RabbitMQ(一) 初识RabbitMQ

RabbitMQ是一个开源的消息代理和队列服务器，用来通过普通协议在完全不同的应用之间共享数据，RabbitMQ是使用Erlang语言来编写的，并且RabbitMQ是基于AMQP协议的。

哪些大厂在用RabbitMQ，为什么

• 滴滴、美团、头条
• 开源、性能优秀、稳定性保障
• 提供可靠性消息投递模式(confim)、返回模式(return)
• 与SpringAMQP完美结合、API丰富
• 集群模式丰富，表达式配置，HA模式，镜像队列模型
• 保证数据不丢失的前提做到高可靠性、可用性

什么是AMQP高级消息队列协议

AMQP:Advance Message Queuing Protocol

AMQP翻译：高级消息队列协议

AMQP定义：是具有现代特征的二进制协议。是一个提供统一消息服务的应用层标准高级队列协议，是应用层协议的一个开放标准，为面向消息的中间件设计。

AMQP协议模型

AMQP核心概念

Server:又称Broker,接受客户端的连接，实现AMQP实体服务

Connection:连接，应用程序与Broker的网络连接

Channel:网络信道，几乎所有的操作都在channel中进行，Channel是进行消息读写的通道。客户端可建立多个Channel，每个Channel代表一个会话任务。

Message:消息，服务器和应用程序之间传送的数据，由Properties和Body组成。Properties可以对消息进行修饰，比如消息的优先级，延迟等高级特性；Body则就是消息体内容。

Virtual host:虚拟地址，用于进行逻辑隔离，最上层的消息路由。一个Virtual Host里面可以有若干个Exchange和Queue,统一Virtual Host里面不能有相同名称的Exchange和Queue

Exchange:交换机，接收消息，根据路由键转发消息到绑定的队列

Binding:Exchange和Queue之间的虚拟连接，binding中可以包含routing key

Routing key:一个路由规则，虚拟机可用它来确定如何路由一个特定消息

Queue:也成为Mesage Queue,消息队列，保存并将它们转发给消费者

RabbitMQ的整体架构

RabbitMQ消息是如何流转的

RabbitMQ的安装与使用

• 官网地址：http://www.rabbitmq.com/

• 提前准备：安装Linux必要依赖

• 下载RabbitMQ必须安装包（简单RPM安装）

• 配置文件修改

• 服务启动:rabbitmq-server start &

• 服务的停止:rabbitmqctl stop_app

• 管理插件:rabbitmq-plugins enable rabbitmq_management

• 访问:http://locahost:15672

准备：
yum install 
build-essential openssl openssl-devel unixODBC unixODBC-devel 
make gcc gcc-c++ kernel-devel m4 ncurses-devel tk tc xz

下载：
wget www.rabbitmq.com/releases/erlang/erlang-18.3-1.el7.centos.x86_64.rpm
wget http://repo.iotti.biz/CentOS/7/x86_64/socat-1.7.3.2-5.el7.lux.x86_64.rpm
wget www.rabbitmq.com/releases/rabbitmq-server/v3.6.5/rabbitmq-server-3.6.5-1.noarch.rpm

配置文件：
vim /usr/lib/rabbitmq/lib/rabbitmq_server-3.6.5/ebin/rabbit.app
比如修改密码、配置等等，例如：loopback_users 中的 <<"guest">>,只保留guest
服务启动和停止：
启动 rabbitmq-server start &  (&表示后台启动)
停止 rabbitmqctl app_stop

默认插件列表: rabbitmq-plugins  list
管理插件：rabbitmq-plugins enable rabbitmq_management
访问地址：http://localost:15672/

rabbitmqctl --help 查询具体参数

快速入门-消息生产与消费

• ConnectionFactory:获取连接工厂
• Connection:一个连接
• Channel:数据通信信道，可发送和接收消息
• Queue:具体的消息存储队列
• Producer&Consumer生产者和消费者

生产者代码

需要引入

<dependency>
	<groupId>com.rabbitmq</groupId>
	<artifactId>amqp-client</artifactId>
	<version>3.6.5</version>
</dependency>

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
/**
 * 生产者
 *
 * @author niugang
 */
public class Producer {


    public static void main(String[] args) throws Exception {
        //1 创建一个ConnectionFactory, 并进行配置
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("localhost");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");

        //2 通过连接工厂创建连接
        Connection connection = connectionFactory.newConnection();

        //3 通过connection创建一个Channel
        Channel channel = connection.createChannel();

        //4 通过Channel发送数据
        for (int i = 0; i < 15; i++) {
            String msg = "Hello RabbitMQ!";
            //1 exchange   2 routingKey
            //exchange 为 空字符串 为走默认的exchange  (AMQP default)  根据路由key 和消息队列  名称 是否匹完全匹配进行投递、
            // 从控制台 Exchanges->(AMQP default)
            // The default exchange is implicitly bound to every queue, with a routing key equal to the queue name. It is not possible to explicitly bind to, or unbind from the default exchange. It also cannot be deleted.
            //默认交换被隐式地绑定到每个队列，路由键等于队列名称。无法显式绑定到默认交换器或从默认交换器取消绑定。它也不能被删除。
            channel.basicPublish("", "test001", null, msg.getBytes());
        }

        //5 记得要关闭相关的连接
        channel.close();
        connection.close();
    }
}

消费者代码

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.QueueingConsumer;
import com.rabbitmq.client.QueueingConsumer.Delivery;
import lombok.extern.slf4j.Slf4j;

/**
 * 消费者
 *
 * @author niugang
 */
@Slf4j
public class Consumer {

    public static void main(String[] args) throws Exception {

        //1 创建一个ConnectionFactory, 并进行配置
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("localhost");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");

        //2 通过连接工厂创建连接
        Connection connection = connectionFactory.newConnection();

        //3 通过connection创建一个Channel
        Channel channel = connection.createChannel();

        //4 声明（创建）一个队列
        String queueName = "test001";
        //exclusive 如果我们声明一个排他队列(仅限于此连接)，则为true。
        channel.queueDeclare(queueName, true, false, false, null);

        //5 创建消费者
        QueueingConsumer queueingConsumer = new QueueingConsumer(channel);

        //6 设置Channel
        channel.basicConsume(queueName, true, queueingConsumer);

        while (true) {
            //7 获取下一个消息,方法阻塞
            Delivery delivery = queueingConsumer.nextDelivery();
            String msg = new String(delivery.getBody());
            log.info("消费端: {}", msg);
            //封装一些发送参数
          //  Envelope envelope = delivery.getEnvelope();
        }

    }
}

Exchange交换机

Exchange接收消息，并根据路由键转发消息所绑定的队列

交换机属性

Name:交换机名称

Type:交换器类型direct、topic、fanout、headers

Durability:是否需要持久化，true为持久化

Auto Delete:当最后一个绑定到Exchange上的队列删除后，自动删除该Exchange

Internal:当前Exchange是否用于RabbitMQ内部使用，默认为false

Arguments:扩展参数，用于扩展AMQP协议自制定化使用

Direct Exchange

所有发送到Direct Exchange的消息被转发到RouteKey中指定的Queue

direct 直连模式 routing_key必须完全匹配

注意：Direct模式可以使用RabbitMQ自带的Exchange:fefault Exchange,所以不需要将Exchange进行任何绑定(binding)操作，消息传递，RouteKey必须完全匹配才会被队列接收，否则该消息会被抛弃

生产者代码

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;

/**
 * @author niugang
 */
public class Producer4DirectExchange {

	
	public static void main(String[] args) throws Exception {
		
		//1 创建ConnectionFactory
		ConnectionFactory connectionFactory = new ConnectionFactory();
		connectionFactory.setHost("localhost");
		connectionFactory.setPort(5672);
		connectionFactory.setVirtualHost("/");
		
		//2 创建Connection
		Connection connection = connectionFactory.newConnection();
		//3 创建Channel
		Channel channel = connection.createChannel();  
		//4 声明
		String exchangeName = "test_direct_exchange";
		String routingKey = "test.direct";
		//5 发送
		
		String msg = "Hello World RabbitMQ 4  Direct Exchange Message 111 ... ";
		channel.basicPublish(exchangeName, routingKey , null , msg.getBytes()); 		
		
	}
	
}

消费者代码

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.QueueingConsumer;
import com.rabbitmq.client.QueueingConsumer.Delivery;

/**
 * @author niugang
 */
public class Consumer4DirectExchange {

	public static void main(String[] args) throws Exception {
		
		
        ConnectionFactory connectionFactory = new ConnectionFactory() ;  
        
        connectionFactory.setHost("localhost");
        connectionFactory.setPort(5672);
		connectionFactory.setVirtualHost("/");
		
        connectionFactory.setAutomaticRecoveryEnabled(true);
        connectionFactory.setNetworkRecoveryInterval(3000);
        Connection connection = connectionFactory.newConnection();
        
        Channel channel = connection.createChannel();  
		//4 声明
		String exchangeName = "test_direct_exchange";
		String exchangeType = "direct";
		String queueName = "test_direct_queue";
		String routingKey = "test.direct";
		
		//表示声明了一个交换机
		channel.exchangeDeclare(exchangeName, exchangeType, true, false, false, null);
		//表示声明了一个队列
		channel.queueDeclare(queueName, false, false, false, null);
		//建立一个绑定关系:
		channel.queueBind(queueName, exchangeName, routingKey);
		
        //durable 是否持久化消息
        QueueingConsumer consumer = new QueueingConsumer(channel);
        //参数：队列名称、是否自动ACK、Consumer
        channel.basicConsume(queueName, true, consumer);  
        //循环获取消息  
        while(true){  
            //获取消息，如果没有消息，这一步将会一直阻塞  
            Delivery delivery = consumer.nextDelivery();  
            String msg = new String(delivery.getBody());    
            System.out.println("收到消息：" + msg);  
        } 
	}
}

Topic Exchange

• 所有发送到Topic Exchange 的消息被转发到所有关心RouteKey指定Topic的Queue上
• Exchange将RouteKey和某Topic进行模糊匹配，此时队列需要绑定到一个Topic

注意：可以使用通配符进行模糊匹配

符号"#"匹配一个或多个词

符号"*"匹配不多不少一个词

例如“log.#”能够匹配到“log.info.oa”

例如“log.*“能够匹配到“log.error”

生产者代码

/**
 * @author niugang
 */
public class Producer4TopicExchange {

	
	public static void main(String[] args) throws Exception {
		
		//1 创建ConnectionFactory
		ConnectionFactory connectionFactory = new ConnectionFactory();
		connectionFactory.setHost("localghost");
		connectionFactory.setPort(5672);
		connectionFactory.setVirtualHost("/");
		
		//2 创建Connection
		Connection connection = connectionFactory.newConnection();
		//3 创建Channel
		Channel channel = connection.createChannel();  
		//4 声明
		String exchangeName = "test_topic_exchange";
		String routingKey1 = "user.save";
		String routingKey2 = "user.update";
		String routingKey3 = "user.delete.abc";
		//5 发送
		
		String msg = "Hello World RabbitMQ 4 Topic Exchange Message ...";
		channel.basicPublish(exchangeName, routingKey1 , null , msg.getBytes()); 
		channel.basicPublish(exchangeName, routingKey2 , null , msg.getBytes()); 	
		channel.basicPublish(exchangeName, routingKey3 , null , msg.getBytes()); 
		channel.close();  
        connection.close();  
	}
	
}

消费者代码

/**
 * @author niugang 
 */
public class Consumer4TopicExchange {

	public static void main(String[] args) throws Exception {
		
		
        ConnectionFactory connectionFactory = new ConnectionFactory() ;  
        
        connectionFactory.setHost("localhost");
        connectionFactory.setPort(5672);
		connectionFactory.setVirtualHost("/");
		
        connectionFactory.setAutomaticRecoveryEnabled(true);
        connectionFactory.setNetworkRecoveryInterval(3000);
        Connection connection = connectionFactory.newConnection();
        
        Channel channel = connection.createChannel();  
		//4 声明
		String exchangeName = "test_topic_exchange";
		String exchangeType = "topic";
		String queueName = "test_topic_queue";
		//String routingKey = "user.*";
		String routingKey = "user.#";
		// 1 声明交换机 
		channel.exchangeDeclare(exchangeName, exchangeType, true, false, false, null);
		// 2 声明队列
		channel.queueDeclare(queueName, false, false, false, null);
		// 3 建立交换机和队列的绑定关系:
		channel.queueBind(queueName, exchangeName, routingKey);
		
        //durable 是否持久化消息
        QueueingConsumer consumer = new QueueingConsumer(channel);
        //参数：队列名称、是否自动ACK、Consumer
        channel.basicConsume(queueName, true, consumer);  
        //循环获取消息  
        while(true){  
            //获取消息，如果没有消息，这一步将会一直阻塞  
            Delivery delivery = consumer.nextDelivery();  
            String msg = new String(delivery.getBody());    
            System.out.println("收到消息：" + msg);  
        } 
	}
}

Fanout Exchange

• 不处理路由键。只需要简单的将队列绑定到交换机上

• 发送到交换器的消息都会被转发到与交换机绑定的所有队列上

• Fanout交换机转发消息最快

  fanout类型的exchange不会和routing_key产生任何关系(不会走路由键)
  
  生产者代码

/**
 * @author niugang 
 */
public class Producer4FanoutExchange {

	
	public static void main(String[] args) throws Exception {
		
		//1 创建ConnectionFactory
		ConnectionFactory connectionFactory = new ConnectionFactory();
		connectionFactory.setHost("localhost");
		connectionFactory.setPort(5672);
		connectionFactory.setVirtualHost("/");
		
		//2 创建Connection
		Connection connection = connectionFactory.newConnection();
		//3 创建Channel
		Channel channel = connection.createChannel();  
		//4 声明
		String exchangeName = "test_fanout_exchange";
		//5 发送
		for(int i = 0; i < 10; i ++) {
			String msg = "Hello World RabbitMQ 4 FANOUT Exchange Message ...";
			channel.basicPublish(exchangeName, "", null , msg.getBytes()); 			
		}
		channel.close();  
        connection.close();  
	}
	
}

消费者代码

/**
 * @author niugang
 */
public class Consumer4FanoutExchange {

	public static void main(String[] args) throws Exception {
		
        ConnectionFactory connectionFactory = new ConnectionFactory() ;  
        
        connectionFactory.setHost("localhost");
        connectionFactory.setPort(5672);
		connectionFactory.setVirtualHost("/");
		
        connectionFactory.setAutomaticRecoveryEnabled(true);
        connectionFactory.setNetworkRecoveryInterval(3000);
        Connection connection = connectionFactory.newConnection();
        
        Channel channel = connection.createChannel();  
		//4 声明
		String exchangeName = "test_fanout_exchange";
		String exchangeType = "fanout";
		String queueName = "test_fanout_queue";
		String routingKey = "";	//不设置路由键
		channel.exchangeDeclare(exchangeName, exchangeType, true, false, false, null);
		channel.queueDeclare(queueName, false, false, false, null);
		channel.queueBind(queueName, exchangeName, routingKey);
		
        //durable 是否持久化消息
        QueueingConsumer consumer = new QueueingConsumer(channel);
        //参数：队列名称、是否自动ACK、Consumer
        channel.basicConsume(queueName, true, consumer); 
        //循环获取消息  
        while(true){  
            //获取消息，如果没有消息，这一步将会一直阻塞  
            Delivery delivery = consumer.nextDelivery();  
            String msg = new String(delivery.getBody());    
            System.out.println("收到消息：" + msg);  
        } 
	}
}

Binding-绑定

• Exchange和Exchange、Queue之间的连接关系
• Binding中可以包含RoutingKey或者参数

Queue-消息队列

• 消息队列，实际存储消息数据
• Durability:是否持久化，Durable : 是，Transient :否
• Auto delete:如选yes,代码当最后一个监听被移除之后，该Queue会自动被删除

Message-消息

• 服务器和应用之间传送的数据

• 本质上就是一段数据，由Properties和Payload(Body)组成

• 常用属性：delivery mode 、headers

  delivery mode 为2 标识持久化消息

其他属性

• content_type、content_encoding、priority
• correlation_id、reply_to、expiration、message_id
• timestamp、type、user_id、app_id、cluster_id

Virtual host(虚拟主机)

• 虚拟地址，用于进行逻辑隔离，最上层的消息路由
• 一个Vitual Host里面可以有若干个Exchange和Queue
• 同一个Virtual Host里面不能有相同名称的Exchange和Queue