RabbitMQ入门学习系列(六) Exchange的Topic类型

雨点打透心脏的1/2处 2021-11-02 03:36 304阅读 0赞

### 快速阅读 ###

介绍exchange的topic类型，和Direct类型相似，但是增加了"."和"\#"的匹配。比Direct类型灵活

### Topic消息类型 ###

特点是：topic消息类型不能是任意的routing key, 必须是有点"."组成的单词列表。

和dirct类似，最后也是也相应的key进行匹配

例如：speed.color.sepcies

\*\*注意可以用\*号和\#号出现，和我们日常用的正则表达式含义相近\*\*

"\*"号代表任意一个单词

"\#"号代表0个或多个单词

### 生产者代码 ###

1.  创建连接和信道
2.  声明exchange类型
3.  设置两个routingkey 各自发送两次。一共发送四条消息

static void Main(string[] args)
    {
        var factory = new ConnectionFactory() { HostName = "localhost" };
        using (var connection = factory.CreateConnection())
            using (var channel = connection.CreateModel())
        {
            channel.ExchangeDeclare(exchange: "topicType", type: "topic");
    
            var list = new List<string>();
            list.Add("www.baidu.com");
            list.Add("www.google.com");
            for (var i = 0; i < 2; i++)
            {
                var routingKey = list[0];
                string message = "Hello World!this  message routingkey is  " + routingKey;
                var body = Encoding.UTF8.GetBytes(message);
                var properties = channel.CreateBasicProperties();
                properties.Persistent = true;
    
                channel.BasicPublish(exchange: "topicType",
                                     routingKey: routingKey,
                                     basicProperties: null,
                                     body: body);
    
                Console.WriteLine(" [x] Sent {0},id={1}", message,i);
                Thread.Sleep(1000);
            }
    
            for (var i = 0; i < 2; i++)
            {
                var routingKey = list[1];
                string message = "Hello World!this  message routingkey is  " + routingKey;
                var body = Encoding.UTF8.GetBytes(message);
                var properties = channel.CreateBasicProperties();
                properties.Persistent = true;
    
                channel.BasicPublish(exchange: "topicType",
                                     routingKey: routingKey,
                                     basicProperties: null,
                                     body: body);
    
                Console.WriteLine(" [x] Sent {0},id={1}", message, i);
                Thread.Sleep(1000);
            }
    
        }
    
        Console.WriteLine(" Press [enter] to exit.");
        Console.ReadLine();
    }

### 消费者代码 ###

1.  创建连接和信道
2.  为了测试 topic 类型，限制输入中含 有baidu,google两个关键词和发送的routing key相匹配。
3.  声明交换器类型
4.  队列声明
5.  把exchange和队列绑定到信道上
6.  接受消息

static void Main(string[] args)
    {
        bool flag = true;
        string level = "";
        while (flag)
        {
            Console.WriteLine("请选择要查看的消息类型");
            level = Console.ReadLine();
            if (level.IndexOf(".baidu.")>0 || level.IndexOf(".google.") > 0 )
                flag = false;
            else
                Console.Write("不支持你输入的消息");
        }
    
        var factory = new ConnectionFactory() { HostName = "localhost" };
        using (var connection = factory.CreateConnection())
        {
            using (var channel = connection.CreateModel())
            {
                channel.ExchangeDeclare(exchange: "topicType", type: "topic");
                var queueName = channel.QueueDeclare().QueueName;
                channel.QueueBind(queue: queueName, exchange: "topicType", routingKey: level);
                //以下是区别生产者的
                var consumer = new EventingBasicConsumer(channel);
                consumer.Received += (sender, e) =>
                {
                    var body = e.Body;
                    var message = Encoding.UTF8.GetString(body);
                    var rk = e.RoutingKey;
                    Console.WriteLine("Received {0},routingKey:{1}", message, rk);
                    Thread.Sleep(3000);//模拟耗时任务 ，
                    Console.WriteLine("Received over");
                    channel.BasicAck(deliveryTag: e.DeliveryTag, multiple: false);
                };
                channel.BasicConsume(queue: queueName, autoAck: false, consumer: consumer);
                Console.WriteLine("");
                Console.ReadLine();
            }
    
        }

### 测试结果 ###

我们启动消费者以后，输入四个routingkey去测试

分别是

*.google.\#， \#.google.* , *.google.com,* .baidu.com

分别监听中间是google 或者baidu的消息

结果符合要求

![1562379605711-1.png][]

转载于:https://www.cnblogs.com/hsapphire/p/11148874.html

[1562379605711-1.png]: /images/20211102/71bbe71db5004df98be35d45595eacfe.png