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官方说明:http://www.rabbitmq.com/getstarted.html

什么是MQ?

       MQ全称为Message Queue, 消息队列(MQ)是一种应用程序对应用程序的通信方法。MQ是消费-生产者模型的一个典型的代表,一端往消息队列中不断写入消息,而另一端则可以读取队列中的消息。

      RabbitMQ是MQ的一种。下面详细介绍一下RabbitMQ的基本概念。

1、队列、生产者、消费者

      队列是RabbitMQ的内部对象,用于存储消息。生产者(下图中的P)生产消息并投递到队列中,消费者(下图中的C)可以从队列中获取消息并消费。

      多个消费者可以订阅同一个队列,这时队列中的消息会被平均分摊给多个消费者进行处理,而不是每个消费者都收到所有的消息并处理。

2、Publish/Subscribe订阅发布模式,每个通道都会收到消息

 

3、Exchange、Binding

      刚才我们看到生产者将消息投递到队列中,实际上这在RabbitMQ中这种事情永远都不会发生。实际的情况是,生产者将消息发送到Exchange(交换器,下图中的X),再通过Binding将Exchange与Queue关联起来。  

  a.Direct exchange,一个exchange和多个queue绑定,会根据绑定的不同routingKey,发送到不同的Queue中

  b.Topic exchange,按模式匹配路由键。模式符号 "#" 表示一个或多个单词,"*" 仅匹配一个单词。

  c.RPC

 

4、Exchange Type、Bingding key、routing key

      在绑定(Binding)Exchange与Queue的同时,一般会指定一个binding key。在绑定多个Queue到同一个Exchange的时候,这些Binding允许使用相同的binding key。

      生产者在将消息发送给Exchange的时候,一般会指定一个routing key,来指定这个消息的路由规则,生产者就可以在发送消息给Exchange时,通过指定routing key来决定消息流向哪里。

      RabbitMQ常用的Exchange Type有三种:fanout、direct、topic。

      fanout:把所有发送到该Exchange的消息投递到所有与它绑定的队列中。

      direct:把消息投递到那些binding key与routing key完全匹配的队列中。

      topic:将消息路由到binding key与routing key模式匹配的队列中。

      附上一张RabbitMQ的结构图:

      

 

    

最后来具体解析一下几个问题:

1、可以自动创建队列,也可以手动创建队列,如果自动创建队列,那么是谁负责创建队列呢?是生产者?还是消费者? 

      如果队列不存在,当然消费者不会收到任何的消息。但是如果队列不存在,那么生产者发送的消息就会丢失。所以,为了数据不丢失,消费者和生产者都可以创建队列。那么如果创建一个已经存在的队列呢?那么不会有任何的影响。需要注意的是没有任何的影响,也就是说第二次创建如果参数和第一次不一样,那么该操作虽然成功,但是队列属性并不会改变。

      队列对于负载均衡的处理是完美的。对于多个消费者来说,RabbitMQ使用轮询的方式均衡的发送给不同的消费者。

2、RabbitMQ的消息确认机制

      默认情况下,如果消息已经被某个消费者正确的接收到了,那么该消息就会被从队列中移除。当然也可以让同一个消息发送到很多的消费者。

      如果一个队列没有消费者,那么,如果这个队列有数据到达,那么这个数据会被缓存,不会被丢弃。当有消费者时,这个数据会被立即发送到这个消费者,这个数据被消费者正确收到时,这个数据就被从队列中删除。

     那么什么是正确收到呢?通过ack。每个消息都要被acknowledged(确认,ack)。我们可以显示的在程序中去ack,也可以自动的ack。如果有数据没有被ack,那么:

     RabbitMQ Server会把这个信息发送到下一个消费者。

     如果这个app有bug,忘记了ack,那么RabbitMQServer不会再发送数据给它,因为Server认为这个消费者处理能力有限。

    而且ack的机制可以起到限流的作用(Benefitto throttling):在消费者处理完成数据后发送ack,甚至在额外的延时后发送ack,将有效的均衡消费者的负载。

 

 使用springboot调用RabbitMQ例子 

环境:

apache-tomcat-8.5.15

jdk1.8.0_172

IDEA

搭建好RabbitMQ服务器环境,这点就不在叙述了。

使用RabbitTemplate的convertAndSend发送自定义的类消息的时候要统一类的包路径,不然在序列化的时候要报错,

通过IDEA创建springboot的WEB项目,引入了freemarker和和rabbitmq

创建完后的pom.xml文件为:

<?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.xuan</groupId>
    <artifactId>springrabbitmq</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springrabbitmq</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <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-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-freemarker</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

配置运行环境

修改application.yml文件,配置freemarker和rabbitmq的相关参数:

# Tomcat
server:
    tomcat:
        uri-encoding: UTF-8
        max-threads: 1000
        min-spare-threads: 30
    port: 8070
    servlet:
        context-path: /rabbitmq

spring:
    servlet:
        multipart:
            max-file-size: 100MB
            max-request-size: 100MB
            enabled: true
    freemarker:
      suffix: .html
    rabbitmq:
      host: localhost
      port: 5672
      username: admin
      password: 123456
      virtual-host: /testmq
      listener:
        simple:
          #acknowledge-mode: manual #设置确认模式手工确认
          concurrency: 3 #消费者最小数量
          max-concurrency: 10 # 消费者最大数量

如果配置acknowledge-mode为manual则需要在消费消费的地方调用channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);进行确认,不然消息会一直保存在通道中,指定concurrency最小的消费者数量和max-concurrency最大的消费者数量后,是多线程消费消息

这点的rabbitmq配置也可以通过RabbitConfig.java类来配置:

package com.xuan.springrabbitmq.config;

import org.springframework.amqp.core.AcknowledgeMode;
import org.springframework.amqp.core.AmqpAdmin;
import org.springframework.amqp.rabbit.annotation.EnableRabbit;
import org.springframework.amqp.rabbit.config.SimpleRabbitListenerContainerFactory;
import org.springframework.amqp.rabbit.connection.CachingConnectionFactory;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.core.RabbitAdmin;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

//连接rabbitMQ的基本配置
@Configuration
@EnableRabbit
public class RabbitConfig {
         @Bean
        public ConnectionFactory connectionFactory() {
             CachingConnectionFactory connectionFactory = new CachingConnectionFactory("localhost");
             connectionFactory.setUsername("admin");
             connectionFactory.setPassword("123456");
             connectionFactory.setPort(5672);
            connectionFactory.setVirtualHost("/testmq");
             return connectionFactory;
        }

        @Bean
        public AmqpAdmin amqpAdmin() {
            return new RabbitAdmin(connectionFactory());
        }

        @Bean
        public RabbitTemplate rabbitTemplate() {
            return new RabbitTemplate(connectionFactory());
        }

        //配置消费者监听的容器
        @Bean
        public SimpleRabbitListenerContainerFactory rabbitListenerContainerFactory() {
            SimpleRabbitListenerContainerFactory factory = new SimpleRabbitListenerContainerFactory();
            factory.setConnectionFactory(connectionFactory());
            factory.setConcurrentConsumers(3);
            factory.setMaxConcurrentConsumers(10);
            //factory.setAcknowledgeMode(AcknowledgeMode.MANUAL);//设置确认模式手工确认
            return factory;
        }
}

 

配置路由和通道

配置最简单的生产者消费者模式ProducerConsumerConfig.java

package com.xuan.springrabbitmq.config;

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

//生产者消费者模式的配置,包括一个队列和两个对应的消费者
@Configuration
public class ProducerConsumerConfig {

    @Bean
    public Queue myQueue() {
        Queue queue = new Queue("myqueue");
        return queue;
    }

}

配置订阅发布模式PublishSubscribeConfig.java

package com.xuan.springrabbitmq.config;

import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.FanoutExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

//发布订阅模式的配置,包括两个队列和对应的订阅者,发布者的交换机类型使用fanout(子网广播),两根网线binding用来绑定队列到交换机
@Configuration
public class PublishSubscribeConfig {

    @Bean
    public Queue myQueue1() {
        Queue queue = new Queue("queue1");
        return queue;
    }

    @Bean
    public Queue myQueue2() {
        Queue queue = new Queue("queue2");
        return queue;
    }

    @Bean
    public FanoutExchange fanoutExchange() {
        FanoutExchange fanoutExchange = new FanoutExchange("fanout");
        return fanoutExchange;
    }

    @Bean
    public Binding binding1() {
        Binding binding = BindingBuilder.bind(myQueue1()).to(fanoutExchange());
        return binding;
    }

    @Bean
    public Binding binding2() {
        Binding binding = BindingBuilder.bind(myQueue2()).to(fanoutExchange());
        return binding;
    }

}

配置direct直连模式DirectExchangeConfig.java

package com.xuan.springrabbitmq.config;

import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.DirectExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

//direct直连模式的交换机配置,包括一个direct交换机,两个队列,三根网线binding
@Configuration
public class DirectExchangeConfig {

    @Bean
    public DirectExchange directExchange() {
        DirectExchange directExchange = new DirectExchange("direct");
        return directExchange;
    }

    @Bean
    public Queue directQueue1() {
        Queue queue = new Queue("directqueue1");
        return queue;
    }

    @Bean
    public Queue directQueue2() {
        Queue queue = new Queue("directqueue2");
        return queue;
    }

    //3个binding将交换机和相应队列连起来
    @Bean
    public Binding bindingorange() {
        Binding binding = BindingBuilder.bind(directQueue1()).to(directExchange()).with("orange");
        return binding;
    }

    @Bean
    public Binding bindingblack() {
        Binding binding = BindingBuilder.bind(directQueue2()).to(directExchange()).with("black");
        return binding;
    }

    @Bean
    public Binding bindinggreen() {
        Binding binding = BindingBuilder.bind(directQueue2()).to(directExchange()).with("green");
        return binding;
    }


}

配置topic交换机模型TopicExchangeConfig.java

package com.xuan.springrabbitmq.config;

import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.Queue;
import org.springframework.amqp.core.TopicExchange;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

//topic交换机模型,需要一个topic交换机,两个队列和三个binding
@Configuration
public class TopicExchangeConfig {
    @Bean
     public TopicExchange topicExchange(){
        TopicExchange topicExchange=new TopicExchange("mytopic");
         return topicExchange;
     }
    
    @Bean
    public Queue topicQueue1() {
       Queue queue=new Queue("topicqueue1");
       return queue;
    }
     
     @Bean
    public Queue topicQueue2() {
       Queue queue=new Queue("topicqueue2");
       return queue;
    }
    
     //3个binding将交换机和相应队列连起来
     @Bean
     public Binding bindingtopic1(){
         Binding binding= BindingBuilder.bind(topicQueue1()).to(topicExchange()).with("*.orange.*");//binding key
         return binding;
     }
     
     @Bean
     public Binding bindingtopic2(){
         Binding binding= BindingBuilder.bind(topicQueue2()).to(topicExchange()).with("*.*.rabbit");
         return binding;
     }
     
     @Bean
     public Binding bindingtopic3(){
         Binding binding= BindingBuilder.bind(topicQueue2()).to(topicExchange()).with("lazy.#");//#表示0个或若干个关键字,*表示一个关键字
         return binding;
     }
}

定义发送的消息Mail.java

package po;

import java.io.Serializable;

public class Mail implements Serializable {

    private static final long serialVersionUID = -8140693840257585779L;
    private String mailId;
    private String country;
    private Double weight;


    public Mail() {
    }

    public Mail(String mailId, String country, double weight) {
        this.mailId = mailId;
        this.country = country;
        this.weight = weight;
    }

    public String getMailId() {
        return mailId;
    }

    public void setMailId(String mailId) {
        this.mailId = mailId;
    }

    public String getCountry() {
        return country;
    }

    public void setCountry(String country) {
        this.country = country;
    }

    public double getWeight() {
        return weight;
    }

    public void setWeight(double weight) {
        this.weight = weight;
    }

    @Override
    public String toString() {
        return "Mail [mailId=" + mailId + ", country=" + country + ", weight="
                + weight + "]";
    }

}

继承的消息TopicMail.java

package po;

public class TopicMail extends Mail {
    String routingkey;

    public String getRoutingkey() {
        return routingkey;
    }

    public void setRoutingkey(String routingkey) {
        this.routingkey = routingkey;
    }

    @Override
    public String toString() {
        return "TopicMail [routingkey=" + routingkey + "]";
    }

}

 

定义发送接口的实现ProducerImpl.java

package com.xuan.springrabbitmq.service.impl;

import com.xuan.springrabbitmq.service.Producer;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import po.Mail;

@Transactional
@Service("producer")
public class ProducerImpl implements Producer {
    @Autowired
    RabbitTemplate rabbitTemplate;
    public void sendMail(String queue, Mail mail) {
        rabbitTemplate.setQueue(queue);
        rabbitTemplate.convertAndSend(queue,mail);
    }

}

订阅发布时的发送消息实现PublisherImpl.java

package com.xuan.springrabbitmq.service.impl;

import po.Mail;
import com.xuan.springrabbitmq.service.Publisher;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service("publisher")
public class PublisherImpl implements Publisher {
    @Autowired
    RabbitTemplate rabbitTemplate;

    public void publishMail(Mail mail) {
        rabbitTemplate.convertAndSend("fanout", "", mail);
    }

    public void senddirectMail(Mail mail, String routingkey) {
        rabbitTemplate.convertAndSend("direct", routingkey, mail);
    }

    public void sendtopicMail(Mail mail, String routingkey) {
        rabbitTemplate.convertAndSend("mytopic", routingkey, mail);
    }
    
    
}

消费者的实现代码QueueListener1.java

package com.xuan.springrabbitmq.listener;

import com.rabbitmq.client.Channel;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;
import po.Mail;

@Component
@RabbitListener(queues = "myqueue")
public class QueueListener1 {

    @RabbitHandler
    public void displayMail(Mail mail, Channel channel, Message message) throws Exception {
        System.out.println("队列监听器1号收到消息" + mail.toString());
        //channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);//如果需要确认的要调用
    }
}

或者QueueListener2.java

package com.xuan.springrabbitmq.listener;


import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;
import po.Mail;

@Component
public class QueueListener2 {
    
    @RabbitListener(queues = "myqueue")
    public void displayMail(Mail mail) throws Exception {
        System.out.println("队列监听器2号收到消息"+mail.toString());
    }
}

其它模式的消费者也是类似的,指定queues 的名称就可以了。

源码位置:https://gitee.com/xuantest/SpringBoot-RabbitMQ

posted on 2018-08-10 09:51 xuanm 阅读(...) 评论(...) 编辑 收藏