RabbitMQ交换机

RabbitMQ交换机

交换机属性：
Name：交换机名称
Type：交换机类型 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，定制化使用

直流交换机

直连交换机Direct Exchange（完全匹配路由key）

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

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

消费端代码

package com.xieminglu.rabbitmqapi.exchange.direct;

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

public class Consumer4DirectExchange {
    public static void main(String[] args) throws Exception {

        ConnectionFactory connectionFactory = new ConnectionFactory() ;
        connectionFactory.setHost("192.168.248.134");
        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
            QueueingConsumer.Delivery delivery = consumer.nextDelivery();
            String msg = new String(delivery.getBody());
            System.out.println("收到消息：" + msg);
        }
    }
}

生产端代码

package com.xieminglu.rabbitmqapi.exchange.direct;

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

/**
 * @author 小李飞刀
 * @site www.javaxl.com
 * @company
 * @create  2019-11-18 10:22
 */
public class Producer4DirectExchange {
    public static void main(String[] args) throws Exception {

        //1 创建ConnectionFactory
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.248.134");
        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";
//        String routingKey = "test.direct111"; //收不到
        //5 发送

        String msg = "Hello World RabbitMQ 4  Direct Exchange Message 111 ... ";
        channel.basicPublish(exchangeName, routingKey , null , msg.getBytes());

    }
}

代码的区别：
一条消息只会发送在一个队列里

创建一个交换机与队列

所绑定的交换机
控制台输出

主题交换机

主题交换机Topic Exchange（匹配路由规则的交换机）

所有发送到Topic Exchange的消息被转发到所有关系RouteKey中指定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：“#” 匹配一个或者多个词
符号：“” 匹配不多不少一个词
列如：
“log.#” 能够匹配到 “log.info.oa”
“log.” 能够匹配到 “log.err”

消费端代码

package com.xieminglu.rabbitmqapi.exchange.topic;

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

public class Consumer4TopicExchange {
    public static void main(String[] args) throws Exception {


        ConnectionFactory connectionFactory = new ConnectionFactory() ;

        connectionFactory.setHost("192.168.248.134");
        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
            QueueingConsumer.Delivery delivery = consumer.nextDelivery();
            String msg = new String(delivery.getBody());
            System.out.println("收到消息：" + msg);
        }
    }
}

生产端代码

package com.xieminglu.rabbitmqapi.exchange.topic;

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

public class Producer4TopicExchange {
    public static void main(String[] args) throws Exception {

        //1 创建ConnectionFactory
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.248.134");
        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();
    }
}

代码的区别：
一条消息会发送在多个队列里
消费端：

生产端：

控制台输出

并且可以同时绑定多个交换机

输出交换机

输出交换机Fanout Exchange（不做路由）

不处理路由键，只需要简单的将队列绑定到交换机上；
发送到交换机的消息都会被转发到与该交换机绑定的所有队列上；
Fanout交换机转发消息是最快的

消费端代码

package com.xieminglu.rabbitmqapi.exchange.fanout;

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

public class Consumer4FanoutExchange {
    public static void main(String[] args) throws Exception {

        ConnectionFactory connectionFactory = new ConnectionFactory() ;

        connectionFactory.setHost("192.168.248.134");
        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
            QueueingConsumer.Delivery delivery = consumer.nextDelivery();
            String msg = new String(delivery.getBody());
            System.out.println("收到消息：" + msg);
        }
    }
}

生产端代码

package com.xieminglu.rabbitmqapi.exchange.fanout;

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

public class Producer4FanoutExchange {
    public static void main(String[] args) throws Exception {

        //1 创建ConnectionFactory
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.248.134");
        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();
    }
}

消费端：

生产端：


控制台输出

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，代表当最后一个监听被移除之后，该Queue会自动被删除

Message-消息
服务器和应用程序之间传递的数据
本质上就是一段数据，由Properties和Payload（Body）组成
常用属性：delivery model、headers（自定义属性）

Message-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Virtual 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或Queue

小结：
交换机的概念，
在没有交换机的时候，我们的消息队列会处理所有发给这个消息队列的消息，然后由消费者一个一个消费这个队列里面的消息，如果由集群的话还会分摊对这个消息队列的处理。只不过这里面有一个
Message acknowledgment的概念，这将会导致严重的bug——Queue中堆积的消息会越来越多

当然一般的消息中间件都不会这么干，我们使用了交换机后，我们看到我们的三种策略，其实都可以说由交换机去找跟它所绑定的消息队列，如果生产端的路由键不符合要求或找不到消息队列定好的路由键的话就会进行其他处理。

来源：CSDN

作者：迷鹿小女子

链接：https://blog.csdn.net/xieminglu/article/details/103653895