.NET中RabbitMQ的使用
概述
MQ全称为Message Queue, 消息队列（MQ）是一种应用程序对应用程序的通信方法。RabbitMQ是一个在AMQP基础上完整的，可复用的企业消息系统。他遵循Mozilla Public License开源协议。AMQP(高级消息队列协议) 是一个异步消息传递所使用的应用层协议规范，作为线路层协议，而不是API（例如JMS），AMQP 客户端能够无视消息的来源任意发送和接受信息。AMQP的原始用途只是为金融界提供一个可以彼此协作的消息协议，而现在的目标则是为通用消息队列架构提供通用构建工具。因此，面向消息的中间件 （MOM）系统，例如发布/订阅队列，没有作为基本元素实现。AMQP当中有四个概念非常重要（一个虚拟主机持有一组交换机、队列和绑定）：
virtual host，虚拟主机exchange，交换机queue，队列binding，绑定
更多理论性东西可以参考（在Windows上安装Rabbit MQ 指南），针对队列的讲解相当详细
Window下安装RabbbitMQ
文件下载安装
Rabbit MQ 是建立在强大的Erlang OTP平台上，因此安装Rabbit MQ的前提是安装Erlang。通过下面两个连接下载安装3.2.3 版本：
- 下载并安装 Erlang OTP For Windows (vR16B03)
- 运行安装 Rabbit MQ Server Windows Installer (v3.2.3)
默认安装的Rabbit MQ 监听端口是5672。先安装Erlang OTP后安装RabbitMQ，安装方式默认即可，RabbitMQ可以勾选安装后台服务、服务启动和停止等操作。
激活Rabbit MQ's Management Plugin
使用Rabbit MQ 管理插件，可以更好的可视化方式查看Rabbit MQ 服务器实例的状态，打开CMD命令，cd到安装目录（..\rabbitmq_server-3.2.3\sbin）下，输入下面的命令激活：
rabbitmq-plugins enable rabbitmq_management
要重启服务才能生效，可以执行
net stop RabbitMQ && net start RabbitMQ
输入网址，打开监控页面： http://localhost:15672 (默认账号和密码：guest 和guest)
配置RabbitMQ用户权限
RabbitMQ是存在用户权限的，默认是guest 密码也是guest，隶属于Administrator管理员下。现需要配置新用户和权限，继续打开CMD命令，cd到安装目录sbin下：
用户操作指令：
::查询服务状态
rabbitmqctl status
::列举虚拟主机列表
rabbitmqctl list_vhosts
::列举用户列表
rabbitmqctl list_users
:: 添加用户和密码 rabbitmqctl add_user hao abc123 :: 设置权限 rabbitmqctl set_permissions yy ".*" ".*" ".*" :: 分配用户组 rabbitmqctl set_user_tags yy administrator
:: 删除guest用户
rabbitmqctl delete_user guest
::修改用户密码
rabbitmqctl change_password {username} {newpassowrd}
.NET中RabbitMQ使用
1、Nuget下载RabbitMQ.Client第三方类库，版本V3.6.5，高版本与.NET Framework 4.5有冲突，RabbitMQ Client地址
2、利用RabbitMQ Clinet类库编码(代码内容有注释，此处不做详细解释，文章后有完整代码的下载地址)
<1>RabbitMQ的direct类型Exchange
Producter发送消息代码：
/// <summary>
/// 连接配置
/// </summary>
private static readonly ConnectionFactory rabbitMqFactory = new ConnectionFactory(){
HostName ="192.168.1.8",UserName="hao",Password="abc123",Port= 5672
};
/// <summary>
/// 路由名称
/// </summary>
const string ExchangeName = "justin.exchange";
//队列名称
const string QueueName = "justin.queue";
public static void DirectExchangeSendMsg()
{
using (IConnection conn = rabbitMqFactory.CreateConnection())
{
using (IModel channel = conn.CreateModel())
{
channel.ExchangeDeclare(ExchangeName, "direct", durable: true, autoDelete: false, arguments: null);
channel.QueueDeclare(QueueName, durable: true, autoDelete: false, exclusive: false, arguments: null);
channel.QueueBind(QueueName, ExchangeName, routingKey: QueueName);
var props = channel.CreateBasicProperties();
props.Persistent = true;
string vadata = Console.ReadLine();
while (vadata != "exit")
{
var msgBody = Encoding.UTF8.GetBytes(vadata);
channel.BasicPublish(exchange: ExchangeName, routingKey: QueueName, basicProperties: props, body: msgBody);
Console.WriteLine(string.Format("***发送时间:{0}，发送完成，输入exit退出消息发送",DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")));
vadata = Console.ReadLine();
}
}
}
}
Customer接收消息代码：
/// <summary>
/// 连接配置
/// </summary>
private static readonly ConnectionFactory rabbitMqFactory = new ConnectionFactory() {
HostName = "192.168.1.8", UserName = "hao", Password = "abc123", Port = 5672
};
/// <summary>
/// 路由名称
/// </summary>
const string ExchangeName = "justin.exchange";
//队列名称
const string QueueName = "justin.queue";
public static void DirectAcceptExchange()
{
using (IConnection conn = rabbitMqFactory.CreateConnection())
{
using (IModel channel = conn.CreateModel())
{
channel.ExchangeDeclare(ExchangeName, "direct", durable: true, autoDelete: false, arguments: null);
channel.QueueDeclare(QueueName, durable: true, autoDelete: false, exclusive: false, arguments: null);
channel.QueueBind(QueueName, ExchangeName, routingKey: QueueName);
while (true)
{
BasicGetResult msgResponse = channel.BasicGet(QueueName, noAck: true);
if (msgResponse != null)
{
var msgBody = Encoding.UTF8.GetString(msgResponse.Body);
Console.WriteLine(string.Format("***接收时间:{0}，消息内容：{1}", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"),msgBody));
}
//BasicGetResult msgResponse2 = channel.BasicGet(QueueName, noAck: false);
////process message ...
//channel.BasicAck(msgResponse2.DeliveryTag, multiple: false);
System.Threading.Thread.Sleep(TimeSpan.FromSeconds(1));
}
}
}
}
但是这种处理速度较慢，因为循环线程等待。高效的接收消息的方式可以使用EventingBasicConsumer进行消息接收处理，修改代码内容如下：
public static void DirectAcceptExchangeEvent()
{
using (IConnection conn = rabbitMqFactory.CreateConnection())
{
using (IModel channel = conn.CreateModel())
{
//channel.ExchangeDeclare(ExchangeName, "direct", durable: true, autoDelete: false, arguments: null);
channel.QueueDeclare(QueueName, durable: true, autoDelete: false, exclusive: false, arguments: null);
//channel.QueueBind(QueueName, ExchangeName, routingKey: QueueName);
var consumer = new EventingBasicConsumer(channel);
consumer.Received += (model, ea) =>
{
var msgBody = Encoding.UTF8.GetString(ea.Body);
Console.WriteLine(string.Format("***接收时间:{0}，消息内容：{1}", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"), msgBody));
};
channel.BasicConsume(QueueName, noAck: true, consumer: consumer);
//已过时用EventingBasicConsumer代替
//var consumer2 = new QueueingBasicConsumer(channel);
//channel.BasicConsume(QueueName, noAck: true, consumer: consumer);
//var msgResponse = consumer2.Queue.Dequeue(); //blocking
//var msgBody2 = Encoding.UTF8.GetString(msgResponse.Body);
Console.WriteLine("按任意值，退出程序");
Console.ReadKey();
}
}
}
但是有些时候，消费者同一时间没有能力处理太多的业务，导致分配过来的队列消息不能及时处理完成，这个时候，我们可以设置BasicQos属性，告诉Broker同一时间将未处理完成的消息分配其他消费者，所以接收消息的地方需要略做修改，代码如下：
public static void DirectAcceptExchangeTask()
{
using (IConnection conn = rabbitMqFactory.CreateConnection())
{
using (IModel channel = conn.CreateModel())
{
//channel.ExchangeDeclare(ExchangeName, "direct", durable: true, autoDelete: false, arguments: null);
channel.QueueDeclare(QueueName, durable: true, autoDelete: false, exclusive: false, arguments: null);
channel.BasicQos(prefetchSize: 0, prefetchCount: 1, global: false);//告诉broker同一时间只处理一个消息
//channel.QueueBind(QueueName, ExchangeName, routingKey: QueueName);
var consumer = new EventingBasicConsumer(channel);
consumer.Received += (model, ea) =>
{
var msgBody = Encoding.UTF8.GetString(ea.Body);
Console.WriteLine(string.Format("***接收时间:{0}，消息内容：{1}", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"), msgBody));
int dots = msgBody.Split('.').Length - 1;
System.Threading.Thread.Sleep(dots * 1000);
Console.WriteLine(" [x] Done");
//处理完成，告诉Broker可以服务端可以删除消息，分配新的消息过来
channel.BasicAck(deliveryTag: ea.DeliveryTag, multiple: false);
};
//noAck设置false,告诉broker，发送消息之后，消息暂时不要删除，等消费者处理完成再说
channel.BasicConsume(QueueName, noAck: false, consumer: consumer);
Console.WriteLine("按任意值，退出程序");
Console.ReadKey();
}
}
}
<2> RabbitMQ的Topic类型Exchange
Producter 发送消息代码：
/// <summary>
/// 连接配置
/// </summary>
private static readonly ConnectionFactory rabbitMqFactory = new ConnectionFactory(){
HostName ="192.168.1.8",UserName="hao",Password="abc123",Port= 5672
};
/// <summary>
/// 路由名称
/// </summary>
const string TopExchangeName = "topic.justin.exchange";
//队列名称
const string TopQueueName = "topic.justin.queue";
public static void TopicExchangeSendMsg()
{
using (IConnection conn = rabbitMqFactory.CreateConnection())
{
using (IModel channel = conn.CreateModel())
{
channel.ExchangeDeclare(TopExchangeName, "topic", durable: false, autoDelete: false, arguments: null);
channel.QueueDeclare(TopQueueName, durable: false, autoDelete: false, exclusive: false, arguments: null);
channel.QueueBind(TopQueueName, TopExchangeName, routingKey: TopQueueName);
//var props = channel.CreateBasicProperties();
//props.Persistent = true;
string vadata = Console.ReadLine();
while (vadata != "exit")
{
var msgBody = Encoding.UTF8.GetBytes(vadata);
channel.BasicPublish(exchange: TopExchangeName, routingKey: TopQueueName, basicProperties: null, body: msgBody);
Console.WriteLine(string.Format("***发送时间:{0}，发送完成，输入exit退出消息发送", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")));
vadata = Console.ReadLine();
}
}
}
}
Customer接收消息代码：
/// <summary>
/// 连接配置
/// </summary>
private static readonly ConnectionFactory rabbitMqFactory = new ConnectionFactory() {
HostName = "192.168.1.8", UserName = "hao", Password = "abc123", Port = 5672
};
/// <summary>
/// 路由名称
/// </summary>
const string TopExchangeName = "topic.justin.exchange";
//队列名称
const string TopQueueName = "topic.justin.queue";
public static void TopicAcceptExchange()
{
using (IConnection conn = rabbitMqFactory.CreateConnection())
{
using (IModel channel = conn.CreateModel())
{
channel.ExchangeDeclare(TopExchangeName, "topic", durable: false, autoDelete: false, arguments: null);
channel.QueueDeclare(TopQueueName, durable: false, autoDelete: false, exclusive: false, arguments: null);
channel.BasicQos(prefetchSize: 0, prefetchCount: 1, global: false);
channel.QueueBind(TopQueueName, TopExchangeName, routingKey: TopQueueName);
var consumer = new EventingBasicConsumer(channel);
consumer.Received += (model, ea) =>
{
var msgBody = Encoding.UTF8.GetString(ea.Body);
Console.WriteLine(string.Format("***接收时间:{0}，消息内容：{1}", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"), msgBody));
int dots = msgBody.Split('.').Length - 1;
System.Threading.Thread.Sleep(dots * 1000);
Console.WriteLine(" [x] Done");
channel.BasicAck(deliveryTag: ea.DeliveryTag, multiple: false);
};
channel.BasicConsume(TopQueueName, noAck: false, consumer: consumer);
Console.WriteLine("按任意值，退出程序");
Console.ReadKey();
}
}
}
参考资料：
在 Windows 上安装Rabbit MQ 指南（http://www.cnblogs.com/shanyou/p/4067250.html）
.NET 环境中使用RabbitMQ（http://www.cnblogs.com/yangecnu/p/4227535.html）
RabbitMQ Tutorial（http://www.rabbitmq.com/tutorials/tutorial-six-dotnet.html）
