Enterprise JavaBeans 3.1, 6th Edition

SOAP 1.1

SOAP 1.1 is simply a distributed object protocol, similar to DCOM, CORBA’s IIOP, and JRMP (the primary transport used by RMI). The most significant difference between SOAP 1.1 and other distributed object protocols is that SOAP 1.1 is based on XML.

SOAP is defined by its own XML Schema and relies heavily on the use of XML Namespaces. Every SOAP message that is sent across the wire is an XML document consisting of standard SOAP elements and application data. The use of namespaces differentiates the standard SOAP elements from the application data. Here’s a SOAP request message that might be sent from a client to a server:

<?xml version='1.0' encoding='UTF-8' ?>
<env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/">
   <env:Header />
   <env:Body>
       <reservation xmlns="http://www.titan.com/Reservation">
             <customer>
                      <!-- customer info goes here -->
             </customer>
             <cruise-id>123</cruise-id>
             <cabin-id>333</cabin-id>
             <price-paid>6234.55</price-paid>
       </reservation>
   </env:Body>
</env:Envelope>

The standard SOAP elements are shown in bold, and the application data, or the Reservation XML document fragment, is shown in regular text. SOAP’s primary purpose is to establish a standard XML framework for packaging application data that is exchanged between different software platforms, such as Java and Perl, or Java and .NET. To do this, SOAP defines a set of elements, each designed to carry different data. The <Envelope> element is the root of the SOAP message; all other elements are ...