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This section describes how to configure WSO2 ESB to listen to a JMS Queuequeue.

The following example shows the configuration of WSO2 sections walk you through the steps to configure the ESB to listen to a JMS queue, consume messages, and send them the messages to a HTTP backback­-end service.       Anchorsample1sample1

Prerequisites

• Configure WSO2 ESB with Apache ActiveMQ, and set up the JMS listener. For instructions,

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• see Configure with ActiveMQ.
• Start the

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• ESB server.

Configuring the sample

• Create a proxy service with the following configuration.

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• For information on how to create a proxy service

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• , see

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• Creating a Proxy Service.

  Code Block
  language xml
  <proxy xmlns="http://ws.apache.org/ns/synapse" name="JMStoHTTPStockQuoteProxy" transports="jms"> <target> <inSequence> <property action="set" name="OUT_ONLY" value="true"/> </inSequence> <endpoint> <address uri="http://localhost:9000/services/SimpleStockQuoteService"/> </endpoint>

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• <outSequence/> </target> </proxy>

  Tip
  title Tip
  The OUT_ONLY property is set to true to indicate that message exchange is one-way. You can make the proxy service a JMS listener by setting the transport as jms. Once the JMS transport is enabled for a proxy service, the ESB starts listening on a JMS queue with the same name as the proxy service. If you take a look at the sample configuration above, the ESB listens to a JMS queue named JMStoHTTPStockQuoteProxy. To make the proxy service listen to a different JMS queue, define the transport.jms.Destination parameter with the name of the destination queue.

Testing the sample

To test this sample, you

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need an HTTP back-end service.

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Let's use the SimpleStockQuoteService as the back-end service and test the sample.

1. Follow the steps below to build and deploy the SimpleStockQuoteService:
   1. Open a command prompt (or a shell in Linux) and go to the <ESB_HOME>/samples/axis2Server/src/SimpleStockQuoteService directory.

   2. Run ant. 

2. Follow the steps below to start the Axis2 server:

   1. Open a command prompt (or a shell in Linux) and go to the <ESB_HOME>/samples/axis2Server directory.
   2. Execute one of the following commands 
      
      • On Windows: axis2server.bat

      • On Linux/Solaris: ./axis2server.sh

3. Place Send a message into to the Apache ActiveMQ queue by executing the following command from the <ESB_HOME>/samples/axis2Client folder directory.

   Code Block
   language xml
   ant stockquote -Dmode=placeorder -Dtrpurl="jms:/JMStoHTTPStockQuoteProxy?transport.jms.ConnectionFactoryJNDIName=QueueConnectionFactory&java.naming.factory.initial=org.apache.activemq.jndi.ActiveMQInitialContextFactory&java.naming.provider.url=tcp://localhost:61616&transport.jms.ContentTypeProperty=Content-Type&transport.jms.DestinationType=queue"

Analyzing the output

You can make the proxy service a JMS listener by setting its transport as jms. Once the JMS transport is enabled for a proxy service, ESB will start listening on a JMS queue with the same name as the proxy service. In the sample code above,  ESB listens to a JMS queue named JMStoHTTPStockQuoteProxy. To make the proxy service listen to a different JMS queue, define the transport.jms.Destination parameter with the name of the destination queuewill see the following response on the Axis2 Server console:

Fri Dec 16 10:21:11 GST 2016 samples.services.SimpleStockQuoteService  :: Accepted order #1 for : 7424 stocks of IBM at $ 156.74347214873563

By analyzing the output you can understand that the ESB has read the message from the ActiveMQ queue and sent it to the back-end service.

Two-way HTTP

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back-end

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call

In addition to one-way invocations, WSO2 an ESB proxy service can listen to the queue, pick up a message and do a two-way HTTP call as well. This is done when the client specifies a replyDestination element when placing a request message to a JMS queue. It allows the response to be delivered to the replyDestination a queue specified by the client. The scenario is depicted This is done by specifying a ReplyDestination element when sending a request message to a JMS queue. The two-way HTTP call is illustrated in the diagram below.:

Image RemovedImage Added

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You can have a proxy service similar to the following to simulate

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two-way invocation

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:

<proxy xmlns="http://ws.apache.org/ns/synapse"
       name="Proxy1"
       transports="jms"
       startOnLoad="true"
       trace="disable">
   <description/>
   <target> 
      <inSequence>
         <send>
            <endpoint>
               <address uri="http://localhost:

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9000/services/

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SimpleStockQuoteService"/>
            </endpoint>
         </send>
      </inSequence>
      

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<outSequence/>
   </target>
   <parameter name="transport.jms.ContentType">
      <rules>
         <jmsProperty>contentType</jmsProperty>
         <default>text/xml</default>
      </rules>
   </parameter>
</proxy>

ant stockquote -Dsymbol=WSO2 -Dtrpurl="jms:/JMStoHTTPStockQuoteProxy?transport.jms.ConnectionFactoryJNDIName=QueueConnectionFactory&java.naming.factory.initial=org.apache.activemq.jndi.ActiveMQInitialContextFactory&java.naming.provider.url=tcp://localhost:61616&transport.jms.ContentTypeProperty=Content-Type&transport.jms.DestinationType=queue&transport.jms.ReplyDestination=ResponseQueue" 

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Defining the content type of incoming JMS messages

By default, WSO2 ESB considers all messages consumed from a queue as a SOAP message. To consider accept messages consumed from a queue as in a different format, define the transport.jms.ContentType parameter with the respective content type as a proxy service parameter. The sample code below
 
To demonstrate this, we have modified the above configuration as follows to connect to MyJMSQueue queue and read messages as POX messages.
 To define the content type of incoming JMS messages, you can modify the proxy service that you created above as follows:

 <proxy xmlns="http://ws.apache.org/ns/synapse" name="JMStoHTTPStockQuoteProxy" transports="jms">
       <target>
           <inSequence>
               <property action="set" name="OUT_ONLY" value="true"/>
               <send>
                   <endpoint>
                       <address uri="http://localhost:9000/services/SimpleStockQuoteService"/>
                   </endpoint>
               </send>
           </inSequence>
           <outSequence>
               <send<outSequence/>
           </outSequence>
       </target>
       <parameter name="transport.jms.ContentType">
           <rules>
               <jmsProperty>contentType</jmsProperty>
               <default>application/xml</default>
           </rules>
       </parameter>
       <parameter name="transport.jms.Destination">MyJMSQueue</parameter>
   </proxy>