分布式异步队列学习总结4(生产者和消费者)

生产者向RabbitMQ服务发送消息，消费者从RabbitMQ服务中获取消息。

单生产者单消费者模式

使用程序演示单生产者和单消费者模型：

项目结构为两个.net Core 控制台程序应用程序

程序需要添加引用 RabbitMQ.Client

AspNetCore.RabbitMQ.MessageConsumer_01.MessageConsumer（消费者）

using RabbitMQ.Client;
using RabbitMQ.Client.Events;
using System;
using System.Text;

namespace AspNetCore.RabbitMQ.MessageConsumer_01.MessageConsumer
{
    public class ProductionConsumer
    {
        public static void Show()
        {
            ConnectionFactory factory = new ConnectionFactory();
            factory.HostName = "localhost";//rabbitmq服务在本地运行
            factory.UserName = "guest";//用户名
            factory.Password = "guest";//密码

            //创建链接
            using (IConnection connection = factory.CreateConnection())
            {
                //创建信道
                using (IModel channel = connection.CreateModel())
                {
                    Console.ForegroundColor = ConsoleColor.Green;
                    try
                    {
                        //声明队列
                        channel.QueueDeclare(queue: "OnlyProducerMessage", durable: true, exclusive: false, autoDelete: false, arguments: null);

                        //声明路由
                        channel.ExchangeDeclare(exchange: "OnlyProducerMessageExChange", type: ExchangeType.Direct, durable: true, autoDelete: false, arguments: null);

                        //绑定队列和路由
                        channel.QueueBind(queue: "OnlyProducerMessage", exchange: "OnlyProducerMessageExChange", routingKey: string.Empty, arguments: null);


                        //基于当前信道创建事件
                        var consumer = new EventingBasicConsumer(channel);
                        consumer.Received += (model, ea) =>
                        {
                            var body = ea.Body;
                            var message = Encoding.UTF8.GetString(body.ToArray());
                            Console.WriteLine($"消费者01 接收消息:{message}");
                        };

                        channel.BasicConsume(queue: "OnlyProducerMessage", autoAck: true, consumer: consumer);
                        Console.WriteLine("按下回车退出啊");
                        Console.ReadLine();
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }

                }
            }

        }
    }
}

 Main程序中调用下Show方法 

class Program
    {
        static void Main(string[] args)
        {
            ProductionConsumer.Show();
        }
    }

namespace AspNetCore.RabbitMQ.MessageProducer.MessageProducer（生产者）

using RabbitMQ.Client;
using System;
using System.Text;

namespace AspNetCore.RabbitMQ.MessageProducer.MessageProducer
{
    /// <summary>
    /// 生产者
    /// </summary>
    public class ProductionConsumer
    {
        public static void Show()
        {
            ConnectionFactory factory = new ConnectionFactory();
            factory.HostName = "localhost";//rabbitmq服务在本地运行
            factory.UserName = "guest";//用户名
            factory.Password = "guest";//密码

            //创建链接
            using (IConnection connection = factory.CreateConnection())
            {
                //创建信道
                using (IModel channel = connection.CreateModel())
                {
                 
                    Console.ForegroundColor = ConsoleColor.Red;
                    Console.WriteLine("生产者已准备就绪......");

                    int i = 1;
                    {
                        while (true)
                        {
                            IBasicProperties basicProperties = channel.CreateBasicProperties();
                            basicProperties.Persistent = true;

                            string message = $"消息{i}";
                            byte[] body = Encoding.UTF8.GetBytes(message);
                            channel.BasicPublish(exchange: "OnlyProducerMessageExChange", routingKey: string.Empty, basicProperties: basicProperties, body: body);
                            Console.WriteLine($"消息{message}已发送");
                            i++;
                        }
                    }
                }
            }

        }
    }
}

Main程序中调用下Show方法 

class Program
    {
        static void Main(string[] args)
        {
            ProductionConsumer.Show();
        }
    }

启动两个程序：

启动消费者，在项目目录中进入命令窗口执行dotnet 启动命令

以同样的方式，启动生产者

消费者和生产者都启动以后，可以看到两个命令窗口打印如下信息：

多生产者多消费者模式

模拟多个生产者和多个消费者的情况

AspNetCore.RabbitMQ.MessageConsumer_01.MessageConsumer（消费者）

using RabbitMQ.Client;
using RabbitMQ.Client.Events;
using System;
using System.Text;

namespace AspNetCore.RabbitMQ.MessageConsumer_01.MessageConsumer
{
    public class MultiProductionConsumer
    {
        public static void Show1()
        {
            ConnectionFactory factory = new ConnectionFactory();
            factory.HostName = "localhost";//rabbitmq服务在本地运行
            factory.UserName = "guest";//用户名
            factory.Password = "guest";//密码

            //创建链接
            using (var connection = factory.CreateConnection())
            {
                //创建信道
                using (var channel = connection.CreateModel())
                {
                    Console.ForegroundColor = ConsoleColor.Green;
                    try
                    {
                        //声明队列
                        //channel.QueueDeclare(queue: "OnlyProducerMessage", durable: true, exclusive: false, autoDelete: false, arguments: null);

                        //声明路由
                        //channel.ExchangeDeclare(exchange: "OnlyProducerMessageExChange", type: ExchangeType.Direct, durable: true, autoDelete: false, arguments: null);

                        //绑定队列和路由
                        //channel.QueueBind(queue: "OnlyProducerMessage", exchange: "OnlyProducerMessageExChange", routingKey: string.Empty, arguments: null);


                        //基于当前信道创建事件
                        var consumer = new EventingBasicConsumer(channel);
                        consumer.Received += (model, ea) =>
                        {
                            var body = ea.Body;
                            var message = Encoding.UTF8.GetString(body.ToArray());
                            Console.WriteLine($"消费者01 接收消息:{message}");
                        };

                        channel.BasicConsume(queue: "MultiProducerMessage", autoAck: true, consumer: consumer);
                        Console.WriteLine("按下回车退出啊");
                        Console.ReadLine();
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }

                }
            }

        }


        public static void Show2()
        {
            ConnectionFactory factory = new ConnectionFactory();
            factory.HostName = "localhost";//rabbitmq服务在本地运行
            factory.UserName = "guest";//用户名
            factory.Password = "guest";//密码

            //创建链接
            using (var connection = factory.CreateConnection())
            {
                //创建信道
                using (var channel = connection.CreateModel())
                {
                    Console.ForegroundColor = ConsoleColor.Green;
                    try
                    {
                        //声明队列
                        //channel.QueueDeclare(queue: "OnlyProducerMessage", durable: true, exclusive: false, autoDelete: false, arguments: null);

                        //声明路由
                        //channel.ExchangeDeclare(exchange: "OnlyProducerMessageExChange", type: ExchangeType.Direct, durable: true, autoDelete: false, arguments: null);

                        //绑定队列和路由
                        //channel.QueueBind(queue: "OnlyProducerMessage", exchange: "OnlyProducerMessageExChange", routingKey: string.Empty, arguments: null);


                        //基于当前信道创建事件
                        var consumer = new EventingBasicConsumer(channel);
                        consumer.Received += (model, ea) =>
                        {
                            var body = ea.Body;
                            var message = Encoding.UTF8.GetString(body.ToArray());
                            Console.WriteLine($"消费者02 接收消息:{message}");
                        };

                        channel.BasicConsume(queue: "MultiProducerMessage", autoAck: true, consumer: consumer);
                        Console.WriteLine("按下回车退出啊");
                        Console.ReadLine();
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }

                }
            }

        }



        public static void Show3()
        {
            ConnectionFactory factory = new ConnectionFactory();
            factory.HostName = "localhost";//rabbitmq服务在本地运行
            factory.UserName = "guest";//用户名
            factory.Password = "guest";//密码

            //创建链接
            using (var connection = factory.CreateConnection())
            {
                //创建信道
                using (var channel = connection.CreateModel())
                {
                    Console.ForegroundColor = ConsoleColor.Green;
                    try
                    {
                        //声明队列
                        //channel.QueueDeclare(queue: "OnlyProducerMessage", durable: true, exclusive: false, autoDelete: false, arguments: null);

                        //声明路由
                        //channel.ExchangeDeclare(exchange: "OnlyProducerMessageExChange", type: ExchangeType.Direct, durable: true, autoDelete: false, arguments: null);

                        //绑定队列和路由
                        //channel.QueueBind(queue: "OnlyProducerMessage", exchange: "OnlyProducerMessageExChange", routingKey: string.Empty, arguments: null);


                        //基于当前信道创建事件
                        var consumer = new EventingBasicConsumer(channel);
                        consumer.Received += (model, ea) =>
                        {
                            var body = ea.Body;
                            var message = Encoding.UTF8.GetString(body.ToArray());
                            Console.WriteLine($"消费者03 接收消息:{message}");
                        };

                        channel.BasicConsume(queue: "MultiProducerMessage", autoAck: true, consumer: consumer);
                        Console.WriteLine("按下回车退出啊");
                        Console.ReadLine();
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }

                }
            }

        }
    }
}

 Main程序中调用下Show方法 

 class Program
    {
        static void Main(string[] args)
        {
            //ProductionConsumer.Show();

            //多消费者
            {
                Task.Run(() => { MultiProductionConsumer.Show1(); });
                Task.Run(() => { MultiProductionConsumer.Show2(); });
                Task.Run(() => { MultiProductionConsumer.Show3(); });
            }
            Console.ReadLine();
        }
    }

AspNetCore.RabbitMQ.MessageProducer.MessageProducer（生产者）

using RabbitMQ.Client;
using System;
using System.Text;
using System.Threading;

namespace AspNetCore.RabbitMQ.MessageProducer.MessageProducer
{
    /// <summary>
    /// 生产者
    /// </summary>
    public class MultiProductionConsumer
    {
        public static void Show(string No)
        {
            ConnectionFactory factory = new ConnectionFactory();
            factory.HostName = "localhost";//rabbitmq服务在本地运行
            factory.UserName = "guest";//用户名
            factory.Password = "guest";//密码

            //创建链接
            using (IConnection connection = factory.CreateConnection())
            {
                //创建信道
                using (IModel channel = connection.CreateModel())
                {
                    //声明队列
                    channel.QueueDeclare(queue: "MultiProducerMessage", durable: true, exclusive: false, autoDelete: false, arguments: null);

                    //声明路由
                    channel.ExchangeDeclare(exchange: "MultiProducerMessageExChange", type: ExchangeType.Direct, durable: true, autoDelete: false, arguments: null);

                    //绑定队列和路由
                    channel.QueueBind(queue: "MultiProducerMessage", exchange: "MultiProducerMessageExChange", routingKey: string.Empty, arguments: null);


                    Console.ForegroundColor = ConsoleColor.Red;
                    Console.WriteLine($"生产者{No}已准备就绪......");

                    int i = 1;
                    {
                        while (true)
                        {
                            string message = $"生产者{No},消息{i}";
                            byte[] body = Encoding.UTF8.GetBytes(message);
                            channel.BasicPublish(exchange: "MultiProducerMessageExChange", routingKey: string.Empty, basicProperties: null, body: body);
                            Console.WriteLine($"消息{message}已发送");
                            i++;
                            Thread.Sleep(200);
                        }
                    }
                }
            }

        }
    }
}

  Main程序中调用下Show方法 

 class Program
    {
        static void Main(string[] args)
        {
            //ProductionConsumer.Show();

            //多生产者
            {
                //这是添加命令行功能
                IConfigurationRoot config = new ConfigurationBuilder()
                    .SetBasePath(Directory.GetCurrentDirectory())
                    .AddCommandLine(args)
                    .Build();

                string strMinute = config["minute"];//什么时间开始执行
                string No = config["no"];//生产者编号
                int minute = Convert.ToInt32(strMinute);

                bool flag = true;
                while (flag)
                {
                    if (DateTime.Now.Minute == minute)
                    {
                        Console.WriteLine($"到{strMinute}分钟,开始写入消息...");
                        flag = false;
                        MultiProductionConsumer.Show(No);
                    }
                }

            }
        }
    }

同时启动三个生产者服务，命令中的minute参数代表程序执行的分钟数字，从几分钟开始执行（表示当前时间的分钟数，13代表21:13开始执行）。no参数表示服务的编号，用于方便观察打印信息。

接着启动消费者服务

可以看到三个生产者同时向消息队列中发送消息。消费者服务开启三个线程，模拟三个消费者同时接收不同生产者发送的消息。

应用案例：商品秒杀实现

一共有10个商品，实现10个商品卖出后不再调用数据库进行操作（过滤无效请求，减少数据库压力）。

下面程序中写的生成者和消费者是从消息队列的角度出发的，发送数据的为生产者，接收数据的为

消费者。

AspNetCore.RabbitMQ.MessageConsumer_01.MessageConsumer（消费者）

using RabbitMQ.Client;
using RabbitMQ.Client.Events;
using System;
using System.Text;

namespace AspNetCore.RabbitMQ.MessageConsumer_01.MessageConsumer
{
    public class SeckillConsumer
    {
        public static void Show()
        {
            ConnectionFactory factory = new ConnectionFactory();
            factory.HostName = "localhost";//rabbitmq服务在本地运行
            factory.UserName = "guest";//用户名
            factory.Password = "guest";//密码

            //创建链接
            using (IConnection connection = factory.CreateConnection())
            {
                //创建信道
                using (IModel channel = connection.CreateModel())
                {
                    Console.ForegroundColor = ConsoleColor.Green;
                    try
                    {
                        //声明队列
                        channel.QueueDeclare(queue: "SeckillProducerMessage", durable: true, exclusive: false, autoDelete: false, arguments: null);

                        //声明路由
                        channel.ExchangeDeclare(exchange: "SeckillProducerMessageExChange", type: ExchangeType.Direct, durable: true, autoDelete: false, arguments: null);

                        //绑定队列和路由
                        channel.QueueBind(queue: "SeckillProducerMessage", exchange: "SeckillProducerMessageExChange", routingKey: string.Empty, arguments: null);


                        //基于当前信道创建事件
                        var consumer = new EventingBasicConsumer(channel);
                        int count = 0;
                        consumer.Received += (model, ea) =>
                        {
                            if (count >= 10)
                            {
                                Console.WriteLine("商品秒杀结束,已经不再调用数据库操作");
                            }
                            else
                            {
                                var body = ea.Body;
                                var message = Encoding.UTF8.GetString(body.ToArray());
                                Console.WriteLine($"{message} 秒杀成功");
                                count++;
                            }

                        };

                        channel.BasicConsume(queue: "SeckillProducerMessage", autoAck: true, consumer: consumer);
                        Console.WriteLine("按下回车退出啊");
                        Console.ReadLine();
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }

                }
            }

        }
    }
}

main方法：

  class Program
    {
        static void Main(string[] args)
        {
            SeckillConsumer.Show();
            Console.ReadLine();
        }
    }

AspNetCore.RabbitMQ.MessageProducer.MessageProducer（生产者）

using RabbitMQ.Client;
using System;
using System.Text;

namespace AspNetCore.RabbitMQ.MessageProducer.MessageProducer
{
    /// <summary>
    /// 单生产者
    /// </summary>
    public class ProductionConsumer
    {
        /// <summary>
        /// 秒杀商品
        /// </summary>
        public static void SkillShow()
        {
            ConnectionFactory factory = new ConnectionFactory();
            factory.HostName = "localhost";//rabbitmq服务在本地运行
            factory.UserName = "guest";//用户名
            factory.Password = "guest";//密码

            //创建链接
            using (IConnection connection = factory.CreateConnection())
            {
                //创建信道
                using (IModel channel = connection.CreateModel())
                {

                    Console.ForegroundColor = ConsoleColor.Red;
                    Console.WriteLine("秒杀已准备就绪......");

                    int i = 1;
                    {
                        while (true)
                        {
                            IBasicProperties basicProperties = channel.CreateBasicProperties();
                            basicProperties.Persistent = true;

                            string message = $"粉丝{i}";
                            byte[] body = Encoding.UTF8.GetBytes(message);
                            channel.BasicPublish(exchange: "SeckillProducerMessageExChange", routingKey: string.Empty, basicProperties: basicProperties, body: body);
                            Console.WriteLine($"{message}开始抢购");
                            i++;
                        }
                    }
                }
            }

        }
    }
}

main方法：

class Program
    {
        static void Main(string[] args)
        {
            ProductionConsumer.SkillShow();
        }
    }

启动服务：

 

从打印信息可以看出，前10个用户请求处理完成后，后面的请求就不再调用数据库进行处理。达到了数据库限流的目的。

队列优先级

通过设置Priority的值来控制消息队列中消息被处理的优先级。

应用案例：VIP学员和普通学员同时向老师请教问题，老师优先解答VIP学员的提问。

AspNetCore.RabbitMQ.MessageConsumer_01.MessageConsumer（消费者）

using RabbitMQ.Client;
using RabbitMQ.Client.Events;
using System;
using System.Text;

namespace AspNetCore.RabbitMQ.MessageConsumer_01.MessageConsumer
{
    public class PriorityQueue
    {
        public static void Show()
        {
            ConnectionFactory factory = new ConnectionFactory();
            factory.HostName = "localhost";//rabbitmq服务在本地运行
            factory.UserName = "guest";//用户名
            factory.Password = "guest";//密码

            //创建链接
            using (IConnection connection = factory.CreateConnection())
            {
                //创建信道
                using (IModel channel = connection.CreateModel())
                {
                    Console.ForegroundColor = ConsoleColor.Green;
                    try
                    {
                        //基于当前信道创建事件
                        var consumer = new EventingBasicConsumer(channel);
                        consumer.Received += (model, ea) =>
                        {
                            var body = ea.Body;
                            var message = Encoding.UTF8.GetString(body.ToArray());
                            Console.WriteLine($"{message}");
                        };

                        Console.WriteLine("消费者准备就绪......");

                        //处理消息
                        channel.BasicConsume(queue: "PriorityQueue", autoAck: false, consumer: consumer);

                        Console.ReadLine();
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }

                }
            }

        }
    }
}

main方法：

class Program
    {
        static void Main(string[] args)
        {
            //优先级队列
            PriorityQueue.Show();

            Console.ReadLine();
        }
    }

AspNetCore.RabbitMQ.MessageProducer.MessageProducer（生产者）

using RabbitMQ.Client;
using System;
using System.Collections.Generic;
using System.Text;

namespace AspNetCore.RabbitMQ.MessageProducer.MessageProducer
{
    public class PriorityQueue
    {
        public static void Show()
        {
            ConnectionFactory factory = new ConnectionFactory();
            factory.HostName = "localhost";//rabbitmq服务在本地运行
            factory.UserName = "guest";//用户名
            factory.Password = "guest";//密码

            //创建链接
            using (IConnection connection = factory.CreateConnection())
            {
                //创建信道
                using (IModel channel = connection.CreateModel())
                {
                    Console.ForegroundColor = ConsoleColor.Red;
                    Console.WriteLine("生产者已准备就绪......");

                    channel.QueueDeclare(queue: "PriorityQueue", durable: true, exclusive: false, autoDelete: false, arguments: new Dictionary<string, object>()
                    {
                        //最大级别255
                        { "x-max-priority",10} //指定队列要支持优先级设置
                    });

                    //声明交换机exchange
                    channel.ExchangeDeclare(exchange: "PriorityQueueExchange", type: ExchangeType.Direct, durable: true, autoDelete: false,
                        arguments: null);

                    //绑定exchange和queue
                    channel.QueueBind(queue: "PriorityQueue", exchange: "PriorityQueueExchange", routingKey: "PriorityKey");

                    //待发送的消息
                    {
                        string[] questionList = { "vip学员1 来请教", "甲同学 来请教", "乙同学 来请教", "丙同学 来请教", "丁同学 来请教", "vip学员2 来请教" };

                        //设置消息优先级
                        IBasicProperties props = channel.CreateBasicProperties();
                        foreach (string questionMsg in questionList)
                        {
                            if (questionMsg.StartsWith("vip"))
                            {
                                props.Priority = 9;
                            }
                            else
                            {
                                props.Priority = 1;
                            }
                            channel.BasicPublish(exchange: "PriorityQueueExchange", routingKey: "PriorityKey", basicProperties: props, body: Encoding.UTF8.GetBytes(questionMsg));
                            Console.WriteLine($"{questionMsg}已发送");
                        }
                    }
                }
            }
        }

    }
}

main方法：

class Program
    {
        static void Main(string[] args)
        {
            //队列优先级
            PriorityQueue.Show();

            Console.ReadLine();
        }
    }

启动服务：

从运行结果可以看出，虽然 vip学员2 最后一个进行提问（消息最后添加到队列中），但是因为设置了props.Priority = 9，非VIP学员props.Priority = 1，所以会优先于非VIP学员处理。