ActiveMQ在C#中的应用-白红宇

ActiveMQ在C#中的应用

阅读量：6939 次

发布时间：2019-06-27

本文共 8766 字，大约阅读时间需要 29 分钟。

ActiveMQ是个好东东，不必多说。ActiveMQ提供多种语言支持，如 Java, C, C++, C#, Ruby, Perl, Python, PHP等。由于我在windows下开发GUI，比较关心C++和C#，其中C#的ActiveMQ很简单，Apache提供NMS（.Net Messaging Service）支持.Net开发，只需如下几个步骤即能建立简单的实现。C++的应用相对麻烦些，稍后写文章介绍。

1、去ActiveMQ官方网站下载最新版的ActiveMQ，网址：。我之前下的是5.3.1，5.3.2现在也已经出来了。

2、去ActiveMQ官方网站下载最新版的Apache.NMS，网址：，需要下载Apache.NMS和Apache.NMS.ActiveMQ两个bin包，如果对源码感兴趣，也可下载src包。这里要提醒一下，如果下载 1.2.0版本的NMS.ActiveMQ，Apache.NMS.ActiveMQ.dll在实际使用中有个bug，即停止ActiveMQ应用时会抛 WaitOne函数异常，查看src包中的源码发现是由于Apache.NMS.ActiveMQ-1.2.0-src\src\main\csharp \Transport\InactivityMonitor.cs中的如下代码造成的，修改一下源码重新编译即可。看了一下最新版1.3.0已经修复了这个bug，因此下载最新版即可。

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private void StopMonitorThreads()

{

lock(monitor)

{

if(monitorStarted.CompareAndSet(true, false))

{

AutoResetEvent shutdownEvent = new AutoResetEvent(false);

// Attempt to wait for the Timers to shutdown, but don't wait

// forever, if they don't shutdown after two seconds, just quit.

this.readCheckTimer.Dispose(shutdownEvent);

shutdownEvent.WaitOne(TimeSpan.FromMilliseconds(2000));

this.writeCheckTimer.Dispose(shutdownEvent);

shutdownEvent.WaitOne(TimeSpan.FromMilliseconds(2000));

//WaitOne的定义：public virtual bool WaitOne(TimeSpan timeout,bool exitContext)

this.asyncTasks.Shutdown();

this.asyncTasks = null;

this.asyncWriteTask = null;

this.asyncErrorTask = null;

}

private void StopMonitorThreads()

{

lock(monitor)

{

if(monitorStarted.CompareAndSet(true, false))

{

AutoResetEvent shutdownEvent = new AutoResetEvent(false);

// Attempt to wait for the Timers to shutdown, but don't wait

// forever, if they don't shutdown after two seconds, just quit.

this.readCheckTimer.Dispose(shutdownEvent);

shutdownEvent.WaitOne(TimeSpan.FromMilliseconds(2000));

this.writeCheckTimer.Dispose(shutdownEvent);

shutdownEvent.WaitOne(TimeSpan.FromMilliseconds(2000));

//WaitOne的定义：public virtual bool WaitOne(TimeSpan timeout,bool exitContext)

this.asyncTasks.Shutdown();

this.asyncTasks = null;

this.asyncWriteTask = null;

this.asyncErrorTask = null;

}

3、运行ActiveMQ，找到ActiveMQ解压后的bin文件夹：...\apache-activemq-5.3.1\bin，执行activemq.bat批处理文件即可启动ActiveMQ服务器，默认端口为61616，这可在配置文件中修改。

4、写C#程序实现ActiveMQ的简单应用。新建C#工程（一个Producter项目和一个Consumer项目），WinForm或 Console程序均可，这里建的是Console工程，添加对Apache.NMS.dll和Apache.NMS.ActiveMQ.dll的引用，然后即可编写实现代码了，简单的Producer和Consumer实现代码如下：

producer：

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using System;

using System.Collections.Generic;

using System.Text;

using Apache.NMS;

using Apache.NMS.ActiveMQ;

using System.IO;

using System.Xml.Serialization;

using System.Runtime.Serialization.Formatters.Binary;

namespace Publish

{

class Program

{

static void Main(string[] args)

{

try

{

//Create the Connection Factory

IConnectionFactory factory = new ConnectionFactory("tcp://localhost:61616/");

using (IConnection connection = factory.CreateConnection())

{

//Create the Session

using (ISession session = connection.CreateSession())

{

//Create the Producer for the topic/queue

IMessageProducer prod = session.CreateProducer(

new Apache.NMS.ActiveMQ.Commands.ActiveMQTopic("testing"));

//Send Messages

int i = 0;

while (!Console.KeyAvailable)

{

ITextMessage msg = prod.CreateTextMessage();

msg.Text = i.ToString();

Console.WriteLine("Sending: " + i.ToString());

prod.Send(msg, Apache.NMS.MsgDeliveryMode.NonPersistent, Apache.NMS.MsgPriority.Normal, TimeSpan.MinValue);

System.Threading.Thread.Sleep(5000);

i++;

}

Console.ReadLine();

}

catch (System.Exception e)

{

Console.WriteLine("{0}",e.Message);

Console.ReadLine();

}

using System;

using System.Collections.Generic;

using System.Text;

using Apache.NMS;

using Apache.NMS.ActiveMQ;

using System.IO;

using System.Xml.Serialization;

using System.Runtime.Serialization.Formatters.Binary;

namespace Publish

{

class Program

{

static void Main(string[] args)

{

try

{

//Create the Connection Factory

IConnectionFactory factory = new ConnectionFactory("tcp://localhost:61616/");

using (IConnection connection = factory.CreateConnection())

{

//Create the Session

using (ISession session = connection.CreateSession())

{

//Create the Producer for the topic/queue

IMessageProducer prod = session.CreateProducer(

new Apache.NMS.ActiveMQ.Commands.ActiveMQTopic("testing"));

//Send Messages

int i = 0;

while (!Console.KeyAvailable)

{

ITextMessage msg = prod.CreateTextMessage();

msg.Text = i.ToString();

Console.WriteLine("Sending: " + i.ToString());

prod.Send(msg, Apache.NMS.MsgDeliveryMode.NonPersistent, Apache.NMS.MsgPriority.Normal, TimeSpan.MinValue);

System.Threading.Thread.Sleep(5000);

i++;

}

Console.ReadLine();

}

catch (System.Exception e)

{

Console.WriteLine("{0}",e.Message);

Console.ReadLine();

}

consumer:

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using System;

using System.Collections.Generic;

using System.Text;

using Apache.NMS;

using Apache.NMS.ActiveMQ;

using System.IO;

using System.Xml.Serialization;

using System.Runtime.Serialization.Formatters.Binary;

namespace Subscribe

{

class Program

{

static void Main(string[] args)

{

try

{

//Create the Connection factory

IConnectionFactory factory = new ConnectionFactory("tcp://localhost:61616/");

//Create the connection

using (IConnection connection = factory.CreateConnection())

{

connection.ClientId = "testing listener";

connection.Start();

//Create the Session

using (ISession session = connection.CreateSession())

{

//Create the Consumer

IMessageConsumer consumer = session.CreateDurableConsumer(new Apache.NMS.ActiveMQ.Commands.ActiveMQTopic("testing"), "testing listener", null, false);

consumer.Listener += new MessageListener(consumer_Listener);

Console.ReadLine();

}

connection.Stop();

connection.Close();

}

catch (System.Exception e)

{

Console.WriteLine(e.Message);

}

static void consumer_Listener(IMessage message)

{

try

{

ITextMessage msg = (ITextMessage)message;

Console.WriteLine("Receive: " + msg.Text);

}

catch (System.Exception e)

{

Console.WriteLine(e.Message);

}

using System;

using System.Collections.Generic;

using System.Text;

using Apache.NMS;

using Apache.NMS.ActiveMQ;

using System.IO;

using System.Xml.Serialization;

using System.Runtime.Serialization.Formatters.Binary;

namespace Subscribe

{

class Program

{

static void Main(string[] args)

{

try

{

//Create the Connection factory

IConnectionFactory factory = new ConnectionFactory("tcp://localhost:61616/");

//Create the connection

using (IConnection connection = factory.CreateConnection())

{

connection.ClientId = "testing listener";

connection.Start();

//Create the Session

using (ISession session = connection.CreateSession())

{

//Create the Consumer

IMessageConsumer consumer = session.CreateDurableConsumer(new Apache.NMS.ActiveMQ.Commands.ActiveMQTopic("testing"), "testing listener", null, false);

consumer.Listener += new MessageListener(consumer_Listener);

Console.ReadLine();

}

connection.Stop();

connection.Close();

}

catch (System.Exception e)

{

Console.WriteLine(e.Message);

}

static void consumer_Listener(IMessage message)

{

try

{

ITextMessage msg = (ITextMessage)message;

Console.WriteLine("Receive: " + msg.Text);

}

catch (System.Exception e)

{

Console.WriteLine(e.Message);

}

程序实现的功能：生产者producer建立名为testing的主题，并每隔5秒向该主题发送消息，消费者consumer订阅了testing 主题，因此只要生产者发送testing主题的消息到ActiveMQ服务器，服务器就将该消息发送给订阅了testing主题的消费者。

编译生成producer.exe和consumer.exe，并执行两个exe，即可看到消息的发送与接收了。

这个例子是建的主题（Topic），ActiveMQ还支持另一种方式：Queue，即P2P，两者有什么区别呢？区别在于，Topic是广播，即如果某个Topic被多个消费者订阅，那么只要有消息到达服务器，服务器就将该消息发给全部的消费者；而Queue是点到点，即一个消息只能发给一个消费者，如果某个Queue被多个消费者订阅，没有特殊情况的话消息会一个一个地轮流发给不同的消费者，比如：

msg1-->consumer A

msg2-->consumer B

msg3-->consumer C

msg4-->consumer A

msg5-->consumer B

msg6-->consumer C

特殊情况是指：ActiveMQ支持过滤机制，即生产者可以设置消息的属性（Properties），该属性与消费者端的Selector对应，只有消费者设置的selector与消息的Properties匹配，消息才会发给该消费者。Topic和Queue都支持Selector。

Properties和Selector该如何设置呢？请看如下代码：

producer：

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ITextMessage msg = prod.CreateTextMessage();

msg.Text = i.ToString();