueOf((String) o);int hash = (id % list.size());return list.get(hash);});if (!CollectionUtils.isEmpty(users)) {for (User user : users) {MessageBuilder.withPayload(users.toString()).build();rocketMQTemplate.sendOneWayOrderly(topic+":sendFIFOMsg", user, String.valueOf(user.getId()));}}}
}

1.5消费者服务

import com.alibaba.fastjson.JSON;
import com.example.rocketmqdemo.model.User;
import lombok.extern.slf4j.Slf4j;
import org.apache.rocketmq.common.message.MessageExt;
import org.apache.rocketmq.spring.annotation.ConsumeMode;
import org.apache.rocketmq.spring.annotation.RocketMQMessageListener;
import org.apache.rocketmq.spring.core.RocketMQListener;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;@Slf4j
@Component
public class MQConsumerService {// Tag：用于区分过滤同一主题下的不同业务类型的消息，非常实用// topic需要和生产者的topic一致，consumerGroup属性是必须指定的，内容可以随意// selectorExpression的意思指的就是tag，默认为“*”，不设置的话会监听所有消息@Service@RocketMQMessageListener(topic = "RLT_TEST_TOPIC", selectorExpression = "tag1", consumerGroup = "Con_Group_One")public class ConsumerSend implements RocketMQListener<User> {// 监听到消息就会执行此方法@Overridepublic void onMessage(User user) {log.info("tag1监听到消息：user={}", JSON.toJSONString(user));}}// 注意：这个ConsumerSend2和上面ConsumerSend在没有添加tag做区分时，不能共存，// 不然生产者发送一条消息，这两个都会去消费，如果类型不同会有一个报错，所以实际运用中最好加上tag，写这只是让你看知道就行@Service@RocketMQMessageListener(topic = "RLT_TEST_TOPIC", consumerGroup = "Con_Group_Two",selectorExpression = "xxx")public class ConsumerSend2 implements RocketMQListener<String> {@Overridepublic void onMessage(String str) {log.info("ConsumerSend2监听到消息：str={}", str);}}// MessageExt：是一个消息接收通配符，不管发送的是String还是对象，都可接收，当然也可以像上面明确指定类型（我建议还是指定类型较方便）@Service@RocketMQMessageListener(topic = "RLT_TEST_TOPIC", selectorExpression = "tag2", consumerGroup = "Con_Group_Three")public class Consumer implements RocketMQListener<MessageExt> {@Overridepublic void onMessage(MessageExt messageExt) {byte[] body = messageExt.getBody();String msg = new String(body);log.info("tag2监听到消息：msg={}", msg);}}/*** 消费者顺序消费消息* 顺序消费*/@Service@RocketMQMessageListener(consumerGroup = "Orderly-Consumer", topic = "RLT_TEST_TOPIC",selectorExpression = "sendFIFOMsg", consumeMode = ConsumeMode.ORDERLY)public class OrderlyConsumer implements RocketMQListener<MessageExt> {@Overridepublic void onMessage(MessageExt message) {System.out.println("线程"+Thread.currentThread()+"内容为:"+ new String(message.getBody())+"队列序号:"+message.getQueueId()+",消息msgId:"+message.getMsgId());}}
}

1.6User实体类

import lombok.Data;@Data
public class User {private String id;private String name;private Integer age;private String sex;private String desc;}

1.7开始调用生产者服务、消费者自动监听消费

import com.example.rocketmqdemo.model.User;
import com.example.rocketmqdemo.producer.MQProducerService;
import org.apache.rocketmq.client.producer.SendResult;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import java.util.ArrayList;
import java.util.List;@RestController
@RequestMapping("/rocketmq")
public class MqController {@Autowiredprivate MQProducerService mqProducerService;@GetMapping("/send")public void send() {User user = new User();user.setAge(28);user.setName("曹震");user.setSex("男");mqProducerService.send(user);}@GetMapping("/sendTag")public ResponseEntity<SendResult> sendTag() {SendResult sendResult = mqProducerService.sendTagMsg("带有tag的字符消息");return ResponseEntity.ok(sendResult);}@GetMapping("/sendMsg")public ResponseEntity<SendResult> sendMsg() {SendResult sendResult = mqProducerService.sendMsg("曹震测试");return ResponseEntity.ok(sendResult);}@GetMapping("/sendFIFOMsg")public void sendFIFOMsg() {List<User> users = new ArrayList<>();User user = new User();user.setId("1");user.setSex("男");user.setName("曹震");user.setAge(28);user.setDesc("创建订单");users.add(user);User user1 = new User();user1.setId("2");user1.setSex("男");user1.setName("贾耀旗");user1.setAge(25);user1.setDesc("创建订单");users.add(user1);User user2 = new User();user2.setId("1");user2.setSex("男");user2.setName("曹震");user2.setAge(28);user2.setDesc("订单付款");users.add(user2);User user3 = new User();user3.setId("1");user3.setSex("男");user3.setName("曹震");user3.setAge(28);user3.setDesc("订单完成");users.add(user3);User user4 = new User();user4.setId("1");user4.setSex("男");user4.setName("曹震");user4.setAge(28);user4.setDesc("订单推送");users.add(user4);User user5 = new User();user5.setId("2");user5.setSex("男");user5.setName("贾耀旗");user5.setAge(25);user5.setDesc("订单付款");users.add(user5);User user6 = new User();user6.setId("2");user6.setSex("男");user6.setName("贾耀旗");user6.setAge(25);user6.setDesc("订单完成");users.add(user6);mqProducerService.sendFIFOMsg(users);}}

1.8我们来启动服务，看下效果

我们以

@GetMapping("/sendFIFOMsg")
public void sendFIFOMsg() {} 这个方法进行测试。可以看出这里的代码其实是内容顺序是乱的，我们先看调用成功后的结果：

线程Thread[ConsumeMessageThread_3,5,main]内容为:{"id":"1","name":"曹震","age":28,"sex":"男","desc":"创建订单"}队列序号:1,消息msgId:A9FE29E30E3800DAD5DC7F03A485001C
2023-08-25 15:55:45.162  INFO 3640 --- [MessageThread_3] a.r.s.s.DefaultRocketMQListenerContainer : consume A9FE29E30E3800DAD5DC7F03A485001C cost: 1 ms
线程Thread[ConsumeMessageThread_4,5,main]内容为:{"id":"2","name":"贾耀旗","age":25,"sex":"男","desc":"创建订单"}队列序号:2,消息msgId:A9FE29E30E3800DAD5DC7F03A486001E
2023-08-25 15:55:45.164  INFO 3640 --- [MessageThread_4] a.r.s.s.DefaultRocketMQListenerContainer : consume A9FE29E30E3800DAD5DC7F03A486001E cost: 1 ms
线程Thread[ConsumeMessageThread_4,5,main]内容为:{"id":"2","name":"贾耀旗","age":25,"sex":"男","desc":"订单付款"}队列序号:2,消息msgId:A9FE29E30E3800DAD5DC7F03A4860026
2023-08-25 15:55:45.164  INFO 3640 --- [MessageThread_4] a.r.s.s.DefaultRocketMQListenerContainer : consume A9FE29E30E3800DAD5DC7F03A4860026 cost: 0 ms
线程Thread[ConsumeMessageThread_4,5,main]内容为:{"id":"2","name":"贾耀旗","age":25,"sex":"男","desc":"订单完成"}队列序号:2,消息msgId:A9FE29E30E3800DAD5DC7F03A4870028
2023-08-25 15:55:45.164  INFO 3640 --- [MessageThread_4] a.r.s.s.DefaultRocketMQListenerContainer : consume A9FE29E30E3800DAD5DC7F03A4870028 cost: 0 ms
线程Thread[ConsumeMessageThread_5,5,main]内容为:{"id":"1","name":"曹震","age":28,"sex":"男","desc":"订单付款"}队列序号:1,消息msgId:A9FE29E30E3800DAD5DC7F03A4860020
2023-08-25 15:55:45.164  INFO 3640 --- [MessageThread_5] a.r.s.s.DefaultRocketMQListenerContainer : consume A9FE29E30E3800DAD5DC7F03A4860020 cost: 0 ms
线程Thread[ConsumeMessageThread_5,5,main]内容为:{"id":"1","name":"曹震","age":28,"sex":"男","desc":"订单完成"}队列序号:1,消息msgId:A9FE29E30E3800DAD5DC7F03A4860022
2023-08-25 15:55:45.164  INFO 3640 --- [MessageThread_5] a.r.s.s.DefaultRocketMQListenerContainer : consume A9FE29E30E3800DAD5DC7F03A4860022 cost: 0 ms
线程Thread[ConsumeMessageThread_5,5,main]内容为:{"id":"1","name":"曹震","age":28,"sex":"男","desc":"订单推送"}队列序号:1,消息msgId:A9FE29E30E3800DAD5DC7F03A4860024
2023-08-25 15:55:45.164  INFO 3640 --- [MessageThread_5] a.r.s.s.DefaultRocketMQListenerContainer : consume A9FE29E30E3800DAD5DC7F03A4860024 cost: 0 ms

我们可以看到已经进行了消费操作，大家有没有看到同一个id的用户他们消费队列信息是一样的。