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Table of Contents

Introduction

This Sample demonstrates the Payload-Factory mediator to perform transformations as an alternative to XSLT mediator, which is demonstrated in Sample 8: Introduction to Static and Dynamic Registry Resources and Using XSLT Transformations. In this sample, the ESB implements Message Translator EIP and acts as a translator between the client and the back-end server when mediating a message to a sample back-end server from a sample client.

In this scenario, there is a web service endpoint that has the getQuote operation that expects a 'symbol' parameter. However, the client that invokes the service sends the getQuote operation with the 'Code' parameter. Therefore, the request message will be sent in this format:

Code Block
languagehtml/xml
<p:getquote xmlns:p="http://services.samples">
      <p:request>
       <p:code>IBM</p:code>
      </p:request>
</p:getquote>

But the service expects the message in this format:

Code Block
languagehtml/xml
<p:getquote xmlns:p="http://services.samples">
     <p:request>
       <p:symbol>IBM</p:symbol>
      </p:request>
</p:getquote>

Similarly, the service will send the response in this format:

Code Block
languagehtml/xml
<m:checkpriceresponse xmlns:m="http://services.samples/xsd">
   <m:symbol>IBM</m:symbol>
   <m:last>84.76940826343248</m:last>
</m:checkpriceresponse>  

But the client expects the response in this format:

Code Block
languagehtml/xml
<m:checkpriceresponse xmlns:m="http://services.samples/xsd">
   <m:code>IBM</m:code>
   <m:price>84.76940826343248</m:price>
</m:checkpriceresponse>

To resolve this discrepancy, we will use the PayloadFactory mediator to transform the message into the request format required by the service and the response format required by the client.

Prerequisites

Refer to Prerequisites section in ESB Samples Setup page.

Building the Sample

1. Start the ESB with sample 17 configuration using the instructions given in Starting Sample ESB Configurations.

...

5. 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

The sample client used here is 'Stock Quote Client' which can operate in multiple modes. For instructions on this sample client and its operation modes, refer to Stock Quote Client.

...