NETCORE

NETCORE - RabbitMQ的使用

 NET Core微服务之基于EasyNetQ使用RabbitMQ消息队列

 

安装部署RabbbitMQ：https://www.cnblogs.com/1285026182YUAN/p/12896851.html 

NETCORE中的订阅模式

一、控制台项目

创建三个项目：

• NETCORE.RabbitMQ.Publisher：Console项目
• NETCORE.RabbitMQ.Subscriber1：Console项目
• NETCORE.RabbitMQ.Messages：类库

 Publisher 与 Subscriber1 项目安装 EasyNetQ 插件

NuGet>Install-Package EasyNetQ　　

Messages 项目，新增一个类

    public class TextMessage
    {
        public string Text { get; set; }
    }

Publisher项目，添加以下代码

using EasyNetQ;
using NETCORE.RabbitMQ.Messages;
using System;

namespace NETCORE.RabbitMQ.Publisher
{
    class Program
    {
        static void Main(string[] args)
        {
            var connStr = "host=192.168.122.199:5672;virtualHost=vhost_lihy;username=admin;password=123456";

            using (var bus = RabbitHutch.CreateBus(connStr))
            {
                var input = "";

                Console.WriteLine("I'm Publisher");
                Console.WriteLine("Please enter a message. 'Quit' to quit.");

                while ((input = Console.ReadLine()) != "Quit")
                {
                    bus.Publish(new TextMessage
                    {
                        Text = input
                    });
                }
            }
 

            Console.WriteLine("Hello World!");
        }
    }
}

可以看到，我们在其中使用EasyNetQ高度封装的接口创建了一个IBus接口的实例，通过这个IBus实例我们可以通过一个超级Easy的Publish接口进行发布消息。这里主要是读取用户在控制台中输入的消息字符串进行发送。实际中，发送的一般都是一个或多个复杂的实体对象。

Subscriber项目，添加以下代码

using System;
using EasyNetQ;
using NETCORE.RabbitMQ.Messages;

namespace NETCORE.RabbitMQ.Subscriber1
{
    class Program
    {
        static void Main(string[] args)
        {
            var connStr = "host=192.168.122.199:5672;virtualHost=vhost_lihy;username=admin;password=123456";

            using (var bus = RabbitHutch.CreateBus(connStr))
            {
                bus.Subscribe<TextMessage>("my_test_subscriptionid", HandleTextMessage);


                Console.WriteLine("I'm Subscriber1");
                Console.WriteLine("Listening for messages. Hit <return> to quit.");
                Console.ReadLine();
            }
             
            Console.WriteLine("Hello World!");
        }

        public static void HandleTextMessage(TextMessage textMessage)
        {
            Console.ForegroundColor = ConsoleColor.Red;
            Console.WriteLine("Got message: {0}", textMessage.Text);
            Console.ResetColor();
        }
    }
}

这里主要是通过IBus实例去订阅消息（这里是除非用户关闭程序否则一直处于监听状态），当发布者发布了指定类型的消息之后，这里就把它打印出来（红色字体显示）。

测试：

通过控制台信息查看结果：

 

 

 

二、 WebApi项目

　　创建上面提到的这几个项目，这里我选择ASP.NET Core WebAPI类型。

　　分别为这三个项目通过NuGet安装EasyNetQ组件

PM> Install-Package EasyNetQ

在messages 项目中 下面是这个demo用到的一个消息对象实体：通过标签声明队列名称。

using System;
using System.Collections.Generic;
using System.Text;
using EasyNetQ;

namespace NETCORE.RabbitMQ.Messages
{

    [Queue("Qka.Client", ExchangeName = "Qka.Client")]
    public class ClientMessage
    {
        public int ClientId { get; set; }
        public string ClientName { get; set; }
        public string Sex { get; set; }
        public int Age { get; set; }
        // N: Non-Smoker, S: Smoker
        public string SmokerCode { get; set; }
        // Bachelor, Master, Doctor
        public string Education { get; set; }
        public decimal YearIncome { get; set; }
    }
}

　此外，为了充分简化代码量，EasyNetQ提供了一个AutoSubscriber的方式，可以通过接口和标签快速地让一个类成为Consumer。详细内容参考：https://github.com/EasyNetQ/EasyNetQ/wiki/Auto-Subscriber

　　这里为了快速的在项目中使用Subscriber，添加一个扩展方法，它会从注入的服务中取出IBus实例对象，并自动帮我们进行Subscriber（那些实现了IConsume接口的类）的注册。具体用法见后面的介绍。

Publisher项目：ClientService

　　ClientService作为发布者，这里假设我们在API中处理完业务代码后，将message发布给RabbitMQ：

appsettings.json 配置文件

{
  "Logging": {
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "ConnectionStrings": {
    "RabbitMQ_Conn": "host=192.168.122.199:5672;virtualHost=vhost_lihy;username=admin;password=123456"
  },
  "AllowedHosts": "*"
}

Startup.cs 文件，通过以下代码注入统一的IBus实例对象：

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

            services.AddSingleton(RabbitHutch.CreateBus(Configuration.GetConnectionString("RabbitMQ_Conn")));
        }

创建控制器 ClientController 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using EasyNetQ;
using Microsoft.AspNetCore.Mvc;
using NETCORE.RabbitMQ.Messages;

namespace NETCORE.RabbitMQ.API.Publisher.Controllers
{
    [Produces("application/json")]
    [Route("api/Client")]
    public class ClientController : Controller
    { 
        private readonly IBus bus;

        public ClientController(  IBus _bus)
        { 
            bus = _bus;
        }
         
        [Route("GetVs")]
        [HttpGet]
        public async Task<string> GetVs()
        {
            // Business Logic here...
            // eg.Add new client to your service databases via EF
            // Sample Publish
            ClientMessage message = new ClientMessage
            {
                ClientId = 12,
                ClientName = "lihongyuan",
                Sex ="sss",
                Age = 29,
                SmokerCode = "N",
                Education = "Master",
                YearIncome = 100000
            };
            await bus.PublishAsync(message);

            return "Add Client Success! You will receive some letter later.";
        }
    }
}

当然，你可以使用同步方法：bus.Publish(message);

 

Subscriber项目：

　　订阅者接收消息。

appsettings.json 配置文件

{
  "Logging": {
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "ConnectionStrings": {
    "RabbitMQ_Conn": "host=192.168.122.199:5672;virtualHost=vhost_lihy;username=admin;password=123456"
  },
  "AllowedHosts": "*"
}

Startup.cs 文件，通过以下代码注入统一的IBus实例对象：

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

            services.AddSingleton(RabbitHutch.CreateBus(Configuration.GetConnectionString("RabbitMQ_Conn")));
        }

创建 AppBuilderExtension.cs 类

using EasyNetQ;
using EasyNetQ.AutoSubscribe;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;

namespace NETCORE.RabbitMQ.API.Subscriber
{
    public static class AppBuilderExtension
    {
        public static IApplicationBuilder UseSubscribe(this IApplicationBuilder appBuilder, string subscriptionIdPrefix, Assembly assembly)
        {
            var services = appBuilder.ApplicationServices.CreateScope().ServiceProvider;

            var lifeTime = services.GetService<IApplicationLifetime>();
            var bus = services.GetService<IBus>();
            lifeTime.ApplicationStarted.Register(() =>
            {
                var subscriber = new AutoSubscriber(bus, subscriptionIdPrefix);
                subscriber.Subscribe(assembly);
                subscriber.SubscribeAsync(assembly);
            });

            lifeTime.ApplicationStopped.Register(() => bus.Dispose());

            return appBuilder;
        }
    }
}

 startup.css 文件中 

public void Configure(IApplicationBuilder app, IHostingEnvironment env, IApplicationLifetime lifetime)
    {
        ......

        // easyNetQ
        app.UseSubscribe("ClientMessageService", Assembly.GetExecutingAssembly());
    }

增加订阅类：

using EasyNetQ.AutoSubscribe;
using NETCORE.RabbitMQ.Messages;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace NETCORE.RabbitMQ.API.Subscriber.Consumer
{
    public class ClientMessageConsumer : IConsumeAsync<ClientMessage>
    {
        [AutoSubscriberConsumer(SubscriptionId = "ClientMessageService.ZapQuestion")]
        public Task ConsumeAsync(ClientMessage message)
        {
            // Your business logic code here
            // eg.Generate one ZAP question records into database and send to client
            // Sample console code
            System.Console.ForegroundColor = System.ConsoleColor.Red;
            System.Console.WriteLine("Consume one message from RabbitMQ : {0}, I will generate one ZAP question list to client", message.ClientName);
            System.Console.ResetColor();

            return Task.CompletedTask;
        }
    }
}

启动后，可查看效果

引用：https://www.cnblogs.com/edisonchou/p/aspnetcore_easynetq_basicdemo_foundation.html