Connecting to Tibco EMS from a C# Client

Introduction

This is a slightly esoteric post, but hopefully it will be of use somewhere.  Below is some reasonably simple code that shows the basic use cases for connecting to a Tibco EMS Server topic from a C# client using Tibco’s TIBCO.EMS.dll.

It actually points at a locally installed instance of EMS.  That is, the server code is running on the workstation.  If you have the Windows EMS installation you can just install it in the default path and the instructions below should work.  Alternatively it’s relatively simple to change the server name from ‘localhost’ and put a username and password in the code to connect to a secure EMS Server.

How to Use the Code

• Get hold of the Windows Tibco EMS install, and install it on your workstation on the default path.  Note that Tibco do NOT provide this for free: you need to have paid them for a licence.  If you work for a large organization you will probably find you already have a licence.
• Create a C# console application called ‘TestEMS’, and reference TIBCO.EMS.dll (the C# EMS assembly) from the install.
• Paste in the code below.
• Run the code.  You should see a console window showing that a message has been sent by a publisher and received by a subscriber.

If you want to connect to an existing EMS server in your organization all you need is the TIBCO.EMS.dll assembly, not a full client install. You need to change the appropriate parts of the code below to point to the server: change ‘localhost’ to the server name, and add a username and password if they are needed.  Obviously you don’t need to start the server locally if you do this.

What the Sample Does

As you can see, the code starts the local EMS server, then creates a topic publisher and a subscriber to the same topic.  It then sends a ‘Hello World’ message using the publisher.  The subscriber’s message handler prints out the message to the console when it receives it.

The sample code is slightly more sophisticated than the most basic use case.  It also shows how to set a property on a message, and then to how filter the subscription using a message selector based on the property.  The message is sent with an additional property of ‘Owner’ with value ‘Rich Newman’.  The subscriber is only listening for messages with an Owner property that contains the string ‘Rich Newman’.  You can see this if you change the name of the owner in the message that’s sent: the message listener will not get the message.

Code

using System;
using System.Diagnostics;
using System.Threading;
using TIBCO.EMS;

namespace TestEMS
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Test started");
            new Program().Run();
            Console.ReadLine();
        }

        private void Run()
        {
            StartEMSServer();
            CreateEMSServerTopicPublisher();
            CreateClientTopicSubscriber("Owner LIKE '%Rich Newman%'"); // Pass "" for no message selector
            EMSServerPublishThisMessage("Hello World", "Owner", "Rich Newman");
        }

        #region EMS Server
        private const string tibcoEMSPath = @"C:\tibco\ems\5.0\bin\";
        private readonly string tibcoEMSExecutable = tibcoEMSPath + "tibemsd.exe";
        private Process tibcoEMSProcess;
        public void StartEMSServer()
        {
            tibcoEMSProcess = new Process();
            ProcessStartInfo processStartInfo = new ProcessStartInfo(tibcoEMSExecutable);
            tibcoEMSProcess.StartInfo = processStartInfo;
            processStartInfo.WorkingDirectory = tibcoEMSPath;
            bool started = tibcoEMSProcess.Start();
            Thread.Sleep(500);
        }

        TopicConnection publisherConnection;
        TopicSession publisherSession;
        TopicPublisher emsServerPublisher;
        private void CreateEMSServerTopicPublisher()
        {
            TopicConnectionFactory factory = new TIBCO.EMS.TopicConnectionFactory("localhost");
            publisherConnection = factory.CreateTopicConnection("", ""); // Username, password
            publisherSession = publisherConnection.CreateTopicSession(false, Session.AUTO_ACKNOWLEDGE);
            Topic generalTopic = publisherSession.CreateTopic("GeneralTopic");
            emsServerPublisher = publisherSession.CreatePublisher(generalTopic);

            publisherConnection.Start();
        }

        internal void EMSServerPublishThisMessage(string message, string propertyName, string propertyValue)
        {
            TextMessage textMessage = publisherSession.CreateTextMessage();
            textMessage.Text = message;
            textMessage.SetStringProperty(propertyName, propertyValue);
            emsServerPublisher.Publish(textMessage);
            Console.WriteLine("EMS Publisher published message: " + message);
        }

        #endregion

        #region EMS Client
        TopicConnection subscriberConnection;
        TopicSession subscriberSession;
        private void CreateClientTopicSubscriber(string messageSelector)
        {
            TopicConnectionFactory factory = new TIBCO.EMS.TopicConnectionFactory("localhost");
            subscriberConnection = factory.CreateTopicConnection("", "");  // Username, password
            subscriberConnection.Start();
            subscriberSession = subscriberConnection.CreateTopicSession(false, Session.AUTO_ACKNOWLEDGE);
            Topic clientTopic = subscriberSession.CreateTopic("GeneralTopic");
            TopicSubscriber clientTopicSubscriber = subscriberSession.CreateSubscriber(clientTopic, messageSelector, true);
            clientTopicSubscriber.MessageHandler += new EMSMessageHandler(test_MessageHandler);
        }

        void test_MessageHandler(object sender, EMSMessageEventArgs args)
        {
            Console.WriteLine("EMS Client received message: " + args.Message.ToString());
        }

        #endregion
    }
}