面试官：小伙子，你给我简单说一下RocketMQ 整合 Spring Boot吧

前言

在使用SpringBoot的starter集成包时，要特别注意版本。因为SpringBoot集成RocketMQ的starter依赖是由Spring社区提供的，目前正在快速迭代的过程当中，不同版本之间的差距非常大，甚至基础的底层对象都会经常有改动。例如如果使用rocketmq-spring-boot-starter:2.0.4版本开发的代码，升级到目前最新的rocketmq-spring-boot-starter:2.1.1后，基本就用不了了

应用结构

TestController: 测试入口, 有基本消息测试和事务消息测试
TopicListener: 是监听"topic"这个主题的普通消息监听器
TopicTransactionListener: 是监听"topic"这个主题的事务消息监听器, 和TopicTransactionRocketMQTemplate绑定(一一对应关系)
Customer: 是测试消息体的一个entity对象
TopicTransactionRocketMQTemplate: 是扩展自RocketMQTemplate的另一个RocketMQTemplate, 专门用来处理某一个业务流程, 和TopicTransactionListener绑定(一一对应关系)

pom.xml

org.apache.rocketmq:rocketmq-spring-boot-starter:2.1.1, 引用的springboot版本是2.0.5.RELEASE

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.mrathena.middle.ware</groupId>
    <artifactId>rocket.mq.springboot</artifactId>
    <version>1.0.0</version>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>2.4.0</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.30</version>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.rocketmq</groupId>
            <artifactId>rocketmq-spring-boot-starter</artifactId>
            <version>2.1.1</version>
            <!-- 屏蔽旧版本的springboot, 引用的springboot版本是2.0.5.RELEASE -->
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-core</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-webmvc</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-aop</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-context</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-messaging</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.fasterxml.jackson.core</groupId>
                    <artifactId>jackson-databind</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <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>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-messaging</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.9.2</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.9.2</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

application.yml

server:
  servlet:
    context-path:
  port: 80
rocketmq:
  name-server: 116.62.162.48:9876
  producer:
    group: producer

Customer

package com.mrathena.rocket.mq.entity;

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;

@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
public class Customer {
	private String username;
	private String nickname;
}

生产者 TestController

package com.mrathena.rocket.mq.controller;

import com.mrathena.rocket.mq.configuration.TopicTransactionRocketMQTemplate;
import com.mrathena.rocket.mq.entity.Customer;
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.messaging.Message;
import org.springframework.messaging.MessageHeaders;
import org.springframework.messaging.core.MessagePostProcessor;
import org.springframework.messaging.support.MessageBuilder;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.HashMap;
import java.util.Map;

@Slf4j
@RestController
@RequestMapping("test")
public class TestController {

	private static final String TOPIC = "topic";

	@Autowired
	private RocketMQTemplate rocketMQTemplate;
	@Autowired
	private TopicTransactionRocketMQTemplate topicTransactionRocketMQTemplate;

	@GetMapping("base")
	public Object base() {
		// destination: topic/topic:tag, topic或者是topic拼接tag的整合体
		// payload: 荷载即消息体
		// message: org.springframework.messaging.Message, 是Spring自己封装的类, 和RocketMQ的Message不是一个类, 里面没有tags/keys等内容
		rocketMQTemplate.send(TOPIC, MessageBuilder.withPayload("你好").setHeader("你是谁", "你猜").build());
		// tags null
		rocketMQTemplate.convertAndSend(TOPIC, "tag null");
		// tags empty, 证明 tag 要么有值要么null, 不存在 empty 的 tag
		rocketMQTemplate.convertAndSend(TOPIC + ":", "tag empty ?");
		// 只有 tag 没有 key
		rocketMQTemplate.convertAndSend(TOPIC + ":a", "tag a");
		rocketMQTemplate.convertAndSend(TOPIC + ":b", "tag b");
		// 有 property, 即 RocketMQ 基础 API 里面, Message(String topic, String tags, String keys, byte[] body) 里面的 key
		// rocketmq-spring-boot-starter 把 userProperty 和其他的一些属性都糅合在 headers 里面可, 具体可以参考 org.apache.rocketmq.spring.support.RocketMQUtil.addUserProperties
		// 获取某个自定义的属性的时候, 直接 headers.get("自定义属性key") 就可以了
		Map<String, Object> properties = new HashMap<>();
		properties.put("property", 1);
		properties.put("another-property", "你好");
		rocketMQTemplate.convertAndSend(TOPIC, "property 1", properties);
		rocketMQTemplate.convertAndSend(TOPIC + ":a", "tag a property 1", properties);
		rocketMQTemplate.convertAndSend(TOPIC + ":b", "tag b property 1", properties);
		properties.put("property", 5);
		rocketMQTemplate.convertAndSend(TOPIC, "property 5", properties);
		rocketMQTemplate.convertAndSend(TOPIC + ":a", "tag a property 5", properties);
		rocketMQTemplate.convertAndSend(TOPIC + ":c", "tag c property 5", properties);

		// 消息后置处理器, 可以在发送前对消息体和headers再做一波操作
		rocketMQTemplate.convertAndSend(TOPIC, "消息后置处理器", new MessagePostProcessor() {
			/**
			 * org.springframework.messaging.Message
			 */
			@Override
			public Message<?> postProcessMessage(Message<?> message) {
				Object payload = message.getPayload();
				MessageHeaders messageHeaders = message.getHeaders();
				return message;
			}
		});

		// convertAndSend 底层其实也是 syncSend
		// syncSend
		log.info("{}", rocketMQTemplate.syncSend(TOPIC, "sync send"));
		// asyncSend
		rocketMQTemplate.asyncSend(TOPIC, "async send", new SendCallback() {
			@Override
			public void onSuccess(SendResult sendResult) {
				log.info("onSuccess");
			}

			@Override
			public void onException(Throwable e) {
				log.info("onException");
			}
		});
		// sendOneWay
		rocketMQTemplate.sendOneWay(TOPIC, "send one way");

		// 这个我还是不太清楚是干嘛的? 跑的时候会报错!!!
//		Object receive = rocketMQTemplate.sendAndReceive(TOPIC, "你好", String.class);
//		log.info("{}", receive);

		return "success";
	}

	@GetMapping("transaction")
	public Object transaction() {
		Message<Customer> message = MessageBuilder.withPayload(new Customer("mrathena", "你是谁")).build();
		// 这里使用的是通过 @ExtRocketMQTemplateConfiguration(group = "anotherProducer") 扩展出来的另一个 RocketMQTemplate
		log.info("{}", topicTransactionRocketMQTemplate.sendMessageInTransaction(TOPIC, message, null));
		log.info("{}", topicTransactionRocketMQTemplate.sendMessageInTransaction(TOPIC + ":tag-a", message, null));
		return "success";
	}

}

配置 TopicTransactionRocketMQTemplate

package com.mrathena.rocket.mq.configuration;

import org.apache.rocketmq.spring.annotation.ExtRocketMQTemplateConfiguration;
import org.apache.rocketmq.spring.core.RocketMQTemplate;

/**
 * 一个事务流程和一个RocketMQTemplate需要一一对应
 * 可以通过 @ExtRocketMQTemplateConfiguration(注意该注解有@Component注解) 来扩展多个 RocketMQTemplate
 * 注意: 不同事务流程的RocketMQTemplate的producerGroup不能相同
 * 因为MQBroker会反向调用同一个producerGroup下的某个checkLocalTransactionState方法, 不同流程使用相同的producerGroup的话, 方法可能会调用错
 */
@ExtRocketMQTemplateConfiguration(group = "anotherProducer")
public class TopicTransactionRocketMQTemplate extends RocketMQTemplate {}

消费者 TopicListener

package com.mrathena.rocket.mq.listener;

import lombok.extern.slf4j.Slf4j;
import org.apache.rocketmq.spring.annotation.ConsumeMode;
import org.apache.rocketmq.spring.annotation.MessageModel;
import org.apache.rocketmq.spring.annotation.RocketMQMessageListener;
import org.apache.rocketmq.spring.core.RocketMQListener;
import org.springframework.stereotype.Component;

/**
 * 最简单的消费者例子
 * topic: 主题
 * consumerGroup: 消费者组
 * selectorType: 过滤方式, TAG:标签过滤,仅支持标签, SQL92:SQL过滤,支持标签和属性
 * selectorExpression: 过滤表达式, 根据selectorType定, TAG时, 写标签如 "a || b", SQL92时, 写SQL表达式
 * consumeMode: CONCURRENTLY:并发消费, ORDERLY:顺序消费
 * messageModel: CLUSTERING:集群竞争消费, BROADCASTING:广播消费
 */
@Slf4j
@Component
@RocketMQMessageListener(topic = "topic",
		// 只过滤tag, 不管headers中的key和value
//		selectorType = SelectorType.TAG,
		// 必须指定selectorExpression, 可以过滤tag和headers中的key和value
//		selectorType = SelectorType.SQL92,
		// 不限tag
//		selectorExpression = "*",
		// 不限tag, 和 * 一致
//		selectorExpression = "",
		// 只要tag为a的消息
//		selectorExpression = "a",
		// 要tag为a或b的消息
//		selectorExpression = "a || b",
		// SelectorType.SQL92时, 可以跳过tag, 直接用headers里面的key和value来判断
//		selectorExpression = "property = 1",
		// tag不为null
//		selectorExpression = "TAGS is not null",
		// tag为empty, 证明tag不会是empty, 要么有值要么null
//		selectorExpression = "TAGS = ''",
		// SelectorType.SQL92时, 即过滤tag, 又过滤headers里面的key和value
//		selectorExpression = "(TAGS is not null and TAGS = 'a') and (property is not null and property between 4 and 6)",
		// 并发消费
		consumeMode = ConsumeMode.CONCURRENTLY,
		// 顺序消费
//		consumeMode = ConsumeMode.ORDERLY,
		// 集群消费
		messageModel = MessageModel.CLUSTERING,
		// 广播消费
//		messageModel = MessageModel.BROADCASTING,
		consumerGroup = "consumer"
)
public class TopicListener implements RocketMQListener<String> {
	public void onMessage(String s) {
		log.info("{}", s);
	}
}

消费者 TopicTransactionListener

package com.mrathena.rocket.mq.listener;

import lombok.extern.slf4j.Slf4j;
import org.apache.rocketmq.spring.annotation.RocketMQTransactionListener;
import org.apache.rocketmq.spring.core.RocketMQLocalTransactionListener;
import org.apache.rocketmq.spring.core.RocketMQLocalTransactionState;
import org.apache.rocketmq.spring.support.RocketMQHeaders;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHeaders;
import org.springframework.stereotype.Component;

@Slf4j
@Component
@RocketMQTransactionListener(rocketMQTemplateBeanName = "topicTransactionRocketMQTemplate")
public class TopicTransactionListener implements RocketMQLocalTransactionListener {

	@Override
	public RocketMQLocalTransactionState executeLocalTransaction(Message message, Object o) {
		// message: org.springframework.messaging.Message, 是Spring自己封装的类, 和RocketMQ的Message不是一个类, 里面没有tags/keys等内容
		// 一般来说, 并不会在这里处理tags/keys等内容, 而是根据消息体中的某些字段做不同的操作, 第二个参数也可以用来传递一些数据到这里
		log.info("executeLocalTransaction message:{}, object:{}", message, o);
		log.info("payload: {}", new String((byte[]) message.getPayload()));
		MessageHeaders headers = message.getHeaders();
		log.info("tags: {}", headers.get(RocketMQHeaders.PREFIX + RocketMQHeaders.TAGS));
		log.info("rocketmq_TOPIC: {}", headers.get("rocketmq_TOPIC"));
		log.info("rocketmq_QUEUE_ID: {}", headers.get("rocketmq_QUEUE_ID"));
		log.info("rocketmq_MESSAGE_ID: {}", headers.get("rocketmq_MESSAGE_ID"));
		log.info("rocketmq_TRANSACTION_ID: {}", headers.get("rocketmq_TRANSACTION_ID"));
		log.info("TRANSACTION_CHECK_TIMES: {}", headers.get("TRANSACTION_CHECK_TIMES"));
		log.info("id: {}", headers.get("id"));
		return RocketMQLocalTransactionState.UNKNOWN;
	}

	@Override
	public RocketMQLocalTransactionState checkLocalTransaction(Message message) {
		log.info("checkLocalTransaction message:{}", message);
		// 在调用了checkLocalTransaction后, 另一个常规消息监听器才能收到消息
		return RocketMQLocalTransactionState.COMMIT;
	}
}

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