RabbitMQ入門（六）RabbitMQ交換器之fanout

前言

      本章講解RabbitMQ常用交換器的最後一個類型——fanout

方法

1.概念

fanout（廣播），顧名思義，其可以不依賴路由鍵，向所有綁定了的隊列發送消息。

廣播的含義就是將消息發送給所有訂閱該頻道的聽衆。

需求：我們的用戶下訂單之後，我們會做如下的兩步操作：發短信、推送訂單，在以前的模式上，我們下訂單的業務邏輯和發短信，推送訂單的邏輯是強耦合的，當我們使用RabbitMQ之後，情況將變得十分樂觀。我們可以爲發短信和推送訂單業務各設立一個隊列，當用戶下訂單的時候，會將消息同時傳遞給這兩個隊列，進而進行後續的發短信和推送訂單業務，實現解耦。

2.環境搭建

1）創建Provider和Consumer工程

2）修改pom文件

<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>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.1.7.RELEASE</version>
	</parent>
	<groupId>cn.edu.ccut</groupId>
	<artifactId>rabbitmq-fanout-consumer</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	
	<properties>
		<!-- 設定Java的版本 -->
		<java.version>1.8</java.version>
		<!-- 解決pom.xml首行報錯 -->
		<maven-jar-plugin.version>3.1.0</maven-jar-plugin.version>
	</properties>
	
	<dependencies>
		<!-- 配置springBoot的web啓動器 -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<!-- 配置rabbitmq的啓動器 -->
		<dependency>
		    <groupId>org.springframework.boot</groupId>
		    <artifactId>spring-boot-starter-amqp</artifactId>
		</dependency>
		<!-- 配置devtools  -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
		</dependency>
		<!-- 配置springBoot的test啓動器 -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
		</dependency>
	</dependencies>
	
	 <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <mainClass>cn.edu.ccut.App</mainClass>
                </configuration>
            </plugin>
        </plugins>
    </build>
    
</project>

3）修改application.properties

Provider：

spring.application.name=springboot-rabbitmq
#rabbitmq config
spring.rabbitmq.host=192.168.1.108
spring.rabbitmq.port=5672
spring.rabbitmq.username=jwang
spring.rabbitmq.password=123456

#exchange config
mq.config.exchange=order.fanout

Consumer：

spring.application.name=springboot-rabbitmq
#rabbitmq config
spring.rabbitmq.host=192.168.1.108
spring.rabbitmq.port=5672
spring.rabbitmq.username=jwang
spring.rabbitmq.password=123456

#exchange config
mq.config.exchange=order.fanout

mq.config.queue.sms=order.sms

mq.config.queue.push=order.push

3.編寫Consumer代碼

創建兩個Consumer類，PushConsumer和SmsConsumer來分別處理訂單的推送和短信功能

注意：廣播模式不需要路由鍵啦！

PushConsumer:

package cn.edu.ccut;

import org.springframework.amqp.core.ExchangeTypes;
import org.springframework.amqp.rabbit.annotation.Exchange;
import org.springframework.amqp.rabbit.annotation.Queue;
import org.springframework.amqp.rabbit.annotation.QueueBinding;
import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;

@Component
@RabbitListener(bindings=
		@QueueBinding(
				value=@Queue(name="${mq.config.queue.push}",autoDelete="true"),
				exchange=@Exchange(name="${mq.config.exchange}",type=ExchangeTypes.FANOUT)
		)
)
public class PushConsumer {

	@RabbitHandler
	public void receiveMsg(String msg){
		System.out.println("Push Message is "+msg);
	}
}

SmsConsumer：

package cn.edu.ccut;

import org.springframework.amqp.core.ExchangeTypes;
import org.springframework.amqp.rabbit.annotation.Exchange;
import org.springframework.amqp.rabbit.annotation.Queue;
import org.springframework.amqp.rabbit.annotation.QueueBinding;
import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;

@Component
@RabbitListener(bindings=
		@QueueBinding(
				value=@Queue(name="${mq.config.queue.sms}",autoDelete="true"),
				exchange=@Exchange(name="${mq.config.exchange}",type=ExchangeTypes.FANOUT)
		)
)
public class SmsConsumer {

	@RabbitHandler
	public void receiveMsg(String msg){
		System.out.println("Sms Message is "+msg);
	}
}

4.編寫Provider

Provider:

package cn.edu.ccut;

import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component
public class Provider {

	@Autowired
	private AmqpTemplate rabbitTemplate;
	@Value("${mq.config.exchange}")
	private String exchange;
	
	public void sendMsg(String msg){
		rabbitTemplate.convertAndSend(exchange, "", msg);
	}
}

注意：此處不需要傳遞路由鍵啦！

5.編寫測試代碼進行測試

package cn.edu.ccut;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest(classes=App.class)
public class RabbitMQTest {
	
	@Autowired
	private Provider provider;
	
	@Test
	public void testSendMsg() throws Exception{
		provider.sendMsg("hello rabbitmq !");
	}
}

接下來我們首先啓動消費者端：

再次運行我們測試代碼，觀察控制檯效果：

我們發現，SMS和Push端都接收到了消息，可見我們的測試是成功的。