【NetCore】RabbitMQ 封裝

wosperry發表於2021-12-05

RabbitMQ 封裝

程式碼

https://gitee.com/wosperry/wosperry-rabbit-mqtest/tree/master

參考Abp事件匯流排的用法,對拷貝的Demo進行簡單封裝

定義 RabbitMQOptions 用於配置

{ 
  "MyRabbitMQOptions": {
    "UserName": "admin",
    "Password": "admin",
    "Host": "192.168.124.220",
    "Port": 5672,
    "ExchangeName": "PerryExchange"
  }
}

    public class MyRabbitMQOptions
    {
        public string UserName { get; set; }
        public string Password { get; set; }
        public string Host { get; set; }
        public int Port { get; set; }
        public string ExchangeName { get; set; } = "";
    }

定義 QueueNameAttribute 控制佇列名字

    /// <summary>
    /// 定義佇列名字,優先順序高於類完整名
    /// </summary>
    [AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = false)]
    public class QueueNameAttribute : Attribute
    {
        public string QueueName { get; }
        public QueueNameAttribute(string queueName)
        {
            QueueName = queueName;
        }
    }

定義 IMyPublisher<T>,通過注入某個型別的 IMyPublisher<T>,自動序列化物件併發布到配置好的MQ裡

    /// <summary>
    /// 用於注入使用
    /// </summary>
    public interface IMyPublisher<T> where T : class
    {
        Task PublishAsync(T data, Encoding encoding = null);
    }
    public class MyPublisher<T> : IMyPublisher<T>, IDisposable where T : class
    {
        private readonly MyRabbitMQOptions _myOptions;
        private readonly IConnection _connection;
        private readonly IModel _channel;
        private readonly string _queueName;


        /// <summary>
        /// 非注入時使用此構造方法
        /// </summary>
        public MyPublisher(IConnection connection)
        {
            _connection = connection;
        }

        /// <summary>
        /// 依賴注入自動走這個構造方法
        /// </summary>
        /// <param name="optionsMonitor"></param>
        /// <param name="factory"></param>
        public MyPublisher(IOptionsMonitor<MyRabbitMQOptions> optionsMonitor, ConnectionFactory factory)
        {
            _myOptions = optionsMonitor.CurrentValue;
            _connection = factory.CreateConnection();

            // 建立通道
            _channel = _connection.CreateModel();

            // 宣告一個Exchange
            _channel.ExchangeDeclare(_myOptions.ExchangeName, ExchangeType.Direct, false, false, null);


            var type = typeof(T);
            // 獲取類上的QueueNameAttribute特性,如果不存在則使用類的完整名
            var attr = type.GetCustomAttribute<QueueNameAttribute>();
            _queueName = string.IsNullOrWhiteSpace(attr?.QueueName) ? type.FullName : attr.QueueName;

            // 宣告一個佇列 
            _channel.QueueDeclare(_queueName, false, false, false, null);

            //將佇列繫結到交換機
            _channel.QueueBind(_queueName, _myOptions.ExchangeName, _queueName, null);
        }

        /// <summary>
        /// 釋出訊息
        /// </summary>
        public Task PublishAsync(T data, Encoding encoding = null)
        {
            // 物件轉 object[] 傳送
            var msg = JsonConvert.SerializeObject(data);
            byte[] bytes = (encoding ?? Encoding.UTF8).GetBytes(msg);
            _channel.BasicPublish(_myOptions.ExchangeName, _queueName, null, bytes);

            return Task.CompletedTask;
        }

        public void Dispose()
        {
            // 結束
            _channel.Close();
            _connection.Close();
        }
    }

定義 IMyEventHandler<T> ,供 NetCore 專案注入使用,配置後,可以在程式啟動的時候,找到該介面所有的實現類,並開啟消費者

    /// <summary>
    /// Handler的配置
    /// </summary>
    public class MyEventHandlerOptions
    {
        /// <summary>
        /// 禁用 byte[] 解析
        /// </summary>
        public bool DisableDeserializeObject { get; set; } = false;
        /// <summary>
        /// 配置Encoding
        /// </summary>
        public Encoding Encoding { get; set; } = Encoding.UTF8;
    }
    public abstract class MyEventHandler<T> : IMyEventHandler<T> where T : class
    {
        private IModel _channel;
        private string _queueName;
        private EventingBasicConsumer _consumer;
        public MyEventHandlerOptions Options = new()
        {
            DisableDeserializeObject = false
        };

        public void Begin(IConnection connection)
        {
            var type = typeof(T);
            // 獲取類上的QueueNameAttribute特性,如果不存在則使用類的完整名
            var attr = type.GetCustomAttribute<QueueNameAttribute>();
            _queueName = string.IsNullOrWhiteSpace(attr?.QueueName) ? type.FullName : attr.QueueName;

            //建立通道
            _channel = connection.CreateModel();

            _consumer = new EventingBasicConsumer(_channel);
            _consumer.Received += MyReceivedHandler;
            //消費者
            _channel.BasicConsume(_queueName, false, _consumer);
        }

        // 收到訊息後
        private void MyReceivedHandler(object sender, BasicDeliverEventArgs e)
        {
            try
            {
                // 如果未配置禁用則不解析,後面抽象方法的data引數會始終為空
                if (!Options.DisableDeserializeObject)
                {
                    T data = null;
                    // 反序列化為物件
                    var message = Options.Encoding.GetString(e.Body);
                    data = JsonConvert.DeserializeObject<T>(message);
                    OnReceivedAsync(data, message).Wait();

                    // 確認該訊息已被消費
                    _channel?.BasicAck(e.DeliveryTag, false);
                }
            }
            catch (Exception ex)
            {
                OnConsumerException(ex);
            }
        }

        /// <summary>
        /// 收到訊息 
        /// </summary>
        /// <param name="data">解析後的物件</param>
        /// <param name="message">訊息原文</param> 
        /// <remarks>Options.DisableDeserializeObject為true時,data始終為null</remarks>
        public abstract Task OnReceivedAsync(T data, string message);

        /// <summary>
        /// 異常
        /// </summary>
        /// <param name="ex">派生類不重寫的話,異常被隱藏</param>
        public virtual void OnConsumerException(Exception ex)
        {

        }
    }


給依賴注入寫一些擴充方法

    public static class MyRabbiteMQExtensions
    {
        /// <summary>
        /// 初始化訊息佇列,並新增Publisher到IoC容器
        /// </summary>
        /// <remarks>從Configuration讀取"MyRabbbitMQOptions配置項"</remarks>
        public static IServiceCollection AddMyRabbitMQ(this IServiceCollection services, IConfiguration configuration)
        {
            #region 配置項
            // 從Configuration讀取"MyRabbbitMQOptions配置項
            var optionSection = configuration.GetSection("MyRabbitMQOptions");

            // 這個myOptions是當前方法使用
            MyRabbitMQOptions myOptions = new();
            optionSection.Bind(myOptions);

            // 加了這行,才可以注入IOptions<MyRabbitMQOptions>或者IOptionsMonitor<MyRabbitMQOptions>
            services.Configure<MyRabbitMQOptions>(optionSection);
            #endregion

            // 加了這行,才可以注入任意型別引數的 IMyPublisher<> 使用
            services.AddTransient(typeof(IMyPublisher<>), typeof(MyPublisher<>));

            // 建立一個工廠物件,並配置單例注入
            services.AddSingleton(new ConnectionFactory
            {
                UserName = myOptions.UserName,
                Password = myOptions.Password,
                HostName = myOptions.Host,
                Port = myOptions.Port
            });

            return services;
        }

        /// <summary>
        /// IServiceCollection的擴充方法,用於發現自定義的EventHandler並新增到服務容器
        /// </summary> 
        /// <param name="types">包含了自定義Handler的類集合,可以使用assembly.GetTypes()</param> 
        /// <remarks>遍歷所有types,將繼承自IMyEventHandler的類註冊到容器</remarks>
        public static IServiceCollection AddMyRabbitMQEventHandlers(this IServiceCollection services, Type[] types)
        {
            var baseType = typeof(IMyEventHandler);

            foreach (var type in types)
            {
                // baseType可以放type,並且type不是baseType
                if (baseType.IsAssignableFrom(type) && baseType != type)
                {
                    // 瞬態注入配置
                    services.AddTransient(typeof(IMyEventHandler), type);
                }
            }

            return services;
        }

        /// <summary>
        /// 給app擴充方法
        /// </summary>
        /// <remarks>
        /// 在IoC容器裡獲取到所有繼承自IMyEvetnHandler的實現類,並開啟消費者
        /// </remarks>
        public static IApplicationBuilder UseMyEventHandler(this IApplicationBuilder app)
        {
            var handlers = app.ApplicationServices.GetServices(typeof(IMyEventHandler));
            var factory = app.ApplicationServices.GetService<ConnectionFactory>();

            // 遍歷呼叫自定義的Begin方法
            foreach (var h in handlers)
            {
                var handler = h as IMyEventHandler;
                handler?.Begin(factory.CreateConnection());
            }

            return app;
        }
    }

在Net6 WebApi中使用

program.cs

    var builder = WebApplication.CreateBuilder(args);
    builder.Services.AddControllers();


    // 新增MyRabbitMQ到services
    builder.Services.AddMyRabbitMQ(builder.Configuration);
    builder.Services.AddMyRabbitMQEventHandlers(typeof(PerryTest).Assembly.GetTypes());

    var app = builder.Build();

    // 使用 MyEventHandler
    app.UseMyEventHandler();


    app.MapControllers();
    app.Run();

定義ETO

    [QueueName("perry.test")]
    public class PerryTest
    {
        public Guid Id { get; set; }
        public string? Name { get; set; }
        public int Count { get; set; }
        public string? Remark { get; set; }
    }

定義EventHandler

    public class PerryTestEventHandler : MyEventHandler<PerryTest>
    {
        public override Task OnReceivedAsync(PerryTest data, string message)
        {
            Console.WriteLine(message);
            return Task.CompletedTask;
        }

        public override void OnConsumerException(Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
    }

控制器中檢查是否可以正常使用

    [Route("api")]
    [ApiController]
    public class TestController : ControllerBase
    {
        public IMyPublisher<PerryTest> TestPublisher { get; }

        public TestController(IMyPublisher<PerryTest> testPublisher)
        {
            TestPublisher = testPublisher;
        }
        [HttpGet("test")]
        public async Task<string> TestAsync()
        {
            var data = new PerryTest()
            {
                Id = Guid.NewGuid(),
                Name = "AAA",
                Count = 123,
                Remark = "哈哈哈"
            };

            await TestPublisher.PublishAsync(data);

            return "傳送了一個訊息";
        }
    }

執行截圖

參考 .NET Core 使用RabbitMQ,拷貝了一些Demo

文章裡的生產者Demo

    //建立連線工廠
    ConnectionFactory factory = new ConnectionFactory
    {
        UserName = "admin",//使用者名稱
        Password = "admin",//密碼
        HostName = "192.168.157.130"//rabbitmq ip
    };

    //建立連線
    var connection = factory.CreateConnection();
    //建立通道
    var channel = connection.CreateModel();
    //宣告一個佇列
    channel.QueueDeclare("hello", false, false, false, null);

    Console.WriteLine("\nRabbitMQ連線成功,請輸入訊息,輸入exit退出!");

    string input;
    do
    {
        input = Console.ReadLine();
        var sendBytes = Encoding.UTF8.GetBytes(input);
        //釋出訊息
        channel.BasicPublish("", "hello", null, sendBytes);
    } while (input.Trim().ToLower()!="exit");
    channel.Close();
    connection.Close();

文章裡的消費者Demo

    //建立連線工廠
    ConnectionFactory factory = new ConnectionFactory
    {
        UserName = "admin",//使用者名稱
        Password = "admin",//密碼
        HostName = "192.168.157.130"//rabbitmq ip
    };

    //建立連線
    var connection = factory.CreateConnection();
    //建立通道
    var channel = connection.CreateModel();

    //事件基本消費者
    EventingBasicConsumer consumer = new EventingBasicConsumer(channel);

    //接收到訊息事件
    consumer.Received += (ch, ea) =>
    {
        var message = Encoding.UTF8.GetString(ea.Body);
        Console.WriteLine($"收到訊息: {message}");
        //確認該訊息已被消費
        channel.BasicAck(ea.DeliveryTag, false);
    };
    //啟動消費者 設定為手動應答訊息
    channel.BasicConsume("hello", false, consumer);
    Console.WriteLine("消費者已啟動");
    Console.ReadKey();
    channel.Dispose();
    connection.Close();

這次封裝的總結

  1. 上網找個Demo
  2. 先按最簡單的寫法,寫完能正常使用的,功能獨立的程式碼。其實是提醒自己,不要陷入到雜七雜八的各項優化中去,先寫完實現再考慮怎麼去改成更加好的。
  3. 腦袋裡想著,我要怎麼樣使用這個功能,怎麼樣才能讓用的時候寫的程式碼少一些,配置簡單一些
  4. 檢查哪些內容應該分離到配置項,然後抽離出去
  5. 考慮要支援哪些型別的專案,如果想要支援低版本,可能需要降級一些依賴包
  6. 支援建構函式注入的話,要注意最多引數的建構函式給依賴注入使用,依賴注入用的建構函式不好被非注入時使用的話,考慮多提供一個給Framework用。

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