Amazon Hacks

SOAP Web Services

Working with SOAP is quite a bit different from working with XML/HTTP because it involves sending and receiving structured messages. Instead of creating requests yourself as a URL, requests are made via XML messages. Here’s a typical SOAP request to retrieve a book’s details with its ASIN:

<?xml version="1.0" encoding="UTF-8" ?> 
<SOAP-ENV:Envelope 
xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" [RETURN]
xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
<SOAP-ENV:Body>
  <namesp1:AsinSearchRequest xmlns:namesp1="urn:PI/DevCentral/SoapService">
    <AsinSearchRequest xsi:type="m:AsinRequest">
      <asin>0596004478</asin> 
      <page>1</page> 
      <mode>books</mode> 
      <tag>insert associate tag</tag> 
      <type>lite</type> 
      <dev-tag>insert developer token</dev-tag> 
      <format>xml</format> 
      <version>1.0</version> 
    </AsinSearchRequest>
  </namesp1:AsinSearchRequest>
</SOAP-ENV:Body>
</SOAP-ENV:Envelope>

You’ll notice that although SOAP uses the same bits of information you use when requesting data via the URL-based XML/HTTP method, it wraps the request in substantial structure. Generating these XML requests “by hand” each time you need one would be time consuming; instead, there are packages (typically called SOAP toolkits) in every programming language that do the heavy lifting for you. These toolkits provide a simple interface ...