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Producing JMS Messages

This section describes how to configure WSO2 Micro Integrator to send messages to a JMS Queue. In this example, the Micro Integrator accepts messages via HTTP and sends them to a JMS queue.

Synapse configuration

Given below is the synapse configuration of the proxy service that mediates the above use case. Note that you need to update the JMS connection URL according to your broker as explained below. See the instructions on how to build and run this example.

<proxy xmlns="http://ws.apache.org/ns/synapse" name="StockQuoteProxy" transports="http https" startOnLoad="true">
        <target>
            <inSequence>
                <property action="set" name="OUT_ONLY" value="true"/>
                <property name="FORCE_SC_ACCEPTED" value="true" scope="axis2"/>
                <call>
                    <endpoint>
                        <address uri="jms:/SimpleStockQuoteService?transport.jms.ConnectionFactoryJNDIName=QueueConnectionFactory&amp;java.naming.factory.initial=org.apache.activemq.jndi.ActiveMQInitialContextFactory&amp;java.naming.provider.url=tcp://localhost:61616&amp;transport.jms.DestinationType=queue"/>
                    </endpoint>
                </call>
            </inSequence>
        </target>
</proxy>

The Synapse artifacts used are explained below.

Artifact Type Description
Proxy Service A proxy service is used to receive messages and to define the message flow.
Property Mediator The OUT ONLY property is set to true, which indicates that the message exchange is one-way.
Property Mediator The FORCE_SC_ACCEPTED property is set to true, this property forces a 202 HTTP response to the client so that the client stops waiting for a response.
Call Mediator To send a message to a JMS queue, you should define the JMS connection URL as the endpoint address (which should be invoked via the Send mediator). There are two ways to specify the endpoint URL:
  • Specify the JNDI name of the JMS queue and the connection factory parameters in the JMS connection URL as shown in the example below. Values of connection factory parameters depend on the type of the JMS broker.

    When the broker is ActiveMQ
    jms:/SimpleStockQuoteService?transport.jms.ConnectionFactoryJNDIName=QueueConnectionFactory&java.naming.factory.initial=org.apache.activemq.jndi.ActiveMQInitialContextFactory&java.naming.provider.url=tcp://localhost:61616&transport.jms.DestinationType=queue

    When the broker is WSO2 Message Broker
    jms:/StockQuotesQueue?transport.jms.ConnectionFactoryJNDIName=QueueConnectionFactory&java.naming.factory.initial=org.wso2.andes.jndi.PropertiesFileInitialContextFactory&java.naming.provider.url=conf/jndi.properties&transport.jms.DestinationType=queue

  • If you have already specified the endpoint's connection factory parameters (for the JMS sender configuration) in the deployment.toml file, the connection URL in the proxy service should be as shown below. In this example, the endpoint URL of the proxy service refers the relevant connection factory in the deployment.toml file:

    When the broker is ActiveMQ
    jms:/SimpleStockQuoteService?transport.jms.ConnectionFactory=QueueConnectionFactory

    When the broker is WSO2 Message Broker
    jms:/StockQuotesQueue?transport.jms.ConnectionFactory=QueueConnectionFactory

Info

To refer details on JMS transport parameters, you can follow JMS transport parameters used in the Micro Integrator.

Note

Be sure to replace the '&' character in the endpoint URL with '&amp;' to avoid the following exception: 

com.ctc.wstx.exc.WstxUnexpectedCharException: Unexpected character '=' (code 61); expected a semi-colon after the reference for entity 'java.naming.factory.initial' at [row,col {unknown-source}

Build and run

Create the artifacts:

  1. Launch Visual Studio Code with the Micro Integrator for VS Code extension (MI for VS Code) installed.

    Info

    Follow the Install Micro Integrator for VS Code documentation for a complete installation guide.

  2. Create an integration project.

  3. Create the proxy service with the configurations given above.
  4. Deploy the artifacts in your Micro Integrator.

Set up the broker:

  1. Configure a broker with your Micro Integrator instance. Let's use Active MQ for this example.
  2. Start the broker.
  3. Start the Micro Integrator (after starting the broker).

Invoke the proxy service by sending a simple message. You can view the message added to the SimpleStockQuoteService queue from the ActiveMQ Web Console.