教程说明

本系列教程目录大纲：《RabbitMQ系列教程-目录大纲》

本系列教程配套代码：https://gitee.com/Horizon1024/rabbitmt.git（码云地址）

RabbitMQ工作模式之Topics主题模式

4.5.1 简介

在Routing模式下，一个Exchange绑定Queues时可以指定Routing Key，但Routing Key都是固定的值，如果想要通配符的匹配（类似于模糊匹配）我们就得使用Topics模式了，例如red开头的Routing key我都进行消息路由，以green结尾的Routing key的我都进行消息路由等；

Topics模式强调的是topic模式的Exchange，Topics模式也叫主题模式，该模式下的Exchange在绑定Queues时可以指定的一定的通配符，这些通配符指定了路由的规则；

Topics模式下有两个符号：

符号 #：匹配零个或多个词。（0个或多个）
符号 *：匹配不多不少一个词。（必须是一个，0个不行）

因此 red.# 能够匹配到 red.green.xxx，但是 red.*只会匹配到 red.xxx。

小练习：

red.green.green			1/2/3/4
green.green				3/4	
green.red.blue
green.green.green		3/4		
green.red.green			3

red.#.green		
red.green.*			
#.green	
*.green.#

Topics模式官网介绍：https://www.rabbitmq.com/tutorials/tutorial-five-java.html

4.5.2 生产者

package com.lscl.rabbitmq;

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

public class Producer05_Topic {

    public static void main(String[] args) throws Exception {
        // 创建连接工厂,用于获取频道channel
        ConnectionFactory factory = new ConnectionFactory();

        factory.setHost("192.168.40.132");
        factory.setPort(5672);
        factory.setUsername("lscl");
        factory.setPassword("admin");
        factory.setVirtualHost("/lscl");

        // 2.创建连接
        Connection connection = factory.newConnection();

        // 3.创建频道
        Channel channel = connection.createChannel();

        String exchangeName = "test_topic";

        //5. 创建交换机
        channel.exchangeDeclare(exchangeName, BuiltinExchangeType.TOPIC,true,false,false,null);

        //6. 创建队列
        String queue1Name = "test_topic_queue1";
        String queue2Name = "test_topic_queue2";
        String queue3Name = "test_topic_queue3";
        String queue4Name = "test_topic_queue4";

        channel.queueDeclare(queue1Name,true,false,false,null);
        channel.queueDeclare(queue2Name,true,false,false,null);
        channel.queueDeclare(queue3Name,true,false,false,null);
        channel.queueDeclare(queue4Name,true,false,false,null);

        //7. 绑定队列和交换机
        channel.queueBind(queue1Name,exchangeName,"red.#.green");
        channel.queueBind(queue2Name,exchangeName,"red.green.*");
        channel.queueBind(queue3Name,exchangeName,"#.green");
        channel.queueBind(queue4Name,exchangeName,"*.green.#");

        String body = "topic....";
        //8. 发送消息
        /*
            red.green.green			1/2/3/4
            green.green				3/4
            green.red.blue
            green.green.green		3/4
            green.red.green			3

            red.#.green
            red.green.*
            #.green
            *.green.#
         */
//        channel.basicPublish(exchangeName,"red.green.green",null,body.getBytes());
//        channel.basicPublish(exchangeName,"green.green",null,body.getBytes());
//        channel.basicPublish(exchangeName,"green.red.blue",null,body.getBytes());
//        channel.basicPublish(exchangeName,"green.green.green",null,body.getBytes());
        channel.basicPublish(exchangeName,"green.red.green",null,body.getBytes());

        //9. 释放资源
        channel.close();
        connection.close();
    }
}

4.5.3 消费者-1

package com.lscl.rabbitmq;

import com.rabbitmq.client.*;

import java.io.IOException;

public class Consumer07_Topic_01 {

    public static void main(String[] args) throws Exception{
        // 创建连接工厂,用于获取频道channel
        ConnectionFactory factory=new ConnectionFactory();

        factory.setHost("192.168.40.132");
        factory.setPort(5672);
        factory.setUsername("lscl");
        factory.setPassword("admin");
        factory.setVirtualHost("/lscl");

        // 2.创建连接
        Connection connection = factory.newConnection();

        // 3.创建频道
        Channel channel = connection.createChannel();

        // 定义队列
        String queueName="test_topic_queue1";
        channel.queueDeclare(queueName,true,false,false,null);

        Consumer consumer = new DefaultConsumer(channel){

            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {

                System.out.println("body："+new String(body));
            }
        };

        // 接受queue的消息
        channel.basicConsume(queueName,true,consumer);

        // 不释放资源,让rabbitmq一直监听
    }
}