欢迎大家来到IT世界,在知识的湖畔探索吧!
前言
在如今的互联网时代,消息队列中间件已然成为了分布式系统中重要的组件,它可以解决应用耦合,异步消息,流量削峰等应用场景。借助消息队列,我们可以实现架构的高可用、高性能、可伸缩等特性,是大型分布式系统架构中不可或缺的中间件。
目前比较流行的消息队列中间件主要有:RabbitMQ, NATS, Kafka, ZeroMQ, Amazon SQS, ServiceStack, Apache Pulsar, RocketMQ, ActiveMQ, IBM MQ等等。
本文主要为大家分享的是在.NET 5应用程序中使用消息中间件RabbitMQ的示例教程。
准备工作
在开始本文实战之前,请准备以下环境:
- 消息中间件:RabbitMQ
- 开发工具:Visual Studio 2019或VS Code或Rider
笔者使用的开发工具是Rider 2021.1.2。
准备解决方案和项目
创建项目
打开Rider,创建一个名为RabbitDemo的解决方案,再依次创建三个基于.NET 5的项目,分别为:RabbitDemo.Shared, RabbitDemo.Send以及RabbitDemo.Receive。
- RabbitDemo.Shared 项目主要用于存放共用的RabbitMQ的连接相关的类;
- RabbitDemo.Send 项目主要用于模拟生产者(发布者);
- RabbitDemo.Receive 项目主要用于模拟消费者(订阅者)
安装依赖包
首先,在以上创建的三个项目中分别使用包管理工具或者命令行工具安装RabbitMQ.Client依赖包,如下:
编写RabbitDemo.Shared项目
RabbitDemo.Shared项目主要用于存放共用的RabbitMQ的连接相关的类。这里我们创建一个RabbitChannel类,然后在其中添加创建一些连接RabbitMQ相关的方法,包括初始化RabbitMQ的连接,关闭RabbitMQ连接等,代码如下:
using RabbitMQ.Client;
namespace RabbitDemo.Shared
{
public class RabbitChannel
{
public static IModel Channel;
private static IConnection _connection;
public static IConnection Connection => _connection;
public static void Init()
{
_connection = new ConnectionFactory
{
HostName = "xxxxxx", // 你的RabbitMQ主机地址
UserName = "xxx", // RabbitMQ用户名
VirtualHost = "xxx", // RabbitMQ虚拟主机
Password = "xxxxxx" // RabbitMQ密码
}.CreateConnection();
Channel = _connection.CreateModel();
}
public static void CloseConnection()
{
if (Channel != null)
{
Channel.Close();
Channel.Dispose();
}
if (_connection != null)
{
_connection.Close();
_connection.Dispose();
}
}
}
}
欢迎大家来到IT世界,在知识的湖畔探索吧!
编写消息生产者
在项目RabbitDemo.Send中,引用项目RabbitDemo.Shared,然后创建一个名为Send.cs类,并在其中编写生产者的代码,如下:
欢迎大家来到IT世界,在知识的湖畔探索吧!using System;
using System.Text;
using System.Threading;
using RabbitDemo.Shared;
using RabbitMQ.Client;
namespace RabbitDemo.Send
{
public class Send
{
public static void Run()
{
for (var i = 0; i < 5; i++)
{
Publish(i);
Thread.Sleep(500);
}
}
private static void Publish(int index)
{
RabbitChannel.Channel.QueueDeclare(queue: "hello",
durable: false,
exclusive: false,
autoDelete: false,
arguments: null);
var message = #34;Hello World from sender({index})!";
var body = Encoding.UTF8.GetBytes(message);
RabbitChannel.Channel.BasicPublish(exchange: "",
routingKey: "hello",
basicProperties: null,
body: body);
Console.WriteLine(" [x] Sent {0}", message);
}
}
}
以上示例模拟的是一个生产者一次生产了5条消息,并将消息存储到了RabbitMQ的消息队列中。
修改此项目中的Program.cs代码如下:
using System;
using RabbitDemo.Shared;
namespace RabbitDemo.Send
{
static class Program
{
static void Main(string[] args)
{
Console.WriteLine("按任意键退出.");
RabbitChannel.Init();
Send.Run();
Console.ReadKey();
Console.WriteLine("正在关闭连接...");
RabbitChannel.CloseConnection();
Console.WriteLine("连接已关闭,退出程序.");
}
}
}
编写消息消费者
在项目RabbitDemo.Receive中,引用项目RabbitDemo.Shared,然后创建一个名为Receive.cs的类,并在其中编写消费者的代码,如下:
欢迎大家来到IT世界,在知识的湖畔探索吧!using System;
using System.Linq;
using System.Text;
using RabbitDemo.Shared;
using RabbitMQ.Client;
using RabbitMQ.Client.Events;
namespace RabbitDemo.Receive
{
public class Receive
{
public static void Run()
{
RabbitChannel.Channel.QueueDeclare(queue: "hello",
durable: false,
exclusive: false,
autoDelete: false,
arguments: null);
var consumer = new EventingBasicConsumer(RabbitChannel.Channel);
consumer.Received += (model, ea) =>
{
var body = ea.Body.ToArray();
var message = Encoding.UTF8.GetString(body);
Console.WriteLine(" [x] Received {0}", message);
RabbitChannel.Channel.BasicAck(deliveryTag:ea.DeliveryTag,multiple:false);
};
RabbitChannel.Channel.BasicConsume(queue: "hello",
autoAck: false,
consumer: consumer);
}
}
}
修改此项目中的Program.cs代码如下:
using System;
using RabbitDemo.Shared;
namespace RabbitDemo.Receive
{
static class Program
{
static void Main(string[] args)
{
Console.WriteLine("按任意键退出.");
RabbitChannel.Init();
Receive.Run();
Console.ReadKey();
Console.WriteLine("正在关闭连接...");
RabbitChannel.CloseConnection();
Console.WriteLine("连接已关闭,退出程序.");
}
}
}
运行
分别生成和运行生产者和消费者项目,运行效果如下:
从上图可以看出,整个演示过程,RabbitMQ的消息消息是非常即时的,消费者几乎可以实时地消费生产者生产的消息。
需要确认的消息队列
在上面的生产者/消费者示例中,消息一经消费者消费,RabbitMQ会立即将消息从队列中移除。但在某些场景中,我们需要消费者确认消息被正确消费后再将其从队列中移除,RabbitMQ提供了消费确认的功能,下面我们来使用示例演示。
首先在RabbitDemo.Send中创建名为Worker.cs的类,并编写如下代码:
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Text;
using System.Threading;
using RabbitDemo.Shared;
using RabbitMQ.Client;
namespace RabbitDemo.Send
{
public class Worker
{
public static void Run()
{
for (var i = 0; i < 5; i++)
{
Thread.Sleep(1000);
Publish(i);
}
}
private static void Publish(int index)
{
var args = new Dictionary<string, object>
{
{"x-max-priority", 0}
};
RabbitChannel.Channel.QueueDeclare(queue: "task_queue",
durable: true,
exclusive: false,
autoDelete: false,
arguments: args);
var message = #34;Hello({index}) at {DateTime.Now.ToString(CultureInfo.InvariantCulture)}";
var body = Encoding.UTF8.GetBytes(message);
var properties = RabbitChannel.Channel.CreateBasicProperties();
properties.Persistent = true;
properties.Headers = new Dictionary<string, object>
{
{"order-no", #34;1001{index}"}
};
RabbitChannel.Channel.BasicPublish(exchange: "",
routingKey: "task_queue",
basicProperties: properties,
body: body);
Console.WriteLine(" [x] Sent {0}", message);
}
}
}
此示例模拟生和了5条消息,并将消息存放到了RabbitMQ的task_queue队列中,其中我们还通过QueueDeclare()方法的arguments参数设置了队列的优先级,也通过basicProperties参数添加了自定义的消息头(Header)参数order-no。
接着,在项目RabbitDemo.Receive项目中创建一个名为Task.cs的类,并编写如下的消费者代码:
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using RabbitDemo.Shared;
using RabbitMQ.Client;
using RabbitMQ.Client.Events;
namespace RabbitDemo.Receive
{
public class Task
{
public static void Run()
{
Console.WriteLine(" [*] Waiting for messages.");
Consume();
}
private static void Consume()
{
var args = new Dictionary<string, object>
{
{"x-max-priority", 0}
};
RabbitChannel.Channel.QueueDeclare(queue: "task_queue",
durable: true,
exclusive: false,
autoDelete: false,
arguments: args);
RabbitChannel.Channel.BasicQos(prefetchSize: 0, prefetchCount: 1, global: false);
var consumer = new EventingBasicConsumer(RabbitChannel.Channel);
consumer.Received += (sender, ea) =>
{
var body = ea.Body.ToArray();
var message = Encoding.UTF8.GetString(body);
Console.WriteLine(" [x] Received {0}", message);
var messageBuilder = new StringBuilder();
foreach (var headerKey in ea.BasicProperties.Headers.Keys)
{
var value = ea.BasicProperties.Headers[headerKey] as byte[];
messageBuilder.Append("Header key: ")
.Append(headerKey)
.Append(", value: ")
.Append(Encoding.UTF8.GetString(value))
.Append("; ");
}
Console.WriteLine(#34;Customer properties:{messageBuilder.ToString()}");
var sleep = 6;
Thread.Sleep(sleep * 1000);
Console.WriteLine(" [x] Done");
((EventingBasicConsumer)sender)?.Model.BasicAck(deliveryTag: ea.DeliveryTag, multiple: false);
};
RabbitChannel.Channel.BasicConsume(queue: "task_queue",
autoAck: false,
consumer: consumer);
}
}
}
在这段消费者代码中,我们主要关注的是如何向RabbitMQ确认消息的正确消费,与上面的Receive.cs消费者相比,此示例中设置了
RabbitChannel.Channel.BasicQos(prefetchSize: 0, prefetchCount: 1, global: false);
这里的设置表示:一个消费者最多只能一次拉取1条消息
和
((EventingBasicConsumer)sender)?.Model.BasicAck(deliveryTag: ea.DeliveryTag, multiple: false);
这条语句表示消息已确认被正常消费。
修改生产者的Program.cs:
using System;
using RabbitDemo.Shared;
namespace RabbitDemo.Send
{
static class Program
{
static void Main(string[] args)
{
Console.WriteLine("按任意键退出.");
RabbitChannel.Init();
Worker.Run();
Console.ReadKey();
Console.WriteLine("正在关闭连接...");
RabbitChannel.CloseConnection();
Console.WriteLine("连接已关闭,退出程序.");
}
}
}
修改消费的Program.cs:
using System;
using RabbitDemo.Shared;
namespace RabbitDemo.Receive
{
static class Program
{
static void Main(string[] args)
{
Console.WriteLine("按任意键退出.");
RabbitChannel.Init();
Task.Run();
Console.ReadKey();
Console.WriteLine("正在关闭连接...");
RabbitChannel.CloseConnection();
Console.WriteLine("连接已关闭,退出程序.");
}
}
}
效果如下:
注:本文首发于码友网–《.NET 5/.NET Core应用程序中使用消息队列中间件RabbitMQ示例教程》
前言
在如今的互联网时代,消息队列中间件已然成为了分布式系统中重要的组件,它可以解决应用耦合,异步消息,流量削峰等应用场景。借助消息队列,我们可以实现架构的高可用、高性能、可伸缩等特性,是大型分布式系统架构中不可或缺的中间件。
目前比较流行的消息队列中间件主要有:RabbitMQ, NATS, Kafka, ZeroMQ, Amazon SQS, ServiceStack, Apache Pulsar, RocketMQ, ActiveMQ, IBM MQ等等。
本文主要为大家分享的是在.NET 5应用程序中使用消息中间件RabbitMQ的示例教程。
准备工作
在开始本文实战之前,请准备以下环境:
- 消息中间件:RabbitMQ
- 开发工具:Visual Studio 2019或VS Code或Rider
笔者使用的开发工具是Rider 2021.1.2。
准备解决方案和项目
创建项目
打开Rider,创建一个名为RabbitDemo的解决方案,再依次创建三个基于.NET 5的项目,分别为:RabbitDemo.Shared, RabbitDemo.Send以及RabbitDemo.Receive。
- RabbitDemo.Shared 项目主要用于存放共用的RabbitMQ的连接相关的类;
- RabbitDemo.Send 项目主要用于模拟生产者(发布者);
- RabbitDemo.Receive 项目主要用于模拟消费者(订阅者)
安装依赖包
首先,在以上创建的三个项目中分别使用包管理工具或者命令行工具安装RabbitMQ.Client依赖包,如下:
编写RabbitDemo.Shared项目
RabbitDemo.Shared项目主要用于存放共用的RabbitMQ的连接相关的类。这里我们创建一个RabbitChannel类,然后在其中添加创建一些连接RabbitMQ相关的方法,包括初始化RabbitMQ的连接,关闭RabbitMQ连接等,代码如下:
using RabbitMQ.Client;
namespace RabbitDemo.Shared
{
public class RabbitChannel
{
public static IModel Channel;
private static IConnection _connection;
public static IConnection Connection => _connection;
public static void Init()
{
_connection = new ConnectionFactory
{
HostName = "xxxxxx", // 你的RabbitMQ主机地址
UserName = "xxx", // RabbitMQ用户名
VirtualHost = "xxx", // RabbitMQ虚拟主机
Password = "xxxxxx" // RabbitMQ密码
}.CreateConnection();
Channel = _connection.CreateModel();
}
public static void CloseConnection()
{
if (Channel != null)
{
Channel.Close();
Channel.Dispose();
}
if (_connection != null)
{
_connection.Close();
_connection.Dispose();
}
}
}
}
编写消息生产者
在项目RabbitDemo.Send中,引用项目RabbitDemo.Shared,然后创建一个名为Send.cs类,并在其中编写生产者的代码,如下:
using System;
using System.Text;
using System.Threading;
using RabbitDemo.Shared;
using RabbitMQ.Client;
namespace RabbitDemo.Send
{
public class Send
{
public static void Run()
{
for (var i = 0; i < 5; i++)
{
Publish(i);
Thread.Sleep(500);
}
}
private static void Publish(int index)
{
RabbitChannel.Channel.QueueDeclare(queue: "hello",
durable: false,
exclusive: false,
autoDelete: false,
arguments: null);
var message = #34;Hello World from sender({index})!";
var body = Encoding.UTF8.GetBytes(message);
RabbitChannel.Channel.BasicPublish(exchange: "",
routingKey: "hello",
basicProperties: null,
body: body);
Console.WriteLine(" [x] Sent {0}", message);
}
}
}
以上示例模拟的是一个生产者一次生产了5条消息,并将消息存储到了RabbitMQ的消息队列中。
修改此项目中的Program.cs代码如下:
using System;
using RabbitDemo.Shared;
namespace RabbitDemo.Send
{
static class Program
{
static void Main(string[] args)
{
Console.WriteLine("按任意键退出.");
RabbitChannel.Init();
Send.Run();
Console.ReadKey();
Console.WriteLine("正在关闭连接...");
RabbitChannel.CloseConnection();
Console.WriteLine("连接已关闭,退出程序.");
}
}
}
编写消息消费者
在项目RabbitDemo.Receive中,引用项目RabbitDemo.Shared,然后创建一个名为Receive.cs的类,并在其中编写消费者的代码,如下:
using System;
using System.Linq;
using System.Text;
using RabbitDemo.Shared;
using RabbitMQ.Client;
using RabbitMQ.Client.Events;
namespace RabbitDemo.Receive
{
public class Receive
{
public static void Run()
{
RabbitChannel.Channel.QueueDeclare(queue: "hello",
durable: false,
exclusive: false,
autoDelete: false,
arguments: null);
var consumer = new EventingBasicConsumer(RabbitChannel.Channel);
consumer.Received += (model, ea) =>
{
var body = ea.Body.ToArray();
var message = Encoding.UTF8.GetString(body);
Console.WriteLine(" [x] Received {0}", message);
RabbitChannel.Channel.BasicAck(deliveryTag:ea.DeliveryTag,multiple:false);
};
RabbitChannel.Channel.BasicConsume(queue: "hello",
autoAck: false,
consumer: consumer);
}
}
}
修改此项目中的Program.cs代码如下:
using System;
using RabbitDemo.Shared;
namespace RabbitDemo.Receive
{
static class Program
{
static void Main(string[] args)
{
Console.WriteLine("按任意键退出.");
RabbitChannel.Init();
Receive.Run();
Console.ReadKey();
Console.WriteLine("正在关闭连接...");
RabbitChannel.CloseConnection();
Console.WriteLine("连接已关闭,退出程序.");
}
}
}
运行
分别生成和运行生产者和消费者项目,运行效果如下:
从上图可以看出,整个演示过程,RabbitMQ的消息消息是非常即时的,消费者几乎可以实时地消费生产者生产的消息。
需要确认的消息队列
在上面的生产者/消费者示例中,消息一经消费者消费,RabbitMQ会立即将消息从队列中移除。但在某些场景中,我们需要消费者确认消息被正确消费后再将其从队列中移除,RabbitMQ提供了消费确认的功能,下面我们来使用示例演示。
首先在RabbitDemo.Send中创建名为Worker.cs的类,并编写如下代码:
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Text;
using System.Threading;
using RabbitDemo.Shared;
using RabbitMQ.Client;
namespace RabbitDemo.Send
{
public class Worker
{
public static void Run()
{
for (var i = 0; i < 5; i++)
{
Thread.Sleep(1000);
Publish(i);
}
}
private static void Publish(int index)
{
var args = new Dictionary<string, object>
{
{"x-max-priority", 0}
};
RabbitChannel.Channel.QueueDeclare(queue: "task_queue",
durable: true,
exclusive: false,
autoDelete: false,
arguments: args);
var message = #34;Hello({index}) at {DateTime.Now.ToString(CultureInfo.InvariantCulture)}";
var body = Encoding.UTF8.GetBytes(message);
var properties = RabbitChannel.Channel.CreateBasicProperties();
properties.Persistent = true;
properties.Headers = new Dictionary<string, object>
{
{"order-no", #34;1001{index}"}
};
RabbitChannel.Channel.BasicPublish(exchange: "",
routingKey: "task_queue",
basicProperties: properties,
body: body);
Console.WriteLine(" [x] Sent {0}", message);
}
}
}
此示例模拟生和了5条消息,并将消息存放到了RabbitMQ的task_queue队列中,其中我们还通过QueueDeclare()方法的arguments参数设置了队列的优先级,也通过basicProperties参数添加了自定义的消息头(Header)参数order-no。
接着,在项目RabbitDemo.Receive项目中创建一个名为Task.cs的类,并编写如下的消费者代码:
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using RabbitDemo.Shared;
using RabbitMQ.Client;
using RabbitMQ.Client.Events;
namespace RabbitDemo.Receive
{
public class Task
{
public static void Run()
{
Console.WriteLine(" [*] Waiting for messages.");
Consume();
}
private static void Consume()
{
var args = new Dictionary<string, object>
{
{"x-max-priority", 0}
};
RabbitChannel.Channel.QueueDeclare(queue: "task_queue",
durable: true,
exclusive: false,
autoDelete: false,
arguments: args);
RabbitChannel.Channel.BasicQos(prefetchSize: 0, prefetchCount: 1, global: false);
var consumer = new EventingBasicConsumer(RabbitChannel.Channel);
consumer.Received += (sender, ea) =>
{
var body = ea.Body.ToArray();
var message = Encoding.UTF8.GetString(body);
Console.WriteLine(" [x] Received {0}", message);
var messageBuilder = new StringBuilder();
foreach (var headerKey in ea.BasicProperties.Headers.Keys)
{
var value = ea.BasicProperties.Headers[headerKey] as byte[];
messageBuilder.Append("Header key: ")
.Append(headerKey)
.Append(", value: ")
.Append(Encoding.UTF8.GetString(value))
.Append("; ");
}
Console.WriteLine(#34;Customer properties:{messageBuilder.ToString()}");
var sleep = 6;
Thread.Sleep(sleep * 1000);
Console.WriteLine(" [x] Done");
((EventingBasicConsumer)sender)?.Model.BasicAck(deliveryTag: ea.DeliveryTag, multiple: false);
};
RabbitChannel.Channel.BasicConsume(queue: "task_queue",
autoAck: false,
consumer: consumer);
}
}
}
在这段消费者代码中,我们主要关注的是如何向RabbitMQ确认消息的正确消费,与上面的Receive.cs消费者相比,此示例中设置了
RabbitChannel.Channel.BasicQos(prefetchSize: 0, prefetchCount: 1, global: false);
这里的设置表示:一个消费者最多只能一次拉取1条消息
和
((EventingBasicConsumer)sender)?.Model.BasicAck(deliveryTag: ea.DeliveryTag, multiple: false);
这条语句表示消息已确认被正常消费。
修改生产者的Program.cs:
using System;
using RabbitDemo.Shared;
namespace RabbitDemo.Send
{
static class Program
{
static void Main(string[] args)
{
Console.WriteLine("按任意键退出.");
RabbitChannel.Init();
Worker.Run();
Console.ReadKey();
Console.WriteLine("正在关闭连接...");
RabbitChannel.CloseConnection();
Console.WriteLine("连接已关闭,退出程序.");
}
}
}
修改消费的Program.cs:
using System;
using RabbitDemo.Shared;
namespace RabbitDemo.Receive
{
static class Program
{
static void Main(string[] args)
{
Console.WriteLine("按任意键退出.");
RabbitChannel.Init();
Task.Run();
Console.ReadKey();
Console.WriteLine("正在关闭连接...");
RabbitChannel.CloseConnection();
Console.WriteLine("连接已关闭,退出程序.");
}
}
}
效果如下:
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