我如何调用 rabbitMq 从 asp.net Webapi 获取消息？答案

【问题标题】：How can i call rabbitMq get message from asp.net Webapi?我如何调用 rabbitMq 从 asp.net Webapi 获取消息？
【发布时间】：2017-07-23 10:24:05
【问题描述】：

我的问题很简单。我想使用rabbitmq通过asp.net webapi制作消息队列。另一方面，GetAllQueues 不返回任何消息。消息始终为空。下面的代码在控制台应用程序中完美，但当我在帖子下方运行时消息始终为空：

http://localhost:53301/api/CustomerPipline/?queueName=test123


using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using RabbitMQ.Client;
using System.Text;
using RabbitMQ.Client.Events;
using System.Diagnostics;
using RabbitMQ.Client.Exceptions;

namespace Atom.Mqpipline.Controllers
{
    public class CustomerPiplineController : ApiController
    {
        private static readonly string _queueName = "test123";


        [HttpPost]
        public HttpResponseMessage AddQueue(int customerId)
        {

           var  publisher = new Publisher(_queueName, "Hello RabbitMQ World!");
            var resp = Request.CreateResponse(HttpStatusCode.OK, JsonConvert.SerializeObject("OK"));

            return resp;
        }
        [HttpGet]
        public HttpResponseMessage GetAllQueues(string queueName)
        {
            var consumer = new Consumer(queueName);
            var resp = Request.CreateResponse(HttpStatusCode.OK, JsonConvert.SerializeObject(consumer.Message));
            return resp;
        }
    }

}

public class RabbitMQService
{
    private readonly string _hostName = "localhost";

    public IConnection GetRabbitMQConnection()
    {
        ConnectionFactory connectionFactory = new ConnectionFactory()
        {
            HostName = _hostName
        };

        return connectionFactory.CreateConnection();
    }
}
public class Publisher
{
    private readonly RabbitMQService _rabbitMQService;

    public Publisher(string queueName, string message)
    {
        _rabbitMQService = new RabbitMQService();

        using (var connection = _rabbitMQService.GetRabbitMQConnection())
        {
            using (var channel = connection.CreateModel())
            {
                channel.QueueDeclare(queueName, false, false, false, null);
                channel.BasicPublish("", queueName, null, Encoding.UTF8.GetBytes(message));
            }
        }
    }
}

public class Consumer
{
    private readonly RabbitMQService _rabbitMQService;
    public string Message { get; set; }
    public Consumer(string queueName)
    {

        _rabbitMQService = new RabbitMQService();

        using (var connection = _rabbitMQService.GetRabbitMQConnection())
        {
            using (var channel = connection.CreateModel())
            {
                var consumer = new EventingBasicConsumer(channel);
                // Received event'i sürekli listen modunda olacaktır.
                consumer.Received += (model, ea) =>
                {
                    var body = ea.Body;
                    var message = Encoding.UTF8.GetString(body);
                    Debug.WriteLine(message);
                    Message = message;
                };

                channel.BasicConsume(queueName, true, consumer);
            }
        }
    }
}

【问题讨论】：

标签： c# .net asp.net-web-api rabbitmq message-queue

【解决方案1】：

你不能打电话给消费者。消费者操作在收到消息时运行，而不是在您调用时运行。

在您的应用上仅创建一个 Consumer 实例..
添加队列接收消息。或通过SignalR直接向客户端推送消息。

【讨论】：

能否请您详细说明或提供真正的 ipmlementation“在您的应用中仅创建一个 Consumer 实例”

【解决方案2】：

我认为您不能在回发或休息端点中使用消息。但是您可以在项目启动时启动一个接收队列的任务。

        public void Configure(IApplicationBuilder app)
        {
            [...]
            Task.Run(GetAllQueues(queueName));
        }

        public void GetAllQueues(string queueName)
        {
            var consumer = new Consumer(queueName);
            var resp = Request.CreateResponse(HttpStatusCode.OK, JsonConvert.SerializeObject(consumer.Message));
            return resp;
        }

【讨论】：