通配符模式（Topics）

根据通配符（Topics）来接收消息，将路由key和某模式进行匹配，此时队列需要绑定在一个模式上，#匹配一个词或多个词，*只匹配一个词。

使用的Exchange类型为Topic

Topic类型的Exchange：

（1）Topic类型与Direct相比，都是可以根据RoutingKey将消息路由到不同的队列，只不过Topic类型可以让队列在绑定路由时使用通配符

（2）Topic类型的RoutingKey一般是由一个或多个单词构成，多个单词之间用“.”分割，如item.insert

（3）Topic类型通配符规则：#匹配一个或多个词，*恰好匹配一个词，例如item.#，可以匹配item.insert或item.insert.user，item.*只能匹配

         item.insert或item.user

Demo 

生产者类WeatherTopic.cs

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Text;
 4 using RabbitMQ.Client;
 5 using RabbitMQ.Client.Events;
 6 using RabbitMQ.Common;
 7 
 8 namespace RabbitMQ.Producer.Producer
 9 {
10     public class WeatherTopic
11     {
12         public static void SendWeather()
13         {
14             Dictionary<string, string> area = new Dictionary<string, string>();
15             area.Add("china.hunan.changsha.20211231", "中国湖南长沙20211231天气数据");
16             area.Add("china.hubei.wuhan.20211231", "中国湖北武汉20211231天气数据");
17             area.Add("china.hubei.xiangyang.20211231", "中国湖北襄阳20211231天气数据");
18             area.Add("us.cal.lsj.20211231", "美国加州洛杉矶20211231天气数据");
19 
20             using (var connection = RabbitUtils.GetConnection().CreateConnection())
21             {
22                 using (var channel = connection.CreateModel())
23                 {
24                     foreach (var item in area)
25                     {
26                         channel.BasicPublish(RabbitConstant.EXCHANGE_WEATHER_TOPIC, item.Key, null, Encoding.UTF8.GetBytes(item.Value));
27                     }
28                     Console.WriteLine("气象信息发送成功！");
29                     Console.WriteLine("Press [Enter] to exit");
30                     Console.ReadLine();
31                 }
32             }
33         }
34     }
35 }

消费者01 WeatherTopic.cs

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Text;
 4 using RabbitMQ.Client;
 5 using RabbitMQ.Client.Events;
 6 using RabbitMQ.Common;
 7 
 8 namespace RabbitMQ.Consumer01.Consumer
 9 {
10     public class WeatherTopic
11     {
12         public static void ReceiveWeatherInfo()
13         {
14             using (var connection = RabbitUtils.GetConnection().CreateConnection())
15             {
16                 using (var channel = connection.CreateModel())
17                 {
18                     channel.ExchangeDeclare(RabbitConstant.EXCHANGE_WEATHER_TOPIC, ExchangeType.Topic);
19                     channel.QueueDeclare(RabbitConstant.QUEUE_BAIDU, true, false, false, null);
20                     /*
21                      * QueueBind用于将队列与交换机绑定
22                      * queue:队列名
23                      * exchange:交换机名
24                      * routingKey：路由key
25                      */
26                     channel.QueueBind(queue: RabbitConstant.QUEUE_BAIDU,
27                                       exchange: RabbitConstant.EXCHANGE_WEATHER_TOPIC,
28                                       routingKey: "china.hubei.*.20211231");
29                     channel.BasicQos(0, 1, false);
30                     var consumer = new EventingBasicConsumer(channel);
31 
32                     consumer.Received += (model, ea) =>
33                     {
34                         var message = Encoding.UTF8.GetString(ea.Body.ToArray());
35                         Console.WriteLine($"百度收到的气象信息：{message}");
36                         channel.BasicAck(ea.DeliveryTag, false);
37                     };
38                     channel.BasicConsume(queue: RabbitConstant.QUEUE_BAIDU,
39                                  autoAck: false,
40                                  consumer: consumer);
41                     Console.WriteLine(" Press [enter] to exit.");
42                     Console.ReadLine();
43                 }
44             }
45         }
46     }
47 }

消费者02 WeatherTopic.cs代码

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Text;
 4 using RabbitMQ.Client;
 5 using RabbitMQ.Client.Events;
 6 using RabbitMQ.Common;
 7 
 8 namespace RabbitMQ.Consumer02.Consumer
 9 {
10     public class WeatherTopic
11     {
12         public static void ReceiveWeatherInfo()
13         {
14             using (var connection = RabbitUtils.GetConnection().CreateConnection())
15             {
16                 using (var channel = connection.CreateModel())
17                 {
18                     channel.ExchangeDeclare(RabbitConstant.EXCHANGE_WEATHER_TOPIC, ExchangeType.Topic);
19                     channel.QueueDeclare(RabbitConstant.QUEUE_SINA, true, false, false, null);
20                     /*
21                      * QueueBind用于将队列与交换机绑定
22                      * queue:队列名
23                      * exchange:交换机名
24                      * routingKey：路由key
25                      */
26                     channel.QueueBind(queue: RabbitConstant.QUEUE_SINA,
27                                       exchange: RabbitConstant.EXCHANGE_WEATHER_TOPIC,
28                                       routingKey: "china.#");
29                     channel.BasicQos(0, 1, false);
30                     var consumer = new EventingBasicConsumer(channel);
31 
32                     consumer.Received += (model, ea) =>
33                     {
34                         var message = Encoding.UTF8.GetString(ea.Body.ToArray());
35                         Console.WriteLine($"新浪收到的气象信息：{message}");
36                         channel.BasicAck(ea.DeliveryTag, false);
37                     };
38                     channel.BasicConsume(queue: RabbitConstant.QUEUE_SINA,
39                                  autoAck: false,
40                                  consumer: consumer);
41                     Console.WriteLine(" Press [enter] to exit.");
42                     Console.ReadLine();
43                 }
44             }
45         }
46 
47     }
48 }

执行结果

运行前配置：删除原来的Exchange,具体操作如下

  参考链接：https://www.bilibili.com/video/BV1GU4y1w7Yq?p=8

                    https://mp.weixin.qq.com/s/QG3uXhhpkE_Uo6Me15mxdg