溪客(编程代码)

exchange-direct

直连交换机，交换机根据生产者指定的key，直接投递到跟key完全匹配的队列

exchange在和queue进行binding时会设置routingkey

channel.QueueBind(queue: "create_pdf_queue",
                    exchange: "pdf_events",
                    routingKey: "pdf_create",
                    arguments: null);

然后我们在将消息发送到exchange时会设置对应的routingkey：

channel.BasicPublish(exchange: "pdf_events",
                        routingKey: "pdf_create",
                        basicProperties: properties,
                        body: body);

在direct类型的exchange中，只有这两个routingkey完全相同，exchange才会选择对应的binging进行消息路由。

代码示例：

var factory = new ConnectionFactory() { HostName = "localhost" };
using (var connection = factory.CreateConnection())
using (var channel = connection.CreateModel())
{
    // Direct类型的exchange, 名称 pdf_events
    channel.ExchangeDeclare(exchange: "pdf_events",
                            type: ExchangeType.Direct,
                            durable: true,
                            autoDelete: false,
                            arguments: null);

    // 创建create_pdf_queue队列
    channel.QueueDeclare(queue: "create_pdf_queue",
                            durable: true,
                            exclusive: false,
                            autoDelete: false,
                            arguments: null);

    //创建 pdf_log_queue队列
    channel.QueueDeclare(queue: "pdf_log_queue",
                            durable: true,
                            exclusive: false,
                            autoDelete: false,
                            arguments: null);

    //绑定 pdf_events --> create_pdf_queue 使用routingkey:pdf_create
    channel.QueueBind(queue: "create_pdf_queue",
                        exchange: "pdf_events",
                        routingKey: "pdf_create",
                        arguments: null);

    //绑定 pdf_events --> pdf_log_queue 使用routingkey:pdf_log
    channel.QueueBind(queue: "pdf_log_queue",
                        exchange: "pdf_events",
                        routingKey: "pdf_log",
                        arguments: null);


    var message = "Demo some pdf creating...";
    var body = Encoding.UTF8.GetBytes(message);
    var properties = channel.CreateBasicProperties();
    properties.Persistent = true;

    //发送消息到exchange :pdf_events ,使用routingkey: pdf_create
    //通过binding routinekey的比较，次消息会路由到队列 create_pdf_queue
    channel.BasicPublish(exchange: "pdf_events",
                routingKey: "pdf_create",
                basicProperties: properties,
                body: body);

    message = "pdf loging ...";
    body = Encoding.UTF8.GetBytes(message);
    properties = channel.CreateBasicProperties();
    properties.Persistent = true;

    //发送消息到exchange :pdf_events ,使用routingkey: pdf_log
    //通过binding routinekey的比较，次消息会路由到队列 pdf_log_queue
    channel.BasicPublish(exchange: "pdf_events",
            routingKey: "pdf_log",
            basicProperties: properties,
            body: body);

    
}