Page Comparison

...

----invoking updateCustomer, Customer name is: ESB

Enabling REST to JMS

This section describes how a REST API can receive an HTTP message sent from a REST client and place it on a JMS queue.

 Image Added 
 

The API receives the HTTP message and sends it to a JMS queue that resides in a message broker. The back-end service listens and picks up the message from this queue. For the back-end service, we are using the StockQuote Service that is shipped with ESB. Configure and start the back-end service as described in Starting Sample Back-End Services. We will use cURL as the REST client to invoke the ESB REST API.

For this sample, we use ActiveMQ 5.5.1 as the message broker. Start ActiveMQ and configure the JMS transport in ESB to work with ActiveMQ before you proceed.

Following is a sample ESB API configuration that we can used to implement this scenario:

<api xmlns="http://ws.apache.org/ns/synapse" name="RestToJmsAPI" context="/stockquote">
   <resource methods="POST" url-mapping="/order/*">
      <inSequence>
         <property name="FORCE_SC_ACCEPTED" value="true" scope="axis2"/>
         <property name="OUT_ONLY" value="true"/>
         <send>
            <endpoint>
               <address uri="jms:/SimpleStockQuoteService?transport.jms.ConnectionFactoryJNDIName=QueueConnectionFactory&java.naming.factory.initial=org.apache.activemq.jndi.ActiveMQInitialContextFactory&java.naming.provider.url=tcp://localhost:61616" format="soap11"/>
            </endpoint>
         </send>
      </inSequence>
   </resource>
</api>

In this API configuration, we have set the OUT_ONLY property to true, as it is a one-way invocation. The message is sent to the JMS queue using the JMS Transport sender. (Note the prefix “jms” in the address endpoint URI.) Since we have set the FORCE_SC_ACCEPTED property value to true, the ESB returns a 202 response back to the client. 

Following is a sample cURL command to invoke this API:

curl -v -d @placeorder.xml -H "Content-type: application/xml" http://127.0.0.1:8280/stockquote/order/

Save the following sample place order request as "placeorder.xml" in your local file system and execute the above command.

<placeOrder xmlns="http://services.samples">
  <order>
     <price>50</price>
     <quantity>10</quantity>
     <symbol>IBM</symbol>
  </order>
</placeOrder>

You will see the something similar to the following printed in the sample axis2 server (back-end server) console:

Tue Mar 19 09:30:33 IST 2013 samples.services.SimpleStockQuoteService  :: Accepted order #1 for : 10 stocks of IBM at $ 50.0


Shut down the back-end server and execute the command again. If you go to the ActiveMQ Console and inspect the SimpleStockQuoteService queue, you will see a message queued there.