Sample 253: Bridging from JMS to HTTP and Replying with a 202 Accepted Response

Introduction

This sample demonstrates how the ESB performs transport switching between JMS and HTTP, and also demonstrates how to configure a one-way HTTP proxy.

Prerequisites

• Configure WSO2 ESB's JMS transport with ActiveMQ and enable the JMS transport listener. For information on how to configure WSO2 ESB's JMS transport with ActiveMQ, see Configure with ActiveMQ.

  Note

  If you are using ActiveMQ version 5.8.0 or above, you need to copy the hawtbuf-1.2.jar file from the <ActiveMQ>/lib directory to the <ESB_HOME>/repository/components/lib directory.

• For a list of prerequisites, see Prerequisites to Start the ESB Samples.

Building the sample

The XML configuration for this sample is as follows:

<definitions xmlns="http://ws.apache.org/ns/synapse">
    <proxy name="JMStoHTTPStockQuoteProxy" transports="jms">
        <target>
            <inSequence>
                <property action="set" name="OUT_ONLY" value="true"/>
            </inSequence>
            <endpoint>
                <address uri="http://localhost:9000/services/SimpleStockQuoteService"/>
            </endpoint>
            <outSequence>
                <send/>
            </outSequence>
        </target>
        <publishWSDL uri="file:samples/service-bus/resources/proxy/sample_proxy_1.wsdl"/>
    </proxy>
    <proxy name="OneWayProxy" transports="http">
        <target>
            <inSequence>
                <log level="full"/>
            </inSequence>
            <endpoint>
                <address uri="http://localhost:9000/services/SimpleStockQuoteService"/>
            </endpoint>
            <outSequence>
                <send/>
            </outSequence>
        </target>
        <publishWSDL uri="file:samples/service-bus/resources/proxy/sample_proxy_1.wsdl"/>
    </proxy>
</definitions>

This configuration file  synapse_sample_253.xml is available in the <ESB_HOME>/repository/samples directory.

To build the sample

1. Start the ESB with the sample 253 configuration. For instructions on starting a sample ESB configuration, see Starting the ESB with a sample configuration.
   
   The operation log keeps running until the server starts, which usually takes several seconds. Wait until the server has fully booted up and displays a message similar to "WSO2 Carbon started in n seconds."

2. Start the Axis2 server. For instructions on starting the Axis2 server, see Starting the Axis2 server.

3. Deploy the back-end service SimpleStockQuoteService. For instructions on deploying sample back-end services, see Deploying sample back-end services.

   Now you have a running ESB instance and a back-end service deployed. In the next section, we will send a message to the back-end service through the ESB using a sample client.

Executing the sample

This example invokes the one-way placeOrder operation on the SimpleStockQuoteService using the Axis2 ServiceClient.fireAndForget() API at the client. To test this, run the the following command from the <ESB_HOME>/samples/axis2Client directory:

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"

 To test how the ESB responds with a HTTP 202 Accepted response to a request received, run the the following command from the <ESB_HOME>/samples/axis2Client directory:

ant stockquote -Dmode=placeorder -Dtrpurl=http://localhost:8280/services/OneWayProxy

Analyzing the output

When you run the first command specified above, you will see the one-way JMS message flowing through the ESB into the sample Axis2 server instance over HTTP, and you will also see how Axis2 acknowledges it with a HTTP 202 Accepted response.

SimpleStockQuoteService :: Accepted order for : 7482 stocks of IBM at $ 169.27205579038733

When you run the next command, you will see that the proxy service simply logs the message received and acknowledges it. On the ESB console you will see the logged message, and if TCPMon is used at the client, you will also see the 202 Accepted response that is sent back to the client from the ESB.

HTTP/1.1 202 Accepted
Content-Type: text/xml; charset=UTF-8
Host: 127.0.0.1
SOAPAction: "urn:placeOrder"
Date: Sun, 06 May 2007 17:20:19 GMT
Server: Synapse-HttpComponents-NIO
Transfer-Encoding: chunked

0