Sample 152: Switching Transports and Message Format from SOAP to REST POX

Note that WSO2 EI is shipped with the following changes to what is mentioned in this documentation :

<PRODUCT_HOME>/ repository/samples/ directory that includes all Integration profile samples is changed to <EI_HOME>/ samples/service-bus/.
<PRODUCT_HOME>/ repository/samples/resources/ directory that includes all artifacts related to the Integration profile samples is changed to <EI_HOME>/ samples/service-bus/resources/.

Introduction

This sample demonstrates how a proxy service can be exposed on a subset of available transports and how it could switch from one transport to another.

Prerequisites

For a list of prerequisites, see the prerequisites for starting 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="StockQuoteProxy" transports="https">
        <target>
            <endpoint>
                <address uri="http://localhost:9000/services/SimpleStockQuoteService" format="pox"/>
            </endpoint>
            <outSequence>
                <property name="messageType" value="text/xml" scope="axis2"/>
                <send/>
            </outSequence>
        </target>
        <publishWSDL uri="file:repository/samples/resources/proxy/sample_proxy_1.wsdl"/>
    </proxy>
</definitions>

This configuration file synapse_sample_152.xml is available in the <EI_HOME>/samples/service-bus directory.

To build the sample

Start the ESB with the sample 152 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."
Start the Axis2 server. For instructions on starting the Axis2 server, see Starting the Axis2 server.
Deploy the back-end service SimpleStockQuoteService. For instructions on deploying sample back-end services, see Deploying sample back-end services.

Executing the sample

The sample client used here is the Stock Quote Client, which can operate in several modes. For further details on this sample client and its operation modes, see Stock Quote Client.

To execute the sample client

Run the following command from the <EI_HOME>/samples/axis2Client directory.

 
ant stockquote -Dtrpurl=https://localhost:8243/services/StockQuoteProxy

Analyzing the output

This example exposes the created proxy service only on HTTPS. Therefore, if you try to access it over HTTP, it would result in a fault.

ant stockquote -Dtrpurl=http://localhost:8280/services/StockQuoteProxy
...
     [java] org.apache.axis2.AxisFault: The service cannot be found for the endpoint reference (EPR) /services/StockQuoteProxy

Accessing this over HTTPS using the command ant stock quote -Dtrpurl= href="https://localhost:8243/services/StockQuoteProxy">https://localhost:8243/services/StockQuoteProxy causes the proxy service to access the SimpleStockQuoteService on the sample Axis2 server using REST/POX.

If you capture the message exchange using TCPMon, you will see that the REST/POX response is transformed back into a SOAP message and returned to the client as follows:

POST http://localhost:9000/services/SimpleStockQuoteService HTTP/1.1
Host: 127.0.0.1
SOAPAction: urn:getQuote
Content-Type: application/xml; charset=UTF-8;action="urn:getQuote";
Transfer-Encoding: chunked
Connection: Keep-Alive
User-Agent: Synapse-HttpComponents-NIO

75
<m0:getQuote xmlns:m0="http://services.samples/xsd">
   <m0:request>
      <m0:symbol>IBM</m0:symbol>
   </m0:request>
</m0:getQuote>

HTTP/1.1 200 OK
Content-Type: application/xml; charset=UTF-8;action="http://services.samples/SimpleStockQuoteServicePortType/getQuoteResponse";
Date: Tue, 24 Apr 2007 14:42:11 GMT
Server: Synapse-HttpComponents-NIO
Transfer-Encoding: chunked
Connection: Keep-Alive

2b3
<ns:getQuoteResponse xmlns:ns="http://services.samples/xsd">
   <ns:return>
      <ns:change>3.7730036841862384</ns:change>
      <ns:earnings>-9.950236235550818</ns:earnings>
      <ns:high>-80.23868444613285</ns:high>
      <ns:last>80.50750970812187</ns:last>
      <ns:lastTradeTimestamp>Tue Apr 24 20:42:11 LKT 2007</ns:lastTradeTimestamp>
      <ns:low>-79.67368355714606</ns:low>
      <ns:marketCap>4.502043663670823E7</ns:marketCap>
      <ns:name>IBM Company</ns:name>
      <ns:open>-80.02229531286982</ns:open>
      <ns:peRatio>25.089295161182022</ns:peRatio>
      <ns:percentageChange>4.28842665653824</ns:percentageChange>
      <ns:prevClose>87.98107059692451</ns:prevClose>
      <ns:symbol>IBM</ns:symbol>
      <ns:volume>19941</ns:volume>
   </ns:return>
</ns:getQuoteResponse>