原文:RabbitMQ与.net core(二)Producer与Exchange
Producer：消息的生产者，也就是创建消息的对象
Exchange：消息的接受者，也就是用来接收消息的对象，Exchange接收到消息后将消息按照规则发送到与他绑定的Queue中。下面我们来定义一个Producer与Exchange。
1.新建.netcore console项目，并引入RabbitMQ.Client的Nuget包
2.创建Exchange
using RabbitMQ.Client;
namespace RabbitMQConsole
{
class Program
{
static void Main(string[] args)
{
ConnectionFactory factory = new ConnectionFactory();
factory.HostName = "39.**.**.**";
factory.Port = 5672;
factory.VirtualHost = "/";
factory.UserName = "root";
factory.Password = "root";
var exchange = "change2";
var route = "route2";
var queue = "queue2";
using (var connection = factory.CreateConnection())
{
using (var channel = connection.CreateModel())
{
channel.ExchangeDeclare(exchange, type:"direct", durable: true, autoDelete: false); //创建Exchange
}
}
}
}
}
可以看到Echange的参数有：
type：可选项为，fanout，direct，topic，headers。区别如下：
fanout：发送到所有与当前Exchange绑定的Queue中
direct：发送到与消息的routeKey相同的Rueue中
topic：fanout的模糊版本
headers：发送到与消息的header属性相同的Queue中
durable：持久化
autoDelete：当最后一个绑定（队列或者exchange）被unbind之后，该exchange自动被删除。
运行程序，可以在可视化界面看到change2
接下来我们可以创建与change2绑定的queue
3.创建Queue
using (var channel = connection.CreateModel())
{
channel.ExchangeDeclare(exchange, type: "direct", durable: true, autoDelete: false);
channel.QueueDeclare(queue, durable: true, exclusive: false, autoDelete: false); #创建queue2
channel.QueueBind(queue, exchange, route); #将queue2绑定到exchange2
}
可以看到Echange的参数有：
durable：持久化
exclusive：如果为true，则queue只在channel存在时存在，channel关闭则queue消失
autoDelete：当最后一个绑定（队列或者exchange）被unbind之后，该exchange自动被删除。
去可视化界面看Queue
4.发送消息
using (var channel = connection.CreateModel())
{
channel.ExchangeDeclare(exchange, type: "direct", durable: true, autoDelete: false);
channel.QueueDeclare(queue, durable: true, exclusive: false, autoDelete: false);
channel.QueueBind(queue, exchange, route);
var props = channel.CreateBasicProperties();
props.Persistent = true; #持久化
channel.BasicPublish(exchange, route, true, props, Encoding.UTF8.GetBytes("hello rabbit"));
}
5.消费消息
using RabbitMQ.Client;
using System;
using System.Text;
namespace RabbitMQClient
{
class Program
{
private static readonly ConnectionFactory rabbitMqFactory = new ConnectionFactory()
{
HostName = "39.**.**.**",
Port = 5672,
UserName = "root",
Password = "root",
VirtualHost = "/"
};
static void Main(string[] args)
{
var exchange = "change2";
var route = "route2";
var queue = "queue2";
using (IConnection conn = rabbitMqFactory.CreateConnection())
using (IModel channel = conn.CreateModel())
{
channel.ExchangeDeclare(exchange, "direct", durable: true, autoDelete: false);
channel.QueueDeclare(queue, durable: true, exclusive: false, autoDelete: false);
channel.QueueBind(queue, exchange, route);
while (true)
{
var message = channel.BasicGet(queue, true); #第二个参数说明自动释放消息，如为false需手动释放消息
if(message!=null)
{
var msgBody = Encoding.UTF8.GetString(message.Body);
Console.WriteLine(string.Format("***接收时间:{0}，消息内容：{1}", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"), msgBody));
}
System.Threading.Thread.Sleep(TimeSpan.FromSeconds(1));
}
}
}
}
}
运行查看结果
查看可视化界面
6.手动释放消息
while (true)
{
var message = channel.BasicGet(queue, false);#设置为手动释放
if(message!=null)
{
var msgBody = Encoding.UTF8.GetString(message.Body);
Console.WriteLine(string.Format("***接收时间:{0}，消息内容：{1}", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"), msgBody));
}
channel.BasicAck(message.DeliveryTag, false); #手动释放
System.Threading.Thread.Sleep(TimeSpan.FromSeconds(1));
}
我们再发一条消息，然后开始消费，加个断点调试一下
查看一下Queue中消息状态
然后直接取消调试，不让程序走到释放的那一步，再查看一下消息状态
这么说来只要不走到 channel.BasicAck(message.DeliveryTag, false);这一行，消息就不会被释放掉，我们让程序直接走到这一行代码，查看一下消息的状态
如图已经被释放了
7.让失败的消息回到队列中
while (true)
{
var message = channel.BasicGet(queue, false);
if(message!=null)
{
var msgBody = Encoding.UTF8.GetString(message.Body);
Console.WriteLine(string.Format("***接收时间:{0}，消息内容：{1}", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"), msgBody));
Console.WriteLine(message.DeliveryTag); #当前消息被处理的次序数
if (1==1)
channel.BasicReject(message.DeliveryTag, true);
}
System.Threading.Thread.Sleep(TimeSpan.FromSeconds(1));
}
重新发送4条消息
开始消费
我们可以看到消息一直没有没消费，因为消息被处理之后又放到了队尾
8.监听消息
using (IConnection conn = rabbitMqFactory.CreateConnection())
using (IModel channel = conn.CreateModel())
{
channel.ExchangeDeclare(exchange, "direct", durable: true, autoDelete: false);
channel.QueueDeclare(queue, durable: true, exclusive: false, autoDelete: false);
channel.QueueBind(queue, exchange, route);
channel.BasicQos(prefetchSize: 0, prefetchCount: 10, global: false); #一次接受10条消息，否则rabbit会把所有的消息一次性推到client，会增大client的负荷
EventingBasicConsumer consumer = new EventingBasicConsumer(channel);
consumer.Received += (model, ea) =>
{
Byte[] body = ea.Body;
String message = Encoding.UTF8.GetString(body);
Console.WriteLine( message+Thread.CurrentThread.ManagedThreadId);
channel.BasicAck(deliveryTag: ea.DeliveryTag, multiple: false);
};
channel.BasicConsume(queue: queue, autoAck: false, consumer: consumer);
Console.ReadLine();
}
原文地址：https://www.cnblogs.com/lonelyxmas/p/10237139.html
时间： 2024-11-05 20:40:50