How to set up a Mule Publisher Subscriber model

Question

How do I go about setting up a Mule Publisher Subscriber model using ActiveMQ? I’ve been looking around the web for a complete example that is simple and easy to follow but was not able to. All i want to do is sent a string to a MQ topic (using a publisher) and then read the message from the topic (using a subscribeer). Nothing too complex

Need more info on what you are up to. Publishing data to AMQ from Mule is straight forward but can be done in many ways depending on the complexity of your scenario — Petter Nordlander, Jan 19 '16 at 15:21

score 3 · Answer 1 · answered Jan 19 '16 at 15:44

The following step describe how to use Apache MQ as part of a Mule Pub/Sub Model

Setting up Active MQ

• Download ActiveMQ by Apache. I’m currently using version “apache-activemq-5.2.0”

• Extract download into a known location (eg C:\MQ\apache-activemq-5.2.0)

• Setup Environment Variable for ACTIVEMQ_HOME (C:\MQ\apache-activemq-5.2.0\bin\win32)

• Run C:\MQ\apache-activemq-5.2.0\bin\win32\InstallService.bat (to uninstall run unInstallService.bat)

• To verify, go to control panel -> administrative tools -> services and look for the ActiveMQ service

• Start the Service (Can set it to start automatically)

• Browse to http://localhost:8161/admin/ to see MQ dashboard

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Setting up a Mule Publisher

Create a Mule Project
Right click on the Project properties and select “Java Build Path”
Select the “Libraries” tab and click on “Add External Jars”
Browse to the location of the MQ jar file (eg C:\MQ\apache-activemq-5.2.0\ activemq-all-5.2.0.jar) and select OK to accept
Newly added Jar file should be in the list
Select OK to close the properties window

Create a Global Element for the project

Select “Create”
Select Connector Configuration --> JMS --> ActiveMQ and OK to accept (MQ will have default settings which is OK for this example)

Drag a HTTP Connector and Configure

Set port number to an port that is free (eg 8075)
Set “Path” to “/pub”

Drag a JMS Connector to the Right of the HTTP connector and Configure

Set Exchange Pattern to “OneWay”
Select “Topic” and give it a name (eg MyLocalTopic)
From the Connector Configuration drop down – Select the Global Active-MQ element created earlier
Set Transaction (eg “XATransaction”)
Set Action (eg “ None”)

The Flow should be like the below

<flow name="pubsubFlow1">
    <http:listener config-ref="HTTP_Listener_Configuration_8075" path="/pub" doc:name="HTTP_8075"/>
    <jms:outbound-endpoint  connector-ref="Active_MQ" doc:name="JMS" topic="MyLocalTopic">
        <xa-transaction action="NONE"/>
    </jms:outbound-endpoint>

Setting up a Mule Subscriber

Create a Mule Project
Right click on the Project properties and select “Java Build Path”
Select the “Libraries” tab and click on “Add External Jars”
Browse to the location of the MQ jar file (eg C:\MQ\apache-activemq-5.2.0\ activemq-all-5.2.0.jar) and select OK to accept
Newly added Jar file should be in the list
Select OK to close the properties window Create a Global Element for the project
Select “Create”
Select Connector Configuration --> JMS --> ActiveMQ and OK to accept (MQ will have default settings which is OK for this example)

Drag a JMS Connector onto the design pallet and configure

Set Exchange Pattern to “OneWay”
Select “Topic” and give it a name (eg MyLocalTopic)
From the Connector Configuration drop down – Select the Global Active-MQ element created earlier
Set Transaction Type (eg “NoTransaction ”)
Set Action (eg “ None”)
Drag a “Logger” connector to the right of the JMS connector and configure
Set message eg “FIRST SUBSCRIBER - PAYLOAD FROM MQ #[payload]”

Create a Second Mule subscriber project as described above, but this time set the Logger message to “SECOND SUBSCRIBER - PAYLOAD FROM MQ #[payload]”. This will allow you to see two subscribers subscribing to the same topic

    <flow name="pubsub_readqueueFlow">
    <jms:inbound-endpoint topic="MyLocalTopic" connector-ref="Active_MQ" doc:name="JMS">
    </jms:inbound-endpoint>
    <logger message="FIRST SUBSCRIBER - PAYLOAD FROM MQ #[payload]" level="INFO" doc:name="Logger"/>
</flow>

Applications in Action Publishing a message to the Queue

Run the publishing application
Use a Soap Client (eg SoapUI) to post a message to http://localhost:8075/pub
From the Active-MQ dashboard browse to topics(http://localhost:8161/admin/topics.jsp) to see the newly added message

Consuming the message

Run both subscribing application
Refresh the dash board to see that consumers added. (see example of my Dashboard below)

You are also able to send messages to the topic my Clicking on the “MyLocalTopic” topic. Enter a message in the “Message Body” tex filed and sent. The message count in the Topic should increment.

Subscriber Output

Browse to the location of your application logs (for me its located at: C:\Program Files\mule-standalone-3.7.0\logs)
A log files should be present for each subscriber. The content should look like the below

How to set up a Mule Publisher Subscriber model

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