一、 Direct模式

类型：direct
特点：Direct模式是fanout模式上的一种叠加，增加了路由RoutingKey的模式。

二、coding

Ⅰ 生产者

1、引入相应的pom文件 pom.xml

<?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 https://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>2.1.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.xpf</groupId>
    <artifactId>rabbitmq-springboot</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>rabbitmq-springboot</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>8</java.version>
    </properties>
    <dependencies>
        <!--rabbitmq依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-amqp</artifactId>
        </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>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.amqp</groupId>
            <artifactId>spring-rabbit-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter</artifactId>
            <version>RELEASE</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
 
            <scope>test</scope>
        </dependency>
    </dependencies>
 
 
</project>

2、配置文件 application.properties

server.port=8080
spring.rabbitmq.username=admin
spring.rabbitmq.password=admin
spring.rabbitmq.virtual-host=/
spring.rabbitmq.host=192.168.199.20
spring.rabbitmq.port=5672

3、写一个生产者 DirectOrderService.java

import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.UUID;

@Service
public class DirectOrderService {
    @Autowired
    private RabbitTemplate rabbitTemplate;

    /**
     * 模拟用户下单，发送消息给下游系统
     * @param user
     * @param num
     */
    public void makerOrder(String user,  int num){
        //1、查询库存是否有剩余
        //2、保存订单
        String orderId = UUID.randomUUID().toString();
        System.out.println("订单生产成功：" + orderId);
        //3、通过mq给下游系统发送消息
        String exchangeName = "direct_order_exchange";
        rabbitTemplate.convertAndSend(exchangeName, "sms", orderId);
        rabbitTemplate.convertAndSend(exchangeName, "email", orderId);
        System.out.println("完成");
    }
}

（从代码中可以看到，direct_order_exchange交换机分别给绑定的路由key为sms和email的消息队列发送了消息）

4、写一个测试类，发送消息

import com.xpf.rabbitmqspringboot.service.DirectOrderService;
import com.xpf.rabbitmqspringboot.service.FanoutOrderService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class RabbitmqSpringbootApplicationTests {

    @Autowired
    private FanoutOrderService fanoutOrderService;

    @Autowired
    private DirectOrderService directOrderService;

    /**
     * Direct模式生产者发送消息
     */
    @Test
    public void setDirectOrderService(){
        directOrderService.makerOrder("用户2", 10);
    }
}

（先别启动测试类，因为交换机和队列的声明放在下面的消费者中。）

Ⅱ 消费者

1、新建一个springboot项目，其中pom.xml 和 application.properties和上述生产者文件相同，但是如果在一个电脑模拟同启动两个项目时，记得把application.properties中的端口换成不同的

2、使用springboot写一个配置文件 RabbitMqConfiguration.java

关于为啥在消费者中建配置文件而不是在生产者，请看rabbitmq使用springboot实现fanout模式_p＆f°的博客-CSDN博客

import org.springframework.amqp.core.*;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class RabbitMqConfiguration {

    //1、声明注册Direct模式交换机
    @Bean
    public DirectExchange DirectExchange(){
        return new DirectExchange("direct_order_exchange", true, false);
    }

    //2、声明队列 sms.Direct.queue、email.Direct.queue、duanxin.Direct.queue
    @Bean
    public Queue smsQueue(){
        return new Queue("sms.direct.queue", true);
    }

    @Bean
    public Queue emailQueue(){
        return new Queue("email.direct.queue", true);
    }

    @Bean
    public Queue duanxinQueue(){
        return new Queue("duanxin.direct.queue", true);
    }

    //3、完成绑定关系（队列绑定交换机）
    @Bean
    public Binding smsBinding(){
        return BindingBuilder.bind(smsQueue()).to(DirectExchange()).with("sms");
    }

    @Bean
    public Binding emailBinding(){
        return BindingBuilder.bind(emailQueue()).to(DirectExchange()).with("email");
    }

    @Bean
    public Binding duanxinBinding(){
        return BindingBuilder.bind(duanxinQueue()).to(DirectExchange()).with("duanxin");
    }
}

3、写三个消费者分别监听路由key为sms、email、duanxin的消息队列

（这里举例两个 SmsDirectConsumer.java 和 EmailDirectConsumer.java）

import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;

/**
 * @Author xpf
 * @Date 2023/7/9 1:27
 * @Version 1.0
 */
@Component
@RabbitListener(queues = "sms.direct.queue")
public class SmsDirectConsumer {

    @RabbitHandler
    public void receiveMessage(String message){
        System.out.println("接收到来自队列sms.direct.queue消息订单的message是：" + message);
    }
}

import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;

/**
 * @Author xpf
 * @Date 2023/7/9 1:27
 * @Version 1.0
 */
@Component
@RabbitListener(queues = "email.direct.queue")
public class EmailDirectConsumer {

    @RabbitHandler
    public void receiveMessage(String message){
        System.out.println("接收到来自队列email.direct.queue消息订单的message是：" + message);
    }
}