04-RabbitMQ常用的六种模型以及在SpringBoot中的应用

￡神魔★判官ぃ 2021-10-06 15:50 287阅读 0赞

在RabbitMQ中，我们常用的模型主要有六种，分别是：

*  Hello World
 *  Work queues
 *  Publish/Subscribe
 *  Routing
 *  Topic
 *  RPC

俗话说得好，光说不练假把式，下面我们结合springBoot逐一实现这六种模型。

### Hello World ###

![aHR0cHM6Ly93d3cucmFiYml0bXEuY29tL2ltZy90dXRvcmlhbHMvcHl0aG9uLW9uZS1vdmVyYWxsLnBuZw][]

从上图可以看出，这是一个默认交换机的单播路由，并且每个队列只有一个消费者。

### Work queues ###

![aHR0cHM6Ly93d3cucmFiYml0bXEuY29tL2ltZy90dXRvcmlhbHMvcHl0aG9uLXR3by5wbmc][]

从上图可以看出，主要的部分是：默认交换机的单播路由，并且每个队列有多个消费者。

### Publish/Subscribe ###

![aHR0cHM6Ly93d3cucmFiYml0bXEuY29tL2ltZy90dXRvcmlhbHMvZXhjaGFuZ2VzLnBuZw][]

从上图可以看出，主要的部分是：扇形交换机的多播路由。

### Routing ###

![aHR0cHM6Ly93d3cucmFiYml0bXEuY29tL2ltZy90dXRvcmlhbHMvcHl0aG9uLWZvdXIucG5n][]

从上图可以看出，主要的部分是：直连交换机的多播路由。

### Topic ###

![aHR0cHM6Ly93d3cucmFiYml0bXEuY29tL2ltZy90dXRvcmlhbHMvcHl0aG9uLWZpdmUucG5n][]

从上图可以看出，主要的部分是：主题交换机的多播路由。

### RPC ###

![aHR0cHM6Ly93d3cucmFiYml0bXEuY29tL2ltZy90dXRvcmlhbHMvcHl0aG9uLXNpeC5wbmc][]

从上图可以看出，主要的部分是：默认交换机的单播路由。

### 环境 ###

*  下面我们代码演示一下除了RPC之外的其他五种模型，在SpringBoot中的用法

![aHR0cDovL3VweXVuLnF1Ymlhbnpob25nLmNuL3BpY3R1cmUvaWRlYTY0X0pZbW1TcWtnaDQucG5n][]

**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 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>2.1.6.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>cn.qbz</groupId>
        <artifactId>rabbit-mq-test</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>rabbit-mq-test</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-amqp</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    </project>

**application.yml**

spring:
      rabbitmq:
        host: 127.0.0.1
        port: 5672
        virtual-host: /qbz-test #虚拟主机，必须存在，不然会报错。
        username: guest
        password: guest
        publisher-confirms: true #消息发送到交换机确认机制，是否确认回调，默认false
        publisher-returns: true #消息发送到交换机确认机制，是否返回回调，默认false
        listener:
          simple:
            prefetch: 1 #预先载入数量，默认值250
            concurrency: 10 #指定最小消费数量
            max-concurrency: 20 #指定最大的消费者数量,当并行消费者数量到达concurrency后会开至最大max-concurrency
            acknowledge-mode: manual # 采用手动应答，设置为手动应答后，消费者如果不进行手动应答，会处于假死状态，不能再消费。默认auto
            retry:
              enabled: true # 失败重试机制，默认为false.
              max-attempts: 1 # 失败后，再重试几次,默认为：3

**RabbitMqTestApplication.java**

package cn.qbz.rabbitmqtest;
    
    import org.springframework.amqp.rabbit.annotation.EnableRabbit;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    /** * RabbitMQ 测试 * * @author qubianzhong * @Date 13:42 2019/7/26 */
    @SpringBootApplication
    @EnableRabbit //新增开启Rabbit注解
    public class RabbitMqTestApplication { 
    
        public static void main(String[] args) { 
            SpringApplication.run(RabbitMqTestApplication.class, args);
        }
    
    }

**RabbitMqProduceController.java**

package cn.qbz.rabbitmqtest.controller;
    
    import org.springframework.amqp.core.*;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RestController;
    
    /** * @author qubianzhong * @date 2019/7/22 13:51 */
    @RestController
    public class RabbitMqProduceController { 
    
        @Autowired
        private AmqpTemplate amqpTemplate;
        @Autowired
        private AmqpAdmin amqpAdmin;
    
        @GetMapping(value = "/produce")
        public String produceMsg(@RequestParam(value = "msg") String msg) { 
            /****************************hello/work start**************************** * hello-world、work queues 均是只绑定队列 * 发布消息时，如下所示，推荐使用第二种 */
            //1.如果队列不存在，则消息会进入“黑洞”
            amqpTemplate.convertAndSend("hello", msg + System.currentTimeMillis());
            /** * 2.如果队列不存在，则进行创建，如果队列已存在，则使用此队列 * public Queue(String name) { * //The queue is durable, non-exclusive and non auto-delete. * this(name, true, false, false); * } */
            Queue queue = new Queue("hello");
            amqpAdmin.declareQueue(queue);
            amqpTemplate.convertAndSend(queue.getName(), msg + System.currentTimeMillis());
    
            //3.work
            queue = new Queue("work");
            amqpAdmin.declareQueue(queue);
            for (int i = 0; i < 30; i++) { 
                amqpTemplate.convertAndSend(queue.getName(), "wwoork" + i);
            }
            /****************************hello/work end****************************/
    
            /****************************Publish/Subscribe start**************************** * 生产者只向扇形交换机发送消息，扇形交换机负责向绑定其队列上的所有消费者进行分发。 * public AbstractExchange(String name) { * //Construct a new durable, non-auto-delete Exchange with the provided name. * this(name, true, false); * } */
            for (int i = 0; i < 5; i++) { 
                Exchange pubSubExchange = new FanoutExchange("pub-sub-exchange");
                amqpAdmin.declareExchange(pubSubExchange);
                amqpTemplate.convertAndSend(pubSubExchange.getName(), null, msg + System.currentTimeMillis());
            }
            /****************************Publish/Subscribe end****************************/
    
            /****************************Routing start**************************** * Routing 消费者消费的时候，多个路由键绑定一个队列 */
            Exchange routeExchange = new DirectExchange("routing-exchange");
            amqpAdmin.declareExchange(routeExchange);
            amqpTemplate.convertAndSend(routeExchange.getName(), "routing-log-error", "routing-log-error：" + System.currentTimeMillis());
            amqpTemplate.convertAndSend(routeExchange.getName(), "routing-log-info", "routing-log-info：" + System.currentTimeMillis());
            amqpTemplate.convertAndSend(routeExchange.getName(), "routing-log-waring", "routing-log-waring：" + System.currentTimeMillis());
    
            /****************************Routing end****************************/
    
            /****************************Topic start**************************** * Topic 消费者消费的时候，多个路由键,模糊匹配，绑定一个队列，其实和routing差不多 */
            Exchange topicExchange = new TopicExchange("topic-exchange");
            amqpAdmin.declareExchange(topicExchange);
            amqpTemplate.convertAndSend(topicExchange.getName(), "topic-log-error.20190706", "topic-log-error.20190706：" + System.currentTimeMillis());
            amqpTemplate.convertAndSend(topicExchange.getName(), "topic-log-info.20190606", "topic-log-info.20190606：" + System.currentTimeMillis());
            amqpTemplate.convertAndSend(topicExchange.getName(), "topic-log-error.20190708", "topic-log-error.20190708：" + System.currentTimeMillis());
            amqpTemplate.convertAndSend(topicExchange.getName(), "topic-log-waring.20190506", "topic-log-waring.20190506：" + System.currentTimeMillis());
            amqpTemplate.convertAndSend(topicExchange.getName(), "topic-log-waring.20190516", "topic-log-waring.20190516：" + System.currentTimeMillis());
            amqpTemplate.convertAndSend(topicExchange.getName(), "topic-log-info.20190723", "topic-log-info.20190723：" + System.currentTimeMillis());
    
            /****************************Topic end****************************/
    
            return "success";
        }
    }

**RabbitTestListener.java**

package cn.qbz.rabbitmqtest.rabbit;
    
    import com.rabbitmq.client.Channel;
    import org.springframework.amqp.core.ExchangeTypes;
    import org.springframework.amqp.core.Message;
    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.RabbitListener;
    import org.springframework.stereotype.Component;
    
    import java.io.IOException;
    
    /** * @author qubianzhong * @date 2019/7/26 14:40 */
    @Component
    public class RabbitTestListener { 
        /****************************demo 演示如何消费消息 start**************************** * 推荐使用第二种或第三种 * 当不需要绑定交换机的时候，如果使用第三种，exchange置为空会报错 */
    
        /** * 1.此种用法需要手动创建队列，不然会报错 */
        @RabbitListener(queues = "demo-1")
        public void demo1(Message message, Channel channel) throws IOException { 
            System.err.println("demo-1:" + new String(message.getBody()));
            //信道上发布的消息都会被指派一个唯一的ID号:message.getMessageProperties().getDeliveryTag()
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
    
            //1:接收到的被指派一个唯一的ID号:deliveryTag;
            // 2:true当前consumer拒绝所有的deliveryTag包括此次的，false当前consumer只拒绝此次的这个deliveryTag;
            // 3:true此消息重新排队，而不是被丢弃或者扔进死信队列中
            //channel.basicNack(message.getMessageProperties().getDeliveryTag(), true, true);
        }
    
        /** * 2.如果队列不存在，则会新建；如果队列已存在，则使用此队列 */
        @RabbitListener(queuesToDeclare = @Queue("demo-2"))
        public void demo2(Message message, Channel channel) throws IOException { 
            System.err.println("demo-2:" + new String(message.getBody()));
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
        }
    
    
        /** * 3.绑定队列、交换机 * 如果队列或交换机不存在，则新建；如果已存在，则使用。 */
        @RabbitListener(bindings = @QueueBinding(
                value = @Queue("demo-3"),
                exchange = @Exchange("demo-exchange-3")
        ))
        public void demo3(Message message, Channel channel) throws IOException { 
            System.err.println("demo-3:" + new String(message.getBody()));
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
        }
    
        /****************************demo 演示如何消费消息 start****************************/
    
        /****************************hello start**************************** * 消费 hello-world */
        @RabbitListener(queuesToDeclare = { @Queue("hello")})
        public void hello(Message message, Channel channel) throws IOException { 
            System.err.println("hello:" + new String(message.getBody()));
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
        }
        /****************************hello end****************************/
    
        /****************************work start**************************** * 消费 work 一个队列对应多个消费者，此时，消息是平均分配到每个消费者手里的。 */
        @RabbitListener(queuesToDeclare = { @Queue("work")})
        public void work1(Message message, Channel channel) throws IOException { 
            System.err.println("work1:" + new String(message.getBody()));
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
        }
    
        @RabbitListener(queuesToDeclare = { @Queue("work")})
        public void work2(Message message, Channel channel) throws InterruptedException, IOException { 
            Thread.sleep(1230);
            System.err.println("work2:" + new String(message.getBody()));
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
        }
    
        @RabbitListener(queuesToDeclare = { @Queue("work")})
        public void work3(Message message, Channel channel) throws InterruptedException, IOException { 
            Thread.sleep(30);
            System.err.println("work3:" + new String(message.getBody()));
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
        }
        /****************************work end****************************/
    
    
        /****************************Publish/Subscribe start**************************** * 消费 Publish/Subscribe 扇形交换机负责向绑定其队列上的所有消费者进行分发。 * 此处,exchange和queue如果不存在，则会新建。 * 注意：@Exchange注解属性 type需要定义为 fanout，不然会是默认的 direct */
        @RabbitListener(bindings = { @QueueBinding(
                value = @Queue("sub-pub-queue1"),
                exchange = @Exchange(value = "pub-sub-exchange", type = ExchangeTypes.FANOUT)
        )})
        public void pubSub1(Message message, Channel channel) throws IOException { 
            System.err.println("sub-pub-queue1:" + new String(message.getBody()));
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
        }
    
        @RabbitListener(bindings = { @QueueBinding(
                value = @Queue("sub-pub-queue2"),
                exchange = @Exchange(value = "pub-sub-exchange", type = ExchangeTypes.FANOUT)
        )})
        public void pubSub2(Message message, Channel channel) throws IOException { 
            System.err.println("sub-pub-queue2:" + new String(message.getBody()));
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
        }
        /****************************Publish/Subscribe end****************************/
    
    
        /****************************Routing start**************************** * 消费 Routing * 其中一个队列，只消费error信息，一个队列消费所有信息 */
        @RabbitListener(bindings = { @QueueBinding(value = @Queue("routing-log-error"), key = { "routing-log-error"}, exchange = @Exchange(value = "routing-exchange"))})
        public void routing1(Message message, Channel channel) throws IOException { 
            System.err.println("routing-log-error:" + new String(message.getBody()));
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
        }
    
        @RabbitListener(bindings = { @QueueBinding(value = @Queue("routing-log-all"), key = { "routing-log-error", "routing-log-info", "routing-log-waring"}, exchange = @Exchange(value = "routing-exchange")
        )})
        public void routing2(Message message, Channel channel) throws IOException { 
            System.err.println("routing-log-all:" + new String(message.getBody()));
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
        }
        /****************************Routing end****************************/
    
    
        /****************************Topic start**************************** * 消费 Topic * 其中一个队列，消费前缀为'topic-log-info.'的信息， * 一个队列消费前缀为'topic-log-error.'的和模糊匹配'.201907.'的信息 */
        @RabbitListener(bindings = { @QueueBinding(value = @Queue("topic-log-1"), key = { "topic-log-info.*"}, exchange = @Exchange(value = "topic-exchange", type = ExchangeTypes.TOPIC))})
        public void topic1(Message message, Channel channel) throws IOException { 
            System.err.println("所有的info:" + new String(message.getBody()));
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
        }
    
        @RabbitListener(bindings = { @QueueBinding(value = @Queue("topic-log-2"), key = { "*.201907.*", "topic-log-error.*"}, exchange = @Exchange(value = "topic-exchange", type = ExchangeTypes.TOPIC))})
        public void topic2(Message message, Channel channel) throws IOException { 
            System.err.println("所有的error and 7月份:" + new String(message.getBody()));
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
        }
        /****************************Routing end****************************/
    
    }

**RabbitTemplateCallback.java**

package cn.qbz.rabbitmqtest.rabbit;
    
    import org.springframework.amqp.core.Message;
    import org.springframework.amqp.rabbit.connection.CorrelationData;
    import org.springframework.amqp.rabbit.core.RabbitTemplate;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Component;
    
    /** * @author qubianzhong * @date 2019/7/31 10:56 */
    @Component
    public class RabbitTemplateCallback implements RabbitTemplate.ConfirmCallback, RabbitTemplate.ReturnCallback { 
    
        private RabbitTemplate rabbitTemplate;
    
        @Autowired
        public void setRabbitTemplate(RabbitTemplate rabbitTemplate) { 
            this.rabbitTemplate = rabbitTemplate;
            this.rabbitTemplate.setMandatory(true);
            this.rabbitTemplate.setConfirmCallback(this::confirm);
            this.rabbitTemplate.setReturnCallback(this::returnedMessage);
        }
    
        /** * Confirmation callback. * * @param correlationData correlation data for the callback. * @param ack true for ack, false for nack * @param cause An optional cause, for nack, when available, otherwise null. */
        @Override
        public void confirm(CorrelationData correlationData, boolean ack, String cause) { 
            if (!ack) { 
                System.err.println("消息未能在交换机上得到确认！异常处理......");
            }
        }
    
        /** * Returned message callback. * * @param message the returned message. * @param replyCode the reply code. * @param replyText the reply text. * @param exchange the exchange. * @param routingKey the routing key. */
        @Override
        public void returnedMessage(Message message, int replyCode, String replyText, String exchange, String routingKey) { 
            System.err.println("消息未能到达队列！" + "return exchange: " + exchange + ", routingKey: "
                    + routingKey + ", replyCode: " + replyCode + ", replyText: " + replyText);
        }
    }

### RPC 补充 ###

我们并不推荐RPC式的mq调用，这么做完全没有发挥mq异步削峰的作用。如果有使用RPC的需求，请移步SpringCloud或者Dubbo。

我们虽然不使用RabbitMQ来进行RPC调用，但是我们也要了解，RabbitMQ为啥子可以实现RPC。

当使用RabbitMQ来实现RPC时.你只是简单地发布消息而已。RabbitMQ会负责使用绑定来路由消息到达合适的队列。RPC服务器会从这些队列上消费消息。RabbitMQ替你完成了所有这些艰难的工作:将消息路由到合适的地方，通过多台RPC服务器对RPC消息进行负载均衡，甚至当处理消息的服务器崩溃时，将RPC消息重发到另一台。

问题在于。如何将应答返回给客户端呢?毕竟，到目前为止你体验的RabbitMQ是发后即忘模型。

RabbitMQ团队想出了一个优雅的解决方案:使用消息来发回应答。在每个AMQP消息头里有个字段叫作reply\_ to,消息的生产者可以通过该字段来确定队列名称，并监听队列等待应答。然后接收消息的RPC服务器能够检杳reply \_to字段，并创建包含应答内容的新的消息，并以队列名称作为路由键。

你也许想:“光是每次创建唯一队列名就得花很多工夫吧。我们怎样阻止其他客户端读到应答消息呢?”

我们前面说过，如果你声明了没有名字的队列，RabbitMQ会为你指定一个。这个名字恰好是唯一的队列名;同时在声明的时候指定exclusive参数.确保只有你可以读取队列上的消息。所有RPC客户端需要做的是声明临时的、排他的、匿名队列，并将该队列名称包含到RPC消息的reply \_to头中。于是服务器端就知道应答消息该发往哪儿了。值得注意的是我们并没有提到将应答队列绑定到交换器上。这是因为当RPC服务器将应答消息发布到RabbitMQ而没有指定交换器时.RabbitMQ就知道目的地是应答队列，路由键就是队列的名称。

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