• Topic类型的Exchange与Direct相比，都是可以根据RoutingKey把消息路由到不同的队列。只不过Topic类型Exchange可以让队列在绑定Routing key 的时候使用通配符！

• Routingkey 一般都是有一个或多个单词组成，多个单词之间以”.”分割，例如： item.insert

通配符规则：

• #：匹配一个或多个词

• *：匹配不多不少恰好1个词

举例：

• item.#：能够匹配item.spu.insert 或者 item.spu

• item.*：只能匹配item.spu

解释：

• Queue1：绑定的是china.# ，因此凡是以 china.开头的routing key 都会被匹配到。包括china.news和china.weather
• Queue2：绑定的是#.news ，因此凡是以 .news结尾的 routing key 都会被匹配。包括china.news和japan.news

举例:

public_topic 消息生产者

@RunWith(SpringRunner.class)
@SpringBootTest
public class TestMqTopic {@Autowiredprivate RabbitTemplate rabbitTemplate;@Testpublic void testTopic1(){//发送的目标交换机String exchange = "itcast.topic";String message="我王二天下无敌1";rabbitTemplate.convertAndSend(exchange,"china.RAP",message);}@Testpublic void testTopic2(){//发送的目标交换机String exchange = "itcast.topic";String message="我王二天下无敌2";rabbitTemplate.convertAndSend(exchange,"yangshi.news",message);}@Testpublic void testTopic3(){//发送的目标交换机String exchange = "object.json";Student stu = new Student("王二", 1, new String[]{"sing", "dance", "rap"});rabbitTemplate.convertAndSend(exchange,"china.json",stu);}
}

配置

spring:rabbitmq:host: 192.168.23.130port: 5672username: itcastpassword: 123321virtual-host: /

consumer_topic 消息消费者

@Component
public class SpringRabbitListener {//- Topic交换机接收的消息RoutingKey必须是多个单词，以 `**.**` 分割//- Topic交换机与队列绑定时的bindingKey可以指定通配符//- `#`：代表0个或多个词//- `*`：代表1个词@RabbitListener(bindings = @QueueBinding(value = @Queue("topicQueue1"),exchange = @Exchange(value = "itcast.topic",type = ExchangeTypes.TOPIC),key = {"china.#"}))public void listenerTopicQueue1(String msg){System.out.println("topicQueue1接收的消息为"+msg);}@RabbitListener(bindings = @QueueBinding(value = @Queue("topicQueue2"),exchange = @Exchange(value = "itcast.topic",type = ExchangeTypes.TOPIC),key = {"#.news"}))public void listenerTopicQueue2(String msg){System.out.println("topicQueue2接收的消息为"+msg);}@RabbitListener(bindings = @QueueBinding(value = @Queue("topicQueue3"),exchange = @Exchange(value = "object.json",type = ExchangeTypes.TOPIC),key = {"#.json"}))public void listenerTopicQueue3(Student msg){System.out.println("topicQueue3接收的对象为"+msg);}
}

启动类配置对象转化可在可视化界面查看

@SpringBootApplication
public class MqTopicApplication {public static void main(String[] args) {SpringApplication.run(MqTopicApplication.class);}//配置消息转换器@Beanpublic MessageConverter jsonMessageConverter(){return new Jackson2JsonMessageConverter();}
}

配置

spring:rabbitmq:host: 192.168.23.130port: 5672username: itcastpassword: 123321virtual-host: /

所需依赖

<!--AMQP依赖，包含RabbitMQ-->
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-amqp</artifactId>
</dependency><!--json转化依赖--><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId></dependency>

父依赖

    <parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.3.9.RELEASE</version><relativePath/></parent><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target></properties><!--AMQP依赖，包含RabbitMQ--><dependencies><!--json转化依赖--><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency><!--AMQP依赖，包含RabbitMQ--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-amqp</artifactId></dependency><!--单元测试--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId></dependency></dependencies>