五种服务异步通信（MQ）-详解、代码案例

简介：本篇文章主要是介绍了常用的异步通信原理，主要是RabbitMQ技术

1、初始MQ（异步通讯）

[1.1 同步通讯](#1.1 同步通讯)

[1.2 异步通讯](#1.2 异步通讯)

[1.3 MQ常见框架](#1.3 MQ常见框架)

2、RabbitMQ快速入门

[2.1 RabbitMQ概述和安装](#2.1 RabbitMQ概述和安装)

[2.2 常见消息模型](#2.2 常见消息模型)

[2.3 快速入门](#2.3 快速入门)

3、SpringAMQP

[3.1 什么是SpringAMQP](#3.1 什么是SpringAMQP)

[3.2 SimpleQueue案例](#3.2 SimpleQueue案例)

[3.3 SpringAMQP（发布、订阅模式）](#3.3 SpringAMQP（发布、订阅模式）)

[3.3.1 广播模式](#3.3.1 广播模式)

[3.3.2 路由模式代码演示](#3.3.2 路由模式代码演示)

[3.3.3 话题模式](#3.3.3 话题模式)

4、SpringAMQP-消息转换器

5、总结

1、初始MQ（异步通讯）

1.1 同步通讯

图 1.1-1 同步通讯存在的问题

上图中展示的就是同步通讯的问题

1.2 异步通讯

图 1.2-1 异步通讯优缺点
异步通信的优点： * 耦合度地 * 吞吐量提升 * 故障隔离 * 流量削峰异步通信的缺点： * 依赖于Broker的可靠性、安全性、吞吐能力 * 架构复杂了、业务没有明显的流程线、不好追踪管理
上图中展示的就是异步通信的优缺点

1.3 MQ常见框架

图 1.3-1 MQ产品

上图中展示的便是四款常见的MQ产品，他们之间的优势性能也有清晰地比对

2、RabbitMQ快速入门

2.1 RabbitMQ概述和安装

图 2.1-1 RabbitMQ安装
所需要的安装包、详细记录安装步骤的MD文件，因为内容过多，我放在网盘里面了
百度网盘地址：https://pan.baidu.com/s/1FZtWCWMl_QpZEIcGNnpwKA 提取码：6666

图 2.1-2 RabbitMQ概述

上图中展示的便是RabbitMQ的内部流程、逻辑，即消息发送者发送消息后传递给交换机，交换机将其消息存储到queue队列中，等待消息接受者获取

2.2 常见消息模型

图 2.2-1 五种消息模型

上图中展示的就是常用的五种消息队列模型，其官网地址：[RabbitMQ Tutorials \| RabbitMQ](https://www.rabbitmq.com/tutorials "RabbitMQ Tutorials

2.3 快速入门

java 复制代码

package cn.itcast.mq.helloworld;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import org.junit.Test;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

public class PublisherTest {
    @Test
    public void testSendMessage() throws IOException, TimeoutException {
        // 1.建立连接
        ConnectionFactory factory = new ConnectionFactory();
        // 1.1.设置连接参数，分别是：主机名、端口号、vhost、用户名、密码
        factory.setHost("192.168.150.101");
        factory.setPort(5672);
        factory.setVirtualHost("/");
        factory.setUsername("itcast");
        factory.setPassword("123321");
        // 1.2.建立连接
        Connection connection = factory.newConnection();

        // 2.创建通道Channel
        Channel channel = connection.createChannel();

        // 3.创建队列
        String queueName = "simple.queue";
        channel.queueDeclare(queueName, false, false, false, null);

        // 4.发送消息
        String message = "hello, rabbitmq!";
        channel.basicPublish("", queueName, null, message.getBytes());
        System.out.println("发送消息成功：【" + message + "】");

        // 5.关闭通道和连接
        channel.close();
        connection.close();

    }
}

java 复制代码

package cn.itcast.mq.helloworld;

import com.rabbitmq.client.*;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

public class ConsumerTest {

    public static void main(String[] args) throws IOException, TimeoutException {
        // 1.建立连接
        ConnectionFactory factory = new ConnectionFactory();
        // 1.1.设置连接参数，分别是：主机名、端口号、vhost、用户名、密码
        factory.setHost("192.168.150.101");
        factory.setPort(5672);
        factory.setVirtualHost("/");
        factory.setUsername("itcast");
        factory.setPassword("123321");
        // 1.2.建立连接
        Connection connection = factory.newConnection();

        // 2.创建通道Channel
        Channel channel = connection.createChannel();

        // 3.创建队列
        String queueName = "simple.queue";
        channel.queueDeclare(queueName, false, false, false, null);

        // 4.订阅消息
        channel.basicConsume(queueName, true, new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope,
                                       AMQP.BasicProperties properties, byte[] body) throws IOException {
                // 5.处理消息
                String message = new String(body);
                System.out.println("接收到消息：【" + message + "】");
            }
        });
        System.out.println("等待接收消息。。。。");
    }
}

3、SpringAMQP

3.1 什么是SpringAMQP

图 3.1-1 SpringAMQP介绍

上图中展示的是关于SpringAMQP的消息发送和接收的标准

3.2 SimpleQueue案例

图 3.2-1 消息发送者

上图中展示的是消息发送者的代码案例：即配置连接信息、编写测试代码

3.3 SpringAMQP（发布、订阅模式）

图 3.3-1 发布、订阅模式

上图中展示的是三种通过路由器转发消息的模型，即广播模式、路由模式、话题模式

3.3.1 广播模式

1、消息发送者代码

java 复制代码

package cn.itcast.mq.helloworld;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import org.junit.Test;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

public class PublisherTest {
    @Autowired
    private RabbitTemplate rabbitTemplate;

    @Test
    public void testFanoutExchange(){
        // 交换机名称
        String exchangeName = "itcast.fanout";

        // 消息
        String message = "hello,everyone!";

        // 发送消息
        rabbitTemplate.convertAndSend(exchangeName, "", message);
    }
}

2、交换机、队列配置类代码

java 复制代码

package cn.itcast.mq.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.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class FanoutConfig {
    // 1.声明广播交换机
    @Bean
    public FanoutExchange fanoutExchange(){
        return new FanoutExchange("itcast.fanout");
    }
    @Bean
    public Queue fanoutQueue1(){
        return new Queue("fanout.queue1");
    }
    @Bean
    public Queue fanoutQueue2(){
        return new Queue("fanout.queue2");
    }
    // 2.交换机绑定队列一
    @Bean
    public Binding fanoutBinding1(Queue fanoutQueue1, FanoutExchange fanoutExchange){
        return BindingBuilder
                .bind(fanoutQueue1)
                .to(fanoutExchange);
    }
    // 3.交换机绑定队列二
    @Bean
    public Binding fanoutBinding2(Queue fanoutQueue2, FanoutExchange fanoutExchange){
        return BindingBuilder
                .bind(fanoutQueue2)
                .to(fanoutExchange);
    }
}

3、消息接受者代码

java 复制代码

package cn.itcast.mq.listener;

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

import java.time.LocalTime;
@Component
public class SpringRabbitListener {

/*    @RabbitListener(queues = "simple.queue")
    public void listenWorkQueue1(String msg) throws InterruptedException{
        System.out.println("消费者1接收到消息: 【" + msg + "】" + LocalTime.now());
    }*/

    @RabbitListener(queues = "fanout.queue1")
    public void listenFanoutQueue1(String msg){
        System.out.println("消费者1接收到消息: 【" + msg + "】" + LocalTime.now());
    }

    @RabbitListener(queues = "fanout.queue2")
    public void listenFanoutQueue2(String msg){
        System.out.println("消费者1接收到消息: 【" + msg + "】" + LocalTime.now());
    }
}

3.3.2 路由模式代码演示

1、消息发送者代码

java 复制代码

package cn.itcast.mq.helloworld;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import org.junit.Test;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

public class PublisherTest {
    @Autowired
    private RabbitTemplate rabbitTemplate;

    @Test
    public void testFanoutExchange(){
        // 交换机名称
        String exchangeName = "itcast.direct";

        // 消息
        String message = "hello,everyone!";

        // 发送消息
        rabbitTemplate.convertAndSend(exchangeName, "red", message);
    }
}

2、消息接受者代码

java 复制代码

package cn.itcast.mq.listener;
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.RabbitListener;
import org.springframework.stereotype.Component;
import java.time.LocalTime;

@Component
public class SpringRabbitListener {

    @RabbitListener(bindings = @QueueBinding(value = @Queue(name = "direct.queue1"), exchange = @Exchange(name = "itcast.direct", type = ExchangeTypes.DIRECT), key = {"red", "blue"}))
    public void listenDirectQueue1(String msg){
        System.out.println("消费者接收到direct.queue1的消息: 【" + msg + "】");
    }
    @RabbitListener(bindings = @QueueBinding(value = @Queue(name = "direct.queue2"), exchange = @Exchange(name = "itcast.direct", type = ExchangeTypes.DIRECT), key = {"red", "yellow"}))
    public void listenDirectQueue2(String msg){
        System.out.println("消费者接收到direct.queue1的消息: 【" + msg + "】");
    }
}

3.3.3 话题模式

1、消息发送者代码

java 复制代码

package cn.itcast.mq.helloworld;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import org.junit.Test;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

public class PublisherTest {
    @Autowired
    private RabbitTemplate rabbitTemplate;
/*
    @Test
    public void testFanoutExchange(){
        // 交换机名称
        String exchangeName = "itcast.direct";

        // 消息
        String message = "hello,everyone!";

        // 发送消息
        rabbitTemplate.convertAndSend(exchangeName, "red", message);
    }*/

    @Test
    public void testTopicExchange(){
        // 交换机名称
        String exchangeName = "itcast.topic";

        // 消息
        String message = "hello,everyone!";

        // 发送消息
        rabbitTemplate.convertAndSend(exchangeName, "china.news", message);
    }
}

2、消息接受者代码

java 复制代码

package cn.itcast.mq.listener;
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.RabbitListener;
import org.springframework.stereotype.Component;
import java.time.LocalTime;

@Component
public class SpringRabbitListener {
    /**
     * 话题路由器
     */
    @RabbitListener(bindings = @QueueBinding(
            value = @Queue(name = "topic.queue1"),
            exchange = @Exchange(name = "itcast.topic", type = ExchangeTypes.TOPIC),
            key = "china.#"
    ))
    public void listenTopicQueue1(String msg){
        System.out.println("消费者接收到direct.queue1的消息: 【" + msg + "】");
    }

    @RabbitListener(bindings = @QueueBinding(
            value = @Queue(name = "topic.queue2"),
            exchange = @Exchange(name = "itcast.topic", type = ExchangeTypes.TOPIC),
            key = "#.news"
    ))
    public void listenTopicQueue2(String msg){
        System.out.println("消费者接收到direct.queue1的消息: 【" + msg + "】");
    }
/*    @RabbitListener(bindings = @QueueBinding(value = @Queue(name = "direct.queue1"), exchange = @Exchange(name = "itcast.direct", type = ExchangeTypes.DIRECT), key = {"red", "blue"}))
    public void listenDirectQueue1(String msg){
        System.out.println("消费者接收到direct.queue1的消息: 【" + msg + "】");
    }
    @RabbitListener(bindings = @QueueBinding(value = @Queue(name = "direct.queue2"), exchange = @Exchange(name = "itcast.direct", type = ExchangeTypes.DIRECT), key = {"red", "yellow"}))
    public void listenDirectQueue2(String msg){
        System.out.println("消费者接收到direct.queue1的消息: 【" + msg + "】");
    }*/
}

4、SpringAMQP-消息转换器

图 4-1 SpringAMQP的作用
我们知道 RabbitTemplate 传递的参数中，消息对象是以字节数组传递的，经过序列化（默认是通过JDK实现的）后显示为正常的数据，但是如果传递的是Map，List集合这种数据，SpringCloud自带的序列化就会出现异常，为了解决这一问题，我们需要引入SpringAMQP-消息转换器

图 4-1 项目的总pom文件

在项目的总pom文件中添加相对应的依赖

图 4-3 消息发送端、接收端

在项目的消息发送端、接收端的启动类中创建Bean对象